engine problem, new one for me.
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 1,036
Likes: 2
From: Huntingburg Indiana
engine problem, new one for me.
I put about 100 miles on my freshly rebuilt 71 350 engine when it suddenly started to miss and backfire. I immediately thought electrical problem. Everything checked out OK. I removed the valve covers and found one broken rocker. It looks like the pivot ball galled for some reason and seized causing the ball to break the bottom out of the rocker. I have had a few old vehicles and have never had this happen. I am going to replace them with gm performance parts rockers. The whole set is only about $55. At least it's an easy fix.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Make sure you have oil coming up the pushrod and out through the hole in the rocker arm.During priming the engine you should prime until you see oil come out all pushrods.If the upper end is starving you will continue to have problems.
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 1,036
Likes: 2
From: Huntingburg Indiana
The rockers were all lubed and pushrod holes were clean. Plenty of oil got to the top end. It just doesn't make sense that it took that long for it to happen. The rockers were the originals. One of the guys at work said that if the rocker had a burr on it, it would lock up the pivot ball. The ball is all scratched up, so this could have happened. I am not worried about hurting the cam. As soon as this happened, the motor was shut off. It didn't even bend the push rod. No big deal, I will have a whole new set of rockers monday.
