Don Terrill’s Speed-Talk

levisnteeshirt wrote: If those cams in 'em are that sloppy , thats a raw deal. This day and age , thats in-excuseable.

The crate motor stuff isn't quality constrained like the production stuff is. In most cases crate motors have a pile of Chinese parts blended in together with production intent parts.

The production sitaution is different and I'm 100% certain that spec range for a 2010 model year camshaft is a lot tighter than 5° total spread.

RW TECH wrote: I'm 100% certain that spec range for a 2010 model year camshaft is a lot tighter than 5° total spread.

If it's a GM product, it would be the first.
Their production cams don't look any better.
They still look like they're being ground on gang grinders.

CamKing wrote:

RW TECH wrote: I'm 100% certain that spec range for a 2010 model year camshaft is a lot tighter than 5° total spread.

If it's a GM product, it would be the first.
Their production cams don't look any better.
They still look like they're being ground on gang grinders.

really? I had no idea GMs cam tolerances were so loose. Has it always been this way?

RW Tech..
I got my info on the +/- 5 degrees from John Aller at Audie Tech...they build the Cam Pro System for checking them. I didn't see how that was possible so I called GM Performance and got to the tech line or tech help asked the same question on tolerances and got the same answer... unbelievable! I guess thats why my personal vehicle is a Ford F350 Diesel...LOL

levisnteeshirt wrote: if its found that the engine's owner has enfringed on GM's copyright , you will be prosecuted to the full extent of the law. And actually do it , enforce it , bust a few of 'em hard.

What copyright is that?
There's no laws being broken. Just track rules.
I don't sell my cam as a GM Crate cam. I just say it'll pass tech.
The engine builder buying my cam, doesn't sell the engine as a 100% GM crate engine. He just sells it as an engine that'll pass tech. The end user knows it's not a 100% GM crate engine.

Now if GM really wanted the engines to stay untouched, they would lease them, and not sell them.

CAMKING:

I have no idea what an extra 5 degrees of duration would be worth on a crate motor. I know if the rest of the cam specs remained the same it would move the powerband up 200-250RPM +/- a little...in your experience what would the effect be?

Thanks,

novadude wrote: really? I had no idea GMs cam tolerances were so loose. Has it always been this way?

I don't know, "always" is a very long time span.
They've always been bad.
I think the +/- 5 degrees is double what you would really see, so they don't have to scrap any cams for being out of tolerance.
Seeing +/- 2 or 3 degrees is pretty normal on the stock stuff I've looked at.

LateModel13 wrote:CAMKING:

I have no idea what an extra 5 degrees of duration would be worth on a crate motor. I know if the rest of the cam specs remained the same it would move the powerband up 200-250RPM +/- a little...in your experience what would the effect be?

Thanks,

How about 10hp on a 602, and 15hp on a 604

GM has to worry about staying in the car business! I'm sure selling a handful of Crate Engines is very small in the greater scheme
of things. GM can't afford to police the Crate Engines and I'm sure they could care less anyway. It's just another part for sale.
Ching! Ching! Hit the cash drawer. They are trying to stay afloat just like the rest of us.

CamKing wrote:

LateModel13 wrote:CAMKING:

I have no idea what an extra 5 degrees of duration would be worth on a crate motor. I know if the rest of the cam specs remained the same it would move the powerband up 200-250RPM +/- a little...in your experience what would the effect be?

Thanks,

How about 10hp on a 602, and 15hp on a 604

In a limited class like this on asphalt where the guys are hooked up, cars are free and rolling thru the center of the corner 15HP is big! I know ASA legal 604's with allowed upgrades go 440 ish on the dyno around here..if a guy had 455HP or 3.5% more thats bites...

Thanks Mike!

LateModel13 wrote:thats bites...

Then tell the track owner to outlaw the crate engines, and go back to real racing.

CamKing wrote: Seeing +/- 2 or 3 degrees is pretty normal on the stock stuff I've looked at.

That's why I mentioned production as better than the crate junk. It's still not perfect but it's not as sloppy.

Don't suggest that GM lease the engines...It reminds me of LS1 ASA program & over the long run that didn't work out too swift..

CamKing wrote:

LateModel13 wrote:thats bites...

Then tell the track owner to outlaw the crate engines, and go back to real racing.

Amen!!

RW TECH wrote:

CamKing wrote:

LateModel13 wrote:thats bites...

Then tell the track owner to outlaw the crate engines, and go back to real racing.

Amen!!

Well I tried that before and they looked at me like I was STUPID... they said I was in the minority because only four of use run built motors now and the other 15 that are around run crates.... but wait when they changed to crates we were all running built supper late model motors and everybody had to change motor combinations... now the crate car count is 8-12 the weeks they race them and the SLM are 12-20 when they race them...so we have two classes running part time with low car counts and no fan following! AWESOME...........

Sorry for taking the thread off the cam question...

dang ,, what if you get stuck with an engine that the cam is 5 degrees off on the low side ,,, that would suck