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Guest Message by DevFuse
 

Photo

adjusting valves on 676



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8 replies to this topic

#1 OFFLINE   diggin dirt

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Posted 14 June 2012 - 01:11 PM

the balancer shows 1 and 6 together , then 3 and 4 and so on. do you set all 4 valves say on 1 and 6 together. it seems to me each cylinder would need to be on tdc on the firing stroke. you guys have really helped me put on this in the past and i sure do thank you. i advertised looking for a shop manual but had no luck.

#2 OFFLINE   Mike

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Posted 14 June 2012 - 01:55 PM

the balancer shows 1 and 6 together , then 3 and 4 and so on. do you set all 4 valves say on 1 and 6 together. it seems to me each cylinder would need to be on tdc on the firing stroke. you guys have really helped me put on this in the past and i sure do thank you. i advertised looking for a shop manual but had no luck.




Have you tried www.AUTOLIT.com ? 1970 thru 1979 Item # 119092 Manual from 1967 - 1972 for MACK Highway Vehicles covers F,Mb, R, and U models. $100.00.

I don't have assess of a manual at this time but can look up tonight when at home. Hopefully someone will beat me to it and be more prompt.


Regards

mike

#3 OFFLINE   39 Baby Mack

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Posted 14 June 2012 - 02:04 PM

They have to be adjusted individually in firing order 1-5-3-6-2-4.
Bar engine over in normal rotation- clockwise looking from front of engine.
When #1 is coming up on compression stroke stop at #1- #6 top dead center mark on dampener and set valves for #1 cylinder intake .016" exhaust .024"
After done with #1 bar engine clockwise to next mark which will be #2 -#5 (120 degrees from #1- #6 mark) and set valves for #5, then just keep on going through firing order1-5-3-6-2-4.
If you're having trouble trying to figure out when #1 is on compression stroke watch the valve movement.
When barring over engine watch the intake pushrod and rocker movement(the valve toward the rear of the cylinder) you will see it open and then close- right after you see it close bar engine up to the #1 T.D.C. mark and set valves for #1 and go from there.

Hope this helps,
Ron

#4 OFFLINE   diggin dirt

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Posted 15 June 2012 - 04:58 PM

ah yes, i should have figured that out, really no different than my small block chevy. for some reason my mind stumbles on that big diesel. i got them all adjusted and i noticed a lot of rocker arm slack on part of the stroke but when it came back around to the pointer everything checked out fine. i wonder why?

#5 OFFLINE   theakerstwo

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Posted 15 June 2012 - 06:25 PM

Thatb is because the exhaust ram on the cam has a low area ground lower than the rest so if you have a dynatard brake on it it will activate the hyd cylinder.
glenn akers

#6 OFFLINE   39 Baby Mack

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Posted 15 June 2012 - 08:27 PM

He beat me to it, he's right it's because it has a dynatard camshaft in it. With flat spots on the opposite sides of the exhaust lobes.
They used these cams whether they had the dynatard engine brake or not. Looks really weird though when you see that much slop in the exhaust valve rockers doesn't it?

Ron

Edited by 39 Baby Mack, 20 June 2012 - 08:51 AM.


#7 OFFLINE   diggin dirt

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Posted 16 June 2012 - 11:47 AM

that is some interesting stuff. does that mean i could install a jake or is that to far out of the realm?

#8 OFFLINE   theakerstwo

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Posted 16 June 2012 - 12:01 PM

Yes you can install a jake on that cam.
glenn akers

#9 OFFLINE   39 Baby Mack

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Posted 16 June 2012 - 07:22 PM

It means you could install a dynatard (Mack engine brake)




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