617 into W108? - Page 2 - PeachParts Mercedes-Benz Forum

Whiskeydan · #16 07-31-2007, 10:06 AM

Quote:

Originally Posted by R Leo

Front or rear? My 115 must need bushings; it gets a little hairy during hard braking...

Front.

I plan on doing kingpin bushings as well while I'm there. All associated hardware gets a weekly spray of PB Blaster 'till I get to it. It should be very loose by then.

I did all new rear bushings when I replaced the axle.

tompaah7503 · #17 07-31-2007, 08:04 PM

Quote:

Originally Posted by noah

So other than the oil filter housing everything will just bolt up? Can I use the existing gas tank and lines? Can I use the existing transmission?

You can use the existing gas tank and lines.. I did.
Engine does not fit onto existing mounts, you can either go the way I did and welded new mounts on the subframe that fits the OM617, or fabricate new mounting arms for the OM617 so that it will fit the existing mounts.
Mine is a W111 but they're alike inside..
See this post for a picture of how I did the mountings..
http://fatfranz.wordpress.com/2007/01/11/bright-flashes/

And yes there's some very valid points in this thread, the car is not going to be a rocket. I have the standard fintail 4.08 rear end and top speed in fourth gear with engine screaming is about 65mph. One way to solve this problem I'd think is to use the five-speed manual instead, OR what I'm planning to do next, swap in a 3-something rear axle from a W108 and increase the wheel diametre.

cdodgyd · #18 03-04-2008, 09:10 AM

I've just bought a converted W108 280SE. Its got a 240D engine in it.

Somebody asked why a while back; well here in the UK fuel is now so incredibly expensive I had to have a classic car that could run on veg oil. Diesel here is now the equivalent of $10 per (imperial) gallon!
We also have a law here that pre-1972 cars don't pay road tax (which is the equiv of $360 a year just to be able to use your car on the road!).
There are very few diesels of pre-1972 vintage that are practical for everyday use, and a converted W108 seemed to fit the bill nicely as I wasn't prepared to do a conversion myself.

Anyway, its been converted quite well by the previous owner. Being RHD the battery is more or less in the same position as std, as the brake servo is on the opposite side to LHD cars. The engine mounts are originals that have been cut in half and re-welded at an angle. Pretty they ain't, but they work!
The rear axle is stock and seems well matched for the conversion. It'll do 80+mph (eventually!) and I get 30-40mpg on veg. The exhaust is half original (mufflers) and half 240D (manifold & header).
The floor mounted auto shifter has been taken out and replaced by a manual 4 speed. An aftermarket vacuum cut off has been fitted to the IP and I've wired the glow plugs to the low fuel light to let me know when to fire it up.

I happen to work for a company that uses various oils for the food industry. Guess who has all the rejected waste oil for free?!!! The engine runs well with no modifications at all on a 90% oil and 10% gasoline mix even at sub-zero temps here in Britain. It does need a fair bit of cranking on a cold morning however! I'm doing 50 miles a day and so far so good.

It needs paint and a little bodywork but that aside its providing nearly free motoring in style - I love it!

Johnhef · #19 03-04-2008, 09:17 PM

Thats something I had thought about doing awhile ago. I had posted some pics of one here awhile back: 1969 280sdl

tompaah7503 · #20 03-05-2008, 07:01 AM

My latest purchase is a 1971 280S W108 that has a OM617.910 in it, and the five-speed manual. If anyone is interested in specific details I can post pictures or explain whatever needs explaining..

cdodgyd · #21 03-05-2008, 08:31 AM

Quote:

Originally Posted by tompaah7503

My latest purchase is a 1971 280S W108 that has a OM617.910 in it, and the five-speed manual. If anyone is interested in specific details I can post pictures or explain whatever needs explaining..

That sounds very interesting! I'd certainly like to see some pics. How is the performance and fuel consumption?

I reckon these conversions will become more popular, at least in Europe, as fuel becomes more and more expensive. There's one like mine on Ebay.de now. The original gasoline engines would just be prohibitively costly to use regularly these days.

tompaah7503 · #22 03-05-2008, 09:31 AM

Quote:

Originally Posted by cdodgyd

That sounds very interesting! I'd certainly like to see some pics. How is the performance and fuel consumption?

