Lets see what you all have to say about the "other" GM engine families. Give us the low down on what it takes to get them to work in a 4x4. What are the advantages and disadvantages of running one off road.

I would have to say that the Olds, Pontiac, Buick, and Cadillac engines are really not given the credit they deserve. they are cheap, reasonably easy to find. Problem is parts are a lil more spendy than your average small block chebby parts. I had an olds with the 455 and it was a monster. ran great, idled down to nothing, barely any problems. Also had mucho torque in low RPM. Two problems were cost to rebuild it and that sucker was HEAVY! I would run one. bgreen has a healthy Caddy big block in his truck, check out his Alaska Offroad website. I dig it! :D

My buddy is running a 472 /caddy in his Sami. All kinds of torque!! Most big Caddy motors came with 400 behing them. Easy to adapt to a t-case. In this case he is running a divorced setup because the parts were there. The biggest downfall is the aftermarket prices. Supposedly the weight of the big caddy's is less than the 454, don't know how true it is. But the low end power is definately there!

I'm finishing up stuffing a 472(big block caddy) in a project rig.

The main reason I chose it over some of the others was a stock rebuild will out perform most engines. This met my goal of engine longevity for the simple fact that I don't have to do any hop ups that would decrease the engines life.

Here are a couple of numbers:
Engine W L H Weight
SB Chevy 26" 28" 27" 575lb
BB Chevy 28" 30.5" 29" 685lb
BB Cady 28" 30.5" 28" 600lb

1972 472 = 220hp@4000rpm and 365ftlbs@2400rpm
500 = 235hp@3800rpm and 380ftlbs@2000rpm
1977 425 = 180hp@3600rpm and 260ftlbs@2000rpm

I've heard rumors of getting 15mpg+ using a BB Cady.

The "downside" of the BB Cady is the cost of parts and such. I just spent $2k to get mine rebuilt to stock specs. $900 of that was in parts(pistons, cam, etc) There is only ONE common aluminum intake available(Edlebrok @ $265ish). Recently a set of aluminum heads were created... don't recall the price.

The other downside is trannies. In order to use a manual tranny, you need to have the crank machined for a pilot bearing. Also, it used the BOP bellhousing pattern. They normally came with TH400s... but the output shaft is 19" long. Swapping shafts is fairly easy but requires complete disassembly of the tranny.

The last downside I can think of is oilpans. There is NOT an aftermarket pan available. All rearwheel drive cars used a front sump pan which isn't too desirable for use in a 4x4. The rear sump(aka El Dorado) pans are getting difficult to find and fetch around $150-$200 used.

Originally posted by Lil'John


1972 472 = 220hp@4000rpm and 365ftlbs@2400rpm
500 = 235hp@3800rpm and 380ftlbs@2000rpm
1977 425 = 180hp@3600rpm and 260ftlbs@2000rpm





the 425 maks 320 FLBS at 2000 RPM




I'm rebuilding a Cad 425 for my scout.

A bude had his 62 International pickup body/box sitting on a 79 Cadillac frame with the 425 and that thing was a higway truck the thing hardly broke a sweat when it came to crusing . Such a smoth engine

Originally posted by Chief yelling alot

the 425 maks 320 FLBS at 2000 RPM


Just pulling the numbers from one of my resources... that is what they had at the time(Chilton):p I can't make any assurances as to the accuracy of them. My second different source(thick book at library) and a third resource(Big Inch Cadillac) rates them at 260@2000rpm(efi or carb made no difference in torque... hp "jumped" to 215@3600)

At least I didn't quote the 1971 and early numbers for comparison(ratings were different) but just to throw them out:
1971
472 365hp@4400rpm and 525ftlbs@3000rpm
500 375@4400rpm and 535@2800

Out of curiousity, where are you getting your rating?

Originally posted by Lil'John



Out of curiousity, where are you getting your rating?

well its kida funny but also Chiltons 1979 Motors for 1980 had the same numbers
also look hear
http://100megsfree4.com/cadillac/cad1970/cad79d.htm





that tourqu rating sounds like it should be for the 368

This a buddy of mine's tow-rig.

He's on his second 500 Caddy.

He also wore out the D60 rear and is now running a D70 and duals.

