Jimmy P
Oct 27th, 03, 9:13 AM
A buddy of mine wants to use a very low mileage 99 Vortec motor for his 52 Chevy. He dosen't want to break the heads off, change out springs or do any mods. (???)
He wants to use the GM Hot Cam. I think valve springs/ binding could be an issue with the .510 lift on the exhaust on stock Vortecs.
I've come up with an LG Motorsports cam for an LT-1/LT-4 that I think will work in the 99 Vortec block. It's has 220/230 duration and a .480/.480 lift with 1.5 rockers. Anyone see any holes in that plan? Maybe a set of LT-4 springs?
ZZ69chevelle
Oct 27th, 03, 8:30 PM
I think that cam is right at the limit for lift with Vortec heads. He can always pick up a used LT1 cam dirt cheap if he want's to leave the rest stock. I got one in my 305 that I paid $20 for.
Bob West
Oct 27th, 03, 8:47 PM
I think stock vortec heads are rated for .450 lift, I've got a set with z28 springs and they are supposed to be good for .520 lift.
Wolfplace
Oct 28th, 03, 1:17 AM
Originally posted by Rapid Robert:
I think stock vortec heads are rated for .450 lift, I've got a set with z28 springs and they are supposed to be good for .520 lift. Yep,, With stock retainers anything over .450 is iffy. Had a set on the flow bench & some made about .480 most hit the seals at about .450-.460 on this set.
For info the Z28 springs won't fit on some vortecs without cutting the guide boss. Not a big deal just more details,,,, :D
bored&stroked
Oct 28th, 03, 2:21 PM
Its amazing that people keep finding vortec heads that only go to .460" lift when chevy uses them stock on a .481" motor.
Personally I wouldn't run a cam with more then .480" without checking the heads first. I run a .480" cam on my vortecs but they were checked and have new springs.
Wolfplace
Oct 28th, 03, 10:30 PM
Originally posted by bored&stroked:
Its amazing that people keep finding vortec heads that only go to .460" lift when chevy uses them stock on a .481" motor.
Personally I wouldn't run a cam with more then .480" without checking the heads first. I run a .480" cam on my vortecs but they were checked and have new springs. Actually,, they don't use them stock with a .481" lift cam. They upgrade them with the LT4 or Z28 spring & LT4 retainer.
They are normally listed stock for up to .450 lift at most GM Performance Parts sites. ;)