Cam grinding

[Blue Flame Restorations]

Originally Posted by LGAFF

You can get any # you want on the dyno if you diddle with the system....thats why its hard to compare on dyno to the next

You might have more Brett....

Yeah, Pete's told me all about the dyno tricks that people play. I'll never dyno my motor. No point for me. I just like the way it runs. After driving Kevin's stroker, I want one of my own!!

[ZZZZZR1]

Originally Posted by efnfast

Sooo David, you're around 522 hp. 510 by Marc's numbers, that means 12 hp by cams???

No... At the time I did the dyno, I didn't have some of the items marc uses to get 510hp. (Lightweight flywheel and 63mm throttle boy)

My rwhp should be higher than 444 with those two items added. I don't want to give an estimated dyno # because I don't want to guess wrong

Intake cams add 25 to 30hp and exhaust cams add 8 to 10



David

[Paul Workman]

This is more or less typical of LT5s with stock bottom, cams, & TB. The power adders (call this a "base case") is full porting, relieving, headers, X pipe, 3" free flowing exhaust, and Fidanza FW. Numbers can and do vary, but due to the ambiguity associated with different dynos.



Now...Add cams = +25 ±, 63mm TB = 5-8 more, electric water pump = 8-12±. So, in this 508 "base" example, it would put it around 549 chp, or somewhere in the range of 466 rwhp, ±, depending on the dyno ambiguities and phasing differences. (Pete said he was getting 474 rwhp before his last cam change, FWIW.)

Hope this gives you an idea. Aslo, Marc has all this breakout and more on his website.

One more question comes up often, and that is the loss of low end torque that results from porting the LT5. This graph represents the rear wheel torque results I experienced "before and after". And, I'm not alone! Contrary to most of the car rag articles from "experts", I didn't lose, but in fact GAINED low and mid-range torque! You can ask Dominic or Pete, or Marc, or any of the FBI gang and they'll tell you the same thing. As long as you don't go "nuts" with the cams, it is very possible to have some respectable increase in low/mid range torque and wheel power and not loose tractability at all!



And, this is what makes the LT5 unique, and why it surprises so many people - especially those totally immersed in the characteristics of pushrod platforms.

[tpepmeie]

Originally Posted by Blue Flame Restorations

After driving Kevin's stroker, I want one of my own!!

I'd build another 427 for ya And I'm less than an hour away from you!

Todd

[Blue Flame Restorations]

Originally Posted by tpepmeie

I'd build another 427 for ya And I'm less than an hour away from you!

Todd

Thanks for the offer, Todd. You motor sounds sick!!! (that's a good thing!!!! LOL)

Pete has dibs on the next one. Hope to do a 427 too.

[XfireZ51]

Originally Posted by Bob Eyres

So, are you saying that with the cams the 91' is quicker, but less tractable and less easy to drive than the 95'?
I wonder if the combination of my light flywheel and the cams will make it a strong runner, but take a whole lot of smoothness out.

Bob,

You can come and drive my car , then tell me if smoothness is lost. If anything I think its very smooth particularly at cruise. With 350rwtq or more available anywhere from 3-6000 rpm, just keep it in 5th or 6th.

[Bob Eyres]

After seeing those torque specs I don't doubt it. Gee, this engine is phenomenal.