Pushrod length using base circle! check my math!
Thread Starter
TECH Regular
Joined: Apr 2011
Posts: 403
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Pushrod length using base circle! check my math! Ok guys, Im putting an LS7 cam in my C6 Corvette (LS2)
I chose this cam because I dont want a big cam again, it will be good for boost down the road, have stock driveability and a decent bump in power. I know that there are better cams out there but I can do this for almost nothing so with all that being said-
Im trying to determine my new pushrod length, Ill measure also but this way in conjunction with measuring hasnt failed me yet]
What is the preload set at from the factory?
Stock LS2 cam- 1.552 diameter, .776 radius
Stock LS7 cam- 1.45 diameter, .725 radius
Based on that
1.552-1.45/2 = .051 smaller, Meaning I need a .051 longer PR
Stock PR is 7.385+.051=7.436
I have a set of Comp 7.45 pushrods already that I would love to use but they might be just a little too long. Thats why I need to find out what preload is set at from the factory, a little extra preload wont hurt anything but I dont want to hang the valves open if I have way too much.
Let me know what you guys think.. Will 7.45 work or would I be better off with 7.425? or maybe even 7.400
I chose this cam because I dont want a big cam again, it will be good for boost down the road, have stock driveability and a decent bump in power. I know that there are better cams out there but I can do this for almost nothing so with all that being said-
Im trying to determine my new pushrod length, Ill measure also but this way in conjunction with measuring hasnt failed me yet]
What is the preload set at from the factory?
Stock LS2 cam- 1.552 diameter, .776 radius
Stock LS7 cam- 1.45 diameter, .725 radius
Based on that
1.552-1.45/2 = .051 smaller, Meaning I need a .051 longer PR
Stock PR is 7.385+.051=7.436
I have a set of Comp 7.45 pushrods already that I would love to use but they might be just a little too long. Thats why I need to find out what preload is set at from the factory, a little extra preload wont hurt anything but I dont want to hang the valves open if I have way too much.
Let me know what you guys think.. Will 7.45 work or would I be better off with 7.425? or maybe even 7.400
TECH Apprentice
Joined: Feb 2014
Posts: 328
Likes: 1
From: Baton Rouge La
Ok guys, Im putting an LS7 cam in my C6 Corvette (LS2)
I chose this cam because I dont want a big cam again, it will be good for boost down the road, have stock driveability and a decent bump in power. I know that there are better cams out there but I can do this for almost nothing so with all that being said-
Im trying to determine my new pushrod length, Ill measure also but this way in conjunction with measuring hasnt failed me yet]
What is the preload set at from the factory?
Stock LS2 cam- 1.552 diameter, .776 radius
Stock LS7 cam- 1.45 diameter, .725 radius
Based on that
1.552-1.45/2 = .051 smaller, Meaning I need a .051 longer PR
Stock PR is 7.385+.051=7.436
I have a set of Comp 7.45 pushrods already that I would love to use but they might be just a little too long. Thats why I need to find out what preload is set at from the factory, a little extra preload wont hurt anything but I dont want to hang the valves open if I have way too much.
Let me know what you guys think.. Will 7.45 work or would I be better off with 7.425? or maybe even 7.400
I chose this cam because I dont want a big cam again, it will be good for boost down the road, have stock driveability and a decent bump in power. I know that there are better cams out there but I can do this for almost nothing so with all that being said-
Im trying to determine my new pushrod length, Ill measure also but this way in conjunction with measuring hasnt failed me yet]
What is the preload set at from the factory?
Stock LS2 cam- 1.552 diameter, .776 radius
Stock LS7 cam- 1.45 diameter, .725 radius
Based on that
1.552-1.45/2 = .051 smaller, Meaning I need a .051 longer PR
Stock PR is 7.385+.051=7.436
I have a set of Comp 7.45 pushrods already that I would love to use but they might be just a little too long. Thats why I need to find out what preload is set at from the factory, a little extra preload wont hurt anything but I dont want to hang the valves open if I have way too much.
Let me know what you guys think.. Will 7.45 work or would I be better off with 7.425? or maybe even 7.400
Thread Starter
TECH Regular
Joined: Apr 2011
Posts: 403
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Awesome. Thank you kip! Ive seen a few threads where you guys have thrown an ls7 cam on your cam doctor. Can you confirm that the base circle of the LS7 cam is 1.45? I read that somewhere but just want to verify that its accurate
