DPDISXR4Ti
Well-Known Member
I'm contemplating doing a 4.0 swap into a Merkur Scorpio and I'm trying to decide between an engine with the 93TM oval chambers or the 95TM heart chambers. You can read about it elsewhere, but in short, the 95TM-AD casting that came out in ’95 had the heart-shaped, fast-burn chambers that shrouded the intake valves.
The data is a little sketchy, but it seems from what I've read that there was a 8HP drop (160 to 152) in performance from the later 95TM-headed engine. If true, that should make the decision easy and the answer is to go with a donor from a '93/4 Ranger or '95/6 Aerostar with the 93TM heads. But I haven't read anything reputable that really discusses why the changes were made (probably emissions-driven) and if it did truly result in a drop of power output.
The data is a little sketchy, but it seems from what I've read that there was a 8HP drop (160 to 152) in performance from the later 95TM-headed engine. If true, that should make the decision easy and the answer is to go with a donor from a '93/4 Ranger or '95/6 Aerostar with the 93TM heads. But I haven't read anything reputable that really discusses why the changes were made (probably emissions-driven) and if it did truly result in a drop of power output.