I reckon these conversions will become more popular, at least in Europe, as fuel becomes more and more expensive. There's one like mine on Ebay.de now. The original gasoline engines would just be prohibitively costly to use regularly these days.

I don't know much about fuel consumption yet, bought the car about four weeks ago, there was some issues I had to work to begin with. Previous owner says it runs well in 110km/h, didn't as about fuel consumption.

My other car, a fintail with a 617/722-transplant does about 90km/h tops and consumes 8L/100km, but that's with an insane rear-end and shopping-cart-13"-wheels. I'd like to change the rear gearing to lower ratio and have 14" wheels on that car, it should make it better on the highways.

As for the popularity of these conversions.. I don't know.. it's pretty much an enthusiast thing, the engines are old and require maintenance, so are the cars.. Not to mention it's not easy to find good used OM617's to begin with, most are worn out and require complete rebuild.

I have a dream and that would be to find a cheap modern diesel engine, like a 4-cyl with turbo, common rail inj. and electronics, all mated to manual gearbox (may I wish a 6-speed?), that would transplant nicely into a W111/W108. It would be the ultimate combination of appearance, fuel economy and performance. I'm always holding one eye open for a completely wrecked 2000-something diesel to gut an engine from.

I'll take some general pictures of the engine bay, with mountings and such, and post them here later.

cdodgyd · #23 03-05-2008, 11:34 AM

Sure, running an old car every day will always be a small niche interest. However, there does seem to be an increasing interest on diesel conversions of classics in general; at least in the UK.

As to more recent engines, my W108 replaced a mid-90's VW Passat Tdi (which also ran on veg oil!). A boring car and it had its fair share of problems too, but the engine was superb. I wanted to put the engine in my other classic - a Frogeye Sprite, but it was just too complex a proposition (and probably too big!).
I do know of someone who has put a VW Tdi motor into an old VW bus. It was so complex he ended up removing the entire dash and electronics and hiding it all under the rear seat! That was on top of all the usual things like new engine mounts, exhaust etc.
At least the Merc 4 and 5 cylinder diesels are fairly simple and mechanical (ie. fixable!) as well as being a fairly easy swap, which influenced my decision to get one.

tompaah7503 · #24 03-09-2008, 04:46 PM

Hi again, took some pictures today and posted them on my site.
It's hard to snap good pictures when everything is dirty, lighting is poor and space is tight, but I hope the pictures will provide some guidance for whoever wishes to do a conversion like this.
http://fatfranz.wordpress.com/2008/03/09/the-other-car/

Flounder · #25 03-09-2008, 05:14 PM

Tomas, thanks for the link to your site. I read everything and watched the videos. Nice job on Franz.

Off-topic but I really like your checkerboard floor!

cdodgyd · #26 03-10-2008, 05:23 AM

Thanks Tomas, great update.
I'm jealous now of that 5 cylinder/5 speed combo. That has to be the ultimate for a vintage Mercedes!

This w/e I found the reason I was getting gunk in my pre-filter, the inlet and return fuel pipes were reversed - I was sucking veggie in through the return pipe! Good job it was really clean fresh stuff.

tompaah7503 · #27 03-10-2008, 05:55 AM

Where are you located?
There's quite a lot of junked W123's in Sweden and it's possible to get a 5-speed transmission for about 400USD/200GBP, if you're in UK the situation should be about the same I suspect, since manual cars are popular in Europe..

cdodgyd · #28 03-10-2008, 09:52 AM

Yes, I'm in the UK.
I think I would only go with the 5 speed if I went to the bigger engine as well. The 4 cylinder in mine just wouldn't have the grunt to pull a taller fifth gear I reckon. It already slows down at the merest hint of a hill!
Whether the 5 speed/5 cyclinder combo is matched to the stock diff ratio in your car, only you will be able to say - I'd like to know when you get it going!
The 4 speed/4 cylinder is well matched to the diff I have (stock 280SE) as I mentioned earlier, but a little more power and top speed would be nice!