need info - PeachParts Mercedes-Benz Forum

bearman554 · #1 10-03-2004, 03:50 PM

I need help i just bought a 1985 380SC 3.8L and i know nothing at all about this auto outher then i fell in love at frist site. have been tolled that it has cermic clynders . the car has 240,000 miles the heads have been repliced 15,000 miles ago . it was a one owner car

i would like any info on this auto. or where i can find the info that i need .also need an owners manul for the car

Thank you all
the bearman
Jbearman554@aol.com

nglitz · #2 10-03-2004, 05:01 PM

The block is cast in a hypereutectic aluminum/silicon alloy. This means that there is more silicon in the mix than can be dissolved by the aluminum, so some precipitates out as crystalline silicon. It's very evenly distributed throughout the block. After the block is machined, the piston bores are acid etched to remove the top few mircons of aluminum, leaving essentially only silicon for the piston rings to ride on. This is probably what he meant by ceramic bores.

Neat car. It's good to have recent head work and (hopefully) timing chains, too.

Proofread, lad. Proofread,

psfred · #3 10-03-2004, 05:31 PM

Actually, it's even more tricky that that -- the silicon is actually precipetated out of the melt around the cylinder bores, so the concentration is very high.

The porous silicon wall will last essentially forever if you don't overheat the engine -- should wear at 1/5 the rate of cast iron, and the iron version of this engine (M116 and M117) usually run 500,000 miles without bottom end work.

Nice car.

Watch the timing chain stretch (hopefully someone swapped the single row chain for the double row). You need to have it checked EVERY oil change, chain must be replaced if significantly "stretched" (actually, worn). Otherwise, they break, and you will be doing another valve job.

Otherwise, a standard W107 or W126 depending on what you have -- there is, to be best of my knowledge, no SC style. Either SL, SEC (coupe) or SEL, large sedan.

Peter

Hatterasguy · #4 10-03-2004, 08:03 PM

Wasn't their a 380SLC? I second the timing chain check. It should be checked, if it hasn't been replaced yet do it. I would imagine it is a double row chain their is no way a single row chain would have lasted that long.

deportes · #5 10-03-2004, 08:52 PM

is that engine the same as the 83 380sl uses

?

Hatterasguy · #6 10-04-2004, 12:31 PM

MB used the 3.8 V8 in a few cars, the 380SEC, 380SL, and 380SE/SEL. I(I could have sworn their was a 380SLC) It was an ok engine but if your paying for the gas your better off with the bigger 8, it has a lot more power.

psfred · #7 10-04-2004, 09:54 PM

M119 engine was 3.8L, 4.2L, 5.0L, or 5.6L. The 3.8L version (I don't know wha the subtype number are) originally came with a single row chain. The 4.2L had a double row chain, but it's still very weak compared to the 5.0 and 5.6L models.

Might have been an SLC rather than an SEC -- would have been then a W107/R107 chassis rather than a W126.

There is a kit to covert the 3.8L to a double row chain, but it's expensive and a real pain unless you need to take the engine apart for another reason.

Else a very nice engine, and someone else has already fixed the other know "goof" at the factory -- the headbolts seize and require steel inserts be installed to repair the now threadless holes. Big PITA and costly -- later engines have the inserts installed during production.

Peter

Gilly · #8 10-04-2004, 10:53 PM

Peter:
Way off on the engine number there, buddy. M119 was used in the 129 and 140 V8, also after 1990 the 124 V8 and 210 V8 (E420 only).
The M116 was the 380 motor and 420 motor in the 126 chassis, M117 was normally a bit larger, like the 450SL, 500SEL and 500SEC, and the 560SL/SEL. That's usually the easiest way to remember the 116/117, the displacement is either 420 and smaller or 450 and larger, unless I am forgetting something. The M119 is the dual cam engine, way different than the 116/117.

Gilly

psfred · #9 10-04-2004, 11:01 PM

Oops!

I forgot the M117 was both iron and aluminum. Must not be getting enough sleep.

I thought the M116 was the 3.5L short stroke, all later engines were the M117, but I will take your word on it.

Either way, the 380 in early versions had the single row chain, not the best design ever. The 420 is much worse than the others, too, in spite of being nearly identical.

Peter

Gilly · #10 10-04-2004, 11:11 PM

I agree, more probs on the M116 4.2 liter than the M117 or even the M116 3.8, but it would be adviseable to check to make sure the chain was updated to dual row (on the 3.8), easy to check it through the oil cap hole usually.

Gilly