380SL Diesel Conversion Project - Page 3 - PeachParts Mercedes-Benz Forum

t walgamuth · #31 11-30-2011, 01:29 PM

He'll find out!

A little vibration may not be an issue. It is after all a sports car!

mach4 · #32 11-30-2011, 06:38 PM

Quote:

Originally Posted by t walgamuth

A little vibration may not be an issue. It is after all a sports car!

I'm expecting some additional vibration... how much, I'll just have to find out. If it's too bad, I've got several choices, including going back to the original engine mounts. Other options include drilling out portions of the urethane to make it softer, or filling with a softer urethane. I'm fairly soft now, but can go quite a bit softer.

This strategy is normally used to firm up the engine for performance reasons. For the track many people go with solid mounts that are terrible for vibration, so this solution is kind of in between normal soft mounts and solid mounts.

t walgamuth · #33 11-30-2011, 06:58 PM

Right. My formula ford bolts right to the frame, no rubber no nothing. Of course every other part on the car turns out to be broken from fatigue after a while!

strelnik · #34 11-30-2011, 07:44 PM

Quote:

Originally Posted by mach4

Hmmmm... That's a very interesting prospect. Did the OM617 that came in the 115 have an oil cooler?

In that same vein, is it possible that the oil pan from that same engine would work on the later OM617.952? If so, that would solve the subframe clearance problem as well?

I'm already using the engine support brackets from a 115 and the other bits should still be there.

It would be nice to keep things as stock as possible.

have you decided what you are going to do with the 3.8 power pack? I have a 380 SL and might be interested. Don't know where you live and if distance would be an issue.

mach4 · #35 11-30-2011, 09:31 PM

Quote:

Originally Posted by strelnik

have you decided what you are going to do with the 3.8 power pack?

Not familiar with the term "power pack". If by that you mean the engine and tranny, I don't plan on doing anything until the conversion is complete. I want it around as reference for wires, hoses, and all the other little bits. At that point I'll be looking to part them out.

I'm in San Diego in the Peoples Republic of Kalifornia, the land of fruits and nuts (as they say). I see that you are in The Peoples' Democratic Socialist Collective of Michigan, so distance on any parts and pieces would be a bit spendy.

By the way, the engine is compromised. It still has the single row timing chain and it allegedly slipped. It was at an indy MB shop when I bought it and the mechanic there indicated that it could be possible that only a valve job might be needed. On the other hand.... maybe the whole thing is toast. The engine was never opened up to do an assessment.

strelnik · #36 12-01-2011, 09:37 AM

Quote:

Originally Posted by mach4

Not familiar with the term "power pack". If by that you mean the engine and tranny, I don't plan on doing anything until the conversion is complete. I want it around as reference for wires, hoses, and all the other little bits. At that point I'll be looking to part them out.

I'm in San Diego in the Peoples Republic of Kalifornia, the land of fruits and nuts (as they say). I see that you are in The Peoples' Democratic Socialist Collective of Michigan, so distance on any parts and pieces would be a bit spendy.

By the way, the engine is compromised. It still has the single row timing chain and it allegedly slipped. It was at an indy MB shop when I bought it and the mechanic there indicated that it could be possible that only a valve job might be needed. On the other hand.... maybe the whole thing is toast. The engine was never opened up to do an assessment.

Well, I might be out that way on business, so someone else may be paying my transpoortation fees. I shall wait and see.

BTW "power pack" is an old diesel truck term from the 70's. I guess it dates me, lol.

mach4 · #37 12-03-2011, 09:17 PM

Well getting the original ribbed pan off and the new non-ribbed one on was a real adventure. In the process of removing the allen head bolts on the pan, I managed to strip two and broke off the hex wrench in a third.

One was on the side of the engine in plain view and a Sears nut extractor did the job in no time. Another one was up in side a recess near the back of the pan (one of the long 5mm bolts) and I used a hex wrench one size larger, ground the end and drove it into the bolt. It too came right out.

