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GeneS
04-19-2000, 11:17 AM
I put a new 383 stroker in a friend's 2+3. We bought a reman short block from SECO because we were getting water into the oil with the old block and assumed it was cracked. Installed the old heads, cam, intake manifold from the old engine onto the new short block. Installed new Stainless Marine exhaust manifolds.

Guess what? Still getting water in the crankcase.

The only pieces that are common to both setups are the cam, the heads and the intake manifold.

We had the heads magnafluxed and found no cracks.

Here's my question. Can the cam geometry be causing back pressure in the exhaust manifolds and drawing water into the cylinders? If so, can someone recommend a cam that would be appropriate for a 383.

Any help would be greatly appreciated.


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Gene Schmidt
'74 X-18 "Chi Chi"

PaulO
04-19-2000, 12:24 PM
You definately can experience the much feared "reversion" which is exactly what you describe. It is a function of the cam overlap. I can't imagine though, that the water would make it into the crankcase especially in any quantity. Reversion happens while the engine runs at low RPM meaning you would first experience steam out the exhaust and then missfiring as the water dilutes the air/fuel mixture beyond its ability to ignite. The water then would have to get by the rings into the crankcase. I think you would be getting hydro-locking before that. How about the intake manifold? Any chance it is craked at the water passage or the intake manifold does not mate correctly to the head(s) at the water passage?
Paul

GeneS
04-19-2000, 12:36 PM
A cracked or warped intake manifold is certainly a possibility and easy enough to change out. I just want to make sure I'm not overlooking anything else.


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Gene Schmidt
'74 X-18 "Chi Chi"

Tony
04-19-2000, 05:42 PM
PaulO,

You are awesome, baby! Your posts regarding engines are good for regular guys who don't know squat about them. Your use of layman's terms helps even me grasp some of these "mechanical type" concepts at least a little bit.

Hotboat
04-19-2000, 06:06 PM
Sometimes a head crack will not open up until the head has reached operating temp. Then the expansion will allow water to seep in. May or may not be your problem. Something to check out.

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Hotboat

klink
04-19-2000, 09:26 PM
I'd pull the exhaust manifolds and look for wet exhaust passages because thats the easy thing to do and would be the deviding line on an exhaust or block problem. Water in the cylinder will eather pass through the rings into the block, be pumped out the exhaust or push a valve through the head.
If the problem is on the block side you might be able to seal up the intake and preasure test it, maybe even the block.
The heads were straight?
Maybe preasure test the new exhaust manifolds(trust no one).
Ive been there twice, one was a cracked exhaust manifold and the other they missed a crack in the block when it was magnafluxed.
Best of luck and let us know how it turns out.....Klink

GeneD
04-20-2000, 08:02 AM
Water in the oil is the worst.
I'm going through that right now with my buddy's Galaxie. Four cylinder Merc. We changed out the block and the head, and still water in the oil. Finally traced it down to a bad riser mating surface. Took that down, had it milled, no more problems.
Until...
Rob decides to take out the 2.5 and install the new 3.0 I have in my shop. Runs awesome.
Same head.
But now, water in the oil. What gives? I'm betting on a riser, he's betting on a manifold.
But that won't help you will it GeneS?
On your bad boy, I'm putting odds on the intake. What have you got left????? The heads have been magged, normally that will show all deformities, right?
Does the motor run good? If so, I think you could forget about a cylinder leak or a combustion chamber problem. Just water leaking into the engine wouldn't always cause foul running, intially anyway. It isn't until the water gets really hot that the problems show up.
Now, just food for thought here Gene, but you did use Mercruiser or equivalent type marine head gaskets right?
Auto head gaskets do not last. Yes, they will work, but not for long.
A leaking intake will put water into the weirdest spots, AND eventually cause blown head gaskets.

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GeneD
007
Melbourne, Florida

[This message has been edited by GeneD (edited 04-20-2000).]

GeneS
04-20-2000, 05:41 PM
GeneD,

Did use marine head gaskets (learned that here). Motor runs awsome. Absolutly no miss at all that would possibly indicate water in the cylinder. I am going to try the intake manifold and keep my fingers crossed.

Should have the results some time next week. I'll let ya'll know.



