406 Test Run

[Bobby D]

Finally took the boat out on the river to see how I made out, not all good but not all bad news. Other than a few minor wiring issues that I have resolved the engine started up and sounds assume. I have a short video of it running on the trailer but have not figured out how to load it yet. I followed Mike and other’s advice and set total timing at 32* a little extra timing seemed to help it idle smoother at 650/700 rpm. I am using a Delco EST 5.7 ignition system and set it at 14* at idle and total advance was all on by 3200. The new motor performs very well up to 3800 rpm / 45mph on boat gauges but falls flat on its face at about 3900 to 4000 rpm’s. The boat feels like something is holding it back or like a large strong water-skier is on the back making hard turns. I hit the key and the motor starts up and idles at 650 to 700 rpm and runs strong thru 3800 and than performance drops and rpm stay at 4000 as I increase throttle. Is it possible my loss of top end power might be due to an incorrect initial timing setting which is resulting in insufficient advance?
Also thinking I may have an octane problem, I have one year old fuel that is 89 E10 treated fuel purchase at my marina last year before the old mill let go. I also added about 15 gallons of fresh 89 E10 fuel that I treated and also used E-Zorb. I don’t know much about this ignition system but it may be smart enough to sense low octane and decrease timing automatically effectively reducing HP and RPM. Also I understand some areas are already pumping E15 even though the pump says it’s E10 resulting in power loss and increased fuel consumption. The motor was built to run on 89 pump gas and I fully expect this cam will run out of steam at 5000 rpm. Also once I discovered this issue the run was over and the boat went back on the trailer. Any thoughts will be greatly appreciated.
Bob

[maddad]

Did you use the timing light to check total advance or use math based on the initial timing? Is the secondary side of the carb coming on?

[Bobby D]

Mike,
Timing light was used along with the information you sent me to set up timing similar to your motor. I had help the day the motor ran on the hose, my buddy who builds motors and also worked for his dad who is a marine mechanic somewhere up in you neck of the woods set the timing. We followed you specification sheet for initial and total timing.
I was also thinking it could be a fuel delivery issue but did not consider the secondary’s not coming on that makes sense and would be about where they should kick in.
Bob

[BOSTONCAMARO]

HEI????

many people will tell you can 'clock' and HEI, stagger the wires so that it runs right....not true, but will happen is a situation like you describe, running OK but not doing what it should.

I would be very interested in seeing pics of your motor in the boat....post pics of how the distributor looks, its actual physical location in the boat....how it is rotated i.e. advanced

post pics and lets go from there, also look into what others suggest, but I have a feeling about this

[Bobby D]

Boston
What do you mean clock and HEI stagger the wires? Not moving number 1 cylinder to firing position and wires on the wrong cylinder? I will take as found pictures and post later.

Fixx,
Thanks the fuel pump is mechanical new out of the box it’s a 712-327-11 110 gph 6.5 to 8psi

[johnnywhale]

HEI is fine to 5000+

[BOSTONCAMARO]

Yes Johnny HEI is fine until 5000rpm and then some, but lets make sure it is set up right...

Yes, that is what I mean Bobby and perhaps that is the issue, so post some pics.....a guy on the Corvette forum just did the same thing, people said it was this that and the other...turned out my suggestion is what worked.

Could be many things, maybe this isnt it but lets all check it out, start with the basics and help you decipher what is going on.

Regards, Tim

[johnnywhale]

Isn't the EST the small style? Magnetic pick up and wire tower position are fixed and advance is in the module, correct? As long as rotor is pointed @ #1 on TDC where it is on the distributor doesn't matter.

Bobby
Are you actually measuring fuel pressure under load?
Did you confirm total timing with a light - either degreed balancer or dial type light?
Maybe try without flame arrestor?
Does sound like a fuel issue though.
Maybe gummed up filter from ethanol residue.
How much old fuel was lef in tank?
Good luck

[BOSTONCAMARO]

yes, with the valves closed on number one, piston up all the way, compression stroke etc...on a small block Chevy, the rotor shoud indeed be pointing at number one around the inside corner of the valve cover in most cases....yes the distributor needs be on number one, the number one that GM determined, not just dropping it in, rotating wires as needed to get it to run

lets see how his is set up, have not seen pics, so do not know...

tim

[Bobby D]

As requested see pictures taken about an hour ago to help understand what the installation looks like and help figure out what wrong. Also to be clear I am not an engine builder just a mechanically inclined guy who knows how to turn a wrench and was not afraid to try something new. Any mistakes made during this build are part of my learning process.
Thanks for all the help.
Respectfully,
Bob

[BOSTONCAMARO]

can you set it up on the compression stroke...on number one...using the timing mark pop the cap off so we can see where the rotor is pointing

i dont mean to be a pain in the ass, just want to help you eliminate all the simple stuff

[silverghost]

Bob~
Sure sounds like a fuel flow low pressure related issue to me also.
I would install a fuel pressure gauge and have someone watch it while you take another test run.

Did you check your carb's fuel foat level & total float drop ?

I assume your Carter/Webber AFB/AVS has mechanical secondaries that are opening properly ?

[Bobby D]

Fixx,
With the tank being in the front that’s a long way to pull the fuel, have you ever had the tank out? Could also be too small of a fuel line feeding the pump, try and mount a fuel pressure gauge and take it out for a test run...pull a plug and see it their white.

The tank was replaced in 2001 and all fuel lines are 3/8”, I’ll be installing a fuel pressure gauge this week. The carburetor is a 750 CFM Edekbrock model number 1410 new out of the box. Owners manual spec at idle should be no more than 6.0 psi and at WOT fuel pressure should not drop below 2.00 psi.

Johnny,
Are you actually measuring fuel pressure under load? Not yet will be installing a fuel pressure gauge this week
Did you confirm total timing with a light - either degreed balancer or dial type light? Yes, total timing confirmed with a light
Maybe try without flame arrestor? Have not run the boat since this happened, may do this next week.
Does sound like a fuel issue though? Yep I agree
maybe gummed up filter from ethanol residue. Could be will probable spin off the filter separator and see what it looks like.
How much old fuel was left in tank? About ½ tank on gauge 39 gallon tank so less than 20 gallons of 1 year old gas.


Fixx,
I’m sure bobby timed it rite and has the distributor in correctly or the boat would not have even started..
yes I am positive t’s installed correctly.

Brad,
Sure sounds like a fuel flow low pressure related issue to me also. I agree
I would install a fuel pressure gauge and have someone watch it while you take another test run. I agree will do the install this week.

Did you check your carb's fuel foat level & total float drop ? No its new out of the box did not think I need to do that, if I do it’s going back.

