Hey everyone, I hope you're all doing well. I got myself a 88 Celica AllTrac ST165 Heres a little background on the car. I bought it from a guy who had swapped the stock motor out for something newer, in this case a ST185 engine. Anyway he had modified the ST165 engine harness to work with the ST185 ECU (and unfortunately didn't use an adaptor). After I spun a bearing, I decided on getting a new motor. But apparently ST185 motors are pretty uncommon compared to AW20 3SGTEs from the MR2s. SO my question finally is, will a 3SGTE from a AW20 MR2 work in a ST165, wired up for a ST185 motor? I know the engine mounts are different, and obviously I'll be using my old transmission. In terms of wiring though is it pretty much just plug and play? Thoughts on what motor I should be looking at getting? Thanks for the help!
AFAIK everything mechanically should be the same. The block will still have the holes in the rear to mount the center differential from your transmission. I think a few differences were the location of the alternator and motor mount placements but the brackets can be swapped with your existing motor as all the holes are the same. Essentially just take the longblock from the AW20 gen2 3SGTE and swap all your accessories, brackets, motor mounts, etc. Would be a good time to also go through your wiring to make sure everything is good to go.
st205 engines are pretty cheap and more a direct swap, i have an mr2 turbo and a st165. you are better off with the st205.
The SW20 (no such thing as an AW20) motor is the exact same thing as the ST185 motor. The only difference is the lack of a TMIC. It uses a side mount IC instead of the top mount. I agree with above. The st205 motor should be a better bet. The mr2 mounts are not all the same as the celica ones