The huge job was due to my absolute stupidity, specifically using a "woggle head" hex wrench. The first bolt came right out, but the next one promptly broke off flush with the top of the nut. It was the larger 6mm bolt that is deeply recessed at the back of pan adjacent to the seal. I tried magnets; I tried making a "chisel" and using a hand impact tool; I tried drilling... absolutely nothing would work. I finally noticed that there was plenty of space inside the casting and if I drilled out the access hole (from around 1/2 inch to 3/4 inch, I could snake a modified bolt extractor in there and hopefully get the bolt out. [Hint: if you ever find yourself in this predicament, don't use a 3/4" drill bit. It grabbed and about broke my arm as the drill ripped from my grip. Use a large step drill, it cuts really nice] The strategy worked. Here is the tool I fabricated - a ground down Sears easy out welded to a 3/8" extension. The bolt was actually too hard to get a bite, but when I drove it onto the bolt it grabbed nicely and came right out.

After all that, it was pretty easy to install the new pan temporarily, drop the engine/transmission in the car and check the clearances.

It was a lot better, but still too close. At once point I actually had the thickness of some cardboard for clearance. It slipped through with just a bit of drag, kind of like using a feeler gauge. So to get to my target 1/2" of clearance I'll need to use a 1/2" spacer under the motor mount. I mocked up this by using some 1/2" stock and positioning it between the engine support arm and the motor mount - worked great. I may now have a rocker cover-hood clearance issue, but the solution to that, if necessary is to just use a subframe spacer of up to 1/2".

I will want to clearance the front cross member a bit just for insurance, but that will be easy and clean.

The last thing for today was to double check the fitting of the remote oil filter. No problems. I'll finish the bracket and mount it next time I have the engine out of the car.

t walgamuth · #38 12-03-2011, 10:10 PM

Good work.

Yeah those allens are sometimes pretty tight. You have to clean the head out before putting your allen wrench in but once you get it in good and all the way down you can put tremendous torque on them without breaking anything. You'lll swear something is going to break but the threads always let loose first.

How much clearance do you have above that cross member?

mach4 · #39 12-04-2011, 02:13 AM

Quote:

Originally Posted by t walgamuth

How much clearance do you have above that cross member?

I'll have at least 1/2" once I get the 1/2" spacers for the motor mounts cut and installed. The picture shows about 3/8" at the minimum point.

t walgamuth · #40 12-04-2011, 09:15 AM

A half inch may be enough, especially with your custom motor mounts.

The 617 hops up and down as it idles, especially with an automatic tranny. With the heavy stick flywheel it is much less active at idle and could be mistaken for a six cylinder.

mach4 · #41 12-04-2011, 10:50 AM

Quote:

Originally Posted by t walgamuth

A half inch may be enough, especially with your custom mounts

I'll be keeping a close eye on clearance. There is always the backup plan of notching the subframe. I'm getting so good at pulling and installing the engine it would be a weekend project at worst

.

mach4 · #42 12-05-2011, 09:38 PM

Not a lot of progress today, but I did pick up the 1/2" steel for the motor mount spacers, some 1-1/2" aluminum rod for the subframe spacers and some 1/2NPT-10AN fittings for the remote oil filter. Fabbed up the mounting nuts which are pop riveted to the inside of the fender and test fit the remote bracket.

Yanked the engine and subframe again. Next time it goes in it will hopefully be for good.... sort of.

The plan is to get everything installed, hooked up and running in order to get it over to the BAR referee and the DMV to get the title changed from gas to diesel, then when I know I'm good with the bureaucrats, I can yank everything again for detailing, painting and powder coating. (No sense in getting everything really pretty if there's going to be a problem).

mach4 · #43 12-06-2011, 07:48 PM

Today was focused on getting the subframe spacers done.

I'm a member of the local EAA (Experimental Aircraft Association) chapter and they have a couple of lathes at the hangar that are available to members, so I was able to go down there and log some lathe time.

They will never win a machinist award, but they are functional. I made them a little more than 1/2" but I can just turn the shoulder a bit if I end up with better hood clearance than I'm anticipating.