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Thread: 406 Test Run

  1. #1
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    406 Test Run

    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

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    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?
    Maddy's Daddy
    L.I.,N.Y.

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    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

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    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

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    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

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    HEI is fine to 5000+

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    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

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    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

  9. #9
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    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

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    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
    Attached Images Attached Images

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    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

  12. #12
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    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 ?
    Last edited by silverghost; 07-21-2012 at 11:09 AM.
    "BENCHSEAT 18" ~~YellowJacket~~ project owner~
    1929 Chris~Craft 28' Tripple Cockpit Mahogany Speedboat / A-120-A 845 Cu.In. 375 H.P. Chris~Craft V-8 racing engine.
    24' American Skier
    Super Eagle 454 HO Skiboat
    1991 454 SS Chevy Super Sport Pick-up for towing my "Toys".

    There is no such thing as going too fast ~ ~~
    OR~ Being too old~ for a new "Toy"!

    Brad Hunter
    Huntingdon Valley Pa (Just outside Philly)~
    Ocean City NJ
    silverghost1926@msn.com
    215 947 4676 (PA Home)

  13. #13
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    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.

  14. #14
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    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.

  15. #15
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    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.
    "BENCHSEAT 18" ~~YellowJacket~~ project owner~
    1929 Chris~Craft 28' Tripple Cockpit Mahogany Speedboat / A-120-A 845 Cu.In. 375 H.P. Chris~Craft V-8 racing engine.
    24' American Skier
    Super Eagle 454 HO Skiboat
    1991 454 SS Chevy Super Sport Pick-up for towing my "Toys".

    There is no such thing as going too fast ~ ~~
    OR~ Being too old~ for a new "Toy"!

    Brad Hunter
    Huntingdon Valley Pa (Just outside Philly)~
    Ocean City NJ
    silverghost1926@msn.com
    215 947 4676 (PA Home)

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