posted July 17, 2002 04:47 PM
I had problem with my engine last weekend (chevy 454). I came off after the race and found it was only running on 7. Both leads & plug ok (not closed the gap). So i loaded & took it home, I then took the rocker cover off to find that both pushrods (3/8") on no.6 were bent. The rockers had not come lose but had managed to turn. So the question is this: what do you think happened? & how do I stop it happening again? I was probably turning the motor to about 6,500 & I dont run a stud girdle or rod guides. The engine has done around 10 meetings since I last rebuilt it. By the way I put in spare rocker arms & pushrods & it started up fine & had between 185 & 200 compression on all cylinders. Thanks. marty.
ryan Dirt Freak
Total posts: 430
posted July 18, 2002 12:00 AM
Coil Bind????? Just a guess. How were your rockers sitting?
[This message has been edited by ryan (edited July 18, 2002).]
marty Dirt Maniac
Total posts: 111
posted July 18, 2002 01:02 PM
Thanks ryan. I can safely rule out coil bind as this was thoroughly checked when it was put together. The only theory I have is that the pushrod on the exhaust side failed first thus creating a very high cylinder pressure & causing the inlet to then fail also. Both rockers had come off the pushrods & turned through about 25 degrees so the rods were just rubbing the sides of the rockers. Any ideas on how to prevent this happening again would be very welcome. Thanks. marty.
Flatlander Dirt Freak
Total posts: 310
posted July 18, 2002 06:37 PM
do you have pressed suds or screwins if they are press and aren't pinned that could be the problem they will come up enough to allow the rocker to come off yet appear tight and will hold when readjusted util you put the pressure on them then they wil do it all over again