Help with Cam Specs..

[rollercoaster]

Looking for some help with cam specs...

Someone has a set of cams they want to sell me and I don't really have a lot of details on them nor am I well versed in the reading of cam specs..

Can anyone give an idea of what these cams are and how they would perform etc..

I have been told the specs are:

Standard 2.5mm ?

.450 lift on both intake and exh

Duration is 250 deg @ .050 (232) ?

.25mm timing

Thanx

[lucittm]

I would not buy a set of cams unless I knew:

1. Who made them? (manufacturer or in the case of OEM if they were modified in any way)
2. What engine the cams came out of (size, year, model) and what was the engine used for?
3. If the cam card (full specs) came with the aftermarket or reground cam.
4. That I could trust the person I am buying them from to be honest.

There are too many variables at play here. Three bearing cams will not work very well in a 3L engine, SC cams will not fit in a 2.7L engine. Do you have a CIS engine? If so, then the lobe overlap cannot be far from 113 degrees. What compression ratio do you have?

I don't know of any stock Porsche cam that had .450 lift on both intake and exhaust. The 911S had .450 intake/.400 exhaust and the RSR had .465 intake/.450 exhaust. What is the P/N on these cams; that would tell you quite a bit unless they have been reground and marked as such.

Do you desire low RPM power and torque or high rpm power?

The .25mm timing has nothing to do with the cams, this measurement is the cam timing in relation to the crankshaft (.25mm of intake valve lift at TDC for #1 and #4) and it is set during the installation of the cams, both sides set to the same number.

Good Luck,
Mark

[Steve@Rennsport]

RC,

Mark offers sound advice and I'd follow that to a "T",...

The only thing I could find thats close to what you are looking at are Webcam's 158i. This is a 450/450 lift, 232 duration, timed at 2.5mm.

They also have a 104l thats also 450/450, 250 duration, and timed at 3.0-3.3mm.

The ONLY you'll know is to find comeone with a Cam Doctor to measure and confirm the profile.