87951

Anyone familiar with a shop located in the Midwest that can hone the cylinders with the silicium material? Appreciate any info- starting on rebuild of a spare 87 turbo motor with 90K miles on it.

AMCPILOT

Hello,

I am also rebuilding a spare 87 944 Turbo engine ... had 215K miles on it and the cylinder lining is perfect and the bores measured well within specs. Unless there was some mechanical damage to the walls, why do you need to have them retreated? I do not know of a place in the midwest, but unless you have cuts, scrapes or other damage, I wouldn't be too quick to put money into it. The alusil coatings are really quite durable and your engine mileage is very low. Hope this helps.

Matt Sheppard

I have a 250K turbo engine I want to rering. It has some scratches I catch a nail on, but no chaffing or such. What can be done to the cyl w/ out ruining the treatment. Can I debur them w/ say 800 grit sand paper? Should I just re-ring and not do anything? I'm re-using old pistons w/ swain-tech coating. The bores are round and true according to the telescoping gauge/ micrometer measurements.

Any INFORMED suggestions?

87951

Matt,
If you have a sleeved block then you are no longer concerned with the alusil coating. You should be able to use a normal cylinder hone to remove scratches. Back to my question - I'm looking for a midwest shop with the capability of honing my block with silicium compound. I am not concerned with the possible redundency of doing this. I want an engine that will last as long as the first one -180K miles at present, and I'm really not interested in having to pull the engine again a year later after a rebuild.

Matt Sheppard

It's a different engine than my 2.7. I'm sorry if you feel I hijacked your thread, I thought it was related. I'll post a new one instead

Good luck w/ your rebuild.

Danno

Shops that are familar with BMW & Mercedes engines should be able to do this final lapping procedure to expose the silicon crystals in your block.

The Alusil material is actually a metal-matrix-composite with embedded silicon crystals. Then the final stage of the block-preparation is a lapping procedure using felt pads and a fine abrasive that will gently grind away the soft aluminum exposing the much, much harder silicon crystals.

cruise98

Danno is right about the Mercedes shops being familiar with the procedure. Check with them first. You can always box it up and ship it to Marcus or someone else familiar with it. Shipping can be expensive and dangerous.

Another idea is to find a reputable racing engine shop in town that uses a Sonnen honing machine. They can get the right felt pads for the job from Sonnen. You might have to buy them though, as they probably never get calls for polishing the alusil bores.

Stefan

I had mine done at the local Mercedes shop in Toronto. It was pretty much the only machine shop near hear that did it.

Check with your local Mercedes Dealers and mchine shops.

BC

Cheaper but may be better:

<a href="http://www.usnicom.com/usbig31.html" target="_blank">http://www.usnicom.com/usbig31.html</a>