Anyone heard of anyone putting grandcherokee 6cyl engine in a 1946 plymouth business coupe, due to all the regulations in Sweden i can not go for 8cyl and keep the original pappers. These engines Run strong and are quite cheap here so it would be great fitting one of those. Grateful for all answers and tips. Cheers.
On some of the 4x4 Offroad websites, there's a lot of good info on building up the Jeep inline 6's. Definitely worth some research. They share a lot with the AMC 256 engines of the 60's and 70's, which might be helpful if you're trying to dress the engine up to look more period, you should be able to run a carburetor on one. You may even be able to use the Jeep rear axle since it shares the same bolt pattern as your Plymouth.
Really great engines in my experience. I have tons of miles on them on the road and a fair amount off road. The 1991 model and later are the HO versions and a better choice if you have a choice. They do have sequential port fuel injection, but the manifold could probably be modified to accept a carb. 1999 and later Cherokeemhave some really cool cast exhaust manifolds. Prior to '99 the manifold is tubular stainless, header like and prone to crack with high miles, but easily replaced. They share almost nothing with the earlier AMC engines from which they were derived. However, that said, the 258 AMC crank can be retrofitted to a 4.0 and get near 5.0 (300 cubes) as I recall. The stock 4.0 though is no slouch. They came with Aisin Warner 4 spdOD trans or AW15 Manual 5 Speed (in both 2 and 4 wheel drive) and can be fitted with a 904 Torqueflite with some parts swapping.
Good engine but much longer than the old sidevalve six. Could be a problem squeezing it in under the hood, unless you cut a hole in the firewall. I am surprised you haven't considered a BMW or Mercedes six. Either would be better than the AMC and should be easy to get where you are. If you chose a Mercedes they would be related by marriage, just like the AMC. Since Chrysler bought AMC and Mercedes bought Chrysler. Engine swaps in Chrysler products of that vintage, run into certain problems related to the fact that they were designed for six cylinder engines. The steering box is quite close to the engine, and the engine was not very long. So the steering box usually interferes with a V8 swap and engine length is a problem with straight sixes. Even a slant six is longer than the old flathead, and they are not a long engine as sixes go.
Since the MOPARS built in Canada, and perhaps for other markets, used the 2" + longer Desoto/Chrysler block based 6 cylinder flatheads, I don't believe the marginal extra length of the Jeep 4.0 would be a problem. Radiator can be moved forward enough to accommodate it. Further, I've owned BMW sixes and I wouldn't call them "short".......I would call them a wonderfully smooth and powerful engine for their displacement.
Not sure bout those motors but a dana35 is a good option for the rear its the same bolt pattern and width. But geard for highway speeds Posted using the Full Custom H.A.M.B. App!
Can't speak to the fit, but as others have said it's a great motor. Run a few of them w/the rockcrawlers i've had. Beat them like they owed me money and never had a lick of problems. I see them regularly with 250-300K miles. Fun little motor when backed w/a manual transmission.
So wich BMW inline6 would you Guys recommend to use in the Old coupe, we have longdistance driving almost evereywhere we are going. Cheers.
You have to use your own judgement. How much power do you want? How much room do you have? What engines are available? Is economy important? If it was my car, I would first try to use the original engine. If it was long gone, or the rod was sticking through the bloc, I would look for a replacement. Only if I could not find a suitable flathead, would I look for a different engine. At that point, I would take some measurements and some pictures of the original engine and engine compartment. Then go shopping in junkyards. I would try to find an engine that would fit with minimal headaches and have the required output without overpowering the original chassis. Look out for things like starter and exhaust interference with the steering, these are 2 common problems. Motor mounts can be made without too much trouble. Things like mounts, wiring, throttle linkage etc are all part of the swap process. The original engine was about 3.5 liters and 100HP. I would look for an engine of similar dimensions and about 200HP more or less. When I found a suitable candidate I would try to buy a complete car. One that has been in an accident, with a good engine that I can buy for a low price. Then I would have engine, transmission, radiator, throttle linkage, wiring, and all the other small details in one package. I would consider Volvo, Mercedes and BMW inline six, or V6 type engines. You would know better than I would, what kind of rear wheel drive cars are available where you are.
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