I assume your Carter/Webber AFB/AVS has mechanical secondaries that are opening properly? The secondaries are vacuum operated so they will only come on under load. The secondary throttles begin to open when the primaries are about 65% open and the primary and secondary throttles arrive at the wide open stop at the same time. This is the first thing I checked and the hand throttle is set up correct and the secondaries are opening.

[blackboat]

I would check fuel pickup ,change filter,blow thru lines,any screens at fuel line to carb?
Sounds like you are running out of fuel from what you describe.

[silverghost]

Bob~
I have ever been a big fan of these very small IN pick-up tube screens.
The very small diameter & surface area make these things clog-up far too easily.
Better to use a large fuel fiter downstream of the pick-up.
The much larger external sock type ON pickup sceens are far better.
The other thing that slows up the flow are the check-valves scewed into the 90* tank pick-up fittings that block much of the fuel flow.
These are a fuel tank anti-drain safety feature but are much too small for high demand/ high horespower engines in my opinion..
I know these are Coast Guard required safety feature on newer boat fuel tanks however.

[BOSTONCAMARO]

As the pics show, it does appear the dist is in right, its physical position does look correct and he has number 1 in the right place on the cap, that being said it is entirely possible to drop a distributor in, gettting running ok, even 'timed' however on an electronic hei, typically when this is the case, the dist is radically rotated in one direction or the other... it will never run as it should...that being said, I would be curious to see where the rotor is pointing, when set up on number one and on the compression stroke...but perhaps there are fuel problems to look at...have a fuel gauge in it, or gonna set one up for testing under speed?

tim

[Bobby D]

This is a 8 inch diameter x 7/8 inch wide x 1/4 inch thick piece that I cut down so the engine hatch would close leaving me with an 8 x 3 x 1/4 element. Does this look rite or did someone get carried away with the stainless mesh? Fuel pressure gauge and fitting scheduled to be delivered Friday so I will know pressure numbers by the weekend however this could also be restricting air flow.

[maddad]

That does not look like enough area for a 406 turning 5000 rpm to breath through.

[Bobby D]

Mike,

This is what I have on the motor now and its way more than the one that was on the 350.

[silverghost]

Bob~
I agree with maddad.
Not much breathing area with such a low profie & very small diameter flame arrestor.

Why not make just one high speed test run with this flame arrestor removed to see if it cures your high speed running issue.

If it cures the problem you need a very low profile large diameter flame arrestor to give you more air inlet surface area.
Or a hatch bump-out for a higher flame arrestor.

[maddad]

The formula for sizing an element for a performance engine using a K&N filter is
A=(CID x RPM)/ 25,500
Your 406 turning 5000 rpm with this formula would need about 80 sq". Because a flame arrestor flows much better than any element, I've been told this can be reduced by 25% with no effect.
Your 6" x 7/8 gets you only 18 sq".
I use a 6" x 3.5" for a bit more than 60 sq" and have no issues even above 5000 rpm.
I hope this helps Bobby.

[Ghost]

I thought Bobby had an 8 inch diameter, 3.25 inch high arrestor, no? (Cut down from 4 inches high).

Running that math, I get 8 in x PI = about 25 inches circumference.

25ish inches x 3.25 in = about 81 square inches of area.

As for the density of the mesh and whether it's too much, dunno.

[Bobby D]

Ghost you are correct and Mike I apologize for not being clear. When I modified the element to close the hatch I did not give it a thought about the thickness of the material and if it could restrict air flow. Last night I stated to think about this and after looking at the piece I cut today I believe it could be the problem. Brad I’m with you and because I need to look at a gauge anyway I plan on running this thing without the flame arrestor and the hatch off this weekend and see what happens. Thanks to all for helping me work this out.

[maddad]

Odd how when I read it a second time, all the numbers changed..:boggled:
I need to pay more attention.
I thought the 7/8 was the area, not what was removed. Oops.

[blackboat]

Something simple ,but did you check the tank vent to make sure it is not blocked and causing a vapor lock condition.
Spiders love to get into small holes and plug them up.

[johnnywhale]

The old spider in the BBQ trick!

[Bobby D]

BostonCamero said:
As the pics show, it does appear the dist is in right, its physical position does look correct and he has number 1 in the right place on the cap, that being said it is entirely possible to drop a distributor in, gettting running ok, even 'timed' however on an electronic hei, typically when this is the case, the dist is radically rotated in one direction or the other... it will never run as it should...that being said, I would be curious to see where the rotor is pointing, when set up on number one and on the compression stroke...but perhaps there are fuel problems to look at...have a fuel gauge in it, or gonna set one up for testing under speed?

tim

Tim,
OK as requested see pictures today I pulled the plug from #1 cylinder, set up on compression stroke and pictures of the rotor.
Bob

Also spun off the fuel filter/water separator and WTFO first picture is when I emptied it into the container the second picture is about 5 minutes later. New Fuel Pressure Guage came in today so I will install tomorrow along with a new filter.

[mattyboy]

the second pic of the gas looks cloudy i would think the gas is reacting with the plastic container

[MOP]

The floats-om bothers me, that stuff can pass through your canister and plug the carbs inlet filter. I have double in line filtration one can on each tank and one just before the engine, my inlet filter plugged after an hour or so this spring. Speaking with the jobbers that come in for parts they are finding the finding the same thing on many of their customers boats. Some are wondering if it is residue from the processing of the corn, it is a fine tan dust when dry. I would check you carb filter periodically.

[Bobby D]

Phil and Matt,
Thanks I was hoping you guys would lean in and comment, I only have the one filter installed before the fuel pump (same as the old motor was set up) and never gave it a thought that a second on needed to be added. Edelbrock sells the inline filter as an option but it is very small. I took everything back to the shop after work and performed an autopsy of the filter that had about 3 hours of run time on it. The fuel in the plastic container did clear up but the floatsom is exactly what you described a fine tan dust when it dry’s. The bad news is to the best of my knowledge this tank has only had treated E-10 gas pumped in once and yes it was the same time I had the motor problems last year. The good news I believe most of the E10 has been used up and I put about 12 gallons of non ethanol 89 gas in it last week and that will be the only fuel going in moving forward. Also I had time before dark last night so I installed the fuel pressure gauge. My thoughts are spin a new fuel filter on light it off and go see if anything changes.
Bob


Also since there has been no response on ignition configuration is it fair to say that its installed rite?

