262/268 cam base circle query

[TimDart]

Tried comp cams spec sheet on website without luck.
i have just changed from comp cams XE266 cam to XE268. Just broke it in last night.
It occured to me that i might have to make pushrod/rocker adjustments if the base circles were different. Anyone able to advise? I havent road tested the motor yet, just thought I should enquire.

 

[myasylum]

Sorry, just a bit off topic... but did you degree the cam? I'll be doing the same soon, and wondering the importance of it. Thanks!

 

[lead69]

Tried comp cams spec sheet on website without luck.
i have just changed from comp cams XE266 cam to XE268. Just broke it in last night.
It occured to me that i might have to make pushrod/rocker adjustments if the base circles were different. Anyone able to advise? I havent road tested the motor yet, just thought I should enquire.

I assume your using non adjustable valvetrain?,I would not worry about it,base circles usually are not a problem unless its a re-grind or a much higher lift cam,roller ect.I built an engine using a h.p. re-grind form oregon cams not long ago (basicly a copy of a well known grind but alot cheaper) and when I measured the base circle it was .012 down from new.After figuring things out I wound up with .025 lifter pre-load with stock n/a rocker shafts,still well within safe for paper clip lifters.

 

[TimDart]

Thanks for that. i'm going to road test the car today, so should have a better feel for it. The cam break in is as far as I have got.
I didnt degree the cam as I havent the tools. Also, I have a mild build and ont think that it was essential. I guess i'l know when its on the road as i'm expecting a real 'seat of the pants' increase!
I hope...

 

[moper]

Every cam should be degreed, regardless of performance expectations. A stock engine will still run like crap if the cam is ground wrong. That being said, I've never had a Comp cam that was more than 2° off.. which isnt a big deal.