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472 upgrades

Started by Greasemykey, December 29, 2016, 09:09:07 PM

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Greasemykey

I have 2 high compression 472 engines and I'm tring to figure out what to do to them. I have read how some people have a modified intake manifold but who mods them or makes them? Any other suggestions besides HEI, and rocker arm mods?

TJ Hopland

500cid.com and cad500parts.com are the big players for these motors.    Both sell products they have developed themselves.   Both I think also sell used and modified used parts like intakes.

Edelbrock makes a 'performer' intake that is available from most of the online places.   There are a few other bits too like distributors from big names. 

Quality replacement OE style rockers are a problem.  There are several shaft style replacement options available only catch is cost and they usually won't clear stock covers. 

Most people get rid of the smog pump/system if it had one.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Jeff Rosansky CLC #28373

Before you get new rockers, please pm me. I am not an expert by any means but I have had rocker issues that I would be happy to discuss with you.
Jeff
Jeff Rosansky
CLC #28373
1970 Coupe DeVille (Big Red)
1955 Series 62 (Baby Blue)
Dad's new 1979 Coupe DeVille

"Cadillac Kid" Greg Surfas 15364

Might suggest you check out the Cadillac Power forum.  A real wealth of info and experience there.

http://www.cadillacpower.com/forum/index.php?sid=665416e13b15fedc2d01da3caba0bede

Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Scot Minesinger

Also Maximum Torque Specialties in CA (MTS) is a great source for this info.  You can keep them stock or modify them, probably either will be enjoyable.  Replace the timing chain if original no matter what you decide.

What are you looking to do, increase power and torque?  These engines are quite capable, and I have three 1970 Cadillacs.  Usually I modify them if something else is required.  The only quality source of rocker arms is used or modified.  Rocker arms sold as replacements for original are junk, and that is putting it kindly. 

Normally the two maintenance/repair items that these engines require are a timing chain at any mileage(need to replace it before problems develop due to nylon coated cam sprocket) and valve job at past 50k miles.  The timing chain work - might as well replace cam.  The valve job work, might as well improve intake manifold, exhaust manifolds and heads.  Improvements to heads can mean larger valves and better rockers (roller type), and for low compression 472/500 (1971-76), increase compression ratio.  The intake and exhaust manifold improvements are usually internal machining. 

What I like about MTS is they give valuable tech tips over the phone to avoid the common mistakes installers make when using their products - such as intake manifold - most fail to seal it well and vacuum leaks abound (rough idle, fluttering pulley mark when setting timing).

I have a very stock 472 and a slightly modified 472.  The stock runs great.  The modified has a little more snap and sounds better.  The modified has electronic ignition, improved intake manifold and dual exhausts with H pipe.  Both are a joy to drive.

The 1970 is only year of 472 with no smog pump, I would get rid of that on any other year - MTS sells the pulleys to make it happen.

Enjoy your Cadillacs!
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Greasemykey

I'm putting the 472 into my 79 sedan. The 425 just doesn't cut for me. Not my engines are high compression. What I was thinking is stock bottom end, stage 2 heads from cad 500, rocker upgrades, bigger cam, intake to be determined, Holley 850, and HEI ignition with MSD 6AL box. Need to figure out what BBC headers fit that body to make long tubes for it and upgrade the gears and locker option in the rear.

Scot Minesinger

MTS sells the upgrades for the 425 too, and it is very similar to 472.  In fact they advertise 472/500/425/368 family of engines and specialize in that block made from 1968 thru 1981.  You may be surprised the power the 425 is capable off with all the things you just wrote about doing to the 472.  Hard to beat extra displacement - I get it.  The rear diff is fairly tall, less than 3.0, but a performance axle (3.07) was available as an option in 1979.

The 425 and 472 are about the same size, so if the headers fit the current 425 with a little room, you should be OK with the 472. 

