OM617 Timing after Rebuild - Page 2 - PeachParts Mercedes-Benz Forum

leathermang · #16 11-25-2015, 08:21 AM

I agree with Cooljjay and Manny
You are not prepared on any level to rebuild a Mercedes 617.
But it is a free country and your engine...
but we would be amiss not raising a red flag with what we have witnessed from your statements....

BillGrissom · #17 11-25-2015, 02:49 PM

I vote ignore the naysayers and "take it to bits" as Stretch would. You aren't risking much and a great way to learn. Backup plan is another used engine. Forget a "professionally" rebuilt one, unless worth $8500 to you. For sure run it on the ground to verify before installing it. I did that with the used engine I got. Just run the fuel supply & return hoses into a diesel jug. The starter bolts to the block, so you don't need the tranny (like some cars). I hooked up the muffler since neighbors are close by. Ran nice and smooth for me on the ground, so I felt good installing it.

A few details you might miss:

Mark the piston oil squirters first since apparently they differ. I didn't.

The upper oil pan seal to the block is a special "anaerobic sealer/cement". Super-glue is anaerobic and there are industrial high-temp versions. But, try to find the true M-B product (and let us know the source). The upper oil pan likely adds structural support to the block so you want a cemented joint.

Replace the timing chain tensioner spring since cheap and most are worn on the side. Push the tensioner piston thru and return to the starting position on the other side. Once assembled, push in w/ your finger to the last ratchet you get. Oil pressure will keep it tight later.

Great time to replace all the timing chain rails, especially the lower ones. I coated the securing pins w/ gasket sealant so no oil leaks.

MrUkrainian · #18 11-25-2015, 06:09 PM

I like how this thread started asking about IP timing and turned into saying that rebuilding an engine is "not for me." I appreciate the warnings, but i don't think it is anyone's business to tell me what not to do. Even if I run into problems, that will be my own fault. This is my first engine rebuild and I am only 18, but I post on this site for advice, not to be criticized for not owning a FSM. The engine is already dismantled so it's kind of late now.

mannys9130 · #19 11-25-2015, 06:20 PM

Quote:

Originally Posted by MrUkrainian

I like how this thread started asking about IP timing and turned into saying that rebuilding an engine is "not for me." I appreciate the warnings, but i don't think it is anyone's business to tell me what not to do. Even if I run into problems, that will be my own fault. This is my first engine rebuild and I am only 18, but I post on this site for advice, not to be criticized for not owning a FSM. The engine is already dismantled so it's kind of late now.

I never criticized you. I just offered a few helpful tips that I could off the top of my head.

An engine rebuild is daunting, but if you take your time and follow the manual you should be OK. Ask questions here and search to see if it was answered before. We're happy to help you. Just don't cut corners or assume something. Ask us.

Were you the guy who did the 4 speed swap?

MrUkrainian · #20 11-25-2015, 06:27 PM

Yes, that was me. And I appreciate any kinds of advice, but when someone tells me I am not prepared on any kind of level to do something, I will show them I am. Also, to answer your questions, yes I own a torque wrench and I have assembly lube. I attend a school for automotive technology so we have all sorts of things in the shop.

mannys9130 · #21 11-25-2015, 06:38 PM

Cool.

Your immediate priority is to get the manual. Try those links everyone posted and get a complete copy. You will absolutely need it.

Good you have those things. How about plastigauge? RTV (ONLY in the places that need it)?

Did you need to use a ridge remover to get the pistons out or did they just pop out with your hand? Are you going to send the block and head off to a shop to be cleaned, rebuilt and returned?

cooljjay · #22 11-25-2015, 06:50 PM

Everyone has to learn somewhere but you have to understand, that were not criticizing you. Most of us know what is involved in rebuilding one of these motors correctly, cost and sourcing of replacement parts. Take it as a warning not criticisms..

All assemble lube and torque wrenches aside, with the proper knowledge and tools anyone would be able to assemble one of these motors. The issue is, cost...To do a correct rebuild, parts will set you back 4-6k and many of us don't want to invest that in our rides and thus we just suggest finding a good used motor...

Also one must understand, that these motors very seldomly need a rebuild. Before one starts to tear apart one of these motors, they should be very well informed of all the odd maintenance issues these cars have from both age and use.