[BOSTONCAMARO]

yeah, looks like you are timed right, but those plugs definitely look on the rich side!!!!

how did you adjust the carb? are you familiar with how to do so? with the boat running, after it is warmed up and water running through it of course

adjust each of the fuel air mixture screws, one at a time, turn it all the way in then....make half turns coming back out and give it time for the idle to adjust....once you reach your highest idle overall move on to the other mixture screw, adjust that until you get the highest idle

once adjusted, adjust the actual idle screw to get the idle rpm that you want, need for the boat to run

it appears that your boat is running 'fat'

the fuel issues, cloudiness is something to look at, but I am thinking your issue is more in tuning than anything else, also a larger air cleaner would help....if be interested in seeing it run, simply with a screen set up on the carb to see how it runs....couldnt run it like that all the time, but just to determine if breathing is an issue for it

[BUIZILLA]

pic 1 of the spark plug looks like you pulled the last thread in the head... with a plug that black to the eye, and a clean transom, I suspect a vacuum leak which would put the power valve into an enrichment mode at idle, or just off idle... just a guess there though, but it ain't right... you can remove the top cover plate of that carb pretty easy, and look and see if the lower bowl area has the same FOD (foreign object debris) in the bottom

i'm not 100% satisfied the timing is correct either, there is no color separation on the strap

with the different additives you put in the fuel for storage, the cloudiness isn't uncommon, the coagulation you see could be a separation of additives within the additives, the dust you see is what the E10 scrubbed within the tanks inner walls, it ain't from corn husks... :boggled:

[BOSTONCAMARO]

I agree that vacuum lines need to be checked out, also could be some foreign debris.

As a small block chevy distributor is to be lined up, on number one, on the compression stroke...the pics you posted to show it is set up right - to take it a step further it would not hurt to pull off the valve cover for number one i.e. drivers side if it were in a car, to 100 percent confirm both valves are closed on number one when the timing mark and distributor are on number one

However, I would start with carb adjustment.....and if you do not have any rough idle, any popping, I would shy away from further analyzing the timing, I am betting it is set up right.

[BOSTONCAMARO]

On a SBC or BBC if set up on number one correctly, on compression stroke, the rotor should be pointed right at the edge of the valve cover as this is.

[mattyboy]

Bobby
I am very much like you I can do little things, turn a wrench , and basic maint I am no crankshaft whisperer. with my boat I had the engine done by a professional and installed it myself. I am learning the hard way had to find and define tdc and timing marks for the engine dropped the dist in and try to get it running. I had timing issues actually firing order issues on mine not sure they fooled with different firing orders cams on SBC stuff but they did with ford. I had to actually feel each exhaust port to see if each cyl was firing not sure you can do that on a chevy with the two inner cyl ports together. I also eliminated gas system issues at first by running on a 6 gallon OB tank. I am at the point now where the engine is firing on all cyl but still running rich dark plugs and soot on the transom. so now it goes to someone who knows how to tune a holley carb.

how do all the plugs look ? the same??

how does the oil look?

another thing I'll mention I had issues with carb linkage and cable it needed adjustment to have full motion mine was not pulling shut all the way and it was idling at about 1100 rpm .maybe yours is just the opposite

I had old gas and new ethanol gas it will break alot of stuff loose in alum tank I have a can filter then the elec pump then an inline filter( i was only using as a temp til I got the bugs worked out now thinking It may stay full time.)

all the suggestion made by the membership have some merit, you'll need to eliminate/adjust/tune each ,example if you run this weekend on a portable tank and it is ok it is something in the fuel system, if it stays the same then you have carb, timing, and pressure to check.

hope that helps

[Bobby D]

Jim,

Thanks for leaning in as well I appreciate you insight, as for the distributor I don't have any experience with this ignition system. I can't imagine it would be any different than any other one though. As far as I would think, once you shut off the electronic advance setup with the shunt wire it should be just like any other. The simplified timing instructions only give information on a 5.7 Vortec marine engine and state initial base timing is 8 degrees for 87 octane or 10 degrees for 89 or greater octane gas. Then it tells you to check total timing at 2000, 3000 or 4000 rpm and total timing will be 26 or 28 degrees depending on initial timing.

Do you think 14* initial is too much? The module has the advance curve set and is hard programmed into the module, going over the number again I believe the modules have 20* of advance so that would put me at 34* by 3200 rpm.


When I installed the spark plugs the motor was on the stand and they all went in with out any problems and torque to VP owner’s manual spec. Yesterday I had to play around with it figuring out the best way to remove it and could have done something? Is this a problem down the road?

Bob

[Bobby D]

Matt,

Could not have said it any better myself this has truly been a learning experience for me with plenty of failure. I truly felt a sense of accomplishment when the motor started rite up and to be honest it sounds assume. I’ll just have to take my time and figure out what help I need to determine what’s going on here. I did not pull all the plugs just number 1 and my concern was that I would find a white one go figure. My old motor ran rich and the amount of soot it would deposit on the transom was ridiculous so I was pleased to see a very clean transom so far. The temporary portable fuel cell is an excellent idea and I will keep it in mind and my throttle cable is good with no travel issues from idle to WOT. The oil is still clean and on the full line and oil press and temperature are all good.

Bob

[Bobby D]

Tim,
Learning as I go and really appreciate everyone’s input. I was taught at young age that there is no such thing as a dumb question so here goes. What vacuum lines need to be checked? The Performer Series Carburetor Owners Manual for 11 each carburetors including model 1410 provides generic information on vacuum port locations. Where are fittings and vacuum port locations on this carburetor? One is a blank located on the back and it’s a port for power breaks (except marine use) and is not required. There are three locations on the front, timed vacuum port, PCV port, and manifold vacuum port. None of the ports have a barbed fitting but do they still need to be plugged?

No adjustments have been made by me to this carburetor I installed it out of the box. The motor does not idle rough at 650 to 700 rpm and does not pop, backfire or miss.

Bob

[BOSTONCAMARO]

Hello,

I meant check vacuum lines in general, make sure none are cut, leaking, broken as that can affect how it runs as well as the mixture.

I really think carb adjustment is the first/next place to look.

If all plugs are sooty line that, it shows that it is running 'fat' ie rich, ie too much fuel in the air fuel mixture. At speed that may not lead to optimal running conditions, may be doggy at higher speeds as you described.

I think 14 initial is ok, I would check carb first, dont touch the timing, I am betting the timing is in the right ballpark.

Regards, Tim

[BOSTONCAMARO]

Good little video

http://www.youtube.com/watch?v=U9slFOP8R_s

[BOSTONCAMARO]

Going to find some more...

[maddad]

Also check that the choke isn't staying on.

[BOSTONCAMARO]

yes, agree with maddad....

eliminating all the simple stuff will help get the whole thing squared away...a stick choke, would make for rich conditions

[dsparis]

Have you checked vacuum at idle yet ?

[johnnywhale]

[ QUOTE=$originalposter]{$pagetext}[/QUOTE]

Are you saying there are vacuum ports (tubes) without caps on them?
Open ported vacuum fittings will really throw off fuel delivery.