4-5mpg.. and with both rigs on the 30' trailer, doesn't pull up hills as fast as it used to with the single trailer (duh), and with the camper thrown in, wind sucks..

http://tigger.tmcom.com/~tsm1/gallery/albums/albun30/DCP_0005.sized.jpg


But he seems to be happy with the Cad motor, backed up by a TH400, into the (stock) divorced '205.

Originally posted by Chief yelling alot


well its kida funny but also Chiltons 1979 Motors for 1980 had the same numbers
also look hear
http://100megsfree4.com/cadillac/cad1970/cad79d.htm





that tourqu rating sounds like it should be for the 368

Ahh... I see what happened then. The number I quoted was the first year of the motor. I looked at the 79 ones and they had higher numbers :p Odd though :D

Originally posted by tsm1mt
This a buddy of mine's tow-rig.

He's on his second 500 Caddy.

He also wore out the D60 rear and is now running a D70 and duals.

4-5mpg.. and with both rigs on the 30' trailer, doesn't pull up hills as fast as it used to with the single trailer (duh), and with the camper thrown in, wind sucks..

http://tigger.tmcom.com/~tsm1/gallery/albums/albun30/DCP_0005.sized.jpg


But he seems to be happy with the Cad motor, backed up by a TH400, into the (stock) divorced '205.


dude that pimpen

I agree the other GM's don't get the recognition they deserve. No 4x4 experience with them but I built and owned several Pontiacs in the past. Right cylinder head/ cam/ intake combo and those things can make a ton of power.:)

You gotta respect a man who runs a caddy 500(or 513). But for the money cant you get more power from the chevy stuffs.
1972 472 = 220hp@4000rpm and 365ftlbs@2400rpm
500 = 235hp@3800rpm and 380ftlbs@2000rpm
1977 425 = 180hp@3600rpm and 260ftlbs@2000rpm

Chevy
89 454 = 230hp@????rpm and 375ftlbs@2800 or so rpm
87 350 = 210hp@4000rpm and ???
I guess these numbers arent fair because of the FI but parts availablity and price make these fairly similar numbers look a bit better than the caddies numbers. The caddy takes the lead by far in the bragging rights category.


Charlo

Originally posted by charlo
You gotta respect a man who runs a caddy 500(or 513). But for the money cant you get more power from the chevy stuffs.

Charlo

Well, that same friend with the 500 runs Chevys in most of his other stuff.. including a 14:1 454... but for some reason he opted for the 500 for his tow rig.

That said, last I heard his new tow rig is getting an IH 392. :D Might just be a stop over to a 6.9/7.3 though..

Originally posted by charlo
You gotta respect a man who runs a caddy 500(or 513). But for the money cant you get more power from the chevy stuffs.

Chevy
89 454 = 230hp@????rpm and 375ftlbs@2800 or so rpm
87 350 = 210hp@4000rpm and ???
I guess these numbers arent fair because of the FI but parts availablity and price make these fairly similar numbers look a bit better than the caddies numbers. The caddy takes the lead by far in the bragging rights category.


Charlo

For a better comparison to your numbers above, lets use the EFI 500:
76 215hp@3600 and 400ft-lbs@2000b

You are forgetting about two important things on the Caddy when compared to the Chevy:
1) BB Cady weighs 100lbs less than BB Chevy and maybe 25lbs more than SB Chevy
2) Quality of parts... in general, Cady engines are use better materials/design than comparible Chevy engine. A good example is the high nickle content of the BB Cady block.

Also, as I mentioned above, as you start using hi-po stuff, you decrease the longevity of an engine:( Not important for many but for me, I'd like to have a bit of power and NOT have to worry about when the engine will blow up.

Also, from what I've seen, availability of the performance BB Cady parts is increasing lately and the prices are just slightly more than a SB or BB Chevy. (Example headers are ~$250, aluminum heads are ~$2000, intake is ~$250, cams are ~$250)

I'm not sure there are any bragging rights assosiated with BB Cady since most don't think a Cady engine is worth a damn:P Good for me to find used parts, bad for me to find new parts:(

FWIW, once my caddy is up an running, I'm going to dyno it to get a hp/torque reading for a stock rebuild. Then again when I upgrade to an EFI system and intake.

In July of 2000 Hot Rod mag did a junkyard buildup of a 500. Maybe there was some dyno trickery, but here are some of their numbers.

