Just called Comp Cam help line. Wanted to know which push rods to use with 216/220 .525 .532 114 LSA cam. (P/N: 54-414-11) Told me they don't recommend push rods for there cams, have to figure it out on your own. Does not know the base circle its standard. The warehouse is closed for inventory and can't measure. Asked what is standard? The same as the stock LS1 cam, I pretty sure that is wrong.

Does anyone know the base circle and pushrods need? Can use stock but will probably get the sowing machine sound. Want to keep the right geometry for the rockers. Have stock heads, not milled.

Thanks for the help.

Why have a help line if they can't help????? Base circle info shouldn't be that hard or pushrods for that matter.

 

typically the base circle is .030 smaller so with unmilled heads you should do one of 2 things shim the rockers or get a 7.45 pushrod. personally I would suggest shimming the rockers as you can get the shim kit for about $20.00 or so and it has .030 and .060 shims

now that I think about it Comp Cams has a 7.425 push rod pt# 7796

 

Thanks for the help. I figured it was close to .030 which seems to be the magical number for valve noise. (from what I have read) When you say rocker shim all I could find on the camp cam web sight was spring shim?? Raise the spring .030 and balance out the geometry, makes sense. Have not read there is shims before anywhere. A lot cheaper than push rods.

 

I'll check on the pt# on the shims for ya when I get back to the office.

 

Shims under the rockers makes the problem worse. You need to move the rockers closer to the cam not farther away. Unless you mean to shim .030 and then use a .050 longer pushrod. This would net an effective .020 longer pushrod.

 

when changing the cam and using unmilled heads you need a longer pushrod this is true. I was at first talking about one thing and thinking of a cam change and milled heads (low IQ moment), so in this case shims or a shorter pushrod would only worsen the problem. You really need a 7.43 pushrod. Comp cams does have a 7.425 pushrod.