Please don't laugh me off the site, but Has anyone converted the actual gas engine to diesel. Not a engine swap but convert the original engine. Wasn't GM's 5.7L from the late 70's pretty much a converted gas engine. I know it was not a very good engine at first. Also what about the inline 6 from Datsun? How similar is that to the gas 240z engine?
My thought was to maybe sleeve a gaser to reduce the displacement, shave the block to reduce some more, and get the displacement down enough, then use diesel rods and pistons from smaller diesel, and just enough compression to make it run, and not blow up
Well just a thought.
I am about half way through putting a benz 617 in a jeep cherokee. the conversion has been fun, but I wonder how it will drive after all the front suspension mods I am going to have to do. and it seems that there are not too many people still driving the jeeps that have been converted

any thoughts

 

GMC did make a diesel 350, I believe. It wasn't very good, at all.

I think trying to convert a gas to a diesel would cost way more than just getting a diesel that fits. It would also be a huge headache. If something didn't fit just right, you would have to make the piece again. Custom = $$$$.

 

ok this is all pretty much for the fun of the project, and I am tinkering and spending money anyway.
Don't take this the wrong way, but on the fun side look at all the stuff $ you have put into your truck. Engine rebuild parts for a smaller diesel are not that expensive, at least for the benz. new liners for the benz are $35 each I think, injector pumps are pretty cheap as well. or you just buy the whole car/truck wrecked for the parts you need, and sell the rest. most of the time for more than I paid. I have 2 jeep blocks, 2 benz engines, and a vw just sitting in the shop already,
As far as PIA factor, I am going to have to pretty much completely refabricate, or just straight fabricate a whole custom , steering system, and exhaust header, and some suspension, to get the benz into the jeep. or spend the $ for pre made aftermarket parts.
after all we are in the converting business.
If I wanted a 3/4 ton dodge diesel, I would just buy one. Don't get me wrong I love dodge diesel's, but they are just too much truck for my needs, He%% the one I had was almost 20 feet long

 

When I was a little kid my parents bought a 82 olds 88 with the 5.7 diesel. I blew it up at 290,000 miles when I was 16 .

It got awsome fuel mileage, power was ok

 

We had one too when I was a kid, my folks drove it all the way down to South America and back. My dad put Air shocks on the back and he had a giant filter funnel for South American dirty fuel. With the shocks in the back aired up it was lifted pretty high. I remember he let me drive it through the field to test its off road capability before they left. I think ours was a '79- or 80 model

 

from what i heard, the GM 350 failed mainly because the block was not strong enough and developed cracks. i believe this would be an issue with many other gas engines too.

what about the GM 8.1L engine? would this one be strong enough the convert? put injectors in where the plugs went and install some high compression pistons.

ARP studs are likely mandatory as stock bolts would probably stretch too much and it would blow a head gasket

this would be a fun test with a lawn mower engine

 

if my memory is correct gm made 2 engines that used to be gassers the first 5.7 was an olds block and the v6 was a gasser before I think it was a pontiac

sounds like a fun project to play with expensive but fun

now back to those gm engines this is my personal feeling if gm had kept out of the diesel market in the late 70's and early 80's we would be all driving them I had a 82 datsun diesel 720 pickup it was great wish I had it again but at 400k it was shot

one of the biggest issues back then was in the winter 0 degrees and below our fuel gelled up bad most everyone ran #1 and then wrapped filters with heater hose to keep them warm I can remember many days I would just let that datsun run so I didn't have to worry about it gelling up

the gm engines were real bad for gelling up

 

my understanding on the GM 5.7 was that head bolts did stretch, and they fixed it with i think ARP studs and it also had some lower end problems. A lawnmower is not a bad idea. but I think i would just start with a car engine.
I personally was thinking about the jeep 4.0. As it seems it would be easy to sleeve down. Also I don't want a giant engine.
Yes put the injectors in the plug holes. I am pretty sure GM drove the injector pump from the distributor. One of the bosch VE pumps might be adaptable to that drive area.
Also on the jeep there is some mod the stroker guys use to beef up the bottom end. I think they call it a girdle. The stroker race guys also run pretty high compression 14:1 or a little higher. I don't know what the highest compression achieved in a gasser is. but I think diesel compressions on the low end are 15:1 and up.
Well this is a project for a bit down the road. I need to get the OM617 finished in the jeep, I just wanted to talk about the possibility a bit, see if anyone had any other ideas.
Did any manufactures build a straight six or v6 with 4 bolt mains. I think that would be important to keep the lower end together. Is there any way to figure how much diplacement reduction would be required to keep the diesel forces the same as the original gasser. If we are still talking about a jeep/benz. using mercedes bore and stroke in a 6 cyl would take the jeep from 4.0l to 3.5l, which does not seem like much of a reduction.
any body know how to modify rod bearing journals on a crank?

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oops I made a error in my math. The jeep/benz bore and stroke from the om617 in a 6cyl would be 3.6l my bad. but if you used a OM606 then you would get down to 3.0l. So I guess what I am driving at is maybe you could use OE components, just from another engine.
I have a friend from way back when we were kids. He bought a racing Honda CVCC, that must have had over half a dozen different engines components installed So many it was hard for him to keep track of when it came time or overhaul. That was a pretty fast little car pretty reliable too

 

there are a lot of diesel engines that use sleeves not just Mercedes and even some of farm tractors did also Cadillac engines use them also

I have a friend that used to work at a dyno shop that built dragster engines he is retired but I bet he could shed some light on the crank issue

could you use the jeep crank would it be strong enough was there a forged crank made what about the old rambler engines there must still be some around to play with what about making it 4 bolt mains

how much difference is the cam and would you have to have a special one made

could you put on a turbo like the om617a has not to big

you go me thinking now my head hurts

 

well I went looking for a forged crank, and then that got me to thinking about the Stroke length. And that is going to be the hard or hardest part I think. There are a few different cranks that will fit in the jeep 4.0. maybe even one of them has the correct stroke. But I could not find it easily. There are few easy options to increase stroke, but the ones to decrease I am not sure about.
There is just a whole bunch of stuff to try and source. The old cranks I was looking for were from the early '60's. Kind of funny I thought to be looking for a Forged 7 main crank for a 199 cu in. AMC straight 6 from 1965. And I am not sure it will even fit the 4.0, or the 258.
Yes Deck60 the Rambler is the crank I would be looking for I think. I also thought about making 4 bolt mains as well. That might not be too hard. Another hard part would be trying to find a diesel con rod that would fit the new jeep crank.
It really would be a pretty huge project, with tooo much stuff to think about.