[termidore2004]

I have a 1985 Fleetwood hearse that had an HT-4100 engine in it. Well the engine is toast and I would like to replace it with a larger engine. Can anyone tell me what other engine I can fit in it, whether Caddy or other GM. Thinking like a 350, 454----something with more power for this big car.

Thank you for your help,
Jim

 

[pcm]

the easiest would be a 350 1990-1993 broughams had them in them if you can find one for parts

 

[cadillac kevin]

there are many many choices for the car
theres the Cadillac 368-425-472-500 family. all provide good torque for getting the car moving, but the 425-472-500 are torque monsters. and the 472 and 500 will keep you moving. a 500 would be my choice if I could afford 8 mpg. all the cadillac motors will need a turbo 400 trans. changing your rear diff to something stronger is recommended if you have the 7.5'' diff.
then theres the Oldsmobile engines
307
goods- decent highway acceleration (50-70), 15 mpg combined when in proper tune, vin 9 motor has 180 hp- can be tuned to put out roughly 220-230hp and maybe 270 ft/lbs (fuel mileage will suffer) without opening the engine. they're quiet! and reliable as all get out. a low output workhorse. you can also keep your trans.
bads- 0-60 in 13 seconds for a sedan. open up the secondaries and your mileage is DOA. all the damn emissions hoses (my biggest gripe about them)
350- the 307's bigger brother. the 68-72 motors are good for 300hp and 370 ft/lbs. when rebuilt bone stock.
the mileage is a couple mpg worse than the 307. you can keep your trans, but don't romp on it too much, else you'll burn it out in a while. a pre '73 olds 350 provides a good combo of power and mileage.
403 small block- better mileage than the 455. good for 190 hp and 320 ft/lbs stock. motors themselves are tough to find unless someone pulls one out of a trans am. requires a turbo 350 trans. has good performance potential , but parts are costly.
455 rocket- awesome power. 400 hp in pre '73 versions. 510 ft/lbs of torque!!! enough power to make your hearse get up and go with alot of authority. will need a turbo 400 transmission (3 speed auto) and a beefier rear end if you only have the 7.5 inch rear diff.
chevy motors.
305 better power than the 4100. decent mileage (15 mpg roughly, maybe a little more). in my experience, the 305 doesnt move big cars around as well as olds motors. you will need a 700r4 trans. parts are cheap and easy to get
350 small block. cheap, 15-18 mpg combined. plenty of torque, but not as much low end grunt as the olds. pre '73 heads flow better. tons of aftermarket support. this is your best option if you're on a shoestring budget. you will need a 700r4 trans. IMO the best motor for mix of performance, mileage, and cost.
454 big block. great low end torque. post '73 motors dont have much top end power. its a gas hog no matter what you do to it. will need a turbo 400 trans and a beefier rear end if you have the 7.5'' rear diff.

 

[sven914]

the easiest would be a 350 1990-1993 broughams had them in them if you can find one for parts

Actually the easiest would be a 307. The 307 used the same transmission as the 4100, and being a carburetor engine he wouldn't have the mess with computers to get it to run.

 

[outsider]

well 307 does have a computer controlled carb...atleast on my '87

 

[sven914]

Yeah. But the computer is useless and with a few simple modifications, can be successfully disconnected. You're never going to get a TBI engine to function without the ECM.

 

[cadillac kevin]

IMO, get a 350 chevy truck motor and a 700r4 and call it a day.
you can easily get 300hp out of them with a RV style camshaft, headers, and intake. the factory motors were very detuned and made 200hp. the GM crate 350 makes 300hp without accessories and the only performance bit it has is a mild camshaft.
the accessory brackets from the 90-92 fwb with the 350 will work so you can keep your A/C (you will need to change the pulley though)
if you are having a shop do the work, make sure they have a warranty on parts and labor for engines and transmissions (they won't warranty the parts unless they buy them though.)

 

[[email protected]]

IMO go for the BB olds .425 or 455 .My guess is that with the weight of a hearse your mileage would be no worse than a 350.Heaps o 455 parts I see on the olds sites and in craigs n ebay. If you have a 7.5 diff you are going to have to change that out ( mind in a hearse I wonder if the diff is not an 8.5 or similar --don`t know but if so that will be fine ).And you will want a th400 which means you will have no overdrive .Go a bit more modern and you will get overdrive but pay a bit more too .
307? Has to be better than ur 4100 ,is reliable but needs ugrading imo for pulling a hearse. (what were gm thinking putting a 4100 in a hearse ?? must have some real high diff ratio I am guessing
Chev --well , it`s chev isn`t it .Sorta like instant coffee when you want a good fresh ground bean.Nothin wrong with em ,just common .

 

[jayoldschool]

If it is a hearse with a 4100 in it, GM DIDN'T know it was going to be a hearse. It started life as a regular passenger car. If the coach builder had ordered it properly, it would have come with the 368/TH400 combo. Yes, these were still available in the 4100 years, for the exact reason that GM knew the 4100 wasn't up to any heavy duty work.

 

[intragration]

A 4100 in a hearse. Wow. If I'm not mistaken, the Olds 403 was pretty common in the late '70s, I think it was in everything from Olds Toronados to 88s and 98s to Buick LeSabres and Electras and wagons. Some A-bodies too. There are a couple motors on E-Bay right now, used and crate. I don't think a low-output motor is going to destroy your rear if you take it easy. Hard launches are where you'd have problems I believe. Any swap is going to be a can of worms.

 

[sven914]

Are you sure it's a Fleetwood hearse (not that it matters much). During the early 80's, a lot of the coach builders made professional cars (limos, flower car, and hearses) from de Ville's instead of ordering a commercial chassis or going to the trouble of hacking up a Fleetwood.

 

[termidore2004]

Are you sure it's a Fleetwood hearse (not that it matters much). During the early 80's, a lot of the coach builders made professional cars (limos, flower car, and hearses) from de Ville's instead of ordering a commercial chassis or going to the trouble of hacking up a Fleetwood.

Definitely a Fleetwood

 

[termidore2004]

Actually sounds like a lot of options--lot to consider