Hey,
alright...you'll all hate me for this, but i was wondering if there are any kits (engine mounts/tranny crossmembers) out there to put a cadillac 500ci in the rx-7? my rx-7's engine needs a rebuild, and i have a cadillac 500 with a th400 tranny just layin here.... and since i cannot afford to rebuild my rotary..hmm the idea came to me. the engine is a '76 500, tranny is a pontiac th400.

 

Thats a pretty big engine to be putting in an RX-7....

If you want to go V8, youd be better off getting a smaller engine, like a SBC

 

but i have this caddy engine just sittin in the garage!

 

I'm thinking you'll be tight on room since even those 350's look pretty tight in there. I forgot the v8 rx7 forum's web address, was it granny's speed shop or something? I think if you search you'll come accross their webpage and they can probably steer you in the right direction.

 

Do a search for Granny's Speed Shop. They make mounts for v8 engine swaps. You should email them and tell them about your situation. Im sure they will help you out.

I'm not a fan of v8 RX-7s but I guess its better than no RX-7 at all. Most people already think theyre v6 or v8 so the average joe american wont know the difference

 

i e-mailed granny's speed shop. i'm just wondering if i could fit it, without modding the firewall.... it would obviously stick out the hood some, but thats alright.

 

oh they'd know the difference when i pulled up with the rx-7 and my 500ci 12.0:1 engine in it...they'd definatly know the diff. muhahahah

 

This is wierd...500ci Caddy engine? And one with 12.0:1 compression? In 76? what are you gonna do next? Astound them with your automatic wheelchair lift?

Rat

 

you have any pictures of your beast?

 

the engine isn't in the car...i'm tryin to find out if i can get it in still....and yes j-rat, if you know what parts to swap on old caddy engines, you can get a 500ci with 12.0:1 compression for very cheap...and caddy's had 500ci engines in '71-'76. oh and i can get you an automatic wheelchair lift too...smartass

 

Yeah, that was a little smart assed wasnt it? Sorry..Just couldnt resist. I am gonna have to say that there is NO WAY you could get that 500CI in there. I dont know of a swap kit, and with all the torque a 12:1 500 ci could potentially (actually, it WILL) cause CATASTROPHIC damage to the frame, driveline, axles..etc.

But hey, just because it hasnt been done doesnt mean its not possible.... A word of warning. Most people here get a little peeved about V8 swaps. I dont do them, but I generally dont knock people that do. After all, its YOUR car.

Rat

 

you can sell your Caddy 500CI engine, and buy just the "core" of the 13B... . transplant the good stuff over... easy.... atlease sounds easy...

the guy that guy this engine before me paid 300 dollars for just the core....

~Mike

 

As I recall, after 74 (the introduction of cats and emissions equipment) the Caddy 500 was an extremely weak engine, extremely underpowered and incredibly heavy.

I do not reccommend this swap. The amount you will spend in fabrication will soon exceed the $1200 for a rebuild. In the end, you wind up with a car that will not handle b/c you tripled the weight in the engine bay, oversteers like mad, no one respects since its a bastard car, and eventually destroys your chassis.

You want power? Rebuild your engine. Port it, and your intakes, then add 200 hp in nitrous oxide. Trust me, its all you'll need, and its plenty fast.

For and idea of cost: Caddy 500 engine will not fit between the frame rails, so you'd need a tubular front end. It will not clear the hood, or the rad, so you'd need a custom cowl induction hood, and severe relocation of the rad. The FC radiator will not support a 500 CI engine, so add that and install to the budget. Also include new motor mounts, a fabbed transmission crossmember, and a custom driveshaft. Count on your own shifter ($200), tranny oil cooler. Basically, you'd need a race car tubular steel set-up in the front end just to fit that engine in there. This is not something the home emchnaic can do, and the cost of this would be in the 10's of thousands.

I checked the dimensions.

