616 rebuild options - Page 3 - PeachParts Mercedes-Benz Forum

leathermang · #1 08-20-2014, 10:31 AM

Ok... installed sleeves are to be taken to flush with the top of the block.

I encourage people to study the FSM when dealing with the sleeves as the specs... including the chamfer at the top... to allow the compression of the rings as you install the piston is very specific. They give specs for things most people have never even heard of.

subetealabici · #2 08-21-2014, 08:52 PM

... including the chamfer at the top...
I forgot to mention that part, I did put a chamfer at the top, not as bit as the one on the manual or the old cylinder liners.
I figure after the whole rebuild procces that I could have changed more parts and do a cleaner work in any case the idea was to test the boring machine that I make and do a more detail work on the engine from the car, the spare is a 78 and the car is and 82.
There are some more tools that I want to makevalve seat milling atachment, IP adapter plate to set in the lathe and check the injectors and IP, and a bunch off things to change in the engine since it has around 370k miles, timing chain, valve guides, maybe valves, pistons, etc, etc.
Among other things I wanted to see how the use off veggie oil on a straigth/ blend set up affected the engine after 60k miles, take the car to DEQ was other thing to.
I also got some time ago a NOS off 91.5 piston set,

TheDon · #3 08-21-2014, 09:53 PM

So, does it run?

subetealabici · #4 08-23-2014, 09:54 AM

Hi
The car has being running for a couples off weeks so far pretty well, it has about 2000 miles in the rebuild engine
There are no oil leeks and no blow by, I still need to tune a new set off injectors with the injection pump and the timing

funola · #5 08-23-2014, 10:39 AM

subetealabici, it is amazing what you have done by building your own tools to rebuild the engine. Hats off to you! Good that no one jumped in to discourage you by calling you a hack and that you have to abide by every little bit in the FSM etc. etc. Keep us posted on new developments such as the generator project.

leathermang · #6 08-23-2014, 11:07 AM

Quote:

Originally Posted by funola

subetealabici, ...... that you have to abide by every little bit in the FSM etc. etc........

Here is the value to having and following the specific instructions in the manual produced by the people who made the engines and have millions of dollars to spend on R and D...

Pistons are almost always aluminum.... there are typically three or four rings grooves around their outside.... obviously for the rings... which do not sit inside the rings until they are compressed by the piston being INSIDE the bore...
So as you try to put the piston into the bore.. you have these ' fingers' wanting to stick out past the bore.. so you use a tool meant to keep them flush with the edge of the piston... while you slide the piston into the bore..
But all it takes is one tiny slip ... the ring compressor not exactly down to the top of that bore...and you are tapping on the piston to get it in...
and you risk breaking the ring LAND... the part between the rings... which can be fairly narrow depending on the piston length and the number of rings..
The ring compressor does not usually go into the bore at all..
so the Chamfer at the top of the bore needs to be of a design ( ramp) which will allow the rings to be further compressed to slide into the bore...
If they are not.. you can break the ring... or the land.... or both...
This might not be TOO much of a problem on the 616 pistons.. .as they are relatively reasonable in price compared to the turbo 617 pistons..
But if you ruin that piston... which... if you followed the FSM procedure to get the bore to piston distance correct by measuring the piston and boring the sleeve to fit it...
You have a new piston NOT measured and fitted to the bore.. ...
Luck is not the way to increase your chances of getting 300,000 miles out of a rebuilt Mercedes Diesel engine...

subetealabici · #7 09-08-2014, 12:57 AM

Hi
Well last week I made a base to set the IP on the lathe, kind off like something I did before but much nicer this time, today I was checking out and re rebuilding some injectors, I got a really big manometer at the habitat for humanity store, set up some pipes and get a set off injectors and pump calibrated today, I only got to change the injectors I need to get a new gasket to change the IP and figure what to do with the 82 emission controls to set up the 78 IP, it is very interesting to see how they spray and I may need to get some more stuff like some flasks and maybe a new set off nozzles for the next time.
It should be really nice to get a stroboscopic light to take some pictures off the spray and get a clear view off the spray pattern, I can see some off the shape and definitely some mist coming out.

I guess I did follow on part off the manual specifications for the engine rebuild but this rebuild was more like a try out run than a full up to specifications than a complete rebuild there was a bunch off stuff that I needed to change and some more machining on the head, I did no put new pistons, or new valves or valve guides, etc.

Stretch · #8 09-08-2014, 03:19 AM

This is my favourite picture

Cool!

As for the mists be aware of the nastiness of atomised fuel ending up in your lungs - wear a mask or try to cover your test tubes so you don't pressurise them or allow the mists of yuk to escape.

t walgamuth · #9 09-08-2014, 03:52 PM

Good job! Using my machinists hydraulic press I have pressed out most of my own liners. The pressure builds up til you swear the block will explode then moves with a huge noise. I always wonder if this time the block will explode instead of the liner going in.