Ihave a set of 225 Afr,s on a 99 vette, they are for a 4.125 bore. The ploblem is all of the intake pushrods scrub to the unside of the heads. I have already milled the holes, went into the intake ports and still have min. clearance. I called Afr and of course they say there is no ploblem. I've tried comp shaft and jesel sportsman rockers, they show the same thing.Since I've bought 3 sets of Afr's in the last year and had no problem this could be a isolated incident. Tony Mamo ????? Anyone seen this????

 

give tony at afr a call

 

What diameter pushrods are you using??

I have never heard of this problem before....Did you try stock rockers just to see if they fit? We design the head to be a "bolt on" and work perfectly with the stock set up, but I have run Comp stud mounts, Crane stud mounts, and Crane shaft mounts without any issues although the Crane shaft mount did put the pushrod close to the wall where it just removed the black coating during running conditions due to a little pushrod flex (there was minimal clearance there in static conditions).

A shaftmount set-up can require modifications for proper clearance, but I have never seen anyone have problems with any of the aftermarket studmounts like Crane and Comp.

Call me Monday at AFR but I would like more information on your set-up.

Thanks,
Tony
(818)890-0616 Ext. 109

 

Well, I can't comment on the AFR's but every time I have looked into the two shaft rockers you mention (Jesel and the Comps/T&D's) I was told you need to elongate the pushrod hole approximately 0.125" to get them to clear. I went with the Crane setup as a result.

 

The pushrods are 5/16 comps. Tried stock rockers same problem. I would say it is definately a head casting issue.

 

Angle milling also creates push rod to casting issues...

Ed

 

Not angle milled but decked 40.

 

I have the same problem with my head , i took a raimer to remove some aluminum but the intake runner is so thin that it made a small crack in the runner , no big deal my machinist repaired that ,but last week i took the car out for the first time this year and one of the cylinder head lost a seat so you can imagine what it did to my engine (408 stroker from Lunati ) i dont know what i'm going to do but i dont really trust those head anymore.

 

I had a similar problem as Tony described with my Jesel's and the stock rockers. I would get some wear marks on the pr body. I had other issues with the Jesels and when I resolved those I had shimmed the stands .025". When I did this I installed a brand new set of 7.375" pushrods. I looked at the pushrods after about 100 miles and they were perfect. I don't know if the shimming changed the angle just enough or if the shimming moved the stands to the correct spot, but it worked for me. Unfortunately I had other issues and had to swap the Jesel's out for a set of Harland Sharp's that are also fine. I have to admit that they do look a little close to the walls though and I never had a problem with them that way.