[Shotimes] New +20 cam dyno results

[Alan Fanning]

So, since I have the "old school" Stage 1 cams in a SHO Shop 3.2l
high-compression block, how does this relate to my situation - if at all? I
can't tolerate anything that increases the propensity to ping, for sure,
since I'm limited to 91 octane gas here in CA.

    Alan


wrote:

> Alan;
> A recommended procedure would be to adjust the overlap / lobe center on a
> dyno to get the best peak torque, probably wider than stock w/ a +.020 cam.
> Then the overall advance / retard could be done on the street / drags / race
> track under actual conditions. Some type of tuning tool like chrondikes,
> stopwatch, or g-meter is needed. In most cases you will find advanced cams,
> to be actaully faster, regardless of the actual dyno curve / peak HP, cause
> they shift the hump in the torque curve lower. Maybe in Marks case where he
> is above 5k all the time, retarded cams would be faster. I had gotten some
> cam recommendations from one of the best cam tuners at Cam Dynamics (for
> another application), and he recommended a lot of duration, with a wider
> lobe center, for a higher & wider hp/torque curve. In his words it would run
> harder and rev higher for the best of both worlds. Very streetable and very
> fast. Drag racing currently favors just the opposite, with tight lobe
> centers, cause it does make the peak slightly higher, but it also makes the
> power band very narrow, which is OK on a drag car, but not a street car, or
> a low cubic inch car like ours. Chevy numbers say maybe a 6 hp difference at
> peak out of 400, tight vs wide LC.
> ..
> I'm not sure what the SHO cam specs are, but with adjustable sprockets, on
> the +.020, I'd test it first by opening the lobe center up 4 degrees, then
> advancing everything 4 degrees. At that point point it should idle more like
> stock.
> FWIW
> Lee
> (My Z28 street cam had 255 duration at .050, with a custom wide 116 degree
> lobe center. 20-30 degrees more than a stock street cam, and 4-8 more lobe
> center, but that 350 reved to 7300 rpm vs 6000. And it still ran faster
> retarded 4-6).
> I'd even be interested in working with somebody to tame the +.040 cams for
> the street! Anybody interested? Ian? I could see a 7000-7300 power peak with
> an 8000 redline! And we should be able to tune the torque back in.
> 
> ----- Original Message -----
> From: "Alan Fanning" <Awfanning@earthlink.net>
> To: "SHOtimes" <shotimes@autox.team.net>
> Sent: Sunday, May 29, 2005 3:19 PM
> Subject: Re: [Shotimes] New +20 cam dyno results