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I'm looking over my engine and the main caps seem to be part of a larger cradle but I can't find anything regarding if they should be removed before reassembly.
It seems to me the caps need to be removed from the cradle and installed but I'm not sure ? Anyone have some experience
LOL
They are made into the mid pan section of the block. They dont offer any oversized bearings etc. So if your don't need to pull the rods or pistons leave it together.
LOL[/QUOTE]
I'm looking over my engine and the main caps seem to be part of a larger cradle but I can't find anything regarding if they should be removed before reassembly.
It seems to me the caps need to be removed from the cradle and installed but I'm not sure ? Anyone have some experience
LOL
The caps are integral to the lower half of the block. This is a split block design and they do not come out of the lower half of the block. The Bolts for the mains (inner and outer) need to be replaced. The main bearings are color coded and you need to match the color code that the engine came with. The upper is different from the lower. The color codes should be in the snout of the crankshaft for the upper and the lower codes are stamped on the block casting on the passenger side under where the engine mount bracket would mount to the block. You will see a bunck of x's etc. But this stamping is only for the lower shells. You need to find the color code for the upper as well.
Thanks for the info,
I'm evaluating having the engine sleeved and using the original pistons and rods. I'll have to have a set of rings made but really am wandering into unknown territory
These engines are masterfully machined and the goal is to gracefully get it running again. I have no plans to sell the car but putting 25k into the engine just isn't something
I want to do.
Here is some pictures
Green dot here another green dot A different color here Green dot next to #1 main
The dots on the crank are the upper mains and the stamp is the lower. Your lowers are all the same so that is easy. g should be gelb or yellow. The dots on crank I would say are blue and white. There is no green color code for main bearings on our cars. But you should check by the book to be sure to match everything up.
As for the rings, I tried like you to find and I think that NPR made the original rings. I called NPR as I found an old part book with a part number for the ring package for our car. When I called, they spoke with manager and said they are under contract with Mercedes and cannot sell these to the public.
On Alibaba there is a company that shows they have the rings and I even had them send pics and I think they are actually NPR rings. Cannot vouch for it but you might try them and give it a shot. The rings had stamping exactly the same as the rings we have and said japan. Search alibaba M275 E60 piston rings. no guarantee but worth a shot.
I will tell you that depending on how badly your walls are scored you can just have the cylinder lapped because it is Alusil. Here in California there are machine shops that do this with an RA gauge and use AN-30 paste. If your scoring is not that bad, you may be able to just lap them and they will be like new. The major issue with the pistons is that the coating is old and needs to be there for running in alusil cylinders. Nothing seems to work as good as the original mahle ferrocoat so recoating doesn't seem to be a great option. If the skirts are ok you could try to run them but may have wear issues.
Any pics of the scored walls?
Last edited by MooksM275; Oct 29, 2018 at 09:35 PM.
The dots on the crank are the upper mains and the stamp is the lower. Your lowers are all the same so that is easy. g should be gelb or yellow. The dots on crank I would say are blue and white. There is no green color code for main bearings on our cars. But you should check by the book to be sure to match everything up.
As for the rings, I tried like you to find and I think that NPR made the original rings. I called NPR as I found an old part book with a part number for the ring package for our car. When I called, they spoke with manager and said they are under contract with Mercedes and cannot sell these to the public.
On Alibaba there is a company that shows they have the rings and I even had them send pics and I think they are actually NPR rings. Cannot vouch for it but you might try them and give it a shot. The rings had stamping exactly the same as the rings we have and said japan. Search alibaba M275 E60 piston rings. no guarantee but worth a shot.
I will tell you that depending on how badly your walls are scored you can just have the cylinder lapped because it is Alusil. Here in California there are machine shops that do this with an RA gauge and use AN-30 paste. If your scoring is not that bad, you may be able to just lap them and they will be like new. The major issue with the pistons is that the coating is old and needs to be there for running in alusil cylinders. Nothing seems to work as good as the original mahle ferrocoat so recoating doesn't seem to be a great option. If the skirts are ok you could try to run them but may have wear issues.
Any pics of the scored walls?
AGAIN THANKS FOR THE INPUT IT'S VERY HELPFUL,
The reason I went in to the engine was # 1 cyl was at 60 psi, all others were 150-160 psi compression wise cold. My intake "T" between the Intercoolers and the throttle body had a crack, I repaired it by melting plastic around the bottom / hose clamp area. It exploded and the engine inhaled some plastic so I thought maybe that damaged something. Opening up the engine I didn't see any issues. I filled the cylinder at BDC with wd40 and there was no leakage and the valves were tight. WELL F***K the wd40 must have had some metal in it and got hung up scratching the cylinder wall in #1. Otherwise there's no scoring at all in any of the cylinder walls !!! Seems all self-inflicted at this point.
I will keep ya posted !!
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