[tunedbytad]

Millie the "Mid Budget Wagon Project" questions

OK time for something different

Got a cool project that will be fun if you want to tag along, and I have some questions for the well informed.

Here is what I got;

One FREE! 79' ( < i think) Cadillac Fleetwood Limo. 425ci motor w/ TH400 trans as I have been told.

And one budget 65' Chevy Wagon with a fairly clean body, paint and glass.

What is planed here is to freshen the 425 and th 400 and drop it into the 65 Wagon.

 

[tunedbytad]

Question set #1 Caddy Motor

My plans for the motor;
-bump the hone thru it for a light clean up
-new rings and bearings all round
-Zero Deck the block (looking for 10.5:1 CR)
-deck the heads (looking for 10.5:1 CR)
-Port the Iron heads for good flow and bore match the CC
-nice valve job (45deg w/ big cam 40deg if the cam lit sucks)
-Find a nice intake manifold if the OE piece flows bad

Considering,
-New valve springs and bigger camshaft
-Boss at work want me to order custom forged pistons with a massive top on them so I can attach a SCUBA tank to a plate kit and spray it heavy. But that would be definate overkill for a fun "Pop and I" surf car long roof hot rod.

-Does anyone have any links to info about this motor or aftermarket parts?

-the intake manifold looks horrid is there any upgrades I can just "pop on there"

-Whats the comp ratio and head CC on this bad boy?

-I will need long tubes that mate to the caddy motor but fit in the Wagon.... Any suggestions?

-Anyone have any real experience with making street / strip power on one of these bad boys?

 

[Bomber '67]

If you remember last years Hot Rod Magazine Pump Gas drags, then you may recall there was a 5.0 Mustang with a nitroused Caddy 500 engine. The July Hot rod has a small update: with an all cast bottom end he made a 9.97 e.t. @ 136.82 mph pass, and that was using only one stage of nitrous. Three years of pounding on the STOCK Caddy bottom end. The old Caddy engines were very well machined and used quality materials. Leave the short block as is unless there are clear signs of trouble, do take the heads off and clean things up etc.

I wouldn't run 10.5:1 compression on an all cast iron lump. Take the heads to Juan and let him loose.

Do an internet search for CadCompany, MTE - search string Cadillac 425 Cadillac 472/500 etc.

There are aftermarket manifolds made for the Cad 472/500 - I think the 425 has a shorter deck height. I think you should put the Tay to work machining some adapter spacers and adapt a different manifold. Some guys have adapted Ford 429/460 intake manifolds to their Cad 472/500 - I don't know on the 425.

You will not find off the shelf headers for a Cad 425 into a '65 Malibu - custom fab is your friend.

I say you should clean up the heads, put a performance cam in there, run a 250 shot, run 3.08 gears and as tall a slick as you can fit, and keep the rpms below 5,000. If Sean (Mustang + Cad 500) has a 28" tall tire then he is only running just over 5,000 rpm through the lights. You give up torque with your 425 vs. his 500 - but that Caddy was for free so who cares?

Thomas

 

[69boo307]

Looks like you have your work cut out for you!

 

[FO_FDYFO]

why?
for the amount of work why not put a 454 in it? i dont get it.

 

[tunedbytad]

Why?

Well,
-the Caddy motor was FREE w/ th400 trans
-is a fun challenge
-is different from the norm
-a good 454 will cost a decent amount of money if I wanted to spend money I would build a 454 LS1 at work that makes 650HP NA and 1KiloHp on the bottle but this is a fun car for me and pops.
-it may see the track, but the main goal is to go surfing with it. 425 w/ the CR up will move that boat / wagon just fine

 

[tunedbytad]

yes I have my work cut out for me.

-motor pull
-motor fresh
-trans fresh
-motor / trans install
-headers
-pipes
-xross member
-ds
-brakes
-minor electrical
-stereo
-surf accesories

 

[FO_FDYFO]

i love different from the norm but.....
so how much do you think you will have tied up in this project?
take that figure and add it to what you could sell the whole caddy for,
that total is what you could have to put a mild but decent 454 in the wagon?
maybe i'm wrong.

 

[Olle]

why?

