How hard to replace piston rings - Page 2 - PeachParts Mercedes-Benz Forum

pixelsblack009 · #16 01-31-2010, 09:41 PM

Quote:

Originally Posted by kerry

Have you actually had the car emission tested? If so, what method was used and what were the results.

Sorry I don't know what method they use I'm the son my father tell's me there will be emission tests soon though,
I don't think the car has been through any emission tests before, we got the car when we were living back in australia I'm not sure if any tests were conducted then, but this seems to be a new idea the srilankan government has come up with for some reason, I dont think they shine a light through the exhaust, they probably use a little more complexed method.
The engine had been overhauled when it was brought to srilanka and we had a new head installed too, this real rubbish mechanic did the job and it seems he did put in new selves and we used japanese piston rings for the job probably due to availability issues at the time, so we had the engine overhauled new rings, new selves, new head and after the job was done up,
next day the car wouldn't start at all and we had starting issues and would often have to put two batteries in parallel and struggle to get the car started until we got it fixed again, (soon that new mechanic had a go at changing the transmission oil and dropped our automatic 5 speed gearbox from a hight on to the floor and from that day only the first gear would work and some other guy dissembled it to bits and did'nt know how to put it together so we were forced to install a 4 speed manual gear box that's giving us trouble now)
Any other idea's ?
Thanks Jeremy Brett

kerry · #17 01-31-2010, 09:58 PM

I wouldn't worry about the emissions test until you know what they do. Here in Colorado they use the opacity test. Don't know what is done in other states in the US but I think tests for gas engines and diesel engines must be different. The opacity tests here seem pretty easy to pass in my opinion.

Diesel911 · #18 02-01-2010, 12:12 AM

Looks like you will have to get inside of the Engine and take a look.
If it has been Resleeved it may be they tried to reuse the old Pistons. It may be that the Piston; Ring Grooves (grooves in the Piston) are enlarged.
I guess what I am saying is if they did part of the job right it might be fixable.

When you are older you will look back on this Car and realize all the things you had to learn to work on it was actually a great education.

leathermang · #19 02-01-2010, 12:21 AM

Just as a matter of conversation... if by ' piston ring grooves' you mean the lands have excessive wear they can probably be ' cleaned up' and custom rings bought to fit the wider lands... info is in the archives about a company TCane told about who will supply them.

Chas H · #20 02-01-2010, 01:04 AM

Lands are the piston material between the grooves. As pistons age from use the grooves become wider and the lands become smaller. A clever machinist can make the grooves into the proper configuration to accept shims, which allow the use standard rings. The use of custom rings will still require a machinist to "square" the grooves. The choice is yours.

mplafleur · #21 02-01-2010, 07:06 AM

Quote:

Originally Posted by leathermang

If you put new rings into an old bore which is worn AT ALL..
then you have a terrible honing job to get it even close to right..

HOWEVER, if you put in a new sleeve then honing the bore to fit the piston properly is pretty straight forward since you are taking it all down evenly...

Can't you hone the sleeve for a 1st oversize ring set?

Alastair · #22 02-01-2010, 08:43 AM

Quote:

Originally Posted by mplafleur

Can't you hone the sleeve for a 1st oversize ring set?

Yes, He Could do that.....

But he would then need to replace the Pistons as well as the rings....

IME, the ring-grooves on M.B. engines tend not to wear really horribly, and he may get away with a good ring make, -like 'Perfect-Circle' or Hepolite- and a hone on the bores--assuming the liners were replaced not so long ago, and dont show too much wear....

The rings themselves can in some cases wear pretty badly giving a large clearance in the groove--Especially with an El-Cheapo ring set!

...

leathermang · #23 02-01-2010, 10:23 AM

Quote:

Originally Posted by mplafleur

Can't you hone the sleeve for a 1st oversize ring set?

That is one of those things which if you are following the Factory Shop Manual... which I highly recommend..
then you determine that according to the measurements you take in the bore...you have Taper, Out of Round, and basic wear, and maybe some other actual relative measurements to consider..
Which the FSM will give the " GO OR NO GO" for..

