TSP 228R right for me?
I think you will be happy with it, especially on a 112 LSA.
I have a similar cam.
Check out this post as well
https://ls1tech.com/forums/generation-iii-internal-engine/442508-so-lost-cam-done-tons-research-still-lost.html
I have a similar cam.
Check out this post as well
https://ls1tech.com/forums/generation-iii-internal-engine/442508-so-lost-cam-done-tons-research-still-lost.html
Originally Posted by PREDATOR-Z
Because the XE-R lobes with .588 lifts will have a smaller base circle.
My .581 XE-R was .09x smaller which translates in .045 longer p-rods needed (7.445).
The closest without going over is the 7.425
7.40 will be noisy and too light on the preload.
Basicaly when doing a cam swap (stock gasket and stock unmilled heads), you should increase the p-rod length by the amount of the difference in radius of the new cam base circle:
Stock base circle 1.55
Stock radius .775
so extra p-rod length = .775 - (new cam base circle/2)
I hope this makes sense.
My .581 XE-R was .09x smaller which translates in .045 longer p-rods needed (7.445).
The closest without going over is the 7.425
7.40 will be noisy and too light on the preload.
Basicaly when doing a cam swap (stock gasket and stock unmilled heads), you should increase the p-rod length by the amount of the difference in radius of the new cam base circle:
Stock base circle 1.55
Stock radius .775
so extra p-rod length = .775 - (new cam base circle/2)
I hope this makes sense.
Originally Posted by PREDATOR-Z
Because the XE-R lobes with .588 lifts will have a smaller base circle.
My .581 XE-R was .09x smaller which translates in .045 longer p-rods needed (7.445).
The closest without going over is the 7.425
7.40 will be noisy and too light on the preload.
Basicaly when doing a cam swap (stock gasket and stock unmilled heads), you should increase the p-rod length by the amount of the difference in radius of the new cam base circle:
Stock base circle 1.55
Stock radius .775
so extra p-rod length = .775 - (new cam base circle/2)
I hope this makes sense.
My .581 XE-R was .09x smaller which translates in .045 longer p-rods needed (7.445).
The closest without going over is the 7.425
7.40 will be noisy and too light on the preload.
Basicaly when doing a cam swap (stock gasket and stock unmilled heads), you should increase the p-rod length by the amount of the difference in radius of the new cam base circle:
Stock base circle 1.55
Stock radius .775
so extra p-rod length = .775 - (new cam base circle/2)
I hope this makes sense.
TECH Enthusiast
Joined: Dec 2002
Posts: 736
Likes: 0
From: Chattanooga,TN
Originally Posted by PREDATOR-Z
Because the XE-R lobes with .588 lifts will have a smaller base circle.
My .581 XE-R was .09x smaller which translates in .045 longer p-rods needed (7.445).
The closest without going over is the 7.425
7.40 will be noisy and too light on the preload.
Basicaly when doing a cam swap (stock gasket and stock unmilled heads), you should increase the p-rod length by the amount of the difference in radius of the new cam base circle:
Stock base circle 1.55
Stock radius .775
so extra p-rod length = .775 - (new cam base circle/2)
I hope this makes sense.
My .581 XE-R was .09x smaller which translates in .045 longer p-rods needed (7.445).
The closest without going over is the 7.425
7.40 will be noisy and too light on the preload.
Basicaly when doing a cam swap (stock gasket and stock unmilled heads), you should increase the p-rod length by the amount of the difference in radius of the new cam base circle:
Stock base circle 1.55
Stock radius .775
so extra p-rod length = .775 - (new cam base circle/2)
I hope this makes sense.
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Perfect size for cam only (with that .588 lift) would be 7.445 p-rods
Substract .030 (assuming you have stock thickness gasket and stock size valves)
7.445-.030 = 7.415
So the 7.40 are the ones to run.
Now if your head has aftermaket valves it gets trickier because you have to account for the valve length increase while factoring in the rocker ratio.
Substract .030 (assuming you have stock thickness gasket and stock size valves)
7.445-.030 = 7.415
So the 7.40 are the ones to run.
Now if your head has aftermaket valves it gets trickier because you have to account for the valve length increase while factoring in the rocker ratio.
