1992 Force 70HP powerhead exchange

[birdgreen]

I would appreciate advice on the 3 cyl powerheads made from both Chrysler and Force that would work on the above title motor. I'm wondering what range in HP would work and what years those models would to be interchangeable? I hope this makes since.
Thanks:

 

[Frank Acampora]

Re: 1992 Force 70HP powerhead exchange

If I remember correctly, the 70 Force was a "bastard" engine, completely different than any other three cylinder engine except the 75. While any three cylinder block will bolt onto the leg, the 70 and 75 had a single carb and a special boss to mount the shift linkage. Therefore I am relatively sure that only these two engine blocks will swap--not 100% certain, and maybe someone else can either confirm or deny my opinion.

I have a 70 in my garage and have been toying with the idea of mounting a 90 block in it--just to see. There is room for the three carbs if I remove a baffle in the top shroud, and the drive shaft splines match the crank splines. I am trying to figure out what I need to do to mount the shift linkage--perhaps some metal massaging.

 

[birdgreen]

Re: 1992 Force 70HP powerhead exchange

I was hoping to get an older Chrysler powerunit to boltup but was not sure when Merc took over Force engines they might have changed the drive shaft splines so Chrysler powerheads would not interchange.