Valve Spring Specifications
 

I was reading an article in Popular Mechanics about the valve springs
designed by PPI for Nascar back in the late 90's.

This was one of the revolutions in the engine design that led to the
extreme increase in RPMs.

I'd like to investigate using these springs in my RSR engine.
So I inquired to see if they had any for our 964/993 engines.

They didn't but they were willing to see if anything they had already would
work or would consider making some.

I was asked this information -- while I'm learning to turn a wrench,
I do not know these specifications -- so if anyone can help -- maybe
we can collectively benefit.

Appreciate any of the gurus who have this information.

thanks,

Mike

[QUOTE]
Hi Mike,

If you can find out the installed height, valve open height and the loads at those heights along with the inner and outer dimensions of the current spring, I would have enough info to determine what we have that may work in your application. Attached is a diagram for your reference.


Kind regards,
Matt

Matthew Smale | Performance Springs, Inc.

[\QUOTE]

http://forums.pelicanparts.com/uploa...1331129218.jpg

You should call John Dougherty. He already sells some racing springs. Andial makes some as well. Some people like to even use titanium retainers to help lighten the valve train. I believe all the modern air cooled 911 used the same springs. Might not be worth reinventing the wheel. Here are the cam specs you asked for from John's website. Only thing not there is the installed height, which is going to depend on lift, wire diameter, retainer, and base washer thickness, etc. Stock valve install height is 33.5 ex, and 34.5 in, but this number will change depending on the above stated.

Dougherty Racing Cams Porsche 911, 930 and 964 camshaft profiles