Finny engine interchangeability

[roflwaffle]

Provided I have all the engine mounts/transmission, can I swap the the I4/I6 gas/I4 diesel engines between chassis', or were there differences in the points where the engine mounts bolted up between the different engine types?

[cth350]

Little things will cause speed bumps.

The hard points in the car are consistent, but the width of the blocks aren't. For instance swapping out the M180 in a 230/8 for the M130 from a 250/8 means a motor that's 1/2" wider. A tig welder and a muffler saw is needed to shorten one on the aluminum struts to fix that.

If you have a four-speed shifter that you want to move from a 4-cylinder to a 6, you'll soon realize that the shorter (longer) block means needing shift rods that have a different length.

All the carb'd 6 cylinder cars have pretty identical exhaust manifold ports. The FI cars are different. I presume the diesels are also different. Using the correct front pipes welded to any rear half of the exhaust (watching for single/double pipes) should do.

Automatic transmission valve bodies and govenors are matched to the engine characteristics, but with a reasonable tolerance band. So a 220se and a 230sl can use the same transmission (I think), but a 220se and a 250se can't (or at least shouldn't). At least the bolt patterns match up so the transmissions are interchangable.

Unless of course, you have an M189, which doesn't bolt up to anything, nor would one want to marry that crazy engine to anything.


None of these problems are difficult to get past. In most cases, having the donor car on hand is all it takes.
-CTH

[roflwaffle]

Shoot, I won't sweat the small stuff. So long as everything can bolt up with a little bit of alteration I'm golden. Otoh, I'm not too keen on making engine mounts and all of that since I could just as well drop in a newer engine. Thanks for the help!

[Mark DiSilvestro]

Originally Posted by cth350

Little things will cause speed bumps.

The hard points in the car are consistent, but the width of the blocks aren't. For instance swapping out the M180 in a 230/8 for the M130 from a 250/8 means a motor that's 1/2" wider. A tig welder and a muffler saw is needed to shorten one on the aluminum struts to fix that.
-CTH

I wouldn't mess with the aluminum struts.
1/2 inch wider translates to only 1/4 inch per side. If I was replacing an M180 with an M130 six, I'd try to relocate the mounting holes in the subframe. With the 220 mounts, you might even be able to get away with using one existing hole with each mount and redrill the other by rotating the mount slightly.

[cth350]

given a choice between welding new bolts to the subframe or cutting the aluminum arm and rewelding, I went the aluminum welding route. The tig weld lasted longer than the motor did and cost me something like 20$ at the time and was done with the engine in the car (which is how I discovered the arms were too long). -CTH

((No, the welding wasn't done under the hood. Not with all that oil and gas present; just the fitting of the part to make sure the lenght and alignment was correct.))

[Mark DiSilvestro]

CTH,
Did you use the M130 mounts with the M130 engine or the M180 mounts? That might make a difference with the location of the subframe mounting holes.
As I recall, the pressed-steel Fintail subframes have captive nuts spot-welded under the sheet-metal. I figure that the average person might not have tig-welding experience, or access to someone with the experience and equipment to reliably modify those arms.
It should be a simple matter to lower the engine in place and mark the spots where the new holes need to be (At least with the carbed engines), or measure beforehand and predrill the holes. The Fintail subframes already have access holes under the mounts to provide clearance for the engine-mount safety-bolts. I'd make some new captive nuts out of bits of 3/4 x 1/4 bar-stock, then pop-rivet them in place.

Happy Motoring, Mark