carb diesels - Page 3 - PeachParts Mercedes-Benz Forum

J. R. B. · #31 01-17-2006, 07:08 PM

Quote:

Originally Posted by t walgamuth

it was manufactured on t he same type lines as the gas engines and there is enough commonality that you can take out the diesel injection pump and put a distributor in the hole, change to gas heads, add a manifold and carb and run it. the cam even works. they are very strong running gas motors that way, i hear.

not strong enough as a diesel though.

tom w

I just checked my machine shop manual and the head bolt pattern is different between the gasser 5.7 and the diesel 5.7. J.R.B.

ConnClark · #32 01-17-2006, 07:22 PM

Okay,

I stand corrected ( again ). It wasn't an aluminum block ( Note: My boss didn't tell me this, it was another web site.) . I did find that there is a web site dedicated to it however http://olds-diesel.com . On another site I found some info on converting it to a gasser http://www.442.com/oldsfaq/ofedsl.htm

kerry · #33 01-17-2006, 08:21 PM

Those directions for turning on Olds diesel into a gasser could just as well have said, "Take an Olds diesel, melt down all parts, recast as gasser parts and reassemble"

J. R. B. · #34 01-17-2006, 09:23 PM

Quote:

Originally Posted by kerry edwards

Those directions for turning on Olds diesel into a gasser could just as well have said, "Take an Olds diesel, melt down all parts, recast as gasser parts and reassemble"

If you were here I would give you a cigar and pour you a shot of my favorite bourbon.

t walgamuth · #35 01-17-2006, 10:38 PM

your sarcasm is very creative.

but nobody i have heard of has done it your way.

and some have done what i described. why? i suppose they were tired of the diesel and had a gas motor with a bad block.

tom w

kerry · #36 01-17-2006, 11:06 PM

Quote:

Originally Posted by t walgamuth

your sarcasm is very creative.

but nobody i have heard of has done it your way.

and some have done what i described. why? i suppose they were tired of the diesel and had a gas motor with a bad block.

tom w

I was referring to the directions in ConnClark's link. The modifications described there are so extensive as to inspire paroxysms of creativity.

t walgamuth · #37 01-18-2006, 08:00 AM

but while we're on the subject, i offered the story as an example of how similar the engines are to gassers, and if anybody is actually interested, i can find out which heads are needed to do it. apparantely the 350 gasser heads don't match up. my machinist is kindof a olds fan so he will know.

i checked out the 442 site. the info there sounds accurate to me. i noted that i misspoke. the distributor goes in place of the vac pump, not the injection pump.

tom w

J. R. B. · #38 01-18-2006, 09:34 AM

I didn't mean any sarcasm towards you either Tom. What burns me up is the myth that a 5.7diesel is a re-designed gasser and that they are no good. We have driven these things since the mid-80's and worked on them in our shop since they first came out. Most of the problems people had with these things were from poor maintenance and operator error. They weren't a bad engine if you kept it up and knew how to maintain it. Granted it wasn't designed bullet-proof like a Benz but the damn things got good mileage and I think they were a good starting point for our diesel cars. But I don't think America as a whole was ready for a diesel yet and probably still isn't. The elite people here on this forum are just a drop in the population bucket.

Jim H · #39 01-18-2006, 12:27 PM

Quote:

Originally Posted by J. R. B.

...But I don't think America as a whole was ready for a diesel yet and probably still isn't...

Americans (as a whole) will drive diesels right after they start driving manual transmisions...

ConnClark · #40 01-18-2006, 12:50 PM

As I learn more about this engine I realise that the rumors about it being just a reworked gasser are not true. However, this engine suffered some serious design defficencies. I don't think you can blame operator or maintinance problems on a car with a blown head gasket with as little as 50,000 miles on it. Blowing out the bottom end was also a nasty issue you can't blame on maintinance. This engine was so finicky about how it was put together it didn't lend itself to mass production very well.

I can see teething problems in the first couple of years of production, but when they reworked the design they didn't adequately address the head gasket and head bolt issues which were a major problem. This is probably because they didn't want to retool to add more bolts, or spend the money on the high quality bolts required. A lot of people got burned by this engines problems and this is part of the reason we have so few diesels in America.