Considering the projects you show on your web page, I actually thought you would be the last person to ask that question. You're just jealous

 

[FO_FDYFO]

I know i said i like different, but i cant see putting a non chevy engin in a chevy. thats all.

 

[JimN]

Wagons are the best. The bigger Caddy engine should move that thing. How do those engines breathe? Do they need much head work?

 

[daveseitz]

I would say a full port on heads and manifold if replacement can't be found. Just run 9.5-1 max with a bigger cam it will still have the guts as a sleeper. Next thing I would think about is pulling as much of the drivetrain as possible to update the way it handles. The brakes in the Cad front and rear will stop a 65 a whole lot shorter. Caddilac used to have a extra clutch in the trans I think and it should be stronger then a stock 400 after rebuild. Curve on distributor will be real lazy so have that checked also. Steering box might be quicker then the 65 look at that to swap with pump. Cooling system in Caddilacs never seems to be a problem and if radiator fits use it.

 

[Bomber '67]

Well, the Cad Limo has *other* issues and free was the right price for it. The engine actually runs well just as is, just waiting to be super mildly breathed on. I do think a total rebuild of the 425 is uncalled for - instead just free up the restrictions in the intake/heads/exhaust curve the distributor and dial in the Q-Jet. Combine with a 3.08 or so differential gear and GO! I think the whole Millie project could be done for a Grassroots Motorsports kind of $2,005 budget - including the cost to get the '65 wagon.

My prediction is that this project will teach Tad a few things that he wasn't expecting to learn. Not counting the basics of OHV engines, LS1 technology and the Cad 425 definitely do not meet anywhere on this planet. 10.5:1 is simply too much compression on an all iron heatsink like this - unless you install a camshaft designed to bleed off cylinder pressure, which will destroy the Cad's forte of low end torque.

Thomas

 

[tunedbytad]

TC,

The modern motors I tune every day at work have the quench set on kill and run at 180 degs or less at extended WOT. The massive heatsink is a very valid point. And may go a long way to explaining why a radiator swap and timing set would almost double the MPG on Rosie. (327 4bl PG ElCo) Reducing negative torque makes for good milage and a light pedal.

>>instead just free up the restrictions in the intake/heads/exhaust curve the distributor and dial in the Q-Jet.<<

Sounds like a plan. I will leak-down the motor down first b4 I make a final call on the internals though.

As for the $2005 investment it will go over that because of the P EYEeeee Ps (pipes).

Daveseitz

<< would think about is pulling as much of the drivetrain as possible to update the way it handles. The brakes in the Cad front and rear will stop a 65 a whole lot shorter. >>

I plan on robbing that Caddy as much as possible for cool parts. It may have a 12 bolt and the brakes have to be bigger. They definatly work I was doing 2000+ foot all 4 wheels locked up frieght train stops in the Caddy just for fun b4 I took it apart It also has a shock absorber centerlink deal that may be cool. power windows? and AC? No not the AC that compressor weighs as much as a power glide.

 

[FO_FDYFO]

sounds like you really want to do it. good luck. you will learn alot. it will be great. keep us up on how it goes.

 

[zombie1974]

I am pretty much against cross-brand engine swaps in post-WWII cars EXCEPT FOR putting a caddy engine in anything. That's too cool!!

Document everything well, with photos! Most of us will be very interested!
Good luck!

P.S.
Don't forget the expense of different upper control arms for the tall spindle swap if you want the caddy front brakes.

 

[Bomber '67]

Tad, there will NOT be a 12 bolt passenger car differential in the Cad, but it will be at least an 8.5" ring gear. On the factory limos (which that one definitely is), you may well find a pickup truck differential.

Although the quench height and alloy heads/block of modern engines allow much more compression, the shape of the combustion chamber is very important too. The Cad 425 heads have a very poor shape for swirl and mixture motion, keep the camshaft mild.

Thomas

 

[Jim Mac]

is it MTE or some other company that sells a header flange for a caddy head and you adapt it to a big block chevy headers? I remember seeing it in a car craft a couple of years ago, they even sell intakes and I think cams etc. I like those old chevelle wagons, I wish I could find one and have a place to put it, Jim

 

[tunedbytad]

I'l look for MTE header flange adapter deal-E-O. Hell the wagon came with BBC long tubes!