problems with my 390 heads?
New User
Joined: Dec 2002
Posts: 7
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From: California United States of America
problems with my 390 heads?
I just got done rebuilding my 71 390 for my f-100 4wd. When i pulled the heads the first time we found a burn between the number 7 and 8 pistons so i had the block decked .050. I rebuilt everything and put a little bit bigger cam in it and bored it out 30 over. We put it back together and she ran great for about 2 weeks and it developed a knock, so i pulled the valve covers off and found that the pushrods were bent at the number 3 cylinder. I replaced them and it ran fine again for about 3 weeks and it started knocking again. I pulled the valve covers again and, and again found that at the number 3 cylinder i had a bent pushrod and the exhaust pushrod was broke.
Is this because the valve is too close to the piston, and the stock pushrods are to long for the difference in deck highth?
Can somebody please tell me why this keeps happening? I NEED HELP BAD
Is this because the valve is too close to the piston, and the stock pushrods are to long for the difference in deck highth?
Can somebody please tell me why this keeps happening? I NEED HELP BAD
New User
Joined: Dec 2002
Posts: 7
Likes: 0
From: California United States of America
problems with my 390 heads?
Thanks DF,
I am in the prosses of measuring to see if i have a shorter or longer pushrod for that #3 cylinder or not.
I also forgot to post that the front 2 rockers on the right side are not getting oiled for some reason. Any suggestions on that on? I am going to pull the head to make sure that my oil ports are open and free from garbadge but i did see oil flowing at the top. The oil was not spraying though and i was told it is supposed too.
Again thanks........
I am in the prosses of measuring to see if i have a shorter or longer pushrod for that #3 cylinder or not.
I also forgot to post that the front 2 rockers on the right side are not getting oiled for some reason. Any suggestions on that on? I am going to pull the head to make sure that my oil ports are open and free from garbadge but i did see oil flowing at the top. The oil was not spraying though and i was told it is supposed too.
Again thanks........