[Bobby D]

Mike,

You were correct I performed a voltage check and found I did not have 12 volts key on source and the choke plate was staying on. Performance has definitely improved but I still have the top end problem. Sunday I ran it with the motor cover and flame arrestor off so air is not the problem. This motor runs strong up to 3900/4000 rpm and than the carburetor starts to make a fast clicking sound and because I was running with arrestor off I saw what I believe is gas or vapor coming or blowing out of the top of the carburetor. I did replace the fuel filter but something could be fouling the jets or I may have high fuel pressure? I looked over Edelbrock fuel pressure information last night and at idle there should be no than 6.0 psi and if it has a regulator set it at 5.5 psi. I have between 7.5 & 8.0 psi.

No update on whether the secondaries are opening? It sounds like an ignition misfire just causing the engine to stop accelerating. I have not tried to rev it to past 5000 in neutral that will rule out engine issues. I got a confirmation from someone I know, the Edelbrock is mechanical secondary with the flap and the secondary blades should open with the hand throttle. So I will check again that the linkage pulls it far enough open. Then that flap down in there should pull open with airflow. The weather has not been good (thunderstorms) so all in water testing done alone so I will need someone to watch it running under load and record fuel pressure as well.

Mechanically, the one thing I can check is the valve adjustment. The valves are tightened at ½ turn preload. But I can check them to be sure. For now my main focus is stick with ignition or fuel. I’ll leave that for a last ditch attempt. They should be dead on, the engine runs clean all the way to 3900/4000. Lifter pump up doesn’t happen until 6000 or higher, so it probably isn’t that.

Bob

[maddad]

Bob, I'm not an expert, but the combination of vapor or whatever coming out of the carb plus the clicking sound appearing to come from the carb at higher rpms sounds like a valve event issue to me. Maybe an intake valve not closing when it should and cylinder pressure bleeding into the intake manifold? On an engine I had with a leaking valve, the intake and carb got a real sooty appearance, but that wasn't a valve that could close at all. It had tuliped and cracked for about 3/5's of it's diameter. Your carb throat looks clean. I don't know if you adjusted the valves, or what method you used, or why you used half a turn preload, but I would double check all 16 and also what the lifter manufacturer says the preload should be. Maybe some of the real engine guys will see this and chime in. Maybe you could look at all 8 plugs to see if one or two look very different to support my thoughts.
Good luck with this. I can't wait to hear how it runs perfect.
Mike

[dsparis]

vacuum reading ?

[Conquistador_del_mar]

Bob,
My Edelbrocks need the fuel pressure down to around 6PSI or they will sometimes flood the fuel past the float needle. Also Edelbrocks come set fairly lean so you will likely have to change the metering rods and springs to help richen it - a quick and easy change. Bill

[BOSTONCAMARO]

[ QUOTE=$originalposter]{$pagetext}[/QUOTE]

again I agree with maddad, exploring valve adjustment may be a good idea and certainly wont hurt...

hydraulic cam? in general, even though they need to be adjusted correctly, you are always better off on the looser side of correct then too tight...

I had a similar issue before, losing top end power on my Camaro that had a hydraulic cam, we re adjusted, in fact the roller tip rockers were a little clicky...and guess what the car ran like ten bears 12.50's at 108mph for years....

Also adjust the carb as I mentioned..but it may be time to check valve adjustment - I did actually think that before, but with everything else going on, thought it best to check that stuff first.

What rockers do you have? what cam etc?

[BOSTONCAMARO]

I only ever put a 1/4 turn in them after click comes out...

[Bobby D]

Although the other thread died on the vine you can see Another SBC 406 for additional details of the build

However here is some background information from the other thread;
The plan is for this 406 to be a budget build up, my main focus is building it to run all day and have lots of torque under 5000 RPM. I understand you can build 406 small blocks with more HP, but doing that moves the torque/HP curve to a higher RPM range and the build cost would be higher as well, neither of which I want. That being said, I do understand you can easily turn this engine to above 5500 RPM if you would like.

Thanks to Mike (maddad) sharing information on his build I took his no replacement for displacement advice and now there are two 1972 18’s with a 406 motor. The motor is an older build and unfortunately I have not been able to locate the build sheet or cam card. The motor was built/ran on a dyno and than stored on a motor stand. It’s an early SBC 400 4 bolt main block bored .030 that started out as a marine build than my buddy decided to go with a BBC instead and it ended up as a stand by truck motor. We measured the cam (flat tappet) duration with a dial indicator on the lifters since they are exposed and we came up with duration @ .50” lift to be 210 intake and 218 exhaust.

What I do know is the motor was built by Troy Dennis who at the time built motors for Reggie Fountain, the heads are world products S/R Torquer iron heads that were ported and polished by Griffin automotive and marine in North Carolina. The motor and heads are well built and have good heavy duty stuff but nothing fancy or exotic. The motor also came with an Edelbrock performer intake manifold, mechanical fuel pump.
If you go on the World Products website and look up the S/R Torquer heads, it states that a 1.6 rocker WILL require opening the pushrod slot. I decided not to do that and went with the stock long slot rocker Summit G6800. as far as compression, for this 406, it could be either 8.6-1 up to 9.5-1 depending on the head CC my heads are small 67 cc heads based on the I-052 casting number. End of background information.


The issue with engine problems is that it is mechanical. The engine doesn’t fix itself from idle to 4000 and then get stuck. Stuck valves don’t unstick when you slow the engine down. The only POSSIBLE issue is lifter pump up but this is HIGHLY unlikely. We can check the rocker arms to be sure, but they only have ½ a turn of preload. What I learned from the guy who installed the heads and intake manifold is that you can go as high as 1+ turns and they will work fine for a stock type cam. Hydraulic lifters if tightened too much can hold the valves open at high rpm, like 6000 and greater. He told me this is due to what is called lifter pump up. Basically as the oil pressure increases it pushes the lifter cup upward, removing the preload and hanging the valves open. It is not something that happens at 4000 or less. Electrical issues on the other hand are everywhere. I have 12 volts, but what size is the wire supplying it? Is it a good source or is the voltage dropping at higher rpms causing the ignition to cut out? Is there a bad plug? Is a plug wire failing, or not fully seated on the plug tip. Is the coil bad? Is there an issue in the ignition box/module, or whatever it has? Fuel, it could be fuel related if for example, the mechanical pump is a positive displacement “suction” pump, and could be collapsing rubber hoses from the tank to the pump of there are any. Like I said in the other post about running up the rpm in neutral, the fuel requirement in neutral is almost nothing, so if it is fuel it would go past 4000 in neutral, but stumble under load. Detonation or pinging due to too much timing, I would think would show it-self as well when I begin to accelerate the boat from a stop since this is the greatest load. Once the boat is on plane at 45 mph the engine is cruising. But I can adjust the EST as recommended by Michigan Motors to the vendor spec which is 8* to 12* initial depending what document you read into to rule that out. This should also not occur running up the rpm in neutral.

