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Engine REAssembly questions

knuckle47

knuckle47

Advanced Contributor
"Me Again..! Here are a few t

"Me Again..! Here are a few things I thought about while starring into the engine compartment today. I had 4 bent pushrods to replace THEY have a mark on them which the book says they need to go into the block a certain way. THE OLD ones that are still good, don't have a mark on them any more. HOW do I find out the way they need to be put back in?
2.) WHEN adjusting the valves, despite the hydraulic nature, book says set the firing order a certain way and THEN, adjust certain valves by removing the LASH...I am interpreting this to mean up and down slack...IS this correct? ONCE the valve covers are back on, removing them to re-adjust valves is OUT OF THE QUESTION as the manifolds prevent access to the hold downs. SHould I give it and extra 1/4 turn or so to insure enough lift? OR JUST set it and forget it

Rick, Still trying to accomodate that exhaust set up we discussed

Thanks ALL"
 
"don't know about marks. i

"don't know about marks. if you spin the pushrod between your fingers while tightening, you will feel it go tight. (resist spinning) this is zero lash. do not add extra 1/4 turn. set to spec."
 
"Al,
When I've rebuilt he

"Al,
When I've rebuilt heads on big block Fords and small block Chevys with hydraulic lifters in the past, there was a sequence to setting the lash. As Scot said above, you will feel the tightening by spinning the pushrod as you tighten. For example (and this is just that...from memory and not any manual), with the #1 cylinder at TDC, you would adjust the intake on #6 and the exhaust on #3. You would then rotate the engine 90 degrees (clockwise or CCW depending on the rotation) and position the next firing cylinder at TDC and adjust the corresponding valves. You will need to get the sequence specs via a Google inquiry or buying a Rebuilding Your Big Block (or small block)Chevy book. You can do this before putting the exhaust manifolds on if space is tight. It will also help to leave the spark plugs out for rotating the engine and making sure the correct cylinder is on TDC. You can see the top of the piston with a mirror and light if you cannot get eye level with the spark plug holes.

I can't help on the correct orientation on the pushrods. On the two engines I've done head work on, there was no difference between bottom/top of the pushrods."
 
"Thanks Ernie,

I have the b

"Thanks Ernie,

I have the book..You are correct abou the valve adjustment. It also describes the pushrods having a larger hole in one end...ON SOME MODELS. Of course, mine ain't one of em'. They go by color code and ONE of the new rods is coded. It has to do with one end being hardened?

I can't seem to solve this dilema yet,"
 
"Some of them do have a light

"Some of them do have a light polished zone so this helps on several of them. Sad part is that the engine only has about 550 hours...It is a 1990 but the wear internally is SO negligible things inside look and feel and (ones I could measure) fit so very very well.

I have pulled apart 60-70 year old Harley Davidson, Indian and Henderson engines that also looked as good though some were really torn up. Amazing ain't it? Somebody took good care of it. EXCEPT for the elbow corrosion that caused this problem. The engine appears to have been well lubricated. There are no ridges on the cylinder walls and lifters, no carbon build up. In a way it is a blessing things went along as they did. I have learned so much more about seawater...it is amazing what it can do to metal"
 
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