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Gene Schmidt
'74 X-18 "Chi Chi"

Forrest
04-21-2000, 01:31 PM
GeneS, get Chi Chi ready! We need to get together with Emmo and everone else for another Donzi gathering at Lake Eufaula or/and elsewhere in the Florida Panhandle / LA area.

At one time I would get water in the crankcase of the port engine on my Magnum. I though it was the intake or intake gaskets. So I installed a new intake. Nope, that didn't fix the problem. at that point, I was about ready to give up an replace the engine, but then I decided to change the exhaust risers since they were not passing water very well. Once the risers were changed along with the oil and filter, the water in the crankcase problem dissapeared. Upon close inspection of the risers, there were very small rust holes allowing small amounts of water in to the exhaust ports. When the engine was hot, this small amount of water would vaporize, therefore no problem. When the engine hod not been run an a day or two, no hydralic locking occured since there was a very small if any amount of water in the cylinder. In fact, no matter how long you let the engine sit, there was no hydralic locking! The reason? Since this engine has a number of hours on it, and it was set up "loose" to begin with, the water that was got into the cylinder just seeped through the ring gaps and on down into the crank case. Is the compression good in that engine? Yes. How long will will the cylinders hold pressure during a leak down test? Not long. These engine need to go!

GeneS, in your case I would not suspect the exhausts since they are new Stainless Marine units. I too would suspect the intake manifold and gaskets. Make sure that the intake manifold ports align correctly and the intake manifold doesn't sit on the end-seal surfaces. Also, use Fel-Pro Print-O-Seal type gaskets, not the blue Permi-Torque type, and above all don't use the supplied cork or rubber manifold end seals. Use something like Permitex Ultra-Black RTV without the seals. By installing it this way, the intake manifold sets down evenly on the gaskets and is not be propped up by the end seals. If the manifold has little or no clearence on the end seal surfaces, have the intake manifold machined to increase the clearence.

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Forrest

[This message has been edited by Forrest (edited 04-21-2000).]

Richard
04-21-2000, 08:19 PM
There's a lot of good information here, but dont overlook the water shutter valves in the exhaust pipe just below the risers on thru-hub exhaust models. They have been a problem with MC,s after overheats, and will cause water to go thru the engine and into the crankcase. Good luck.

GeneD
04-27-2000, 08:03 AM
Has this problem been solved yet?
Curious minds want to know!
Also, I agree with Forrest on the use of Ultra Black on the front and rear oil seals on the intake. I used to be one to always use the rubber seals until I started playing with milled heads.
One learns rather quickly. The mistakes only happen once. But sometimes once is more than enough since a leaky intake gasket will drive you nuts. When building a motor, everyone takes pains to make sure everything is just right, and it never occurs to anyone right off the bat that a mistake occured during assembly. Making the diagnotic even more frustrating.

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GeneD
007
Melbourne, Florida

[This message has been edited by GeneD (edited 04-27-2000).]

GeneS
04-27-2000, 11:02 AM
Ahhhhh $@%#%@()(&&&#%$,

No, the problem has not been solved. Here's the deal. Forest suggested that possibly the intake manifold was resting on the front and back ledges of the block. This would prevent the manifold from clamping down on the intake manifold gaskets as it should. I carefully removed the intake and noted that the RTV I had used to seal at the front and back was so thin that it was barely visible.

There is the problem, I said. If the intake manifold is prevented from pulling down against the gaskets that join the intake ports on the heads and the intake runners on the manifold, water will leak from the heads into the lifter valley and then into the crankcase and oil pan.

I carefully scribed a line on the intake manifold to remove about 1/16th of an inch of material from the front and rear mating surfaces of the manifold. Some mini-grinder action and I had a nice smooth relief cut. I sat the intake on the block with the heads and gaskets in place and used a feeler gauge to verify that I had clearance front and back.

I laid a bead of RTV front and back and around the front and back water jacket ports between the heads and the intake manifold. Let it set up and put the motor back in the boat.

We ran hard for approximately 20 minutes and removed the valve covers and MILKSHAKE!!!!!

CRAP!

So, that was not the problem. Or maybe it was part of the problem, I don't know.

We took the risers off of the exhaust manifolds and there was water laying in the bottom. What the hell, where did that come from. Must have been sucked back through the exhaust right.

Maybe the cam is wrong for a marine, wet exhaust application. I think someone here may have suggested that.