 

i believe the stock hp/torque was around 300hp/400 torque... and that was with stock heads.

i was figuring it might not fit in there...i already have the caddy radiator, a ford rear end (from a '78 mustang II), with 2.78 gears and posi. as far as a driveshaft goes, i have one from the car i got the tranny from (70's pontiac) that i was going to have shortened.
oil cooler....no problem, plenty of cars in the junkyard with em.
200$ for a shifter? i don't buy new stuff, i have 4 junkyards around me, i make stuff..... make that 20$

for motor mounts and a crossmember i e-mailed granny's speed shop to see if they could make me some

i was hoping with some custom headers and a big sledge hammer, i could fit it in the engine bay...

and as far as a hood goes, sawzall makes me a custom cowl induction hood for cheap...

of course the bad handling part would be true, unless i set the engine back through the firewall to make a 50/50 balance, but then i'd have headers next to my legs... but it'd be fun to drive anyways, and i don't care if anyone respects my car, long as I like it.

 

more power to you, if you get it to work, post pics and movies..i'd like to see htis..

 

You'r right - this I gotta see.
I wonder if a Fiero/Northstar would out run it?

 

Regardless, even without headers attached, the nengine is too wide to fit between the strut towers. Unless you can pick up a chromeoly tubular steel with revamped strut mounting position at the junk yard for $20, then you're fucked.

I really disagree with your whole ideal here: a hole cut in the hood, a $20 shifter, massaging the engine bay with a sledgehammer to get it to fit. To do a swap like this requires money, and getting the swap accomplished for $100 is going to leave you with a pos car. It would be the ultimate definition of redneck: "well, the hood wouldn't close, so I just cut a BF hole in it, now it looks cool."
Expect to spend a LOT of money on this swap.

BTW.... tell me exactly how you were going to mount the soild rear axle.... I can't seem to recall ever seeing 4-link rear suspension with coilovers at the local "Pick-a-part".

 

If it fits, is free, and you have mechanical skills, go for it.
There have been SB V8(ford&chevy), V6 Chevy, and Turbo Buick swaps already. And there are a couple BB V8's in 1st gens.
Just remember that EVERYTHING will have to be fabricated and you will NOT save money when compared to a rotary rebuild.
The 500 Caddy isn't as big as everyone thinks. It is smaller than the BB Ford(460) and Chevy(454). If a 350 fits, the Cad should also. Just think of it as a small engine that is bored/stroked to hell.

http://500cid.com/mts/tech/basics.htm
http://www.cad500parts.com/

Here is a quote from one of the above websites:
"With an aluminum intake manifold it weighs only about 45 lbs more than a Chevy 350 small block. "
But, the Chevy SB also can be had with alloy heads/block/intake also. The car, with a Caddy 500, will be nose heavy. Mounting as low and as far back as possible will be needed.

Good luck. Or, save the engine for a pickup/RV/muscle car from the 50's to early '70s.

 

yeah it isn't that big, i don't know what scathcart is talkin about..... i measured from the tip of the heads and measured the engine bay and i still had bout 1.5" of room, granted it's not much, and when i go to put exhaust in, thats where i'd have troubles...

"External dimensions of the entire 368 - 425 - 472 - 500 Cadillac engines are identical. "

as far as suspention goes for the rearend, i would obviously fit in a leaf spring setup.

regardless of wether you'd like to see me do this or not, you don't need to criticize everything about the project.

nothing with cars requires money if you don't mind used... and have some mechanical skills.

 

Don't run leaf springs out back, there's plenty of solid alxes that use coil springs. It'd be less work

I saw a Caddy 500 in an El Camino. It barely fit. Thing hauled *** though.

 

that engine would rip a rex to pieces. take it from a rex owner that's been around muscle cars his whole life.

 

it's not like i'd be drag racing...i'd just use it as a daily driver...

 

trying,trying,trying,trying nope gotta hate u, sorry
your going to do all that work for a daily driver? i guess it will be find as long as u dont want to turn. u might as well rebuild your motor it will be cheaper,just sell all those parts that u have and then we can all be friends again. but hey it is your car

 

man... just sell the beastly engine and get someone to rebuild the engine for you... Its cheap, easy, AND rotary... what could possibly be better than that??

(and don't say that a monster engine swap is better, 'cause having a car that handles like $hit turning through intersections is NOT better than rotary...)

 

hell, u could prolly get yourself a turbo J-spec and ghetto-swap it in there, if you want speed...