S4 motor in an 86 (s3)

[Yellowb1rd]

Pelicans,

I may be getting access to a spare S4 motor. My question to all of you is this. Is bolting an S4 motor into an S3 engine bay a direct bolt in, or are there modifications that must be made? The s4's have knock sensors, whereas the 85-86 MY do not, so can I use the EZK, and LH from the 86, or do those need to be replaced?

Also, is it worth it to do this?

I would like to hear your thoughts. I've searched, and surprisingly enough, found no pre-existing threads on this topic.

[Danglerb]

Not a good idea, S4 motor generally has some value, so the "best" move is to clean up the motor and sell it to get one that works easily in your model.

You need to swap the brains, which are much less reliable, and do a moderate amount of rewiring. Generally it also lowers the value of the car since its now a lifetime service headache with half the electricals of the S4 and half original.

Search keywords, frankenporsche s4 swap or engine swap.