Good gear ratios for a Diesel?

[Christ]

H.E.A.V.Y

Naw, but seriously... it's all I can do to lift that thing... for comparison, I can lift a D-series Honda engine and carry it on good days, in my arms.

I lifted this OM636 up with a chain around my neck/shoulders on a small pad, and it was all I could do to stand up just to get it to swing where I wanted it, cuz walking with it wasn't an option.

I'd have to chance a guess around 500#.

Reason for choosing the OM636 - it was free.

So could I build more low-end with the 636 by adding a small turbo? Small as in IHI RHB5-VJ11 (OEM on a 2.2L I4 Mazda 626 GT... or I have a OEM T25 too... would either of those work without an intercooler, and without serious mods to the injector pump?

[Christ]

For comparison, these are the Ratios used in the 'Cedes 170D (1949-1955) which also used this engine:

I. 4.025:1
II. 2.280:1
III. 1.420:1
IV. 1.000:1
Rear axle ratio - 4.125:1 (spiral gears)
And 5.50x16 tires.

It weighed in at ~2800#, and had a top speed of 62 MPH, which was achievable in 59 seconds.

I've been going with 170D specs, which may not be correct at all, since the engine is from a Thermo-King reefer unit... I have yet to be able to get anyone from Thermo-King who was willing to look up the details for me, or even email them to me, so this is all I have.

[Christ]

There is an easy way to change ratios in that transmission, using the transfer gears on the side (accessible without pulling the trans). I'm not sure what ratios I can get, but I was reading up on TurboDodge.com about the transmissions and available ratios, and depending on what transfer gears I end up with, I can go a bit deeper with not too much trouble!

So if I find that those gears aren't helping me out at all, I can always go deeper or more shallow with relative ease.

BigDave - Any idea if I could turbo this OM636 for a boost in power (at the cost of a little more fuel, obviously)? I mean, if it doesn't have enough torque, it's at a 19:1 CR from what I read, so maybe I can get a bit more pull out of it with a small turbo?

[Big Dave]

I'm sure if you have the money and time and fab skills, you could probably get a turbo to work for you. How long the OM636 stays together with a turbo...you're on your own.

This engine was designed to be a 25-40 HP motorsailer engine. It would probably stay together OK operating at maybe 70 HP. Get a small motorcycle-sized turbo that spools up quick but won't overboost the engine. What is the overboost pressure of a OM636? I dunno. Most people think 15 psi boost is all a OM617.95x will take.

Be sure to get an injection pump made for automotive service. That reefer motor probably has an industrial injector pump and the vehicle will have weird throttle response.

Unless you intend to do nothing but city driving with Cara, a OM636 may be a bit too small.

On one of the M-B forums a gut put a 617.952 engine in a Chevy pickup and the MPG was worse than the stock 350 gas engine. He had to drive like Dale Earnhardt, Jr. just to keep up.

Cara is lighter than that pickup. Maybe a 617 might be better. 617s work well in Rangers and S-10s.

[Christ]

Well, I can handle driving at 50 MPH and no higher, since that's what I usually do anyway.

I wonder though, if it wouldn't be a better idea to get a smaller car or use the OM636 for a tractor or something, and wait it out for a different diesel engine, and see if I can't just make Cara a E/Gas hybrid or something...

IOW - I'm getting cold feet.

[Big Dave]

If your feet are the least bit lukewarm, do something else. Engine/tranny swaps are daunting for experienced hot-rodders. diesel just complicates things.

[Christ]

It's not that the engine/tranny swap is outside my skill range, I've done plenty of them between Honda and Ford and Chevy and blah...

The problem is, now that I'll have a truck on the road, Cara is just "another vehicle"... and my wife won't drive her, which means that she's just "my other vehicle"... a luxury I prefer not to have, honestly.

We have another car which we can use to haul our Son around in, and I can probably get about $2500 out of Cara, which is enough to buy another $200 truck, another small car, and possibly a Ninja 250 or a scooter.

Frankly, once I get The Taco road legal, Cara is "better as cash". Pains me to say it, but if she's not helping me, she's hurting me, so I'll probably sell her to another owner who will have more use for her, and sport the OM636 in a much smaller, lighter chassis.

Maybe a 240SX or something?

[rmay635703]

You might consider dropping it in a subaru 360 sedan, truck or mini van. They are relatively cheap, easy to fix and probably easy to mod. Best yet they weigh +/- 1000lbs with motor and their gross vehicle weight is around 2100lbs which you could up if you wanted by changing the rearend.

I and several other of the 360 folks would love to see an 80+mpg subaru 360 diesel conversion, there are several motorless rigs laying around, might have to ask the group to see if you can get one cheap. Remember the stock motor was only 25hp on a good day, your diesel would fly.

You would have to EXTEND the rear end to fit the motor and probably install a radiator in the trunk area on the front of the vehicle, but it wouldn't look as bad as the 350 volkswagon up the street.

Cheers
Ryan

[Christ]

Originally Posted by rmay635703

You might consider dropping it in a subaru 360 sedan, truck or mini van. They are relatively cheap, easy to fix and probably easy to mod. Best yet they weigh +/- 1000lbs with motor and their gross vehicle weight is around 2100lbs which you could up if you wanted by changing the rearend.

I and several other of the 360 folks would love to see an 80+mpg subaru 360 diesel conversion, there are several motorless rigs laying around, might have to ask the group to see if you can get one cheap. Remember the stock motor was only 25hp on a good day, your diesel would fly.

You would have to EXTEND the rear end to fit the motor and probably install a radiator in the trunk area on the front of the vehicle, but it wouldn't look as bad as the 350 volkswagon up the street.

Cheers
Ryan

I briefly considered one of those little utility trucks that they use in factories and warehouses...

[cfg83]

Christ -

Originally Posted by Christ

...

Frankly, once I get The Taco road legal, Cara is "better as cash". Pains me to say it, but if she's not helping me, she's hurting me, so I'll probably sell her to another owner who will have more use for her, and sport the OM636 in a much smaller, lighter chassis.

Maybe a 240SX or something?

That makes sense. It would be fantastic to see a diesel 240SX. You have a good aero-model-example in that photo-shop image on the other thread. Would the engine fit in a CRX?

CarloSW2