I called Crane Cams and gave them the cam number which is 113841 grind number F-278-2. It is a mechanical lifter cam and came in the boat when we bought it. The Crane guy said "Hey, what are you doing with that cam in a boat?" Apparently it has too much overlap for a marine application. He confirmed that it may be causing water from the wet exhaust to be sucked into the cylinder and then down through the piston rings and into the bottom end.

He gave us a number for a marine cam with hydraulic lifters.

Now we will try that and report back.



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Gene Schmidt
'74 X-18 "Chi Chi"

Craig
04-27-2000, 12:45 PM
I've always heard that you shouldn't re-use a cam (unless you KNOW its in really good shape). If the lobes are partially worn, which you would assume in an engine thats had much use, and you put the old cam back in with other new components, your not getting the best result for your efforts as it will cause premature wear of other components. Once you've gone to the trouble of removing and disassembling an engine, for whatever reason, why not buy a new cam for $100.00 (+-)? Any opinions (or authoritative statements)on this?

AVickers
04-27-2000, 01:11 PM
If the cam is in really good shape (or really special -- like reverse rotation or set up for a 180-degree crank) and the lifters also look good, you can go back with the same components in the same holes and not worry about much about it.

If you change ANYTHING (like using a different block or even one lifter -- or if you get the lifters mixed up), you might as well get a new cam (or a regrind on your old cam) and new lifters to go with the rest of your new engine.

GeneS
04-27-2000, 01:57 PM
Ok, just to be clear. The cam and lifters were both replaced with new when we picked the boat up. We replaced with the old one with one having an identical profile. Two of the cam lobes on the original cam were wiped when we bought the boat. (Sold to us as in perfect running order by the previous owner who used to be on this list but is long gone.)

So, what I have so far is a good cam and lifters that are apparently not suited for marine use.

New cam's been ordered. I'll let ya'll know how it turns out.

By the time I get to where I know everything, I'll be too old to put any of it to good use.



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Gene Schmidt
'74 X-18 "Chi Chi"

GeneD
04-27-2000, 09:13 PM
Oh Geez!!!
Calgon...take me away!

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GeneD
007
Melbourne, Florida

Craig
04-28-2000, 12:34 PM
Gene,
You won't be too old! The ole' Donzis ride so smooth, I figure a guy could keep playin' with a Donzi 'til he's at least 80 years old! I know a guy in his late 60's that still has, and uses, a '67-16' and an '79-18'!!! I'd say around 75 yrs., you might want to invest in a set of trim tabs, if not already equipped.

GeneD
05-04-2000, 11:45 AM
GeneS,
Any luck yet?
We bought the new manifold and riser for that (practically new-1997) hunk of junk 4 banger and we still are getting water in the oil. This time it showed up during flush-out, and not the exensive sea trials we put it through.
However, due to my dissertation to someone the other day on marine exhausts and the necessary requirement of flappers, I have come to the conclusion that this is a flapper problem. I heard the damn thing making noise when we first started the motor and didn't pay any heed to it. I think the flapper is closed or is staying closed or is restricting.
Anyone whose ever worked on these motors got any suggestions for checking the flapper?
Rich, Cindy?

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GeneD
007
Melbourne, Florida

[This message has been edited by GeneD (edited 05-04-2000).]

Richard
05-04-2000, 09:59 PM
GeneD,
You can remove the exh. elbow & pipe, the valve sits in the top of the pipe that bolts to the transom plate. It should have light pressure keeping it closed. I have not seen them cause a problem on a flush attachment, only on quick stops in the water.
Has the head been off this motor lately? We have seen some (too many) cracked cyl's on 3.0's. Good luck.

GeneD
05-05-2000, 09:01 AM
Cracked cylinders? Geez, that would explain a lot.
But wouldn't you have water in the cylinders at all times? Wouldn't the motor run like dirt? It seems to run great. I haven't checked the plugs lately, but I will today.
What symptoms am I looking for?
Thanks,


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GeneD
007
Melbourne, Florida

GeneD
05-09-2000, 07:58 AM
GeneS, what's the deal? Any progress?


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GeneD
007
Melbourne, Florida

GeneS
05-09-2000, 08:57 AM
OK, here's the update. We installed the new Crane marine cam recommended for the application by the Crane Tech folks. Put it all back together very carefully and.....

