300GD to 617a

[fezcabdriver]

Hi guys,
I'm in the "research" stage of picking up an 84/85 GD with the hopes of swapping either a 617.952 (w123)or 617.951 (w126) engine. Has anyone on the forum done this?
I've been told if the truck is an automatic, I can just drop the engine in with no modifications. I've heard of moving it forward an inch to accommodate the oil pan, but I've also heard that it won't be necessary unless I intend on taking it out on some serious boulders. Anyway, I have a couple of questions?
1. Any difference in the 617.952 vs. 617.951 engine? I think the .951 has an electric oil pressure gauge? Will that cause a problem.
2. I read somewhere that I need to keep the old thermostat so that the gauge doesn't get confused and report that my engine is cooking??
3. Are there any parts from the donor car that I want to hold onto that might be compatible?
4. Anything else to consider?


P.S. If i'm in the wrong forum...please let me know.

 

[artiei]

I actually drive a 280GE that how has a OM617A engine in it. I call it a 300GD Turbo. I can tell you that once the modification is complete it is a nice ride. I've got a blog about the car but I'll give you some basic info. My engine is the '85 California Turbo with the higher turbocharger. There is no pollution control in mine any more but the higher mount provides easier access under the turbo.

I've got the 280 M110 engine in a 1984 280SL and I got to say, it is a GREAT engine. The power it puts out is amazing!

It will be MUCH easier to upgrade a 300GD to the OM167A than any other version of the G.

My understanding is the transmission between the gas and diesel engines is different. So if you are converting from a 280 you will will need to change out the transmission. Be careful here because if you are going to maintain the ability to drive in deep water, you will need to make sure the transmission vents from the top. Marc at Sun Valley Mercedes Transmissions can help you there.

Upgrade the exhaust to a 3". You will have to get this custom made. For the turbo to work well, you will want to make sure you have unrestricted flow. When My upgrade was done by the previous owner and they kept the old 280 exhaust and used a converter after the manifold pipe. I got a power drop off starting at 3500 RPM. Not good!

Unless you are upgrading from a OM617, you will need a new tachometer and maybe even an amplifier for the 5 cyl engine.

Unless upgrading from a OM517 you will need the entire Glow Plug system.