cam/con rod clearance in a stroker
 

Tried installing my Comp Cam solid roller into my 434 stroker this weekend.

The connecting rod ends contact the cam lobes of the cyl on the opposite bank.

No problem clearing the non lobe part of the cam, its ground on a .900 base circle.

It is an Eagle rotating assy, and uses the ESP H-beam rod. The crank is 4.00 inch stroke.

Any body run into this before? Whats the solution? I tried advancing the cam 4 degrees, that didnt work. I dont want to retard it.
Will the rod ends need to be ground down? Is it o.k. to do that?

The engine was balance once already.............:(

Update: (since no one ventured forth any input anyway)

will have to grind the rods down to clear the cam lobes, or go with smaller cam.

Actually it is the shoulder of the rod, about 11:00 from the straight up position that needs to be clearanced.

Am not wild about having to do so, but the cam is custom ground, and is what is needed for the combo.

Gotta make it schwing.....................

yeah, clearancing like his is normal for a stroker motor. you'll have to clearance all the rods and re-balance. sorry but it's that or go with a smaller, custom ground cam.

Vince, shouldn't that be phrased, 'for a big stroker' engine, or when also running a big std. base cam?

Arnie,

i would tend to agree with you if i hadnt had some experience with this specific problem lately. my friend Frank recently built a 383 L98 motor for his vette and will have to clearance his rods or have a smaller BS cam ground in order for it to spin the bottom end. it's a 5.7 rodded motor w/ a cc305 so that might have something to do with it. i dont have a motor here in front of me to measure the diffrence between a 6.0 and 5.7 rod 383 but i imagine that the diffrence would be slim to none.

sorry Arnie, you're right. i missed the cam journal size. but it seems to be SOP for a stroker w/ a STD. journal cam as well.

The engine builder says he hasnt had any trouble with 434's running a .600 lift cam. This being a .630, is the biggest he`s seen.

6 inch rods btw.

They are in process of clearancing the rods right now, he says it is usually just three that need it, Lingenfelter`s book says four rods need it

Not so much the length of the rod, but the type (crankpin end) of rod, with cap screws or bolts, has an impact of cam clearance available. This (rod issue) should have been added to my earlier post.

they have taken 4 grams of matl from 4 rods to achieve the clearance.
And are telling me that re-balance may not be necessary, because of the loacation and the small amount of matl removed.

What do yall think?

Cam to rod clearance is usually an issue with 4" stroke small blocks. Seems like Comp would have made some recommendations before sending you that cam cause you can get the necesary clearance with a wider lobe seperation angle (110+) and a lobe centerline of 106º. That provides a bit of rod-to-cam clearance on the big stroke small blocks with standard cam height.

As for the weight... me being the anal person I am I'd recheck the balance. May not be a big deal but you're spending a bit of money to put this thing together. Your call.

-Mindgame