Thread: head analysis

Tweet

Well I took the heads to the machine shop and the discovery was not great. This newly rebuilt, by a "true Chevy Pro ", engine isn't at all what was described by the seller on E Bay. The heads , that were suppose to have all new parts did not. The valves, rockers and all the rest of the parts were mismatched. A mixed up bag of spare parts. The pushrod crumbled because the adjusting mechanism was not the same as the rest. Now I am worried about the bottom end. It probably also is junk. The heads are going to be redone and then we'll see what happens. I'm just wondering if the pushrods might be wrong size also. With a Comp 292 cam and springs I'm not sure what should be the correct pushrod length. Tried contacting the seller who works for the car dealership that sold the car on E Bay, but he's on vacation until next week. Can't wait to talk to him! I'm sure it will be a run around. I still have the write up that was posted on E Bay. This might give me a little leverage.

Originally posted by Deluga
Well I took the heads to the machine shop and the discovery was not great. This newly rebuilt, by a "true Chevy Pro ", engine isn't at all what was described by the seller on E Bay. The heads , that were suppose to have all new parts did not. The valves, rockers and all the rest of the parts were mismatched. A mixed up bag of spare parts. The pushrod crumbled because the adjusting mechanism was not the same as the rest. Now I am worried about the bottom end. It probably also is junk. The heads are going to be redone and then we'll see what happens. I'm just wondering if the pushrods might be wrong size also. With a Comp 292 cam and springs I'm not sure what should be the correct pushrod length. Tried contacting the seller who works for the car dealership that sold the car on E Bay, but he's on vacation until next week. Can't wait to talk to him! I'm sure it will be a run around. I still have the write up that was posted on E Bay. This might give me a little leverage.

Buy yourself a pushrod length checker when you re-assemble.I doubt the push-rod crumbled because of the adjuster.I would say it has to do more with your rocker arm geometry or spring pressure.

I'm going to say coil bind or some other sort of clearance issue because that is a big cam.

I've had them crumble from excessive heat caused by lack of oil.

Originally posted by techinspector1
I've had them crumble from excessive heat caused by lack of oil.

yes i work on boats and had some bad rockers new from ford and run the push rod thru them on a460 ford head and have see the pushrods and rocker balls burn up from lack of oil sounds like i would go thru every thing on this one

GM doesn't put much effort into cutting valve seats either, which would make it seem like valves are mismatched. On my new Vortec heads, the valve seats were between 1/16th of an inch wide which is good to 1/8th+ of an inch which is bad. Since it's a pretty mild motor and the budget was tight, I just lapped the valves and decided to live with the seats.