500 Cad in a 66 LeMans

[BASHEIII]

I'm toying with the idea of putting a Caddie 500 in a 66 LeMans. From what I've read so far, it will work but there are header and oil pan issues to overcome (among other things, of coarse). I understand the dissadvantages with the 500 but there are also some fantastic advantages as well. Plus, I want to be different. Just curious if any of you have done this or can direct me to someone who has or even some articles to read.

[BASHEIII]

I'm toying with the idea of putting a Caddie 500 in a 66 LeMans. From what I've read so far, it will work but there are header and oil pan issues to overcome (among other things, of coarse). I understand the dissadvantages with the 500 but there are also some fantastic advantages as well. Plus, I want to be different. Just curious if any of you have done this or can direct me to someone who has or even some articles to read.

[einstein]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by BASHEIII:
I'm toying with the idea of putting a Caddie 500 in a 66 LeMans. From what I've read so far, it will work but there are header and oil pan issues to overcome (among other things, of coarse). I understand the dissadvantages with the 500 but there are also some fantastic advantages as well. Plus, I want to be different. Just curious if any of you have done this or can direct me to someone who has or even some articles to read.<HR></BLOCKQUOTE>

If you search around the web, I'm certain you can find a couple of Caddy websites with good technical info.

Also, the Caddy 500 from the 1976 cars was Bosch fuel-injected. You can modify that system as well.

I had a copy of a book (loaned out, can't tell you exactly the title), I think by HP Motobooks, about fuel injection. One section tells of a Caddy 500 installed in a 1978 GMC Motorhome (front wheel drive, 26', 12,000 lbs). He put in the first engine, then built a stroker, at about 530 cubic inches, plus modified the Bosch system. I think it was turbo'd as well, and there's a cool picture of the GMC engulfed in tire smoke from the front tires.

Check out the GMC Motorhome websites for Caddy 500 info.

Glenn Uettwiller - [email protected]
http://firstgenfirebird.org/show/closeup.mv?CarID=209
http://firstgenfirebird.org/show/closeup.mv?CarID=210

"I'm an atheist before my first cup of coffee." - Chuck Colson

[PLAY400]

a few years back Street Rodder did a 500 caddy build up. I set 1 into a 47 Chev which was on a S10 chassis. Fit better because the mounts are up front and looked way better than the small block I had in it.

[b-man]

For headers start with a set of big-block Chevy Chevelle headers. Cut off the Chevy header flanges and spread the tubes to match a set of Caddy flanges. It takes some welding and fab skills, but can be done for a reasonable cost.

Let's go racing!
www.outlawpontiacs.com/members/B-Man2.php (http://www.outlawpontiacs.com/members/B-Man2.php)
www.outlawpontiacs.com/members/B-Man.php (http://www.outlawpontiacs.com/members/B-Man.php)

[t67]

Not sure if you are still considering this swap, but heres some info: Maximum torque specialists (not sure of site address, but they have EVERYTHING.) Also, The Cad Company.
What disadvantage is 550 foot lbs of torque from a nearly stock "lux" motor???

[t67]

also cad500parts.com

[cscottfergus]

Saw an article in Cars magazine in the mid 80s about 500 cu in caddies with Nitrous, Suprised quite a few street racers to be beaten by an old Caddy. This sounds great, keep us up to date on your progress if you don't mind.


http://archives.freaks.net/checker-l/2000/2922.html
quote from this webpage, not me
" got all my hi-po parts from the Cad Company out of lakeland florida. I
dont know if they have a web site yet, but you can call them for a catalog
at 941-648-5114. The catalog is about $5.00, but it's worth it. "

[cscottfergus]

info on caddy use and also nitrous

http://500cid.com/mts/cat/tips.html

"The Cadillac 368 through 500cid engines were produced in various displacements from 1968 until 1984. Displacement of the engine was varied through bore and stroke changes. External dimensions of the entire 368 - 425 - 472 - 500 Cadillac engines are identical.

Most performance use is concentrated on the 425 - 472 - 500 inchers. In stock form theses engines are perfect swap material. A 500cid Cadillac engine weighs about 595 lbs. complete. Change to an aluminum intake manifold and it reduces it by 22 lbs. to lower the overall weight of this engine to about 575 lbs. Big cubes with the weight of a small block!

Use of the Cadillac engine dictates a close look at your vehicles total combination. Most people are not used to the huge amounts of torque the Cadillac produces. The Cadillac big block prefers to pull against a low numerical rear gear set. Most strip only applications only run a 3:73 ratio. Most street vehicles work well with as low as 2:73 to 3:55 ratios. This big boy wants to "tug" not "rev". Keep that in mind and your engine will live longer and perform better.


"Same as stock" engine use is also a very broad term. A stock 500 Cadillac engine will take a 150 hp shot of nitrous oxide for a full quarter mile pass. We have used many engines like this. Some with over 200 nitrous runs! Pop it in drive, nail it and let the trans do the shifting. You will have a deadly, repeatable combination. It will be simple, inexpensive and consistent. Your competition is going to hate you."

[stu]

What does the 500 Caddy look like in terms of heads, valve sizes, ports, ex. manifold exits, etc? I've never seen one, just curious how it compares to a Pontiac. For instance, you would think a Buick 455 is the s**t until you look at the heads and the oiling system. Like what are the weak points, must be a catch somewhere.

[MR. May]

the cylender heads a wedge type that is simalar to an oldsmobile head the 500ci had 2" intake and 1.625" exaust valves. the 70 year had 10:1 compresion and later years were 8.5:1 2.5" rod bearings 3.25" mains 4.300 bore and 3.04 stroke

[MR. May]

Oh and what I mean by oldsmobile style heads is paired intake ports and the two center exaust ports are connected. the distributor and all the accessorys are driven off the front cover.

