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Over tightened rocker arms

  
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Over tightened rocker arms

 
Josh5L Josh5L
New User | Posts: 5 | Joined: 04/13
Posted: 04/07/13
10:01 AM

Hey guys I put some heads on my stock 1972  chevy 350. The only thing not stock is flat top pistons. Well after I got the heads on I went to screw on the rocker arms and had a brain fart. I screwed them all the way down tight! Now I caught the mistake before I fired the motor but I was wondering if that would do any damage to the valves. I was at top TDC when this happened so cyl.1 and 6 were up. Could I have bent a valve on those Cyl. ? Thanks  

zman123 zman123
Enthusiast | Posts: 531 | Joined: 06/08
Posted: 04/07/13
11:22 AM

Hydraulic lifters? Likely no problem, the lifters will take up the slack. Since you caught it before you fired it up and have to start over anyway just pull the pushrods out and roll them on a flat surface to make sure they are all straight. As for the valves again not likely for damage. After you get the valves adjusted properly run a compression check to see if you are balanced on compression in all the cylinders, A bent valve will kill the compression in that cylinder. Good luck.  

Josh5L Josh5L
New User | Posts: 5 | Joined: 04/13
Posted: 04/07/13
11:39 AM

Yeah it has hydraulic lifters. I will check the push rods for bendage. When i backed off the rocker arms in the first place after i had ran them down all the way I could make only a couple of the lifters plunge by pushing on them with the push rod by hand. Is there a chance I damaged the lifters? Thanks for the reply ZMAN Laugh  

Josh5L Josh5L
New User | Posts: 5 | Joined: 04/13
Posted: 04/07/13
11:59 AM

and the lifters are pumped up as this is a old motor i was just replacing the heads.  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 04/07/13
12:24 PM

Icon QuoteJosh5L:
and the lifters are pumped up as this is a old motor i was just replacing the heads.

That's a good recipe for reducing ring seal.  
68scott385 68scott385 68scott385

Josh5L Josh5L
New User | Posts: 5 | Joined: 04/13
Posted: 04/07/13
12:44 PM

The heads are used ones that came off a running motor. What part of the recipe causes the reduced ring seal?  

Dave632 Dave632
Addict | Posts: 2220 | Joined: 07/08
Posted: 04/07/13
03:19 PM

Most likely you will be OK. After you get it running I would check the compression in 1 and 6. You will probably know as soon as you start it up if all is OK.  
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68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 04/07/13
04:53 PM

A fresh top end with all it's pristine new parts and perfectly mated sealing surfaces work to keep pressure where it's supposed to be. Bolt that to a short block with high milage and the old rings have more to contend with. When they cannot hold, it either (1) starts blowing oil out of places it didn't do before, or (2) starts burning oil.

If your heads are not machine shop fresh and have the same size chambers, you may be okay.

I wouldn't mention it if I hadn't seen it happen more than once.  
68scott385 68scott385 68scott385

Josh5L Josh5L
New User | Posts: 5 | Joined: 04/13
Posted: 04/07/13
05:27 PM

Cool guys thanks for the words of advise Grin