It was a bold first step. In fact it was a leap. The problem is they didn't look very carefully where they were leaping. This engine achived great performance, but so does a CART engine and they are only good for about 500 miles before a rebuild. It wasn't ready for the street.

As far as converting these engines to a gasser, the web page I pointed to was geared to the maniac mechanic that wants to build monster engines. Later he does note the following ...

"Add 403 heads, a SB carb and intake manifold, a fuel pump and a gas engine camshaft need to be installed, but I doubt it's just that simple. What other work has to be done?

You need to adjust the spacing in the timing chain area, and add some plugs somewhere. Mondello has the whole kit with all these little miscellaneous pieces. Unless you have a machine shop at your disposal, you'd probably be bucks ahead to get that kit with all the right parts, or else your engine can become a very heavy and expensive failed experiment.

As I said above, you need the little pieces to make up the differences between the gas and the diesel block. I think the Mondello kit has the proper roller timing chain and the like. Give him a call, and see what he recommends. The other parts sound like a great starting point. "

t walgamuth · #41 01-18-2006, 10:03 PM

they were fine as long as they ran. my uncle bought one new and at 12k it broke the crank.

like many things through the years gm put a half developed engine on the market and let the public sort it out.

the sad thing is that gm KNEW how to make a diesel correctly. they have been building detroits since the forties. they CHOSE to build it on the cheap.

and that, sadly, is why now a whole lot of folks that work for them and used to work for them are going to be hurt like hell when they go under.

back in the thirties alfred p sloan (the head of gm) said "we are not in the business of making cars.... we are in the business of making money".

if you want to stay in the car business (or any other business) you have to concentrate on the product. sooner or later folks will quit buying cars cause of patriotism and buy cars that work.

tom w

J. R. B. · #42 01-18-2006, 10:12 PM

Quote:

Originally Posted by ConnClark

Blowing out the bottom end was also a nasty issue you can't blame on maintinance.

Our shop has rebuilt well over 20 of these 5.7s and the only one that had a blown bottom end was due to operator error. If the damn fool that emergency started the car would have read the sticker on the air-cleaner [Do Not Use Starting Fluid]and heeded it's warning he wouldn't have cracked the main bearing bosses and crankshaft. The first SOB with starting fluid that comes within pi$$ing distance of my Benz or my Olds is likely to get shot.

Diesel Giant · #43 01-19-2006, 06:47 PM

No such thing as a carb on a diesel.

rwthomas1 · #44 01-19-2006, 08:16 PM

JRB,
You are fighting a losing battle on this board. No one heard, except me, will give any respect to the GM diesels. Back in HS my buddys dad had 3 GM diesel cars, 2 Pontiacs and a Caddy. Never had a problem with any of them. Granted there were issues with the 5.7, it was released too early and by the time they sorted the whole thing out the bad rep was already there.

People like to forget that it takes a while to develop a vehicle. The Olds 350 diesel was made to fit the V8 rear-drive chassis of the day and it did in fact use some of the dimensions of the Olds gasser blocks for expediency. So what. A Ford/Navistar 7.3 PSD uses the same basic dimensions as an older IH industrial gasser. No one complains about that.

The problem with GM diesels is the average American is an idiot when it comes to automobiles. They expect appliance-like utility without maintenence. I am willing to bet that most problems with GM diesels were operator error. They didn't properly treat the fuel in winter so it gelled. It didn't start so the hit it with ether. They they are shocked it it pukes the headgasket or bottom end.

Lets also consider the price of a GM diesel relative to a MB of the time. My '84 300D cost $32,000+ new. I know, I have the window sticker. I also remember as most of you do that the average domestic car in 1984 cost right around $12,000. So the MB lasts 300K. It should, its three times more expensive! Everyone expected GM to produce the perfect diesel the first time around and at a very low relative cost. This "failure" of the GM diesel is only partly GM's fault. RT

t walgamuth · #45 01-19-2006, 10:01 PM

but my uncle, and engineer and car afficianado, i guarantee you did not abuse his diesel or run the oil low or too long.

tom w