[Pete]

Originally Posted by JWL

If you recall I covered the installation, with pictures, and sealing issues associated with crankcase vacuum pumping, in my book.

> I appreciate you plugging your book on the forum. It is good for business. They won't let me do that on here.

I do not recommend for long term use unless lower vacuum levels are set or there are modifications made to deal with wrist pin problems.

> There are several more than pin problems to deal with. I assumed we were talking about a race engine because welding up heads for compression is NOT normally done on street engines.

Picking up 20 HP is something we can all wish for but is rather optimistic.

> Actually, that is a conservative number.

Of course I have only examined and tested the results on 4 different Flathead engines with a maximum gain of about 6 HP.

> 4 engines? 6 hp..Ok, I get it. You are talking very conservative street engines. Apples and pomegranates.

It is possible to get a 15 to 20 HP improvement with wet sump overhead valve engines.

> Why does the bottom end of an engine like we are talking about (V8) know what type of heads are up above??

Most dry sumps do not need additional vacuum pumps.

> Imagine the numbers we get with a dry sump system with 20 inches of Hg.

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