Pushrod guide Plates binding

[physcult]

Is it normal to have to slightly file compcams pushrod guide plates?

When trying to adjust the (new) rockers I noticed a couple of the (new) pushrods binding on the (new) guides. This means I cant adjust the rockers on these pushrods properly - not without a slight file.

I would of thought these parts were a precise machined fit:confused:

[Morris460]

What engine?

[Roland CAD 500]

Paul i would guess its a sbc. As most of his posts have been about them.

[physcult]

yep, its a 350 sb chevy with comp cam cam/valve train.

[physcult]

these are the type of guide plates http://www.summitracing.com/parts/CCA-4808-8/
http://static.summitracing.com/global/images/prod/large/cca-4800-8.jpg

[331hemi]

these are the type of guide plates http://www.summitracing.com/parts/CCA-4808-8/
http://static.summitracing.com/global/images/prod/large/cca-4800-8.jpg

Yep,
you'll need to ease them with a file and polish ALL the slots to remove any sharp edges especially if you plan to run Moly push rods as they are not hardened unlike OEM. You may be able to slightly re-align the guide plate by slackening the screw in stud. ISKY do two piece ones that you can just tack weld together in place once you've aligned them.

[physcult]

Yep,
you'll need to ease them with a file and polish ALL the slots to remove any sharp edges especially if you plan to run Moly push rods as they are not hardened unlike OEM. You may be able to slightly re-align the guide plate by slackening the screw in stud. ISKY do two piece ones that you can just tack weld together in place once you've aligned them.

Im glad you said that:) , because I already took a file to the three offending slots. - the rest seem to be sliding ok.

Im using compcams chromemoly pushrod with compcams guides - I wasnt expecting to have pushrods jam up using recommended compatible parts. It says heat treated, but Im not sure if thats the same as hardened:confused:

http://www.compperformancegroupstores.com/store/merchant.mvc?Store_Code=CC&Screen=PROD&Product_Code=7372-16
thanks for your reply

[331hemi]

I doubt whether they will be satisfactorily hardened to work with guide plates. You can bet the guide plates have been crudely punched out of flat stock and you will have a nice radius on one side of the slot and a sharp edge on the other side. Push rods do whip about a bit in operation and will have quite a bit of contact with the guide plate. You're going to need to remove the remainder of the guide plates and get rid of that sharp edge with some emery cloth or similar. It's a bit of a faff I know but having a guide plate machine its way through a push rod is not to be recommended.

[physcult]

thanks for the info - cheers.

[Adam]

The guide plates do just that guide the pushrod to try to minimise excessive flexing under extreme conditions. Thats why you have to run hardened pushrods because contact is possible. Not teaching you to suck eggs but do you have the correct guide plate slot for the pushrod? i.e. your not running 5/16 plates with a 3/8 pushrod? Any metal you take off the guide plate should be minimal or it's reason for being there is diminished. Check there are no burrs under the mounting holes pulling them in a certain direction too as they are really just a cheap stamped item regardless of who's name is on the box.

[physcult]

The guide plates do just that guide the pushrod to try to minimise excessive flexing under extreme conditions. Thats why you have to run hardened pushrods because contact is possible. Not teaching you to suck eggs but do you have the correct guide plate slot for the pushrod? i.e. your not running 5/16 plates with a 3/8 pushrod? Any metal you take off the guide plate should be minimal or it's reason for being there is diminished. Check there are no burrs under the mounting holes pulling them in a certain direction too as they are really just a cheap stamped item regardless of who's name is on the box.

It didnt make sense to me that the guide plate would need trimming, as like you say, I thought they would be guiding the pushrod - so therefore precise.:confused: On inspection the guides are not particularly nicely machined, and are just stamped with a slight burr (but no sharp edges)

All the parts numbers/ packets/ match up to what is recommended by comp cams. Three needed trimming, and the rest fit fine. I thought it was the heads at first but I re-trimmed the slots to make sure, and 3 pushrods still jammed up when adjusting. On closer inspection, and after swapping them around, it does appear to be the guides.

[331hemi]

Are they factory heads, with factory tolerances (wide)? If they are factory, be sure you have opened up the redundant as cast guide in the head so they don't interfere. Also some of the aftermarket heads alter the centres of the rocker studs to accomodate wider ports / bigger valves meaning that you need to match up the guide plates.