The 4.2 in my van has gone the way of many, the thrust bearing has failed and the flywheel is hitting the rear of the block due to coolant in the oil before I got it. I am married to this van for the next 2 and a half years (loan) and can not afford the 1800+ dollars for a replacement engine at this time. I am also over the barrel as I need this van for work, my backup van was never ment for day to day use and is sucking my wallet dry (460 V8). I do however have a 95 Thunderbird 3.8 that runs. I have heard that the two motors (3.8 and 4.2) are one in the same. Anyone know if they are so much the same that they interchange? Perhaps as easy as swap the intake and toss it in? Or am I barking up the wrong tree?


Thank!

 

I HAVE SEEN BOTH ENGINES BARE AND THEY ARE HONESTLY IDENTICAL AS A BARE BLOCK. I BELIEVE (IF MY TECHNICAL SOURCES ARE CORRECT) THE 4.2 IS A LARGER BORE INTERNALLY BALANCED 3.8. THIS MAY POSE A PROBLEM WITH THE CRANK PULSE RING BUT I THINK IT IS DEFINTELEY A POSSIBLE SWAP! BOTH PULSE RINGS BOLT ON IN A SIMILAR FASION MAKING IT POSSIBLE TO SWAP THE RINGS SO THE COMPUTER CAN HANDLE THE TIMING.

 

Well your not really barking up the wrong tree here but it's alot more involved then that.

You can swap the shortblocks and be OK but you will have to retain the 4.2's fuel system (I.E. fuel rail) Cylinder heads, Lower intake, upper intake.

The 95 3.8 SC motor is a single port motor while the 4.2 is a splitport so nothing but the shortblock will convert. You would have to use the 4.2 flywheel and both I believe are internally balanced so you could use either the 3.8 or the 4.2 harmonic balancers.