3.7 rocker arm torque?

ericcarr2000

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Ok, this is a follow up to a previous question I had. As I mentioned in my other post, I have a blueprinted 3.7 mercruiser that has only 110 hours on her and I noticed that there is a slight power loss I had after I got it back from new lifter installation. After taking the valve cover off and checking everything over, I had noticed that the rocker arm nuts were over torqued to 25 ft. lbs instead of the recommended 20 ft. lbs. I guess my question is this, would the over torquing of the nuts contribute to power loss?
:pray:
 

achris

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Re: 3.7 rocker arm torque?

... I guess my question is this, would the over torquing of the nuts contribute to power loss?
:pray:

Definitely not... Sorry.

Do a compression test and check the timing and the points dwell (assuming you still have the points).
 
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ericcarr2000

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Re: 3.7 rocker arm torque?

I checked the timing and it is dead on @ 4 degrees BTDC and I converted it over to full electronic so there is no points or condensors to fail. I did notice right after I got it back, with the nuts over torqued that it was sort of hard to start, would take a couple times cranking it over to get her to start. After I retorqued them to manuals specs the thing has started up right every single time with no problem...Im still yet to take her for sea trails.
 

ericcarr2000

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Re: 3.7 rocker arm torque?

Actually I took her out after I did the re-adjustment on them and noticed that there was quite a bit of power increase with them torqued down to the manuals specs....:)
Definitely not... Sorry.

Do a compression test and check the timing and the points dwell (assuming you still have the points).
 

stonyloam

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Re: 3.7 rocker arm torque?

I suspect that they were torqued correctly in the first place, and that it took a little more force to break them loose and that is why they appeared to have a higher torque reading.
 
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Re: 3.7 rocker arm torque?

I suspect that they were torqued correctly in the first place, and that it took a little more force to break them loose and that is why they appeared to have a higher torque reading.

Hey man!!! hope your doing well!! please delete some PM's.... we're trying to get a hold of you!! ;)
 

ericcarr2000

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Re: 3.7 rocker arm torque?

Actually they weren't torqued correctly in the first place, they were over torqued @ 24 ft lbs instead of the 20 recommended.:D
I suspect that they were torqued correctly in the first place, and that it took a little more force to break them loose and that is why they appeared to have a higher torque reading.
 

alldodge

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Re: 3.7 rocker arm torque?

Over torquing a bolt will not cause an engine to run bad, it will only cause the bolt to fail prematurely. Once the bolt fails, only then will it run bad
 

ericcarr2000

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Re: 3.7 rocker arm torque?

I guess we all have our own type in thinking on this one. over OR under torqueing a rocker arm nut will cause it to run poorly. This has been proven in the past.
Over torquing a bolt will not cause an engine to run bad, it will only cause the bolt to fail prematurely. Once the bolt fails, only then will it run bad
 

stonyloam

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Re: 3.7 rocker arm torque?

To tell you the truth I can not see how overtorquing the bolt by a few pounds could possibly have any effect on engine performance, you are just bolting the rocker ball to the head and there should be no effect on the rocker arm at all. But I guess it might be possible:confused:
 

achris

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Re: 3.7 rocker arm torque?

I guess we all have our own type in thinking on this one. over OR under torqueing a rocker arm nut will cause it to run poorly. This has been proven in the past.

On an engine where the position of the nut determines the position of the rocker, and hence the actions of that rocker, yes (like the SBC).... But with your engine the ball unit (that sits inside the rocker, and pokes through the bottom of it) attaches hard to the head and the screw holds it down, 5lb.ft is not going to effect the engine run quality one little bit.... It would have as much effect as having the spark plug a little too tight.... none!

Chris......
 
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