Jeremiah,
I'm in the same position as you, except I'm looking for the "hottest" cam I
can run without freaking the computer (after I heat it up with a Hypertech
III power programmer this summer!). A little "lope" in the idle would be
music to my ears. According to my 97 owner's manual, the stock cam in my
5.2L is: 250/264 (int/exh) duration and the valve overlap is 31 degrees. It
doesn't list the lift and lobe center angle.
The Mopar performance cam is what you quoted and has 270/276 duration, valve
overlap is 55 degrees, lobe separation is 109 degrees, and the lift is
.458/.457 (int/exh). I priced this kit today in Austin, TX and was quoted
$513 for the cam and lifters!!! Ch-Ching!!
I've been looking at Crane and Competition Cams. You can get to their
websites at www.cranecams.com and www.competitioncams.com
Crane has two cams listed. The hotter one is part number 704121 and has the
following specs: 260/264 duration, valve overlap of 34 degrees, lobe
separation of 114 degrees and lift of .458/467 (hmmm...same lift as the
Mopar cam).
Competition cams has three listed. I talked with a guy and he recommended
part 20-608-8 and this one has the following specs: 254/262 duration, valve
overlap is 34 degrees, lobe separation of 112 degrees, and lift of .480.480.
Based on the hotter Mopar cam, Competition Cams has another, part 20-604-8
with the following specs: 264/274 duration, valve overlap of 45 degrees,
lobe separation of 112 degrees, and lift of .512/.512.
I plan on calling Competition cams tomorrow and seeing if that last one I
listed above will work on my 5.2.
No doubt that an aftermarket cam will cost less. Mopar sells the whole kit,
cam and roller lifters. The lifters on the 5.2L magnum engine are already
rollers. They guy at Competition cams said my stock lifters should work
fine with the part 20-608-8 so that saves some $. I think what I will wind
up doing is getting the hottest cam I can get from Competition Cams, use my
existing roller lifters, and also purchase a set of Competition Cams roller
rockers (part # 1425-KIT).
By the way, they usually don't list valve overlap on the cam spec sheets,
but you can calculate it by adding the BTDC intake valve opening degrees to
the ATDC exhaust valve closing degrees to compute the valve overlap. I
belive that as the valve overlap gets larger, the more pronounced and
rougher the idle will become. Valve overlap helps the cylinder "scavenge."
Hope this helps.
Mike
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:48:06 EDT