Problems with dart 335 pro 1 heads breaking guide plates
 

I've got a motor built with 335 pro 1 heads and seem to keep breaking guide plates anybody else come across this problem

are you bending pushrods also?

i have 3 engines with those heads,never had a problem.

Not bending pushrods just the rockers don't sit right on the valves because of the angles just wondering if stud girdles would fix it or not (has anybody had to do this ) couldn't even run the dart guides they were just too week and broke right away

You may need adjustable guide plates. Summit or jegs carries them. Some people cut & weld them also.

Something definitely doesn't sound right. I used the Dart Adjustable guideplates, and like them. However, it sounds like a geometry issue there. Like incorrect pushrod length, incorrect rocker studs, something like that.

What pushrods are you using? 3/8?

or if you dont want to use the adjustable guide plated you may want to look into a set of td shaft style rockers..you can shim the side to side clearance so the rocker is square on the valve stem..

Short,

Do any of your failures resemble any of the guide fractures pictured in these photos??

Bob

The failure is always like the middle shot it always the end off we are using gm guide plates now they are much better but the problem I definitely geometry pushrods length is correct running 1.7 and 1.8 rockers was thinking that the solid shaft rocker might be the only way to go the pushrods are strong but there is obviously some side pressure in order to break the guide plates ????

Does the side of the pushrod have scrape marks on the side of it? once you have shaft rockers you wont go back the a standard roller rocker..fwi everytime you brake one the chances of the rocker pushing on the retainer are greater and will knock the keepers out and the valve may get sucked into the cylinder..what also comes to mind is piston to valve clearance,all it takes is a lite tap and you will break the plate..