CAM Regrinds are back - Page 2 - ZR-1 Net Registry Forums

XfireZ51 · 03-27-2011

What works for me is to think of it as the ratio between base circle height v lobe height. If the base circle represents where the valve is closed, then the valve begins opening sooner, open longer and deeper with the regrind. The center of the base circle is moved closer towards the tip of the lobe. Having just had a larger intake installed, I can tell you it changes the bass note of the idle. You won't be balancing a nickel on the plenum anytime soon.

VetteMed · 03-27-2011

Quote:

Originally Posted by Coupe89

I'm wondering if I got this right.
Do you need to install smaller cam bearing if you do this?

The bearing surfaces are not reground - only the lobes.

LGAFF · 03-27-2011

At Pete's today, we confirmed that the regrind, which is about .025 to .030 ground off the stock cam, will allow me to use the new stock OEM replacement lifters, despite the valves being set in from 2 valve jobs. If Phil lets me, I will write an article on checking the lifter height to ensure that the cams do not hang the valves open.

A26B · 03-27-2011

Let you write an article???? I'm sure he would be very happy to have your contribution. I know you'll put some photos in there too!

Locobob · 03-27-2011

Quote:

Originally Posted by LGAFF

At Pete's today, we confirmed that the regrind, which is about .025 to .030 ground off the stock cam, will allow me to use the new stock OEM replacement lifters, despite the valves being set in from 2 valve jobs. If Phil lets me, I will write an article on checking the lifter height to ensure that the cams do not hang the valves open.

So we have an effective height difference of .025 to .030 to be absorbed by the lifter preload then?

LGAFF · 03-27-2011

Correct!

Locobob · 03-27-2011

Quote:

Originally Posted by LGAFF

Correct!

Well that doesn't seem bad at all if the lifter does indeed have .060 of play like I have heard.

03-27-2011	#11
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,687	Re: CAM Regrinds are back What works for me is to think of it as the ratio between base circle height v lobe height. If the base circle represents where the valve is closed, then the valve begins opening sooner, open longer and deeper with the regrind. The center of the base circle is moved closer towards the tip of the lobe. Having just had a larger intake installed, I can tell you it changes the bass note of the idle. You won't be balancing a nickel on the plenum anytime soon. Last edited by XfireZ51; 03-27-2011 at 10:52 AM.

03-27-2011	#13
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: CAM Regrinds are back At Pete's today, we confirmed that the regrind, which is about .025 to .030 ground off the stock cam, will allow me to use the new stock OEM replacement lifters, despite the valves being set in from 2 valve jobs. If Phil lets me, I will write an article on checking the lifter height to ensure that the cams do not hang the valves open. __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

03-27-2011	#14
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,376	Re: CAM Regrinds are back Let you write an article???? I'm sure he would be very happy to have your contribution. I know you'll put some photos in there too! __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.

03-27-2011	#16
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: CAM Regrinds are back Correct! __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359