Basic boneyard trim
303hp @3900, 468lb@3300

Headers & alum intake
340@3800, 501@3400

They went further with a cam and super high compression and got a lot more. Their numbers, not mine fwiw.

Street Rod mag did a buildup using a offset ground crank, and BBC rods and a mild overbore and got 537ci. The thing had diesel like hp and torque numbers. I believe over 600lbs. Very low rpms. Doc Fromader wrote a book spelling out the whole engine. It was actually a pretty mild buildup. MTS sells a kit to build your own version.

In my view lack of headers are the biggest hassle. I am using sanderson block huggers, and while a good header, the design isn't great for my 4x4 application. Al at MTS has some nova headers that might work well, otherwise reworking BBC or ford headers is the way to go.

I believe that there are at least 2 companies marketing aftermarket rear sumps. Potter Automotive, and FlashCraft.

From what I have read, most built caddys make so much power down low that your average dyno cant even read it. Thats why some dyno numbers seem low.


I read the following on the MTS board (someone elses build up, notice the readings start on the down trend of the torque readings. This prolly means that the peak torque is substatially higher than the best recorded torque. Pretty impressive numbers especially considering that he is using a stock intake manifold)

I had the heads machined to pro-street specs with oversize valves
I had the stock intake ported & polished for better specs.
I had the quadrajet carb rebuilt & jetted
I put in a 300T cam
I added forged rods & Pistons
I added a Stage II rocker set
I added an HEI system
The block was bored .60 over to 507 CID

RPM's Torque Horsepower
3750 525.2 375.0
4000 503.1 383.2
4250 485.7 393.0
4500 470.1 402.8
4750 442.1 399.8
5000 418.8 398.7
5250 394.8 394.6
5500 363.9 383.1
5750 326.3 357.2

True. Most BB Caddy engines have over 400ft lbs @ around 1200 rpms.

Here's another cool spec some of you may not have

1970 Caddy 500 (stock form)
Max HP- 400 HP
Max Torque- 550ft lbs

Also due to a change in HP ratings from GM, (went from measureing at the flywheel to the rear wheels) you should almost always add 125hp to most readings you get of engines from 1972 through 1976

Originally posted by Cliffhanger
add 125hp to most readings you get of engines from 1972 through 1976

what about after 76

I was at this site about caddys (http://100megsfree4.com/cadillac/cad1970/cad72e.htm) and for the 1972 They list the gross at 400 hp and the net at 365hp. The tq number was 535. The 1970 and 1971 numbers gross were 400hp and 565 tq. Compare that to the new 8.1liter chevy at 340hp and 455 tq. And would cost a lot more to get one of those.

Bryan

I run olds 350 68-72
it has mercedes k-jetronic and other home made stuff, works fine for me :D :D and olds engines are cheap here in finland;)

Asked this on the MTS board but didn't get the type of answer I was looking for. What are the essentials to have on a mild 500 Caddy engine? So far I know I should swap the timing chain because the stocker is nylon and I should also get the Edelbrock alum. intake. Other than that are there any other mods necessary to make this motor any more reliable? I have heard some stuff about the stock valvetrain being weak, but is that just for higher revving situations or is that another necessity to be addressed?

Originally posted by DriveTime
Asked this on the MTS board but didn't get the type of answer I was looking for. What are the essentials to have on a mild 500 Caddy engine? So far I know I should swap the timing chain because the stocker is nylon and I should also get the Edelbrock alum. intake. Other than that are there any other mods necessary to make this motor any more reliable? I have heard some stuff about the stock valvetrain being weak, but is that just for higher revving situations or is that another necessity to be addressed?

From my chat with Al(owner of MTS), I got the following:
1) The rockers are unreliable if you are going to be reving more than 5k. He and others make replacements.
2) ANY headers are better than the stock exhaust manifolds.
3) If you go with any of the "aggresive" cams, you will probably need to have the valve stems machined shorter as well as new springs.

You are right about the timing gears. The 472 I just rebuild had one and the oil pan was FULL of little nylon bits(as well as the pickup) From what I recall, it was a $40 fix.