I have not checked all the plugs yet to see if they cleaned up any after fixing the choke but I did confirm that the secondary’s are opening and I did not do vacuum testing yet? I ordered a fuel pressure regulator this week and plan on setting it 5.5 psi as recommended by Edelbrock. The timing is at 14 but to be sure I ordered a timing tape to go on the balancer so that I can see the total timing number. 32-34 advance should not be too much, but with a tape you can be sure of total.

The only thing my motor has in common with Mike's is 406 ci and that’s it. My buddy who had the motor built is in the process of moving and has found some of his lost boat files so I think the build sheet and dyno run information will be found. However going from memory and he has a very good one he thinks this motor is rated at 375 hp and 484 lb ft of torque. It’s a mild low compress motor built to run on 89 octane fuel.

[BOSTONCAMARO]

probably are going to have to chase all the small stuff, then check mechanical, but I do wonder if the valves might be a little too snug, i know you dont want to get into pulling valve covers etc, we just spent 3 hours adjusting the valves in my dads 13 to 1 bbc in his Camaro, so I know it can suck, but hydraulic is way easier.

Get an ohm meter, take off each wire, check it, check cap, rotor, inspect all plugs etc, eliminate all the small stuff, it will be tedious, but I am sure it will be found

400/406 should rev to 4500 - 5000 in a boat in general, I HIGHLY doubt it is the prop, gears etc or something holding it back...

pull plugs, take pics, let us all get a look, check wires, inspect cap, also for one last time too, when in there make sure you dont have two plug wires on wrong i.e. two of them on the wrong cylinder, another common problem wherein a car or in this case boat will still run but feel doggy - more common than not, i bet we will find it it something SIMPLE!!!!


...

[BOSTONCAMARO]

just found this on the hamb, alot of what we are talking about, including checking firing order again, see the response after the guy lists issues, how it is set up






Ok as the header says.

It runs up fine is
you don't hammer it from Idle.
It is worse when under load.
Hei is hooked
to ported vacum on the carb.
Initial timing is 10-12 Deg
Full(total)
timing is 22 deg
I don't think the Vacum adv is working (New vac mod)
Idle
is set at about 600-650 RPM ( Guessing!! no tach)

Any thought
Oh yeh
it will fire through the carb. Somtimes when you stomp the pedal in park and
want to die.

__________________
I feel sorry for people who don't drink. When they
wake up in the morning, that's as good as they're going to feel all day.
---
Frank Sinatra

Rather see my sister in a Whore House.....Than my Brother
in a honda...................OLDBEET





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http://www.donzi.net/forums/hamb/statusicon/post_old.gif 12-24-2005, 02:10 PM

#2 (http://www.donzi.net/forums/showpost.php?p=1022557&postcount=2)





LUX BLUE (http://www.donzi.net/forums/member.php?u=6331)



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Join Date: May 2005

Location: AUSTIN,TX

Posts: 4,407






http://www.donzi.net/forums/images/icons/icon1.gif Re: 350 with HEI and quadrajet, Stumble
when full throttle



I vote for more timing,but I always vote for more
timing...
what is it in?
sounds like distributor, but I need more
info.
what is it idling like lean or fat?
vaccum leaks?
and if all else
fails, check the firing order again.1-8-4-3-6-5-7-2.

[BOSTONCAMARO]

see this thread too

http://www.jalopyjournal.com/forum/showthread.php?t=84835

[maddad]

Bob, I think we use the same Holley fuel pump. Mine makes 7-7.5 lbs at the carb. And just to be sure, yours is a Edelbrock marine carb, with no vacuum ports and no vacuum advance on the dist., correct? The red hose in the pics is from the fuel pump, not the dist ?

[Bobby D]

Mike,
Yes its a Holly SBC 110 gpm fuel pump with shutoff preset @ 7.7 to 8.00 psi, my fuel pressure gauge reads 7.5 to 8.0 psi at the carb. I have the 1410 Marine 750 cfm Edelbrock no vacuum ports and the red piece of tubing is connected to the fuel pump. The distrib advances itself no bushings or springs to control it. Also I think the Michigan Motors rep had no idea and gave standard answers and covered his tracks when I asked about all the different timing instructions and if there’s any operating experience he could share on this ignition system. I have been searching the net trying to see if I can find any info on the ignition. Basically it seems very easy to damage electronically, but I can’t find what happens if you do. It doesn’t show symptoms. It says it needs a good strong 12 volts to the coil, so the wire has to be a non resistor type. The wire should be direct from a keyed source and not fed through anything else. I would guess 12-14 gauge wire. I also found that powering off the back of the alternator is not recommended and we DID power the shunt off there since it was the closest source. Maybe that did something, but I don’t know. It doesn’t say what happens if you do. The engine still fires up and runs clean both cold and hot and idles great so we are not that far off.

Michigan Motors told me the distributor has 18* of advance and to set initial at 8* + 18 =26 total which by the way is for 87 octane fuel. I told him I use 89 octane and according to the instruction sheet initial should be set at 10* his response was set it at 8* and see what happens.
My old VP owners manual for the same setup says set initial at 12* + 18 = 30 total
I have mine set at 14* initial + 18 = 32 total
Bob

[Bobby D]

Mike,
Yes its a Holly SBC 110 gpm fuel pump with shutoff preset @ 7.7 to 8.00 psi, my fuel pressure gauge reads 7.5 to 8.0 psi at the carb. I have the 1410 Marine 750 cfm Edelbrock no vacuum ports and the red piece of tubing is connected to the fuel pump. The distrib advances itself no bushings or springs to control it. Also I think the Michigan Motors rep had no idea and gave standard answers and covered his tracks when I asked about all the different timing instructions and if there’s any operating experience he could share on this ignition system. I have been searching the net trying to see if I can find any info on the ignition. Basically it seems very easy to damage electronically, but I can’t find what happens if you do. It doesn’t show symptoms. It says it needs a good strong 12 volts to the coil, so the wire has to be a non resistor type. The wire should be direct from a keyed source and not fed through anything else. I would guess 12-14 gauge wire. I also found that powering off the back of the alternator is not recommended and we DID power the shunt off there since it was the closest source. Maybe that did something, but I don’t know. It doesn’t say what happens if you do. The engine still fires up and runs clean both cold and hot and idles great so we are not that far off.

Michigan Motors told me the distributor has 18* of advance and to set initial at 8* + 18 =26 total which by the way is for 87 octane fuel. I told him I use 89 octane and according to the instruction sheet initial should be set at 10* his response was set it at 8* and see what happens.
My old VP owners manual for the same setup says set initial at 12* + 18 = 30 total
I have mine set at 14* initial + 18 = 32 total
Bob

[maddad]

Just so you're aware, 26* total advance in a SBC would hurt power and make the exhaust gas temps go through the roof. I wish I had more advice for you, but as a carpenter, I'd be looking for something to hit with a hammer by now.

