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Discussion Starter #1
Hi folks, I finished doing my head. Thanks for everyones help, i got my bolts. Now she doesn't run so S***t hot. Ran great 3 weeks ago. Had a friend help me with it, as i am so new to OH cams. So i told him how i took everything off. we put it together how it said in the book except 0 will not line up on the crank to cam! Closest i can get it is about 10 BTDC. Is this normal? I have a civi conversion. Did all the valves. Another set of plugs tomorrow. I'm Stumped.
Thanks.
 

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Discussion Starter #3
I don't know, but i'll be back at it tomorrow. I have tried half a tooth both ways, It either goes to 20 BTDC or 5-10 ATDC. Now what does everyone set there timing to? Does the chain placement to gears matter, like other OH cam setups?

Sorry for all the newbe questions. I work on heavy equipment and north american engines, not these strange(to me) engines.
 

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With a regular low compression m180, I've always tried to set it at about 10-12 degrees atdc under strobe timing. As long as the advance jumps up to about 35 or 40 at speed, I would imagine things are correct.

The unimog setup for the m180 has a lot of spots to make it run poorly. From the stock shielded wires that can ground out internally, to the carb that drips globs of fuel instead of a spray, to flaky mechanical fuel pumps, all sorts of things can keep it from running "just right".

Do you have a service manual for the truck? It helps to learn the peculiarities of it.




I don't know, but i'll be back at it tomorrow. I have tried half a tooth both ways, It either goes to 20 BTDC or 5-10 ATDC. Now what does everyone set there timing to? Does the chain placement to gears matter, like other OH cam setups?

Sorry for all the newbe questions. I work on heavy equipment and north american engines, not these strange(to me) engines.
 

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I was just thinking - are you checking this after you've pulled the cam chain tensioner? Sometimes they can blow out and not hold pressure anymore, or you may have put it back together wrong. That will greatly affect the physical timing of crank to cam as well.

If you can put it back together reasonably close, crank it over without spark or fuel (pull the plugs) until you get a little bit of oil pressure, then check how close your timing is.


I don't know, but i'll be back at it tomorrow. I have tried half a tooth both ways, It either goes to 20 BTDC or 5-10 ATDC. Now what does everyone set there timing to? Does the chain placement to gears matter, like other OH cam setups?

Sorry for all the newbe questions. I work on heavy equipment and north american engines, not these strange(to me) engines.
 

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Did you figure out what was the problem? Glad to hear you got it back on the road.
 

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Discussion Starter #8 (Edited)
1/4 tooth out. New chain. Thanks Scott. Strange, there was a new chain put on when the head was last done. They did a horible job putting it back together, they droped something into piston #1 which did some good damage, didn't tourque the heads properly, didn't bleed the chain tensioner, broken exaust manifold, and theres more on that list. That's why i had to do the head. Good thing they didn't pouch it to bad. But all is good now. I missed my Mog, she goes to work with me every day.
 

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A worn tensioner, or already slack chain will wear faster as it stretches more. Every time the slack builds or loosens, the thing is stretching. The more it stretches, the more loose weight it has to throw around.
 

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Discussion Starter #10 (Edited)
Yeah i can sue see how one thing can lead to another on these strange motors. I'm prety sure it is good now. The tensioner is fairley tight now. Cross my fingers it's good now. I'll check on monday when i look inside.
 
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