HT4100 4.1, 4.5, 4.9 Discussion, swap 4.1 to a 4.5 or 4.9 in 85 Seville? in Cadillac Engine Technical Discussion; OK, I posted this in the Seville section, but thought this might be a better spot for it. I know ...
OK, I posted this in the Seville section, but thought this might be a better spot for it. I know this is kind of an odd question, especially since so few of us seem to care about this model ..but I'm thinking about getting a bustleback Seville, I know the 80 is the best for engine, but I prefer the looks and equipment of the 82- 85, plus, of the few I see that are still around, I see most of those years.. here's my question.. is it an easy swap to put a 4.5 or 4.9 engine into this car? , particularly an Allante 4.5? ( 89 to 92) or just a seville or eldo engine from the late 80'S ? my thinking is the added horsepower and the fact that most of the bugs were worked out by this time would make this engine a good upgrade..What do you think?
The 85 seville is a longitundinally-mounted FWD car. Swapping in a 4.5 or 4.9 really isn't feasible. Too many transverse engine differences, and you'd need a new computer and wiring harness. What would be feasbile is for you to find a 6.0L from a 1980 or 1981 Seville, a 5.7L Olds FI V8 from a 1979 Eldorado, or just a plain, old Olds 350 V-8 engine. You might even be able to swap a 425 ci or 500 ci Cadillac V-8 from an older Eldorado into your Seville using your current transmission, but you'd need to beef it up. Not sure if the 425 and 500 ci are physically bigger than the 368 ci engine, but some modifications would definitely be necessary.
I'm in California, if it didn't come in it when it was new, I can't do it now and use it as a regular driver legally, due to emission laws 82 to 85 only offered the lousy diesel, the 4.1 and the V6( I think)
Automobile(s): 1988 Allante' (sold), 1984 Eldorado, 84 Sedan DeVille
Re: swap 4.1 to a 4.5 or 4.9 in 85 Seville?
4.5 and 4.9 use completely different engine block castings, wont work! You can however install the throttle body from an 81 Cadillac 8/6/4 368 cu. in. engine that has larger throttle plates, reattach your TPS switch and your injectors from the original and get the one inch spacer from JEGS speed shop for a throttle body Chevy truck engine. The spacer is required to allow the throttle blades to fully open. Then bump timing from 10 to 12. Did this mod years ago on my first 84 Eldo. It would actually chirp the front tires leaving a stop light!!
There use to be a couple of places online that sold 4.5L that would mount in this situation. You could not use the MPFI system. This system was built with the 4T60-E in mind, which is electronic. The DFI system would have to be used and you would only see some minimual gains. Well I guess not to minimual the DFI 4.5L was rated at 150 bHP, not sure that you would see the same in a different mount. In the terms you are talking about, junkyard swapping, neither would work as just a drop in conversion.