Blower Motors With Condensation
 

I have a couple of 454's set-up similar to the 600sc's. I'm running twin 700 Holleys. I'm guessing that the compression is 7.5 or 8. I'm running right at 5 lbs boost. I have the 212* oil thermostes and crossovers with no water thermostats. My water temp is less than 100* and my oil temp runs about 180- 200*. I have aluminum heads. Stock oil coolers.

My problem is that both engines are set up the same but, I'm getting a lot of condensation in the valve covers on just one engine and its the same engine that has the oil thermostat. (You would think it would be the good one). I have tried a number of different brand oil thermostats but, that' as high as I can get the temps. I have tried replacing the intake gasket thinking it could be leaking but, that's not it.

Does anyone have any ideas as to what to look at next?

Thanks Bob

Intake manfold gasket? Have you tried tightening it? Maybe it's seeping...

You can buy a T-Stat plate...goes inside where your T-Stat would normally be , but is a disc that has different size holes in it so the water is not just pouring in...might help the problem..

Too much water pressure.
Do you have a water pressure gauge?
A buddy of mine had the same problem and added dumps to blead off some of the pressure.
I think he's running around 20lbs at WOT these days.
I think his oil temp is still a little low, 180-200°F

I have added a 5/8 restrictor plate. It may have brought the water temp up 2* not really anthing noticeable. My water pressure is still around 20 lbs.

Did your buddy bleed off water before it went to the engine and after the raw water pump?

I have double checked the intake bolts.

The only real difference between the 2 engines is that the one I'm having a problem with runs a Jabsco raw water pump in lieu of the Mercruser. I have noticed more water pressure on this side but, I would think that 20 lbs. is still good.

you need 212+* to burn off the moisture ...both motors run cold water temps ? The 20lbs ... at high rpms ?

I believe the dumps are off the exhaust manifolds so all the water still goes through the engine.
The dump hoses are pretty big, I think 1", same as the jumper hose to the riser. He stuck a pipe plug inside the dump hoses and drilled different size holes until he got the pressure right.
I think his water pressure is like 5lbs at idle and 15-20psi when up and running.
The engine is a built up Merc 525sc making around 575HP. Gregg still kicks himself for removing the stock thermo housing and circ pump.
An oil thermo is next on his list.

Your water temp is less than 100 degrees Fahrenheit? That's way too cold. Remember, you'll get some oil cooling just through the water a jacked of the engine. I would work on getting those water temperatures up first, then go from there.

Michael

Does one engine steam more than the other?

wait to some of the "run it cold as possible" gang see's this thread .. Scares the hell out of me thinking of a motor running 5000 rpm @ 100* ....m

This is kind of odd seeing this topic on water temp, and the lack of it....It has been on my mind all week.
I run on Lake Mich. and as you know the water is very cold at the beginning of the season and doesn't get much past 70 Deg by August if we are lucky.
I have Blower motors with alum. heads and at the moment run with out stats.
One motor had a little more trouble keeping the oil clean of condensation than the other....so we tested the exhaust system and the intake gaskets were replaced for good measure and so on and found no leaks.
The gauge on the dash shows about 210* of oil temp and never more.
The other reads 220*.....
Is 10* that much of a difference? Don't know but this season I'm installing a Merc stat with a few 1/8th holes in it for to see what happens.

I'm building a pair of MIV 496's now ... On the test stand without T'stats I cant get operating temp .. With T'stats the temp is ok but pressure will spike over 3000 rpm ...I drilled 3/16 holes (3) and the pressure spikes came back ... So 1/8 is about right and I would start with one ? Two at the most ...m

:cool:

If you're planning to install thermostats, you will need a thermo housing and crossover with the bypass hose.

I think I mistated about the holes ... If I have spikes with 3/16 holes I need to go larger ....

Oil thermostats would solve the issue with condenstation

I appreciate all the suggestions guys. I thought about running thermostats but, the other engine didm't seem to care if had them or not. My water pressure is about 20 lbs @ WOT. The engine with the problem is running a 5/8 restrictor plate. The other is not running anything. The water psi on that engine is a little less, as would be expected.

I would hate to buy a new set of crossovers with a bypass only to find out it didn't help but, I bought several different oil thermostats and that didn't make any difference so what the heck.

I guess I would of thought the stock oil coolers would be to small but, that doesn't seem to be the case either.

If gas were 1.00 / gal. I guess I wouldn't care how long or hard I had to run it to get the temps up.

Arizona Speed and Marine has a 120 deg. thermostat. Merc. has 140 and 160 degree thermostats. If you raise engine temp and restrict water through the engine with a thermostat, the oil temp will go up. Use a crossover with a bypass and use a water pressure bypass valve if nessesary to control the pressure. You're lucky you don't have the opposite problem.:D

I have the bypass crossovers and pressure reliefs in front of them....just no water temp at the sensors.:(
I have the Merc 140's to try now but thanks on the info about the 120's.:cool:

Bob, get some t stats in there and get those engine temps up. I'll be helping a buddythis weekend that has the same setup as you. I'll pick his brain.

Sorry If I kinda Hyjacked this thread...but the more heads we get together the better.

I had an engine with a small amount of water migrating up a few head studs that were not properly sealed .

Do you by any chance have intercoolers? The symptom you are describing with water in the oil can also be caused by small leaks in an intercooler. After the boat is turned off, water can drip down into an open intake valve and seep past the rings into the oil. This can cause an unusual amount of milky oil in the valve covers. If the leak progresses, it can cause a hydrolock and break stuff. If you do have intercoolers you definatly want to do a leak test before you analyse much more.

Im having the same issue. No chiller lots of condensation on the blower and intake. water temp max has been 140* I dont have a oil temp yet but will. Noticed a oil color change to a tan not frothy just color. could the color be from the condensation or something else? was wondering if you solved you issue.