I would like to recommend anyone looking into getting into rebuilding engines start with the easier v8/slant sixes that were oh so common in American cars and slowly move up to more complicated engines.

MrUkrainian · #23 11-25-2015, 06:56 PM

The Pistons came out easily, pushed them out with the end of a hammer. The plan was to take the block and head to be machined, but it isn't worth the money for me to rebuild the engine for $1500 when I can find a good running one for $500. Also, I should have mentioned this is not a complete rebuild. I will be reusing the Pistons, rod and main bearings because they are in good shape. I plan on installing new rings and resealing the whole engine. For the cylinder head, I will install new valve seals and lap in the valves myself. That will be the "rebuild" for the most part.

MrUkrainian · #24 11-25-2015, 07:17 PM

Many parts I will reuse. I only intend on replacing the parts I need to, or SHOULD. This engine is still in very good shape from the look of the bearings and pistons. I understand that it is easier to find a good running engine, but I won't learn anything from replacing an engine. I'd rather attempt to learn something and gain experience. The consequences are not very bad as replacement engines are not very expensive, so I dont see why I shouldn't try. And as I said, it is already apart, so it's too late to go back now! Haha. Also, I now have a FSM...

mannys9130 · #25 11-25-2015, 07:24 PM

OK, so you're not doing a whole overhaul. Pistons are fine to reuse. New ones are VERY expensive, so most reuse them anyway. I'd rethink the bearings depending on how expensive they are. If you postpone the build for a couple weeks to get more cash, it'd be worth it. Rings, yes. Measure the bores for diameter, roundness, and taper before you start rebuilding. If your bores are too far egg shaped for example, you'll use oil even with new rings.

Inspect the valve seats closely. If they're pitted or flame cut in small spots, a lapping might not be enough to get the valves seated nicely. If they're serviceble, proceed but don't move the margin too far off.

Strongly consider replace the oil pump drive components.

leathermang · #26 11-25-2015, 08:36 PM

Quote:

Originally Posted by mannys9130

OK, so you're not doing a whole overhaul. Pistons are fine to reuse. New ones are VERY expensive, so most reuse them anyway. I'd rethink the bearings depending on how expensive they are. If you postpone the build for a couple weeks to get more cash, it'd be worth it. Rings, yes. Measure the bores for diameter, roundness, and taper before you start rebuilding. If your bores are too far egg shaped for example, you'll use oil even with new rings.....

Strongly consider replace the oil pump drive components.

The FSM will give you exact measurements to determine if the pistons are ok to reuse....
It would really be good to put in new sleeves.....
this is a straight forward procedure described in the FSM...

Mölyapina · #27 11-25-2015, 08:48 PM

I would probably do at least the rings and sleeves, and otherwise sorta go with the flow... do you have a plastigauge kit? That should help you diagnose the crank.

Also, and this is more of a question for everyone else, if the rings/sleeves aren't being replaced, do you need to keep pistons matched with the cylinders they came from? And similarly, do you need to keep the rods associated with their crank lobes? I would think that the answer to the first question is yes, but I'm not sure about the second part...

leathermang · #28 11-25-2015, 08:54 PM

If you take the pistons out of the sleeves.... I can NOT imagine not putting in NEW rings... that is just a no no .... any engine all the time.. a prime directive.... LOL
I would keep the rods and crank matched up....
hopefully it is to where just putting in new ' inserts' ( as the bearings are called ) ..... will be good....
That crank throw and the rod have worn together.... so I am sure it is best to keep them together....only if a complete machining of the crank were done Might it be ok to not keep them together....

Mölyapina · #29 11-25-2015, 09:15 PM

Quote:

Originally Posted by leathermang

If you take the pistons out of the sleeves.... I can NOT imagine not putting in NEW rings... that is just a no no .... any engine all the time.. a prime directive.... LOL

As someone who's never taken an engine apart, why is that?

mannys9130 · #30 11-25-2015, 09:26 PM

Quote:

Originally Posted by Mölyapina

As someone who's never taken an engine apart, why is that?

The rings seat into their cylinder during the first hundred miles or so of engine operation. Once they are worn in and happy, it's bad to disturb them. Similarly, if you put new rings in an old bore they won't seat, and if you hone an old bore and reinstall the old rings it wears the hell out of them and they don't seal properly. New crosshatch, new rings, happy day.