Milk in valve covers
 

I am curious about this issue. Through the years I have built a number of very nice, fast, reliable drag race engines. I rarely have any problems, Just the routine happenings of drag racing.

Mostly small block Chevy's but a few big blocks.

The deal is, some of them milk the valve covers but some of them do not. It does not seem to matter what performance level or what equipment, some do and some don't.

These are engines built for customers and for my own cars and does not seem to cause any problems, oil looks good, engines run fine and perform as expected.

Aluminum heads do it more than iron heads. Also, if you run the engine to 200 degrees or so before putting in in the trailer that seems to help.

Have others of you witnessed this happening? Do you have any explanation of why some do and some don't?

Re: Milk in valve covers
 

I put a PVC valve on mine to stop that in cool damp weather.

Re: Milk in valve covers
 

Ed, I may experiment with a PCV valve. What valve? Got a part number?

Re: Milk in valve covers
 

ARP makes fluid Teflon sealer for head bolts, never had the problem again. Be liberal with use.

Re: Milk in valve covers
 

Don't remember what it was for. Fits a 3/8" hose and plugs into a gromet in a valve cover. I tack welded a baffle over it inside the valve cover to prevent sucking oil. May as well find one that flows plenty of air. It's a legal vacuum leak after all. Think mine is for an early 454". That was 4 years ago, and I'm old.

Re: Milk in valve covers
 

I always sealed head bolt threads. Only showed up on fall mornings after short run times. Mine seldom sees 140 deg that time of the year. Hard to evaporate condensation without warming up.

Re: Milk in valve covers
 

condesation is the culprate and extrem heat,,,,we only run our race engines a short time (yes we get them up to 180-200 during warmup) but during the coarse of the race season we have so many temp and humdity changes thru out the season the condesation will build inside the valve cover and stay there,unless we have an endurance race (many rounds or consistant running of the engine )i have seen it in the oil pan windage tray that the oil doesnt cover ,synthetic oil is not helping to keep this from happening amost like brake fluid ,i have seen it from my fleet to my stocker gmonde

Re: Milk in valve covers
 

if you are using Pennzoil it may happen seems some oil brands are prone to this too --we chased this for almost 3 months thought it was everything from leaky gaskets (head/intake) to condensation etc-- switched to Valvoline problem went away immediately --part of what we found is the condensation gets all whipped up in the oil and the result is that milky look--- so we started the engine ran it for a few minutes pulled the v covers and cleaned em with brake clean left the covers off for 10-15 min to let the stem evaporate and then reinstalled the v covers and went on our way---this only happened if ya only ran the car every so often if ya ran it every weekend did not seem to be a problem--we did install one of those plastic check valves from the v cover to the headers --valve is the vacuum takes about a 3/8inch ID hose the kind that went on a early 60s to mid 70s GM power brake booster seemed to help a lot too--just my experience--Comp 387

Re: Milk in valve covers
 

I used to run a pcv valve on my stocker helped with the milk issue in the v/ covers, one day we pulled the carb, and found the baseplate covered with condensation, which led me to believe it would contaminate the intake charge, also the car would go a few hundreths quicker with just open breathers. So now when I run it for a short time, shut it off, take the breathers off to let some air in to disapate the condensation. gsa 612

Re: Milk in valve covers
 

The only reason I mentioned it was because it happen to me and that remedied the problem.

The other thing to consider is: what is the product of combustion? The pcv may be the solution. I run one but didn't at first.

Re: Milk in valve covers
 

What FED 387 said about the Pennzoil being the worse about milking. I run a fuel injection setup on my sbc dragster and in heavy humidity 40-50% or more I'd still have some stuff in the valve covers. I would pull the exhuast vac off the valve cover after running the motor up to 200 degrees while I loaded it up in the trailer and I have a 12 volt mattress air pump that will push or pull air that would help remove the moisture even faster. I went from changing oil after 10 or 12 runs(twice a month) and now I wait until I start feeling guilty which is usually 4 or 5 races(I could go longer judging by the way my oil looks). I also have a System 1 oil filter so which I check after a race just to keep an eye on things.

Re: Milk in valve covers
 

I have noticed that if we dyno on a day that it is raining the problem will be much more noticable.There are many things that can make this happen including just about every single one that the posters above me mentioned.IMHO the biggest reasons that this happens depends on the humidity and the fact that these engines just are not run long enough to prevent this from happening.A good example is if you have ever known an older person who will only drive their car to church on Sundays,everything on the car stays in excellent shape except for the exhaust system which will rust away in a year because the vehicle just is'nt run long enough to overcome this.This probably does'nt happen with new cars anymore since most of them have stainless or aluminized exhaust.

Re: Milk in valve covers
 

That is interesting about Pennzoil. I use Pennzoil when I dont have synthetic in the engine and I am almost always fighting the milk in the valve covers and condensation on the rockers. I do remove the pan evac lines to let the engine breath when not in use. I am going to try a different oil next time. The humidity is always high in Florida. Any body tried blowing warm air through the engine with something like a blow dryer through the breather hole in the valve cover to chase out the moisture?

Re: Milk in valve covers
 

"I have a 12 volt mattress air pump that will push or pull air that would help remove the moisture even faster." I mentioned earlier works well pulling the moisture out. Any condensation left in the crank case will settle to the bottom and I quickly remove the oil pan drain plug and any milky oil comes out first and I replace the plug quickly as soon as it runs clear, about a 1/2 of a cup or less will do it. If I had the money I would just put a belt driven air-vac pump on it.

Re: Milk in valve covers
 

I never get any moisture in the pan. When I drain the oil you would never know that there is condensation in the valve covers. I think I will try the forced air trick. I also use the System One filter. I lost two engines due to filters collapsing. I would never use an over the counter oil filter again on a race engine.FYI they were AC Delco filters.

Thanks,

Re: Milk in valve covers
 

A buddy of mine shut off his dragster after a burnout last season after a burnout due to little or no oil pressure. Someone suggested he check his oil filter first and sure enough it had collapsed. It was a oem Fram filter.

Re: Milk in valve covers
 

I had this on small block motor, used small amount of thread sealer on the head bolts and the problem went away.

Re: Milk in valve covers
 

Believe me when I tell ya we tried everything--pressure tested the heads/magnafluxed the block/replaced every gasket that was even near water/sealed every bolt that was near water/checked for cracks or leaks every where even swapped out engines but still using Pennzoil and finally after talking to Glidden at the Gators when he borrowed some spark plugs from me he suggested switching brands of oil and it magically went away---seems the moisture mixes with the Pennzoil differently than it does with the other brands of oil resulting in the milky look we switched to Valvoline then and never had a problem like that again

Re: Milk in valve covers
 

This is an ole one that I was thinking about and wondering if this may be the problem. My Dad used to tell his mechanics and me to stay away from Pennsylvania oil because it had a high ash content. It would reck havoc in a Detroit Diesel by clogging the injectors, they switched to Valvoline and the problem went away. This is really ole school stuff here.

http://www.baileycar.com/oil_overview_html.htm

Re: Milk in valve covers
 

This used to happen to our small block. Ever since we warm it up to 180-200 the "milk" went away and the oil looks clean

Re: Milk in valve covers
 

I found this is a fairly common problem when the engine doesn't reach operating temperature. The valve covers are one of the cooler areas on an engine, so they tend to collect the moisture. When the engine warms up the condensation goes away.

Has anyone experimented with a block heater? I seem to remember that someone used to install a heater in the cooling system to bring the engine up to temperature quicker and cut down on the warm-up which just seems to flush the cylinder walls with fuel. It might also help with the condensation in the valve covers.

Lew