Either way reads like the 79 Sedan will be a joy to drive when you finish it.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

"Cadillac Kid" Greg Surfas 15364

Mike,
You did not say what the motors were going in, but if it is a 68-76 ful size Cad, you can get the "}shorty" headers from MTS and modify them like mine as shown in the picture.  They are 1-7/8 inch to 4 inch and have an overall length of about 33 inches to the cut outs and the "muffled" side is a slip fit to the 3 inch system.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Greasemykey

The small journals of the 425 make it no good for high horse power. I don't have a set of headers just yet. Haven't planned that far ahead. I'll probably build my own set since I want to put side pipes on it like the corvette. I know the 79 has a 2.75 gear in it now. I have a limo with 2.93 gears but I want to find a 3.15 with limited slip. Apparently they are hard to find.

"Cadillac Kid" Greg Surfas 15364

Mike,
Sorry I did not read your post carefully.  A '79 has a "corporate" rear end, so you will be able to find any ratio and a good solid set up.  MTS has headers for that car, and modifying them to "full length" will be easier than starting from scratch.
In regards to an upgrade, use the oil pan and pick up from the 425 and it will be a bolt in.  I did that on my 79 "Paris" ("El Camino" style conversion).  It is a 9:1 version of a '74 (large chamber heads) 472.  Cam, carb and exhaust mods.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Greasemykey

Does modifying the headers to full length make a big numbers difference? If I'm going to see maybe 5 or 10 horses I don't think it's worth the time. I will have enough use able power to not notice that.

"Cadillac Kid" Greg Surfas 15364

Mike,
That is a real good point.  From what you have posted so far you re looking at something around 300 HP. The standard "shorty" headers in a '79 will be quite an increase in flow.  My motor should be making North of 500, and the small increase in flow is warranted.
Wit a 10:1 motor, an Edlebrock 2115 intake with a modified (Jet Performance) 1976 Quadrajet, large valves ion the heads, a MTS #q15 cam with shaft roller rockers will get you near 300 (real) HP.  Cadillac motors are low speed torque machines with the flattest torque curve I've seen in an IC motor.
Call MTS,tell them what you want to do and go from there.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Greasemykey

Wasn't that factory number 375/525?

"Cadillac Kid" Greg Surfas 15364

Mike,
The best way to descr4ibe the di9sparity is that horses seem,ed to be smaller back then.  In all seriousness the change in ratings is a discussion for another post.  The actual numbers for a 10:1 472 are 223 HP @ 4000 RPM and 315 pound/feet of Torque at 3500 RPM.  A cam, intake and carburetion will get you to a real 300.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

Greasemykey

Weird. Cad500 was full if it then. Even the catalog that shows the alleged dyno numbers with their performance kits is severely exaggerated.

Scot Minesinger

That 233 hp seems right in real world.  My 1995 Fleetwood RWD with a rated 260hp/330lb-ft torque was faster than my 1970 DeVille with 375hp/525 lb-ft torque.  They weighed about the same and granted the 1995 Cadillac was more aerodynamic, at low speed the difference should not have been as dramatic.  In any event 300/233 hp is a almost a 30% increase, so that would be good.  My 1970 DeVille is faster than my 2007 Avalanche that has a 5.3 engine (285hp?), but it is 1,000 lb heavier.

In any event, few Cadillacs from the 1970's no matter the modifications (except Greg's 1973 for sure) can beat my Mother in law's 2008 Camery V-6.  And neither could just about any stock 1969 Chevelle.  That is why I never bother to really go for the big horsepower increases, these are not racers.  233hp is enough to make it fun.  The main thing is to make your Cadillac so you enjoy it. 
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

35-709

Mike,
This discrepancy has been discussed here before, auto makers changed how they rated the horsepower of their engines in the 70s, the link below should help explain things.  I imagine Cad500 is rating their engines the "old" way.

http://ateupwithmotor.com/terms-technology-definitions/gross-versus-net-horsepower/
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

"Cadillac Kid" Greg Surfas 15364

Mike,
I personally have found that I get "straighter", accurate and less sarcastic information when I talk to MTS.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

chrisntam

Quote from: "Cadillac Kid"  Greg Surfas 15364 on January 03, 2017, 03:23:25 PM
Mike,
I personally have found that I get "straighter", accurate and less sarcastic information when I talk to MTS.
Greg Surfas

+1

1970 Deville Convertible 
Dallas, Texas

Greasemykey

Definitely giving them a call thanks for the info. I had higher hopes for this engine making 600 ft lbs or more with a few mods. Guess I have to make even more mods to it.