Pure Stock Drag Racing tips & tricks

[Salvatore]

Rob, I am not unhappy with my Crane Cam. What I am saying that there was a difference in the early years. The spec cams and the new G.M. cams do not seem to have the pull and strength through the rpm range as do the old cams. The snap just doesn't feel like it is there. I have the same engine builder as I did 30 yrs. ago and we all agree. The seat of the pants feeling just don't seem to be the same, with all things being equal. Ask some more old timers, I think they might agree with this. Just my 2 cents. Sam

[Schonyenko2]

Without trying to start any spitting matches, and fully agreeing with Rob on the spec comparison, and being fully qualified as an old timer, I kinda agree with Sam. Englers red deuce is a dead nuts rebuild of an LT/1. Even has Ross pistons, and I don't believe its as fast as my original deuce. Then again maybe its just my oldtimers kickin up. Schonye

[Salvatore]

There was a difference. The only thing is that you probably just had to have been there. The snap doesn't seem to be there. Whatever [img]/ubbthreads/images/graemlins/dunno.gif[/img]

[Chevy454]

So, what's the difference? Headers then, manifolds now, or vice versa? Trannys? Got an original LT-1 cam? Would be cool to get an "early LT-1 cam" on a cam doctor see what's up.

[Salvatore]

Wish I had an original cam, or early NOS LT1. I would put it in the short block we are am building now. Headers do help, manifolds are restrictive. Wide ratio trans. also get you out of the hole better. Did any body ever really check a spec cam? Lift and duration, lobe centers, ramp speeds, are they really what they say they are. I never personally checked a spec cam from Crane. I just took there word for it being a 1969 302 spec cam. I am going to pay more attention to what cam we use in this motor. Maybe try a different cam company.

[YENKO DEUCE REGISTRY]

I still have my original cam, is it useful for spec'ing against a new Crane? It's got 99k miles on it [img]/ubbthreads/images/graemlins/grin.gif[/img]

[Salvatore]

Put it in, it is probably faster than the crane. [img]/ubbthreads/images/graemlins/[/img] [img]/ubbthreads/images/graemlins/[/img]

[Chevy454]

Call me slow, but...I still don't see how two identically spec'd cams will run differently? [img]/ubbthreads/images/graemlins/dunno.gif[/img] Does your engine guy have a dyno? That would prove/disprove a lot of this, and is calibrated and repeated, as opposed to the seat of your pants! [img]/ubbthreads/images/graemlins/grin.gif[/img] I've been on a LOT of passes where I would have swore I was on a low 12 second pass, only to get my time slip and have it say 13 something!

[Salvatore]

Rob, You are not slow. I am just telling you my experiences over the last 33 years. Lift, duration, lobe center are one thing, but ramp speed and how it is degreed is another thing.I am not sure all the spec cams are really to spec. I just feel that the early 302 cams and the LT1 cams are better than the aftermarket (spec) grinds of today. We don't have to agree on this. I am just telling you from my experiences. None of my motors were on the dyno. Maybe cams are like carbs, there are no 2 alike. Just ask Jerry MacNeish, or any Stock, Super Stock guy. I am not really unhappy with my crane cam, I just like the chevy's performance better. Sam [img]/ubbthreads/images/graemlins/dunno.gif[/img]

[Rowdy Rat]

[ QUOTE ]
Would be cool to get an "early LT-1 cam" on a cam doctor see what's up.

[/ QUOTE ]

Rob & Sam,

Perhaps my first post on this subject was unclear, but this is exactly what I did. Like Sam, I was convinced that there was a difference between the original specification LT-1 camshafts and what Crane was providing to GM. In an effort to prove that theory, I had three cams checked on Jere Stahl's equipement... Cam #1 was an original cam removed from a 1970 LT-1 Corvette at 1,600 miles (I fully intended to use this cam in my own engine). Cam #2 was an original cam removed from a 1970 LT-1 Corvette at 67,000 miles (my own car). Cam #3 was a Crane supplied GM cam purchased a few months before it was discontinued.

After spot checking several intake and exhaust lobes, what I finally ended up proving was that all three were identical (there was some reduced lift on Cam #2, but I attribute this to it having 67,000 miles on it)... There was no difference between the original 1970 LT-1 camshafts and what GM was selling over the counter in 2000-2001.

I would fully expect an original 1971 LT-1 camshaft to be identical to the 1970 version. I would love to check a 1972 LT-1 camshaft though... Just to see if GM carried through the entire LT-1 production run with the same camshaft. My guess is that they did, but I'd still love to prove it just to satisfy my curiosity.

Regards,

Stan Falenski