To keep my Cady engine reliable, I've rebuilt mine to stock and dropped an HEI distrib in it. In the future, I'll go with the Edlebrok intake and a pair of Sanderson headers. I MAY go with the next cam up that doesn't require any other special mods. I will also be going with a retrofited with a TBI system from a 454. This will include the EFI distributor and VSS.

Can't you use BBC headers on this too? I thought I saw bgreen use them on his engine, but I'm not sure.

Originally posted by DriveTime
Asked this on the MTS board but didn't get the type of answer I was looking for. What are the essentials to have on a mild 500 Caddy engine? So far I know I should swap the timing chain because the stocker is nylon and I should also get the Edelbrock alum. intake. Other than that are there any other mods necessary to make this motor any more reliable? I have heard some stuff about the stock valvetrain being weak, but is that just for higher revving situations or is that another necessity to be addressed?

AFAIK that board is a nightmare. I have asked what I thought were a few simple questions there and the info I got back was wrong or useless and sometimes dangerous. I like Al quite a bit, but those guys on the board are numb nuts.

I hate the layout of those boards..........Vbull all the way

ttt

I've scored a Caddy 500 for my Project 1988 GMC 1-ton 4-dr 4wd. Since last fall I've been researching the info on and off. Below is a little of the info I have found on the MTS board, It Sounds like good stuff but it is also heavily pimping MTS goods...(Fact or Fiction you decide). If it's too long or out of place just let me know....
Michael

Detailed reply to a Detailed Question
In mid December of 1999 a Gary G. posted this question on the MTS internet message board. I thought it was excellent and deserved as good a reply.

Q: Posted by Gary G on 12/17/1999, 6:11 am
207.101.12.2

Al, I wonder if you could tell us a little more about 425 heads on 472/500
engines, especially as they would pertain to my intended application. I wantto make a 1987 one-ton Chevy 4wd (currently with diesel power) into
something that will be FUN to drive both "on-road" and off, while being a
reasonably economical daily driver. I would like to have a very broad torque
curve, and be able to run low 14's in the quarter (all day, every day, with no
special preparation or nitrous). I would also like to get fuel mileage
somewhere in the neighborhood of 18mpg on highway. This is in a 6000lb
truck with 4.56 gears (the 37" tires and overdrive 4th gear combine to give
an effective final drive ratio of about 2.75), and a 4L80E transmission. Do
these goals seem realistic?

I am trying to plan an engine combo that will give me the best balance of
performance vs. efficiency. I'm leaning towards the 472 (maybe amStreetsweeper 484)over the 500, because I believe its shorter stroke and
lighter rotating weight will offer significantly better fuel efficiency, and also
because both of the head types that I am considering are supposed to be
somewhat restrictive at high RPM, which should be less of a problem if they
have fewer cubic inches trying to breathe through them. I think the 472 with
a VT5-type cam, Performer manifold, and fuel injection would probably be
best for me, but I'm uncertain as to whether I should use 425 heads or the
120cc heads. I was surprised to see that your website is relatively pessimistic
about using the 425 heads on these engines, because your catalogs have
been a little more enthusiastic about the idea; your old catalog even said
that they have better exhaust ports than the 120cc heads. I was thinking
that the slightly smaller ports might be just what the 472 needs to give
super-peppy street performance and good fuel efficiency. I am definitely more
interested in throttle response and mid-range torque than top-end breathing.
With that in mind, which head would you recommend?

You may have noticed that I didn't specify a compression ratio, or octane
rating. That's because I'd like to ask what you would recommend for each of
them, given my intended usage and performance goals. Can you give me a
rough notion of how much slower I would be for giving up enough compression
to run 87 octane fuel? Do you think the improved miles-per-gallon of a
higher-compression engine would make up for the higher cost per gallon of
the premium fuel (or even come close), so that the overall operating expense
would not be significantly greater than for the low-compression engine?

I appreciate any insights you can offer me on these topics, Al. I know that's a long grocery list of questions, but I am hoping that maybe since we're
online where LOTS of people can benefit from your answers, not just ME,
you'll indulge me. Thanks a bunch, not just for this question but also for this
great board. G.

A: Let me start by explaining my "pessimistic" view on using 425 Cadillac heads on a 500 engine. The majority of questions asked of me are how to get maximum power out of the 500. Typical hot rodder stuff. More is never enough. This means that usually I direct my reply based on achieving every last horsepower.

