As a new member, I thought I would share this winters project. It is a 84 Fiero Pace car with 500 cubes of Cadillac. A long time friend of mine built this car in the early 2000's, he sadly passed away a couple of years ago and I bought this from his wife. The car had been sitting for quite some time and needs some tlc to get it back on the road. Thought you might enjoy.
As a new member, I thought I would share this winters project. It is a 84 Fiero Pace car with 500 cubes of Cadillac. A long time friend of mine built this car in the early 2000's, he sadly passed away a couple of years ago and I bought this from his wife. The car had been sitting for quite some time and needs some tlc to get it back on the road. Thought you might enjoy.
Sorry about your friend... but I had to laugh at this:
Do you mind sharing his Pennock's screen name?
Looks like he's using a Th-425 w/ Caddy 500 from an Eldorado. I pulled one of those motors (an original 27k low mileage one from a show car in the junkyard that a tree had fallen on). Those engines were sick. They didn't have much RPM... but they had almost ~600 ft-lbs of torque (grossly under-rated), and something like 11.25:1 compression. I don't know what year, but it's possible the Th-425 might even be a "Switch Pitch," which is pretty awesome... (look for 2 pins coming off the torque lockup pin).
If it were my car, I'd probably get rid of the big air cleaner stack, and I'd drop a modern fuel injection system on it and see if I could manage to get a semi-normal decklid back onto it. Any one of those modern fuel injection systems are built just for big engines like this.
Have you been able to drive it? I'd love to know what kind of performance you get from it.
Yes it was Matts car. I met Matt when I was 13, he and built many projects over our 39 year friendship. He could engineer anything. Big loss to family and friends.
I spoke to company in New Mexico that only builds Cadillac engines, he said I only gain about 10-15hp with the performer intake and lose the same or more at the bottom end. So I am going to remove it and just run the factory low intake. If I do that I can get the decklid back on. I have to replace the engine as this one got water in it while sitting, the engine I have is 78k miles low compression version, but with cam and a few other tricks from the Caddii Company, it will be around 380hp and 600 ft pounds of tq. My friend use to street race it in Mpls and seldom lost a race. There are pics of it pulling the front wheel off the ground. Should be fun!
I spoke to company in New Mexico that only builds Cadillac engines, he said I only gain about 10-15hp with the performer intake and lose the same or more at the bottom end. So I am going to remove it and just run the factory low intake. If I do that I can get the decklid back on. I have to replace the engine as this one got water in it while sitting, the engine I have is 78k miles low compression version, but with cam and a few other tricks from the Caddii Company, it will be around 380hp and 600 ft pounds of tq. My friend use to street race it in Mpls and seldom lost a race. There are pics of it pulling the front wheel off the ground. Should be fun!
I highly recommend (if you can) to rebuild that Cadillac 500 engine. Are you saying this is the low-compression version, or are you saying the replacement version is?
Do you know for certain that the engine is bad?
Totally agree about using the Eldorado intake... the extra 15hp is not worth everything sticking out the top. Definitely look into a modern fuel injection system... they have a new HEI computer controlled distributor for those motors. You can get better fuel economy, and significantly more usable performance with modern fuel injection... plus, it'll sit lower with a low-rise TBI unit... or if you can get a custom intake plenum... you can go MPFI.
Weird how back in the day, there were so many people getting banned in the Tech section. There seems to be this "one guy" consistent in all of those threads, Shawn. I know nothing about him, but I keep seeing his name pop up in every thread where someone is banned, and there's always a fight it seems.
Originally posted by 82-T/A [At Work]: Weird how back in the day, there were so many people getting banned in the Tech section. There seems to be this "one guy" consistent in all of those threads, Shawn. I know nothing about him, but I keep seeing his name pop up in every thread where someone is banned, and there's always a fight it seems.
Originally posted by 82-T/A [At Work]: ... There seems to be this "one guy" consistent in all of those threads, Shawn. I know nothing about him, but I keep seeing his name pop up in every thread where someone is banned, and there's always a fight it seems.
quote
Originally posted by IMSA GT:
Shawn loved this place
I think y'all are both thinking about a different Shawn. Errr... Shaun.
I could probably dig around and find out myself but I gotta ask, how does it get power to the wheels in that orientation? Is the differential under the oil pan or something? How does the transmission even fit? I see these in the fiero car show videos that FieroAustin posts and I'm always confused on how it even works!
I could probably dig around and find out myself but I gotta ask, how does it get power to the wheels in that orientation? Is the differential under the oil pan or something? How does the transmission even fit? I see these in the fiero car show videos that FieroAustin posts and I'm always confused on how it even works!
It uses a special kind of transmission that's no longer made, it's called the Turbo-Hydromatic 425... .Th425 for short. They also had a TH325 which was a lesser version. They were the front wheel drive versions of the Th-400 and Th-350 respectively ....
Th400 = Th425 Th350 = Th325
The Th425 was found in cars like the Cadillac Eldorado and the Oldsmobile Toronado. The Th325 was found in the same cars, but in the later years... 1978+
The 425 essentially became the 325, though they are slightly different transmissions. When Cadillac and Oldsmobile transitioned from huge big block motors to small block V8s (metaphorically speaking) from the mid 70s to the late 70s, they switched to the lesser version.
There was also something called a "Switch Pitch" version of these, which is super rare, and really, really cool... it basically allowed you to change the stall speed of the torque converter on-command. It allowed you to alternate between a stall speed of about ~1,000 rpms. Lower stall speed for normal driving, and higher stall speed for performance driving. it would essentially be a little switch that mounted under the gas pedal... so when you'd floor it, the gas pedal would push down on the switch and give you a higher stall speed, allowing the motor to rev up before the torque converted engaged... giving you a nice launch.
Click the right button to go to the next image. I start actually thinking it might be a real Diablo, until the shots where I see the good ole-fashioned GM steering column.
[This message has been edited by 82-T/A [At Work] (edited 01-19-2024).]
Originally posted by 82-T/A [At Work]: There was also something called a "Switch Pitch" version of these, which is super rare, and really, really cool... it basically allowed you to change the stall speed of the torque converter on-command. It allowed you to alternate between a stall speed of about ~1,000 rpms. Lower stall speed for normal driving, and higher stall speed for performance driving. it would essentially be a little switch that mounted under the gas pedal... so when you'd floor it, the gas pedal would push down on the switch and give you a higher stall speed, allowing the motor to rev up before the torque converted engaged... giving you a nice launch.
That's so cool!! I love learning about the oddball stuff that came out of the 60s and 70s. That whole transmission is super neat too, I'm amazed they got all that into such a small package given the era.
