What is the difference on the Jspec engine compared to the aspec? Is there more power, better internals, longer lasting, or what? I have a 87 TII and was thinking of puting in a jspec motor but want to know what the positives and negatives in doing this.

 

I'm pretty sure they're the same as far as the short block is concerned. But you'll have to pull all the intake stuff off and put the a spec ones on to pass emissions, plus they're slightly different. And the oil pan has 2 sensors on the a spec and 1 on the jspec so you'll have to change that too. The negative is that it's a used engine and the positive is the price and you'll get a long block(extra parts). I did the same swap this year with a jspec and in retrospect I should have just gone with a rebuilt mazda motor, the jspec only lasted 3000 kms, so now I have to buy another and didn't save any money anyway.

 

I'm thinking of buying a 91 jspec for my 87 tII. I know I have to swap alot of parts off of my engine to get it to work. My question is will all of the motor mounts match up? ALso with I believe the oil pump. I know mine is mechanical and the new one is electrical. Can I just swap mine onto the newer jspec? Thanks

 

^^

 

The motor mounts will be fine. You can try to get the mechanical oil metering pump to fit on the 91 motor, but you can also just put your 87 front cover onto the 91 motor. Just make sure that you use all of the 87 sensors, etc.

 

Dont even worry about swapping front covers. Dont use the OMP at all. Just use premix (2 cycle oil) in the gas tank. It is easier to do and more reliable at the same time. Remember....2 cycle oil burns much cleaner than conventional oil. I have been using this combo for 2 years and my ish is still running strong. Also...you can run synthetic oil in the crankcase because the OMP is not pumping oil into the combustion chamber.