GNJ

After I bought them, I later learned they had to be machined down to fit my 502's, which I had done by a local machine shop. My motors now have about 2 hours on them.
One motor seems to have slight milk coating in the top of the valve cover but the other seems to be OK. Oil on the stick looks good and clean in both motors though.
I have new GM heads, .550lift, 230/236* dur, 112* LSA cam with extra long Eddie Marine risors and so I think I can eliminate any reversion concern. I also checked a few of the plugs and did not notice any corrosion on them.
I can't help but to think that salt water may be leaking into the motor.
Anybody have any advice or experience with these manifolds on GM engines before? I'm stumped! Thanks Gary

BenPerfected

Some "milk" in the VC's doesn't necessarily mean you have a leak. If you get your oil temp up to 215+, the water or condensation will boil/burn off and vent out the breathers. If the milk keeps coming back, it could be a leak. It is very possible that some water got into the engine when the intakes were removed.

GNJ

Ben Perfected: Both motors were completely torn down, built on engine stands and then installed in the boat. Why would one have milk and not the other?

MM1

Let the engines idle for 10 mminutes and pull the risers off and look down inside the manifolds for water. It will only cost you a couple of gaskets but will eliminate the question of weather you have reversion or not. You would be surprized at how long exhaust tailers need to be.

nocigarette

if there was any drastic temperature change before or while the motors were put in, it will cause the blocks to sweat....Sweat=condensation......Good exhaust i am assuming and fresh power with all new gaskets....Does the oil temps between both motors stay consistant with each other.....more info would help...

I think ya might be overreacting when it is just under the valve cover, if you pulled mine off it would scare ya....If it was a water leak your oil would be junk, i think one motor is running a little cooler than the other...

GNJ

I've had the boat out 2 times. Oil temps seem to be the same.
OK, come to think of it, theres a little more. The second time out, I noticed that one of the motors seemed to act up after the idle dropped down below 800 RPM while manuvering several minutes around docks. It behaved like it was running on 6 cylinders and when I put it in neutral and rev'd it up it cleared. (the motor in question) So on second thought maybe reversion is something to look into?

DMOORE

Yep, or a leaky riser gasket. It doesn't take much water to put out the fire.



Darrell.

Westcoast

Checking a couple of plugs is not going to cut it unless you are lucky the first time and pulled a wet one out...Pull them all and rule out the wet plug therory. Or like MM1 suggested, run the engine, drain the manifold and pull the risers. If it is leaking from the gasket you will see it. If the intake was leaking You would not have the rough idle symptom.
Ed

GNJ

OK it sounds like I have a reversion issue. I appreciate everyones input and wish to thank all of you who replied and helped. I have called the risor manufacturer to see what they can do about this since I just bought them a few months ago and they said they have never had any issues with these risors on motors with long overlap cams. Gary

GNJ

Here's more: I talked some more with Eddie Marine and we explored 2 options:

1) There is probably enough room to build in 4 more inches into the risor before butting up and connecting via rubber hose to the transom pipe. Does anyone think 4 more inches would be enough to correct the problem? If I recall correctly, the risors are dry for 9" and at a downward angle of about 8* before the water dumps into the exhaust stream.

2) Modify them to dry pipes and dump the water over the side of the boat.

Anybody share some thoughts on this? Greatly appreciated!

Thanks Gary