[silverghost]

Bob~
Since I at first experienced a flooding issue with the 7-8 PSI fuel pressure you now have I usually keep the fuel pressure at about 6 PSI, or slightly below, on my Edelbrock/Webber Performer carb.
These carbs cannot take higher fuel pressure as the floats are very small, their float arms are short.
Pressures higher tan 6 PSI just pushes the floats open.

I also talked one of the Tech guys at Edelbrock and they sent me a pair of off-road float needle valves & seats.
These off-road float valve needle & seat units have an additional small internal spring that keeps the float valves stable to prevent flooding when the boat bounces around in choppy water, or the bow of the boat is high on plane.

Re; Ignition
If your ignition is still running I really doubt you did any damage to your distributor's electronic ignition module.

[BUIZILLA]

hold on here..

distributor has 18* ????

you better get a timing light and check the total advance reading at 4000-5000 rpm



don't forget that the distributor turns at half engine speed.........................

[johnnywhale]

PM replied
Food for thought as well, did you ever chek that TDC on the balancer is really TDC? Timing may be off a lot. Easy enough to do with a piston stop, but you'll have to pull the raw water pump to easily turn the crank. Still sounds like fuel though.

[Bobby D]

Been quietly working on solving the problem thru the process of elimination and wanted to provide an update on how I’m making out. The 2012 boating season is over and I am walking away form it for now and will start back on it over the winter. The plan is pull the motor in January take it to an engine builder figure out what’s holding it back and fix it. Next set everything up and run it on the dyno (like I should have done in the first place) walk out the door with the run sheet in my hand and than put the motor back in the boat and be done. At this point I don’t know if it’s a wiped or incorrectly degreed cam, bad heads or what ever? All I know is this motor hooks up like a freight train and plants you in the seat taking off form a dead stop. It does not stumble or hesitate taking off and runs and sounds strong up to 3800 rpm and that’s it. It starts rite up and idles perfect every time and is very happy running at 3500 rpm and 50+ mph on the gauges. Last weekend the weather was OK so I took a few videos and when I figure out how to load the files I will post them. Not looking for advice and don’t want any just wanted to update and thank all who have helped me troubleshoot the problem this year.

I have eliminated electrical and fuel as my problem. I went over the entire electrical system and fuel delivery system at least 5 times. Added a fuel pressure gauge, fuel pressure regulator and a vacuum gauge at intake manifold connection and changed fuel filters several times. Fuel pressure is good and steady at 6 to 7 psi under all conditions both idling and WOT and oil pressure is at 40 psi. Engine vacuum reading on the gauge at steady idle from 800 to 1200 rpm is 21-22 and open & close throttle quickly it drops to 0 and then goes up to about 24-25.

Ran the motor with 2 distributors first one was the Delco EST new out of the box and the second was a borrowed known to work HEI and there was no change, like clock work same symptoms at the same RPM. The HEI used was mechanical and set at 12 degrees initial and 32 degrees total all in at 2800. I also hooked up the borrowed HEI direct to the battery to eliminate voltage drop verified 12.7 volts and again no change

Ran motor with 2 different carburetors first was a new out of the box 750 Edelbrock and the second was a known to work 750 Mercury Quadrajet and again no change like clock work the same symptoms at same RPM range. However although the Edelbrock ran well the motor seems to really like the Quadrajet. Made Edelbrock recommended adjustments to the carburetor including identifying the air valve counterweight being too heavy and possibly causing the problem, wired it open and ran it again no change.

Finally pulled valve covers and rotated the motor by hand and went over the valves, pushrods, rockers again as a sanity check, if there is something going on there I can’t see it.

[Just Say N20]

Bobby,

Sorry to hear about your unresolved engine issues. You will get it figured out, and once you do, I'm sure you will be surprised at what it was.

When Keith was finished with my engine, my friend very strongly encouraged me to have them run it on the dyno. Because of the travel involved between my boat, and his shop, I decided to go in that direction. It cost me $110 for fuel, $275 for a set of SBC headers for use on the dyno, and $1,000 for the dyno time, but I'm so glad I did.

There were 2 significant issues that were discovered as a result of running it (stock oil pan wouldn't work as it lost oil pressure after 30 seconds at WOT, and the Thunderbolt IV ignition, which I had used on the original engine, was actually breaking up badly after 4,000 rpms) on the dyno. And had I not done it, I would have had to pull the engine to install a new oil pan. AND I got the exceptionally cool dyno sheet with the hp and torque numbers documented.

I'm still waiting for the conclusion of my CMI exhaust situation to be resolved, so it is likely I won't be boating at all this season. But, next summer. . . . . . we will BOTH be out there running STRONG! :biggrin.:

By the way, you have achieved exactly what I am hoping for: 52 mph at 3,450 rpms. "The effortless cruise!" What prop/outdrive are you running to get those numbers?

Which temp gauge is oil and which temp gauge is water? I had the temp gauge hooked to water with the first engine. With Keith's set up it is running without a thermostat. He said I would never even reach 100 degrees, so I bought a smaller temp sender and plumbed it to the remove oil filter. I was told to wait until the oil temp was 160 before running the engine hard.

[BUIZILLA]

bobby.... did you try running it with the tach disconnected?

[MOP]

Have'nt gone over this one in awhile! My $$ are with mike, you have a intake valve issue. My guess is a weak spring which you can not see, but had you wound it up with the covers off would have become quite evident. The clicking is a dead give away along with raw gas being blown back out of the carb. All you need is for one spring not to be up to spec! Before you pull it pressurize each cylinder, pull the springs and check them for correct tension. Pretty easy to replace a set of springs in the boat and fairly cheap.

Phil

[silverghost]

Bob~
Sorry to hear you have not found that pesky gremlin.

Sounds like you covered the possible carb/fuel pressure, & ignition problem issues~~~

Phil has a good point about a posible weak valve spring letting a valve float.

What about a possible hydraulic valve lifter issue ?

As Phil stated that clicking sound is strange and not normal~~~ Phil is also correct that valve springs are very cheap and can be swapped out with the cylinder heads still on the engine while it's still in the boat with a KD/Lysle lever style valve spring compressor or a small two jaw on engine head valve spring compressor.

You can also easiy remove the intake manifold & swap-out those hyrdraulic valve lifters also.

Iifters are fairly cheap.
There are also sadly some junk new imported valve lifters sold out there under some well-known brand names.

Just curious what prop pitch & diameter you trying to spin with this engine ?
You may have already mentioned the prop spec. in an early post ?
If-so~~~I missed it.

[joseph m. hahnl]

What ignition modulator is in it ?


