need advice on mbz 189 engine
 

300se 1965.engine 189.cylinders worn.i have new cylinder liners
unable to find machine shop to replace them, providing they know mercedes and this particurar engine.
any ideas how to rebuild this block?:rolleyes:

Any reputable shop that does diesel engines will be familiar with replacing liners. Costs as much to remove/replace as it does to bore and hone.

The only thing extra they need to know is the piston clearance, and they can find that (probably 0.001" anyway). You will need the pistons to get the bore and hone done correctly, the shop will need to measure the pistons.

Most automotive only shops will not do this, they don't know how to get the sleeves out and new ones in.

You might check around and see who the local MB independent (or independent foreign car shops) use. Most will be happy to refer you.

Peter

I've got the MB repair manual on these cars and I can scan or copy the pages on liner replacement. and send them to you.

Basically, you heat the block in an oven and press the liners out. The new ones are pressed back in, in the proper alignment since the top of the block is not flat, it's on an angle.

If the deck of the block isn't perpendicular to the crank, that is the problem. You will need a jig to get the liners straight, and I can promise you no one has the apparatus.

I don't know what to recommend -- my personal solution would be to have my brother do some "saturday free time" work and make the jig for a shop -- shouldn't be all that hard, just turn an aluminum cylinder to fit the bore and then machine some "steps" on the sides to match the offset from the perpendicular so that the liner will only fit on correctly, then mount it in a frame to bolt on to the block......etc.

I cannot imagine anyone doing this for you unless you are willing to part with LARGE amounts of money.

The other possibility is that the liners are straight and have to be machined off to match the top of the block after being installed. This is a bit easier, but still out of the normal machine shop range!

I will check with Hans and see if he knows of anyone who would be able to do this for you -- surely there is a restoration shop somewhere that has done this before, or still has the factory tooling floating around.

Peter

The 300SE is an extremely neat fin car but the problem you face is the primary reason that the few 300SE you see no longer have the original engine in them. This aluminum block, iron sleeve setup was unique to this car therefore all the parts are outrageous. The last time I seem the price for new pistons they were around $500 a piece. Also the even numbered cylinders take different liners than the odd numbered cylinders. I have heard of someone getting it done but I can't remember where they got it done. Good Luck with it. Is your car a LWB sedan, SWB sedan, or coupe?

The M189 is a very complex engine. I wonder if the liners could be honed.

It might be better to find an engine and trand from a W124 300E. It would make for a much more reliable car. It would pass emissions testing with flying colors.

No worries on emissions testing for that car. In California it is exempt due to it's age.

Metric Motors in LA has been helpful to me in the past, admittedly not this complicated.

www.mercedesengines.net

I have my friend Hans looking this up. He does not remember liners for that particular engine (OM189 in a 300d.). Will report later.

Peter

Here is the original post:


300se 1965.engine 189.cylinders worn.i have new cylinder liners
unable to find machine shop to replace them, providing they know mercedes and this particurar engine.
any ideas how to rebuild this block?



Peter, it is not a diesel engine. It is an M189 al block gas engine from the 300a/b/c/d/sl/Gullwing of the 50's and as such has cast iron liners. This engine goes into the 300SE/SEl fintail , the S class of the day.

Regards. Warren Bain

start thinking..... big money,...the m189 is a fuel injected gas engine. It doesnet have liners!! you need to rebore with oversize rings...and believe me while your there turn your crank, replace your bearings and rear seal...you are going to easily spend$6-10K yes..thousand!

Rocker arm bushings wear on these engines and you get variable valve lash because of it. each rockerarm is+$100 you have 12, each valve averages +$100 you have 12. head gasket is $+/-375.

Bottom line ...find a used running engine.

I'm sorry, but you are wrong. The M189 does have liners and they are only available in Standard size. There used to be a repair size as well, but that has long since been discontinued.

The M186, predecessor to the M189 does not have liners as it is a cast iron block. The M189 is an alloy block.

Here in Australia, there is a couple of people I know that have the knowledge and equipment to install the liners. I can arrange to have it done, but you would have to send the block. Cost is around A$2,500 to do this, so it is not a cheap exercise. I have also recently re-designed a piston suitable for the M186, M189 and M198 engine. It is a forged alloy, with increased compression, better torque, lighter and more efficient than the original. It also used modern piston rings so that replacement is straight forward.

I'm with Chuck regarding Metric Motors...They are located in west San Fernando valley...you are in Woodland Hills. They are experts!!

These are some newly designed forged alloy pistons we have designed for the M186, M189 and M198 engines.

I have a RHD 300SE here and can tell you they`re not easy to work on. This one had a hole corroded in the block that leaked coolant into the oil galley which filled the rad with oil. We were able to fix that.

I didn`t use new cylinder liners but I had to have the crank journals align bored. This is tricky to do two different materials - the alloy block and steel caps. My shop was able to do this perfectly. I had them install the piston rings and fit the pistons to the block. This is also tricky because you can`t use a regular piston ring compressor - not sure how they did it.

I used new valves, valve guides, rings, crank gear, injection pump gears and a number of other new parts. Being RHD, it made it much more difficult to work on. Before I had it finished the engine was in and out of the car about 5 times - each time with a new problem.

It would of been nice to of had new cylinder liners but it runs pretty good as is. Smokes a bit but I expected that.

BTW, I have NOS 300SE fuel injectors if anyone needs some. NLA for a long time now.