Now that does not mean a really good and dedicated ( read crazy ) DIYer with the right equipment could not carefully take the bore back out to first oversize... but I really believe that would be close to impossible to do...
Part of the larger picture is that in boring it out to take care of the taper and out of round that needs to be done in relation to the center line of the crankshaft AND the centerline of the bore...
Whereas with the installation of a new sleeve... which the FSM shows how to do with relatively simple equipment.... you have the center line determined by the stops cast into the block... so as long as you install the bore to the proper depth ( at which point you still have the problem of taking the top of the sleeve down to the proper amount ABOVE the block deck height ).... then you only have a small amount of honing... which is a cheap machine which can be operated by a good strong electric drill... and the centerline is properly determined by the installation... and you only need to take the sides out evenly... which is done by the hone stones being equal in friction and grit and the up and down motion applied to the drill while it is spinning the self centering hone...
But for taking out the usual problems of a worn bore those stones are not equally pressing on the bore because you are needing to reestablish at least two centerlines for the result to be proper.
So, as a person who likes to encourage DIY fixes.... but want a reasonable chance of successful completion and long life for the engine afterwards I highly suggest the use of the sleeves provided by MB for this job.
As to added spacers in the cleaned up lands.... I suggest that cleaned up lands in a piston with proper fitting wider rings is the right way to do that.. which I think the FSM will verify.
But finding someone these days to do the lands or any other machining operation right seems to be harder than in the past..
So when an OUT OF THE BOX solution is available from MB ... like cheap new pistons,new sleeves,new rings which all fit together with little magic required... I think that is by far the best bet overall to have a long lived engine when you get through.

Diesel911 · #24 02-01-2010, 01:54 PM

Quote:

Originally Posted by leathermang

Just as a matter of conversation... if by ' piston ring grooves' you mean the lands have excessive wear they can probably be ' cleaned up' and custom rings bought to fit the wider lands... info is in the archives about a company TCane told about who will supply them.

(Note:Concerning coustom Piston Rings and other advice; pixelsblack009 is in Srilanka. I have no idea what resources are available to him there.)

Yes, I re-read what I wrote. It needed re-phrasing or punctuation.
Piston; Ring Grooves or Ring Grooves on the Pistons.

The Lands; the un-grooved areas between the Grooves on the Piston. And, as above the Lands are what wears and the Grooves become larger.

tbomachines · #25 02-01-2010, 02:25 PM

Quote:

Originally Posted by leathermang

So when an OUT OF THE BOX solution is available from MB ... like cheap new pistons,new sleeves,new rings which all fit together with little magic required... I think that is by far the best bet overall to have a long lived engine when you get through.

I'm just curious, any idea how much that would cost (ballpark)? I'm considering doing a full rebuild while my OM617 is out, but prices are all over the place...before I spend hours out of my workday calling every place in north america for these, has anyone performed the "easy" rebuild mentioned above (of so, how much did it run as a DIY)?

Sorry for the thread hijack, I guess it is still semi-on-topic

leathermang · #26 02-01-2010, 03:08 PM

I do not know the prices of 617 engine parts .....
remember the pistons for those are the annular ring type to take advantage of the oil squirters in the engine block... so are way more expensive than 240 pistons...

dadette123 · #27 02-01-2010, 03:24 PM

Last time I checked my wholesale parts source for pistons and sleeves it was $221 each for a standard 90.90mm Mahle piston (617 030 10 17) with rings and $19.03 each for a semi-finished Meyle 89.9mm (616 011 12 10 MY) cylinder liner. Just a std 90.90mm piston ring set was about $28 each cylinder. Of course, these are old notes I am trying to decipher...

leathermang · #28 02-01-2010, 03:29 PM

That was a good price for turbo pistons/rings/sleeves combo.....

jt20 · #29 02-02-2010, 03:46 AM

Quote:

Originally Posted by dadette123

Last time I checked my wholesale parts source for pistons and sleeves it was $221 each for a standard 90.90mm Mahle piston (617 030 10 17) with rings and $19.03 each for a semi-finished Meyle 89.9mm (616 011 12 10 MY) cylinder liner. Just a std 90.90mm piston ring set was about $28 each cylinder. Of course, these are old notes I am trying to decipher...

who is your source??

pixelsblack009 · #30 02-02-2010, 05:30 AM

Hello,
Thank you for all your reply's,
I guess replacing the pistons idea is out , That would be hugely expensive assuming they have OEM pistons for a vintage benz in srilanka so I guess I would have to use the same pistons.
My problem is removing the heavy engine out of the car wouldn't I need one of those things that kinda hoist up the engine with chains?
I assume there is no other safe way of removing the engine, I'd definitely need my dads and another guys help, perhaps if we really had to we could rent one for a week
Thanks
PS: I make sure to check updates on threads that I have posted, at least every 24 hours

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