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Technical => Matt Shaff's Engine Shop => Topic started by: spitzerscott on May 13, 2019, 02:20:45 PM

Title: Engine Moisture
Post by: spitzerscott on May 13, 2019, 02:20:45 PM

We run a 336 SBC with a 850 alky carb, after we make five or six passes and I take off the valve covers there is a large amount of moisture on the stud girdles and rocker arms and laying in the corners of the heads. Anyone have good idea as to why?   We run about 180-200 degrees temp wise.

Title: Re: Engine Moisture
Post by: glofria on May 13, 2019, 02:38:47 PM

Your not venting it enough. That moisture should be going into the catch can.

Title: Re: Engine Moisture
Post by: spitzerscott on May 13, 2019, 04:40:51 PM

We just run a crankcase evacuation from the valve covers to the collector, is that not enough?

Title: Re: Engine Moisture
Post by: JrFuel Hayden on May 14, 2019, 12:25:01 AM

I have no experience with alky carbs, but when I had moisture in my oil I leaned the fuel injection barrel valve. Do the plugs show heat , if not enough lean it down. I think you might be too rich.
The engine temps are in the right range, do you run water in the block, what temp do you stage you car with , I like 180° and then 200-220 at the turn off. Alky runs better with higher engine temps.
We also use a puke tank to vent the engine/crankcase/valve covers, and drain it after every run after we check valve lash every run, in our JrFueler. 
Jon

Title: Re: Engine Moisture
Post by: glofria on May 14, 2019, 09:10:10 AM

Good points Jon.

You may want to take a leakdown and see how much fuel is getting past the rings. The humidity your running in may have an affect too. But unless your milking the oil to the point of loosing viscosity, I wouldn't worry about it too much.

Title: Re: Engine Moisture
Post by: spitzerscott on May 14, 2019, 04:25:15 PM

Keep the ideas coming, I'll look into all suggestions,   Thanks

Title: Re: Engine Moisture
Post by: sknopp on May 15, 2019, 09:31:23 AM

Do you ventilate between rounds?  Get an air bed inflator and adapt it to fit your valve cover breather.  Between rounds pull both puke hoses from the covers and put the inflator on to ventilate.  Be sure to put a filter on the inlet side of the inflator. 

Title: Re: Engine Moisture
Post by: Dunc the Funk on May 17, 2019, 01:24:11 PM

I've been thinking of using the trusty old Coleman inflator to vent as we get methanol & some water condensing in the valve covers. Up to now I've just pulled the valve covers as fast as I can after towing back but definitely going to get on with sorting it out.

Title: Re: Engine Moisture
Post by: spitzerscott on May 21, 2019, 04:27:38 PM

We have put in a smaller set of jets and will ventilate it better, we'll try it Friday night.

Title: Re: Engine Moisture
Post by: 32bantam on May 22, 2019, 04:40:20 AM

Make sure you BLOW air into the engine....NOT SUCK it out. If the alky fumes get to the motor it may start a fire that will look like a jet engine !!!!
Ask me how I know !!!!   LOL