240D rebuild questions chapter 2
 

:confused: I am trying to decide where to take my block for sleeves. You may remember I am doing a rebuild on my "80" 240d. I have taken the crank in for reconditioning and am doing the valves with the help of a MB tech friend. I took the block to a local mechanist for boring and found out it must be sleeved. The shop that did the crank has not done a MB but have done other diesels requiring sleeves and has a good reputation in general SOOO my questions would be 1) would you more experienced folks consider a shop like this and if so what would you ask them to do other than the sleeves? 2) In other words is doing a MB that different ?

I am taking some pics of the valve job which I may finish up today if the exhaust valve guides came in.

As far as the cylinders and pistons go, this is really not much different than any other engine. If the bores can be cleaned up at the first oversize, simply buy pistons in first oversize and have them bore the cylinders. If a cylinder will not clean up at first oversize, they can draw a bead down one side of the sleeve, collapse it, pull it out, pack the replaement sleeve in dry ice and put it in place. Then they top and bore the sleeve to your oversize and fit the pistons.

There are some here that are proponents of sleeving the block back standard and reusing the pistons. Although this is probably the most economical approach, I prefer not to do that because the pistons are very stressed in a diesel. I found one piston when overhauling my 240D that was about to fail at the ring land.

A good machine shop with a good boring bar, one that indexes on the main bearing centerline, like a Rottler, can do a good job with one of these.

My $0.02,

I am the one Larry was talking about when he said to resleeve and use the old pistons . I have done this on several engines with great success. It all depends on what kind of shape your old pistons are in . I just got through with another rebuild on a 240D where I had the block bored to oversize ( 91.50 ) and used new pistons. Smittys auto has a great deal on them right now. I paid about $ 317.00 plus shipping and they are Mahle brand complete with rings and wrist pins. Here is their web address.
http://www.sasponline.com/


MBJOE

Give the clearance specs to the machine shop. They will probably do a good job and are probably more than willing to let you bring the parts.

Larry

Thanks...I was planing to replace the pistons in any event. I just returned from taking the block in and they concur with o/s pistons and bore where needed. As far as the different pre chambers you mentioned I would assume if the new o/s pistons have the same configuration on top (I think I have seen the others, they definitely look different??) they would go with the pre chambers I have. I had the head magna fluxed and they said the pre chambers looked good but not pull them, maybe I should have had them do that. Also is it standard practice to replace those little ball bearings and flush out all the oil galleries in the block ?

MBJOE

This engine was ran out of oil by the PO and a couple of journals and the side of a rod was damaged so thats why I am going for new pistons. I am really enjoying learning about these engines and really appreciate the input from you folks.

Make sure the shop will machine to the proper clearances -- about 0.001" for the pistons and ditto for the crank oil clearance. Most shops used to American engines may be reluctant to leave so little clearance on the crank mains (since most Americal engines cannot be rotated with oil clearance so small!), but any good diesel shop will be used to them.

You can use either standard or oversize pistons, whichever is cheaper.

For sure if the engine failed due to oil starvation I'd replace the pistons -- most likely ruined and not worth the chance of rapid failure from re-using them.

Peter