Auto Racing: vacuum pump, dry film lube, small block chevy

Question
Hi Matt, i'm installing a vacuum pump on a small block chevy.i'm pulling the vacuum from one valve cover, should the other valve cover be sealed or vented with a breather?

Answer
Hi Bruce,
The whole purpose of a vacuum pump is to provide a negative atmosphere inside the engine. Pulling from the valve cover will also pull oil mist with the air it takes out. Make sure you have a catch can mounted between the valve cover and the pump.
You will need to seal off more than just the other valve cover. Make sure the timing cover seal is new as well as the rear main seal. Some of the tricks the Pro-Stock teams do is flip the rear main seal backwards with the lip pointing towards the flywheel and then backfill the lip with RTV. Install the crank and main caps while the rtv is wet so that it takes the form of the crank.
Since you are eliminating pressure inside of the crankcase ,you will also be eliminating a majority of the oil mist. This mist helps to lubricate the wrist pins and the valve guides. I recommend dry film lube for the wrist pins and removing the exhaust valve seals to allow oil to get down the guides.
Hope this helps.
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