: 1990 Cadillac Brougham 5.7L V8 Engine Question



xairplanedriverx
12-18-08, 12:56 AM
Hello everyone :)

I'm looking forward to getting my first Cadillac. I found one for a pretty good price of $800 down the road from where I live. It needs a fuel pump, a battery, and a new windshield if I wanna pass inspection. It's cracked from left to right- sadly. It's been sitting for a year or so but is in MINT condition. Anyway- that was just some background info. So like in the tile it's a 5.7L V8. I went on google out of curiosity to see how much horsepower that thing has (expecting something in the 300-400hp range), while all the sources list it at 175-185hp! Big surprise... My old Infiniti has 200hp on a 3L V6! How is all that horsepower limited?? How to get rid of that limitation?? Those are my two main questions. If I'm to have a V8 Caddi I really want to let it breath not have it restricted to the max. Afterall those things should be able to go up to at least 300hp I suppose it's all probably all of the emissions restrictions but professional opinion would be greatly appreciated.

Thanks,
Jake

ShadowLvr400
12-19-08, 09:14 AM
From what I found, in 1990, I just see a 5.0L V8 with 140 horses, 255 torque. However, that site could be wrong. The reasons for such low power, 1, it's a low compression engine, likely in the 8:1 ratio. 2, the heads and intake aren't designed to flow high volumes of air, they're designed to keep the engine smooth and quiet. 3, the engines just aren't tuned to create a lot of power. However, be comforted by the fact that the 5.0L and 5.7 from GM both have loads of aftermarket support, so you should be able to beef up the engine for cheap. One thing to remember when doing it though, in a vehicle that size, torque means more than horsepower. My 96 Fleetwood is only making about 310 horepower, but the torque it's generating is closer to the 400 mark, which is why I run a 14.6 in the 1/4 mile and have a 60' of about 2.2. (Pretty lively for a car with a race weight of 4840.) To make more power on your car though, first thing is a freer exhaust, then a freer air intake. Those 2 alone will probably give you 10-30 horsepower and similar torque. (Depends on how choked down they are on a 90 Brougham.) After that, you have to decide how much more you want and how much you want to spend. An 8:1 compression is a nice base for forced induction, but an engine almost 20 years old, that can be a problem. Just plan ahead.

96Fleetwood
12-19-08, 09:41 AM
Hello everyone :)

I went on google out of curiosity to see how much horsepower that thing has (expecting something in the 300-400hp range), while all the sources list it at 175-185hp! Big surprise...
Thanks,
Jake

These cars were not aimed for speed or agility, the customer base wanted a smooth comfortable ride with some torque.

The TBI motors of that generation are very restricted. A TPI setup would open up some HP and get you over 200. The Vortec heads are also another option.

Go over to some of the third generation fbody forums and ask around. There are plenty of ways to get good power out of a SBC.

VortecCaddy
12-19-08, 07:15 PM
Stroke it out and throw some good flowing cylinder hads on top. Top it off with a set of headers and some computer work. The possibilities are endless. It just costs money to go fast. Like was said before, check over on the thirgen.org site.

xairplanedriverx
12-20-08, 05:52 PM
Thanks for the replies. I figured a turbo wouldn't be such a bad idea- a double turbo. The car has 96000 miles on it. If I want to add more power (torque that is) I'm gonna have to rebuild the engine first and follow that with rebuilding the transmission too. First things first. The exhaust will be taken out as it's all covered with rust anyway. I'm gonna make a custom one myself. I could add high compression pistons but than the turbo is a no no. I think I will rather go with the turbo after the engine is rebuild.

I don't wanna start another post so I'll just ask here if it's a good idea to swap the tranny to a manual. I've been driving stickshifts all my life and I just love them. If I could swap a good tranny in instead of rebuilding the automatic, it would be great. A lot of work but well worth it. The questions is what tranny to put in there that will go together with the engine hehe.

ShadowLvr400
12-21-08, 10:27 AM
I would not recommend a stick if you plan on dumping a lot more horsepower in. Manuals give nice power transfer, but they're not quit as durable, and especially so in a vehicle the size of a brougham. If you're determined to go stick, look at the corvette sticks, and plan on overbuilding one of those. As for slushies, the 700R4 is a stout tranny, especially when built up, and it mounts to many 350's and 305's.

VortecCaddy
01-06-09, 06:20 PM
I would go with a super charger versus a turbo set up. With the turbo you will need to be pretty knowledgable with tuning your car. Why not put a big block under the hood? If your looking for torque a big block will put a big smile on your face.

Aron9000
01-14-09, 05:17 AM
This is what I would do . . . .

Provided that your existing TBI 350 is running great, doesn't use oil, and passes a compression check, keep it. Put some vortec heads on it, change out the intake to better flowing aftermarket unit, add some long tube headers(ones made to fit a 1980's caprice work), get a true dual exhaust, change out the cam(even a very mild cam will net good gains) and change the TBI to a carb. This will get you at least 300 hp, for about $2000 in parts.

The real benefit of keeping the 350 in place is you keep all your acceories the same and the a/c will still work.

MadCaddie69
02-03-09, 11:08 PM
Unfortunately, I got the 307 5.slow motor in mine. I'm going with an LS1.

Aron9000
02-03-09, 11:35 PM
Unfortunately, I got the 307 5.slow motor in mine. I'm going with an LS1.

Ls1's are awesome. I had a 1999 Camaro with the LS1/auto combo. Even though I was just intake/exhaust, it ran a 13.1@107mph. The powerband was awesome on that motor, lots of torque down low, just explosive from 3k to the redline at 6k. Mine made 305rwhp/320rwtq.

xairplanedriverx
04-08-09, 05:47 PM
Some time has passed and I fixed the Caddy up. The fuel pump is replaced with a new one. Im working on the rusts spots. The engine runs great. It will be rebuilt some time when I have more cash handy. Im looking to rebuild the engine, transmission, and the back so I can dump some 500hp and similiar toque in. That should really make my day. Now its time for the sound system, good clean up, and sweet red interior and exterior neons :)

P.S. For double charge what compression ratio would you suggest?? I was thinking about high 8.