Bent push rods

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Apr 1, 2017 | 08:43 PM

21PRO

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1st Gear

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Bent push rods

I have an 88 corvette and I just replaced the head gasket, after putting the heads on and putting the push rods back in the exact place where they came from I wanted to check the compression of each cylinder before putting it all back together. When In turned it over it bent several of the push rods. What dis I do wrong?

Apr 1, 2017 | 09:04 PM

BacknBlack

Pro

Joined: Mar 2004

Posts: 654

Likes: 18

From: Linthicum MD

Quote:

Originally Posted by 21PRO

Your timing is off. Make sure you adjust the valves in the TDC order. There are several ways, can find them with a google search.

Apr 1, 2017 | 09:08 PM

charliet615

Racer

Joined: May 2012

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It sounds like you might have screwed the rocker adjustment nut too tight and when you turned the engine over, bent the push rods........

Apr 1, 2017 | 10:46 PM

Hot Rod Roy

Safety Car

Joined: Sep 2004

Posts: 3,953

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From: Mission Viejo CA

Quote:

Originally Posted by charliet615

It sounds like you might have screwed the rocker adjustment nut too tight and when you turned the engine over, bent the push rods........

The procedure for adjusting the valves is very critical. If you don't follow the exact procedure, you'll bend your pushrods! Hope you didn't bend some valves, too!

Apr 2, 2017 | 01:28 AM

bill mcdonald

Le Mans Master

Joined: Oct 1999

Posts: 6,366

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Quote:

Originally Posted by 21PRO

What dis I do wrong?

Over tightened a hydraulic lifter.

Apr 2, 2017 | 01:38 AM

VikingTrad3r

Oil Producer

Joined: Apr 2014

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agree with both above. rockers too tight + timing off = badoink.

search for joec method of valve lash setting involving .0015 feeler gauge. i used his method and i coated the feeler with engine oil. worked awesome. it would slide back and forth and then suddenly bite. it is precise and measurable. no subjective terms like "wiggling".

Apr 2, 2017 | 08:31 AM

bjankuski

Safety Car

Joined: Sep 2001

Posts: 4,134

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From: Glenbeulah Wi

Quote:

Originally Posted by 21PRO

You must have tightened the rocker arm studs until the valve was lifted off the seat and either went into coil bind on the springs or actually hit the piston with the valve. You need to check and make sure you do not have any bent valves or broken valve stem seals before you put it back together. Once you have either fixed the damage or verified that everything is OK you need to set the valves. When the intake valve is going down set the exhaust valve. When the exhaust valve is just starting to open set the intake valve. You set the valve as soon as the rocker touches the valve with no force on it. One way to determine this is spin the push rod with you finger and as soon as you feel an increase is resistance to movement this will be zero. The rocker should be touching the valve. Then go an additional 3/4 of a turn and you are done.

Apr 2, 2017 | 06:21 PM

Hot Rod Roy

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Joined: Sep 2004

Posts: 3,953

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From: Mission Viejo CA

Quote:

Originally Posted by 21PRO

after putting the heads on and putting the push rods back in the exact place where they came from

You have told us how careful you were to put the pushrods back in the same place (which doesn't matter), please tell us your procedure for adjusting the valves.