As far as valves go if the springs were not set up for the proper valve lift . They will coil bind , collapse and float the valve at high RPM. There is no pre load on a modern Chevy. it is based on clearence "Zero". You have to be careful not to set the lifters in the collapsed position. With the cam lobe at its lowest or nuetral point. You tighten the rocker until the push rod resistance just stops spinning freely or there is no shake side to side in the rocker.


Anyway with all the information you provided in post #55

.210 on the cam would be .315 @ the valve with a 1.5 rocker

.218 0n the cam would be .327 @ the valve with a 1.5 Rocker

I'm also asuming the decimal point is in the Wrong place and is <.050> Not >.500< if you put a 1/2 inch (.500) of movement on the dial before you took the total height then that cam is way to big for the valve springs gauranteed.

So if those are indeed the correct lobe lift numbers you posted. There is no way coil bind would be an issue. The Issue would be the Cam is not the right one for your application. So now that you need a new cam you need to determine what springs you have or buy a new set that match the cam.


oh I forgot to mention, flat tappets don't belong in a performance engine

[hdsadey]

I had a problem with my Vortec 350 in the 16. It would spit and backfire on take off then after 2500 it would run like a bastard. Fiddled with it for a week. All sorts of changes and it boiled down to my timing light! Set it at 32 degrees total or so I thought. My advance dial was loose on the back of the light and it was like advanced 20 degrees of the light. It would run great when the advance weights would open up to catch the cam. Reset the knob and tightened the set screw and timed out fine. Bought new digital timing light for future settings. Bad one was an Acutron advance light.

[Bobby D]

Bill,
Engine water temp is the top gauge and I use a 160 degree thermostat. The other is for head temperature; I may change it in the future for something else but this year I wanted to keep an eye on head temp and make sure they were not getting to hot. Also I use a hand held heat sensor to see what’s going on at the motor, intake, exhaust, and oil filter. I am running a VP SX 1.43:1 outdrive with a 23 Turbo Vector that I got from Big Grizz.

Jim,
Yes when I set up the HEI I did run it with the tach disconnected.


Brad,
The prop is a Turbo EV-14523L.

[Bobby D]

Phil,
When all this started I focused on what is different or changed from when the motor was run on the dyno several years ago. They used a mule 750 carburetor and distributor and everything else remained the same. The motor ran twice, once before pickup and than when my buddy picked it up. I called him last night and we talked about this one more time and here is what I learned. Turns out that when he picked the motor up the heads had not been ported and polished so the builder said no problem we will remove the heads send them out and have them shipped to his house when completed. The heads remained packed in the shipping boxes until I picked the motor up last winter. So if the heads here worked on after the dyno run they would have been disassembled and reassembled and who knows what happened during that time?

[Bobby D]

Joseph,
Thanks for pointing that out to me looks like I fat fingered it should have read duration @ .050” lift: 210 intake 218 exhaust. It’s a comp cams Xtreme hydraulic flat tappet camshaft. Chevrolet 262-400 ci 8 cylinder 1955 -1998, strong low end and mid range torque, good idle.
World Products – SR Torquer iron heads 67 cc casing ID number I-052
I never said or implied that this is a performance engine in fact it is far from that nothing fancy or exotic. I just a wanted a motor that pulled HARD with peak TQ at around 3200-3500 which IMHO is perfect for a boat cruise rpm. Not an engine builder however with these heads, and cam combo I believe that I’m in the ballpark.

[joseph m. hahnl]

I thought you meant .210/.218 thousands of lift,not degrees:bonk:

[Bobby D]

Instead of guessing at what’s wrong and screwing up another boating season troubleshooting I decided to pull the motor find out what the problem is and fix it. It’s been long time so here is some quick background information and also my thoughts from the night we ran the motor on the dyno:
The story goes like this the engine was done a few years ago the heads are pre assembled World S/R torquers and the cam is small and was built for a boat or tow truck but never used. When I got the motor it was a short block and the heads were off I put the heads and intake on and setup the valve train, which is a set of GM performance long slot stamped rockers. The engine has an Edelbrock 750 marine carb on it it starts up and idles at 650-700 rpm, drops in and out of gear fine with the outdrive. It runs smooth and easily goes 45 mph at 3000 rpm in my 18 foot Donzi. It just will not go past 4000 rpm and it makes a machine gun sound like something I have never heard it is like a switch is turned on and off. People have compared it to a truck "jake" brake you hit 3800 and the noise starts and if you drop rpm slightly it’s gone and then engine is back to running fine. I ran it with 2 carburetors, 2 ignitions, 1 was a simple HEI direct wired to the battery to eliminate any issues.
We were able to set it up close to how it was in the boat and now it is doing the same exact thing on the dyno. The valve covers were off, and no sign of flattened lobes, the oil is clean. Fuel, we ran it with a mechanical and an electric with the same issue at 4000 the engine was spun over with the valve covers off on the dyno and all the rockers appeared to be moving the same amount. As far as cam timing, the cam was in when I purchased it all I did was pull the balancer and check .050 duration because I was worried the cam was too big and may start sucking water in the exhaust. The machine shop that has the engine is going to be pulling the cam out to look at it. As far as the cam being small, I measured duration at 50 when i got it, and saw about a 212/220 cam. As of right now, the short block is not coming apart. We are going to pull the cam and lifters and check the cam install. Otherwise, that is where it is for now. Trust me; I have NEVER heard a sound like this. Instinct tells you it must be breaking up or popping. Nope, this is something entirely new. As far as balance, I don't feel any vibrations. I know that the balancer was with the engine and is stock GM 400. The flywheel was bought by me afterwards. The engine came with the flex plate that it was balanced with and supposedly the flywheel was balanced the same as the flex plate. Compression test shows 150 in each cylinder.

[Bobby D]

Here is what I learned:
The timing cover was pulled and the chain was found loose. But there is a BIGGER problem the motor shop sent me a picture and I thought YOU HAVE GOT TO BE KIDDING!!!! Can you see it?

[BUIZILLA]

what spark plugs and gap?

did you re-adjust the valves? say, 3/8 turn down from zero?

[BUIZILLA]

please don't tell me the cam gear is on backwards...

[joseph m. hahnl]

Here is what I learned:
The timing cover was pulled and the chain was found loose. But there is a BIGGER problem the motor shop sent me a picture and I thought YOU HAVE GOT TO BE KIDDING!!!! Can you see it?

Is that a bicycle chain?:rlol: " The Chainomatic" Not the right number roller chain for the sprockets.Not to worry, Just throw a new Chainomatic master link in :tooth:

http://www.donzi.net/forums/attachment.php?attachmentid=75374&stc=1&d=1365341960

[johnnywhale]

oil galley plug leaking?
losing pressure to lifters and causing valve float at higher rpm?