['ol Pinion head]

Buicks are the GM V8 that had the distributer off the front of the cam.

On the big Cadillacs, have pulled quite a few 472's & torn down several 500's as well. IMO, The 500's are prob better suited to pickup motorswap build-up's... Have provided parts for many 500 that ended up in '71+ Chevy pickups, both streetmachines & towrigs.

With better rod to stroke ratio, have always like the 472's. One of my good friends (circle tracker) is track champion 4 years running with a 480 cube Caddy powered '7O Chevelle factory stocker. Due to the rules, the car runs cast iron intake, & two of the championships were won running spliced together rh side Cadillac-BBC exhaust manifold.

The rule at the track Mark & his driver runs this particular car at, states the carbuilder can run any GM engine in SAME year GM car. This rule had long been in place so small block chebbies could be put in about anything GM. With the built "472" under the hood, his SBC competitors cannot claim the engine. It would be different if they also ran Cadillacs & finished in the top 3 & protested. Several have even built Cadillac powered factory-stockers to try & knock him out, but none have ever succeeded. Betting against Mark's ingenuity in engine & chassis building skill would be like betting against Smokey Yunick 40 years ago.

[This message was edited by ol' Pinion head on September 19, 2003 at 07:05 PM.]

[connman]

Watch Popular Hotrodding for their bigger block build up series as they are building a couple of Caddies for the competition.GO FOR IT!

DRIVE IT LIKE U STOLE IT!

connman

[stu]

Hmmm. I did some searching on 500 Caddys, very intriguing. Cast rods seem like the crippler tho. Maybe if you polished the beams and relieved the corners they would live to 6 grand. Cool idea, you could run a 2.73 gear and have a hiway cruiser but still smoke em off around town.

[cscottfergus]

Stu I imagine that you could have the rods cryogenically tempered too help increase longevity also. No personal experience though.

[t67]

There is a olds (I think) rod that fits the big caddy. Cads used arma steel rods from factory. What some do is turn down the crank and use big block chevy rods. The worst part of the big luxers are the crappy rocker arm set-up. Safe to about 4500 rpm, of course thats about 500 ft lbs in a 500 caddy. There are a few compaines offering inexpensive upgrades good to around 5500 rpm, or even full roller systems for the guys who poop gold coins. The engines use basically 2 types of heads, one high comp, and one low. I picked up a set of each at a local yard for 40.00/set. Without changing pistons a head swap will yield way high, or way low compression ratio. The heads can be machined for bigger valves (2.2-2.3?? not sure max size) and even in stock form, they actually flow pretty well. The later low compression heads had a bump on the exhaust floor that reduces flow a little compared to the earlier ones. The intakes suck due to the need to fit the motors under low hoods. Edelbrock makes inexpensive (relativly) replacement good for 20 hp om stock mill accordint to one source. The blocks are high nickel content and the motor weighs only a little more than the small block chevy everybody in the world has. Big block chevy hedders can be welded up to fit. I have heard of some people retrofitting 429 ford heads on the caddy, but I know nothing about that. The motors are very nice as far as casting goes, very little flashing of jagged edges. I'm no expert, but thats my .02.
Pontiacs still rule!

[charles vance]

I have a 79 TA that runs 7.40 in the 1/8 mile, and gets good gas mileage( better than my 87 ford couger, v6 ).

I also have a 68 firebird 4 speed car, but without the engine and trans. A friend at work has a running 500 ci caddy that he will sell to me for 150 bucks.

what do you think? http://forums.performanceyears.com/groupee_common/emoticons/icon_rolleyes.gif

[bullheimer]

cad500parts.com was a great link. i've emailed them as i have a 67 lemans without a motor at the moment and a 70 caddy i cant give away with a running engine.

if OP isn't dead yet, how bout letting us know if anything happened with this swap 8 years old now.

[fbrown]

FWIW on the Cad 500. One you start modding the engine the gas mileage goes to single digits. I have a Potter 500 crate engine with 500HP, 600ft/lb in my 77 DeVille. I only have about 40 miles on the car since installing the Potter engine, I put 10 gallons of gas in an empty tank when installing the engine and the gas gauge is now sitting on E. (on the stop) My engine also isn't happy with 93 octane.

For me the Potter crate was not the right choice. If I can't drive my cars 10K per year and not feel that I going broke at the gas station, then I have made the wrong choice of car/engine. I want to be able to drive my cars to work or take long trips in them. For me one round trip to work and back is about 80 miles with about 60 miles being interstate. While I don't have everything dialed in, I don't think the Potter crate engine is going to do much better than 10mpg. I might be able to get to 14mpg by swapping the carb for FI. But for the price of a FI unit, I would dump the 500 for some other engine.

If gas mileage is of no concern, such as a weekend race car, the Cadillac 500 will do an outstanding job. There are now multiple aftermarket head and intake choices for the Cadillac. However one you pass 500HP the costs go up in a hurry and you may find there is no advantage to the Cadillac engine over other engine choices.

Another source of hard core Cadillac parts http://www.cadillacperformanceparts.com/

[goatwgn]

It depends on what you want. I think the Cadillac 500 would be very good in stock configuration against a 2.73-3.08 rear end ratio. You can add a distributor curve kit and fine tune the engine. You will have a very smooth, low maintenence, quiet torque engine that will pull those lower ratios without any fuss.:2cents: If you don't plan on running air conditioning, you can put a slightly taller intake on it. I beleive Edlebrock makes one. Good luck and post some results when you are finished.:)