Force 120 blocks

[ut_tran]

Ok another newbie question:

Are the engine blocks and cylinder the same for a 1990 and a 1996 force 120? In other word, can I use the engine blocks from a 1996 force to rebuild a 1990? I have twin 1990 force 120 motors one is bad. And I have a complete 96 force 120 power head. I was hoping to use the blocks from the 96 to rebuild the 90. Any suggestions?

 

[Frank Acampora]

Re: Force 120 blocks

The MOUNTING bolt pattern is the same and the bore and stroke is the same, BUT the crankshaft splines are different and there may be an extra boss on the 96 block for Mercury type shift linkage.

If you swap cranks it MAY be possible to use the 96 block on the 90 leg, however, you may also need to use the ignition from the 96 block-- Never having rebuilt a 96 120 and never tried a swap so could not get more specific.

 

[ut_tran]

Re: Force 120 blocks

Frank- Thanks for the info. Sounds like it would make for sense to use the newer 96 motor and swap cranks from the older unit. Pray this works. Any body out there that could enlighten me with this process would greatly be appreciated. Has anyone done anything like this? Will this work?

 

[Faztbullet]

Re: Force 120 blocks

The bore and stroke are the same but thats about all... The 96 uses a totally different rod(top guided), piston,rod bearing,wrist pin brg,upper bearing housing and seal and gaskets. You may be able to swap the pistons and rods from the 1996 to the old (1990) crank but you will need to use the 96 ignition due to different upper crankshaft difference. The 89-94 crankshaft is 1.200 and the 95-99 is 1.390...also check to see if block has mounting holes for the pull /push shifter like the 1990 block, if not back to square one....