[johnnywhale]

that'd be impossible to track down
http://i225.photobucket.com/albums/dd220/johnnywhale/SBCOiling_zps130031e3.gif

[Stevo440]

What's up with the keyway insert in the crank? It looks split!!!! I'm more familiar with Mopars and Turbo Buicks then SBC, only did a recam once years ago on a 307 in a Riva, so don't remember too well what it looked like. Those values last year on the cam at .050 lift had to be duration #'s not lift #'s, 210deg/218deg or whatever values they were but close enough, cause you are measuring at .050" lift already to get a better look at the cams characteristics as to how it will work in the real world. So I'm curious as to the answer

Patiently awaiting
Steve

[joseph m. hahnl]

your not suppose to see the sprocket teeth in the chain. it is the wrong chain all together.
Maybe a double roller chain on a mono sprocket set?
Did the mechanic say "The chain is a little loose"! "But if we take out one more link" :smash:
" I think she'll be good" :doh:





What's up with the keyway insert in the crank? It looks split!!!! I'm more familiar with Mopars and Turbo Buicks then SBC, only did a recam once years ago on a 307 in a Riva, so don't remember too well what it looked like. Those values last year on the cam at .050 lift had to be duration #'s not lift #'s, 210deg/218deg or whatever values they were but close enough, cause you are measuring at .050" lift already to get a better look at the cams characteristics as to how it will work in the real world. So I'm curious as to the answer
Patiently awaiting
Steve


There are two keys one for the timing gear, the other is for the harmonic damper

[MDonziM]

I'm pretty sure I have the same masterlink on my go-cart, its fine. "chainomatic" too funny.

[Bobby D]

Yep Jim you got it, the cam gear is in backwards and it looks like they set it up with some mark on the cam gear that puts the cam in the wrong location. The dowel pin should be at 3 O'clock when set up at dot to dot.
I believe the machine gun sound was caused by the cam bouncing forward and backward in the engine and either the cam timing and/or ignition timing changing drastically. It either moved when the valves were opening and closing or the ignition timing started firing at all different times. Who would have ever begun to think that this was the issue on a newly assembled engine by a professional shop? I did catch when I was putting the heads and intake on that with the S/R torquer heads; it was setup with 1.6 rockers with no pushrod clearance. I swapped to 1.5's before putting the engine in the boat. Who knows how long before it would have snapped a pushrod tip off. Big lesson learned for me is when performing troubleshooting I'm not going to rule stuff out based on "no that can't be". This proves that the most ridiculous is possible.
Also how did a dot get on the wrong side of the timing gear is the next question and I was disappointed to find a cheap timing gear. I don't think I have ever seen a cam gear with "timing" marks on both sides. As of today the engine is stripped to the short block. The valves are not bent, so the engine will be getting new springs, new Cloyes timing chain, and new Comp Cams lifters since the ones in there appear to be junk stock rebuilder parts. The shop wants to rule out lifter pump up as well. Hopefully this week it will be back on the dyno

[Just Say N20]

What an unbelievable story. But. . . .

The good news is, think of how the engine is going to perform NOW, with everything correctly assembled!!!

Very curious to see what kind of numbers you get. :hyper:

[Bobby D]

Jim,
Plugs were changed several times MR43T's, NGK's gap set at .035. We re-adjusted rockers and checked timing. Set the valves to zero lash and went from there. Good eye, yes it is on backwards and another thing to consider is that since the gear is on backwards, there is likely excessive clearance behind the gear. Endplay could have worn out the chain prematurely. Plus, excessive cam endplay will affect timing. The Cam gear had no thrust face to ride on and was free to float. The only thing restraining the cam was the timing chain which is not designed for side loading. With the chain worn the cam timing is completely messed up.

[BUIZILLA]

with the gear like that the cam would have been seriously advanced, which is why it fell on it's face up top but was sprightly down low... had it been the other direction and retarded it would have bent a LOT of stuff and been a low end dog...

the reason I asked about the plugs was someone else here had a tuning issue recently and the wrong short reach plugs(MR43T) were being used for his aftermarket heads (should have been MR43TS), the plug shell should be even or 1/2 thread into the chamber and the extended electrode then protruding further as well, his shell was 4-5 threads into the head, and so far in that the std reach electrode was actually flush or just inside the thread tunnel...

your on the road to recovery, that's for sure :cool:

[joseph m. hahnl]

Makes yah wonder how the dot got on the back side of the gear:confused:

[Bobby D]

I discovered that there is an issue with the oil pan front seals, it’s always a challenge trying to figure out which you have unless you have others to compare it to.

Last week I pulled the engine for the 3rd time in three years to address a 4 drop per minute oil leak that I could not live with. I also learned that I’m getting very good at this and had the engine out in about an hour. I replaced the old cheap timing cover and the one piece blue fel-pro oil pan gasket. Last year when I replaced the oil pan gasket I did not know there was a thick and a thin oil pan gasket and it turned out that the oil pan the engine builder used required the thick seal. The thickness of the front seal is based on the oil pan, there is thick and thin for that area and it is the oil pan that determines the required thickness for the front end seal section of the oil pan gasket. The early pan is
2 1/4" deep at the front and the late pan is 2 3/8" deep at the front. As I recall, the deep pan came out in 76 and I believe 1975 & older stock oil pans use the thin seal.

When I ordered the gasket last year the NAPA guy looked up the casting numbers and gave me the thin one for a 1972 SBC 400. It's not the casting number of the block that matters it's the part number of the pan. Older pans use the thin seal and less-old ones use the thick seal. Measure the distance block mating surface to the lowest point of the lip on the front of the pan. If it's 2 3/8", use the thick seal. If it's 2 1/4", use the thin one.

Last year when I started the engine for the first time I immediately found the leak so I replaced the lip seal on the timing cover and that did not work. So instead of standing on my head I pull the engine and do it right. Monday night I ran the boat on the lake for about an hour and there are no leaks.

Bob

[joseph m. hahnl]

The thick seal thin seal :bonk:Yes they changed to the thick and then they changed the dip stick to the passenger side when they changed to the one piece rear seal. I bought an aluminum pan that was thin front seal and the dipstick was on the passenger side from Skippy White. He listed the one piece gasket number to use, which was a thick seal with a universal dipstick passenger and driver side . Obviously the gasket didn't fit:nilly:. Took me a little research to figure it out. There is no such thing as a one piece thin seal passenger side dipstick gasket, because GM never ever made that oil pan and block in that configuration. It was a bastard pan that some engineer thought they could just switch the mold from drivers side to passenger side for later model engines. WRONG:bonk: Now with the thick seal you could do that, because the seal thickness change occurred before the dipstick change. Not the other way around. The pan I bought could be used with the multi piece gaskets ,most likely you'd have to buy two sets. and use the thin from one and the dipstick side from the other. I ended up reworking the pan to the thick gasket. :kingme: All that changing was GM's quest to get rid of the oil puddle in the drive way:yes: