Technical 500 Caddy ?s

just picked up a 75/76 500
we have it on our run stand at school
Runs great as pulled from the car.
nice steady vacuum
engine looks very clean(under valve covers)
The oil pressure hot at idle, around 500 rpm, is 15-18,. 40 plus revved up.
Oil pressure cold is 40+ at idle (still on oil as bought, will change tomorrow)
The initial compression test (before running up to temp) was 120 +
seems to be a healthy engine, would like to check the compression numbers to see if they come up any after running.
We ran it up to around 220 degrees then shut it down........ ran out of class time.
The plan was to build and put in my bus, now thinking about a re-seal and run as is.
questions are...... thoughts on running as is with a reseal and what is the normal operating temp.

This engine will be used to pull a 6500+ pound 'hot rod' around. Torque is the objective

 

While you have it on a stand, my vote is to take it apart and check it’s condition, fix what’s wrong, new gaskets, put back together. No worries. Just my vote. Bones

 

I have a 1970 472 Cad in my Buick, I just replaced the timing chain and gears and ran it. I would do that on yours for sure, most came with a plastic coated cam gear.

 

The pan, intake and timing cover will be removed for inspection and gasket replacement.
Timing chain, water and fuel pumps will be replaced
Just seems like going further than that may be a waste of money.

 

You just answered your guestion when you said “ may” Bones

 

If you have the pan off, it makes sense to pull a couple of rod caps for a look. If they look good, put them back and run it.

 

I'd say ya got it covered Rite There, Great torque engine! You need 10 psi. Oil pressure for every 1000 rpm to be safe, Ya got it...

 

I’m a little shocked
All the old engines I end up with need total rebuilds
This is a first

 

the final versions of this block were the 425 and then the 368. torquey and trouble-free. the replacement was that awful aluminum engine that was barely a step above the vega 4 cylinder. gm should have kept it!

 

Hi ... I would definalty replace the cam lifters and timing chain set ...they have plastic type teeth which over time disintegrate and partially block the oil pick up in sump..new sets are all steel... I run 2 of these engines in my cars...cant beat them for power and torque........

 

https://www.facebook.com/video.php?v=1772438032779525

 

Me thinks that engine should drag your bus around just fine.
Good luck.Have fun.Be safe.
Leo

 

120 psi seems healthy for a low compression caddy smog motor. Looks like you got a winner.
Last 500 I bought had a busted cylinder wall!

 

we changed the oil
20-25 psi on idle at running temp, hits 50+ on a rev, holds 45
doesn't smoke
need to locate or build a rear sump pan

 

I would change the timing chain and sprocket along with seals and gaskets and leave everything else alone,

Pat

 

I belive Eldorados had rear sump pans. Great engine.

 

I picked a similar 500 up a while ago, just waiting for a project to come along I can put it in. A bunch of those motors went south for the air boat crowd and Florida is a good parts source.
The Cadillac Power Forum is a great source for info, not a lot of traffic but very knowledgeable guys.

 

thats the plan

 

Sounds to me like you have a pretty healthy motor. Keep to your plan of timing chain, fuel pump, and water pump and you should be good. These motors will run from 190 to 205 water temps all day with no worries. If you keep the stock rocker system keep her under 4000 rpm. The Edelbrock intake will also give you a little boost if you have room. Get yourself a copy of the book Big Inch Cadillac, I know Speedway has them, lots of good info. Also for good info on these motors contact Paul at Cad 500.com. Knows his stuff and stands behind it. Also a good source for new and some used parts. Hope this helps and good luck!

 

My bud Bonneville Butch runs two 500 Cads, tandem style in his streamliner. (314 MPH+, two way)
He had a 472 in his '72 Ford pickup, but was surprised that it would labor pulling the heavy streamliner on the 2 wheel Cat trailer! Took wife Joey and me for a ride...Butch laughed as he stated it felt just like the 360 Ford. He and I had collected 500" Cads for months, he had 7 or 8.
The 'liner began with an 8-71 blown 392, and a couple of other hemis of less C.I., for class.
The Cads in tandem were planned from the first, Hemis were really 'shakedown' engines.

So out with the 472, and in with a 500. Stock. Steel timing gear, new water pump.
Night and day. The truck now pulls the 'liner at 90 on the flat, (easy) and hardly slows up the long grade.
Butch's shop is in San Jose, CA.

 

curently debating if the edelbrock intake is worth the investment
plan to use a 1 inch phenolic spacer if the stock intake is used

 

the 500 will end up in this

the current 350 struggles on hills loaded with people
hope this 500 will cure that, I dont need speed just more torque

 

boilermakerdave hit it the old eldies had the rear sump. i have also been told that the 429/460 ford intakes will fit to but i don't know if you have to have a adapter or not. that is what they run for the tunnel ram motors.

 

yep, the adapter is neeeded
would be an option if I was to put the 671 on it

 

I haven't seen Paul in years. How's he doing? Tell him I said Hi. Don't forget the Specter streamliner with one 472 went 356 mph on gas. I think I remember a 400 + one way run.

 

The fellow at CAD Company told me to not buy the intake if not doing head work. I was pretty impressed that he talked me out of buying an intake from him because he felt that would I be wasting my money.

 

Care to expand on the reason he gave.

 

I had a 500 in my 70 chevy short box step side pickup and put the aluminum intake on it after running it stock a while. It really woke it up and was definitely worth it to me!

 

I built a 500 Caddy for an O/T G-Body Malibu. Honed it and re ring and bearing overhaul. Did some head work and bought a Maximum torque specialties cam kit. Ported the intake and exhaust manifolds.
With a 2.41 gear and stock convertor it ran 13's in the 1/4 and got around 16 mpg at freeway speeds.
Drove it back and forth to work everyday for a year before a co-worker bought it from me and back halfed it and made a bracket car out of it. He also put a set of early small chamber heads which bumps the compression over 11 to 1. He built a home made tunnel ram. Ran low 7's in the 1/8th foot braking it.
Bought another 500 and just put a timing chain and gears and installed it in a long bed C-10 to tow my dirt track car . Pulled it great.

 

looks like I got my moneys worth
a dollar per cubic inch

anyone need a used TH400?