WATER IN THE FREAKIN' CRANKCASE!!!!!

Jeez, I'm getting tired of this.

The water has to be leaking from mating surface between the heads and the intake manifold. This is the only place where water pressure is greater than oil pressure, so water in the oil and not oil in the water.
The heads have been pretty heavily worked sometime in the past, so the critical geometry neccessary for a close fit may have been screwed up.

We are going to put on a new intake and try, through a system of careful measurements, to verify that the surfaces are mating correctly. If not, then we will get new heads.

I am confident we will solve this problem eventually.



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Gene Schmidt
'74 X-18 "Chi Chi"

RickR,GroveCity
05-09-2000, 09:15 AM
GeneS
How about pressure testing the cooling system?
Has the head or block ever been frozen?
On BBC an incorrect head gasket will cause a leak.
Keep us updated.

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RickR mailto:riggerb@aol.comriggerb@aol.com</A>

rayjay
05-09-2000, 09:27 AM
Gene,

Did you or the rebuilders mill the heads or deck block? If you did, did you also mill the intake manifold to get the mating surfaces lined up again? If you did this, are all the surfaces flat and aligned? You aren't using heads off a 400 SBC are you? Have you done a leakdown test with water in the block?

rj

GeneS
05-09-2000, 10:22 AM
I'm sure the heads have been milled (before we got the boat). The block is a new short block we got from SECO Performance. I don't know if it has been decked (probably has). The heads have be magnafluxed and checked ok.

I did relieve the intake at the front and back were it mates up to the block so I am sure there is no metal to metal contact. What I am suspecting is that, because of all the previous milling of the heads, the water passage at the forward end of each head is vertically misaligned with the water passage at the forward end of the intake.

If I do a leak down test, how much water pressure can I put on the block without breaking something. City water pressure is about 60psi. Is this enough to show a leak without damaging the block?



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Gene Schmidt
'74 X-18 "Chi Chi"

rayjay
05-10-2000, 03:19 PM
GeneS,

The "leak down" test I was talking about involves using air to pressurize a cylinder to check for pressure leaks such as through the rings, valves, and gaskets. If you have more than 10% leakage there is something wrong or worn, although the engine will run (badly) with up to 15%. Oil down the intake or exhaust will seal the valves (for a few moments) and oil down the sparkplug hole will seal the rings. Although leakage past the valves can usually be heard through the intake or exhaust, leakage through the rings can be heard through the oil filler, and leakage through the gasket can show up as bubbles (or movement) in the cooling system. This is a valuable tool for trying to ascertain how much life is left in an engine and finding where (and what) the problem is.

If you can pressurize the cooling system, you may find where the leak is. 60#'s should not be too much as when you test a cooling system in a car (or motorcycle) you usually go to 45# - 50#'s.

If the heads and the block were milled, then you probably have to mill the head mating surface of the Intake as well as any other edge that causes interference with the manifold sitting that much lower into the valley of the engine. There are charts to tell the machinist how much to mill from the mating surfaces of the manifold based on how much was milled from the head and the block in total. This can cause the intake manifold to not mate correctly with the water passages in the heads, and cause a leak. You may not readily see this from the outside of a raw water cooled boat engine as the cooling system does not run under the same pressures as in a closed cooling system.

Hope this helps. Now I want to know the answer to this mystery. rj

[This message has been edited by rayjay (edited 05-10-2000).]

RickR,GroveCity
05-10-2000, 04:15 PM
GeneS
I'd say 15 lbs would be a good starting point.

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RickR mailto:riggerb@aol.comriggerb@aol.com</A>

GeneS
05-30-2000, 11:40 AM
It was the freekin' heads!!!! We put new World Products cast iron heads ('bout $800 complete) on with a new intake manifold and it is fixed - ran all day and no water in the crankcase.

The old heads had been completely rebuilt and magnafluxed a year ago. We have been replacing everything else trying to isolate the water-in-the-crankcase problem (block, exhaust manifolds, cam, ...) and it was the heads all along. Jeeeeezzzzzz.

The boat is a red and white '73 18' 2+3 with a Volvo 270 and a speedmaster lower unit. I'll get it in the registry with pictures soon.

Thank you all for your input on this one.

YEEE HAAAA


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Gene Schmidt
'74 X-18 "Chi Chi"