That’s the reason for saying that if I were building a maximum effort pump gas 500, I would not use the 425 head to do it. An engine of that caliber can be built better and cheaper using the small chamber early 472/500 heads.

What that above statement doesn’t say is that I personally wouldn’t use that max effort engine in a daily driver. I also don’t think it’s a good choice for a street rod that will see lots of miles.

A "full on" pump gas 500 is going to produce about 435-450hp. It will produce close to 570 ft lbs of torque. With a nasty cam it will idle at 1000 rpm. Barely run power brakes. Need a 3:50 to 4:00 series rear gear. Not to mention suck up 92 octane like no tomorrow. All well and good in a limited use "Saturday night special" car or truck. There is no such thing as too much power for your once in a while boulevard bruiser. It’s just not the hot ticket for a well used daily driver or street rod.

As I stated in my "common Cadillac questions " article. I think the 425 head swapped onto a good running 500 shortblock is a suitable "crutch". It will add 45 dyno proven horsepower to a 1974-76 Cad 500. The conversion will require 92 octane. It will provide a noticeable "feel" to the seat of the pants acceleration of your car. Great results for minimum effort.

However if I were spending the money to fully rebuild a 500 I would choose a different route. Once the need for 92 octane comes into play, the small chamber head 500 engine is my first choice for a rebuild project. Proper choice of camshaft will cure bad idle and mileage concern. To me this is the best way to build a performance 500cid.

I agree with your thoughts on the 472 engine. I am glad to see people are realizing that bigger isn’t always better. This may come as a surprise to many of you. I don’t run a 500 in any of my current vehicles. Here are some of the reasons why.

First of all is the demand for the 500 engine and it’s parts. While not a factor for many of you it is to me. I can’t sell it if it’s between the fenders of my vehicle. Second is the type of driving I do. I daily drive a Cad powered vehicle. I like the slight throttle response advantage the 472 has with its shorter stroke.

My 1983 Chevy Suburban hauls all of the parts for MTS. It also tows home every Caddy parts car we buy. When you fill it to the roof with parts, and hang a Caddy parts car on the trailer in back you’ve got quite a load. I’ve done this dozens of times. I’ve used both the 500 and 472 engines to do it. Here is what I have found.

The 500 has a slight edge in power when the truck is under maximum load. The fuel mpg is identical. The best example is when pulling a full load uphill. When my truck is 500 powered I can press on the gas about half an inch less to tug the load uphill. Going up that same hill with a 472 powering the truck, requires that I press the gas pedal one half an inch further down.

The Suburban is driven empty most of the week. Once a week I work it hard with a load of parts. If I used the truck fully loaded every day. I would opt for the extra grunt the 500 provides.

The Suburban runs a 1972 472 in bone stock form. It gets 15mpg unloaded. 12mpg when fully loaded and towing. These figures are based on a combination city and interstate driving. The usual trip is my 200 mile weekly round trip to Chicago and back.

Part of what triggered my gabby reply to your question was your timing. You hit an area that I am currently working in. I have been experimenting with the 425 engine and heads on several fronts.

I now have a 425 in my 1972 coupe DeVille winter beater. I now have it running as hard as the 472 up to ¾ throttle. It gets much better mpg than the 472. It’s got lot’s zipper throttle response. However when pulling that big DeVille up a steep hill you can feel the missing cubic inches. But that’s only when you are already into the last ¼ of the throttle. I am very impressed with this engine as a daily driver.

Since much of what I am now working on will be future products for the MTS catalog I won’t tell all that’s going on. However I will provide you with a very good point in the right direction.

Your guess is right on. The slightly smaller ports of the 425 heads when used on the "smaller" 472 vs. a 500 will work like a champ. Especially in an engine built for use for 4800 rpm and under. If your engine won’t see much harder use than putting your foot to the floor, and letting the transmission shift by itself. You’re really on the right track.

The use of our lightweight street sweeper package will enhance the street response of the engine. The higher port velocity of the 425 heads will provide greater "snap" and fuel economy.

You are dead on in thinking that the extra power and efficiency from higher compression will almost offset the cost of premium fuel. The cost difference will be slightly higher, but worth the performance. 87 octane fuel would cost you about 35 hp in this case.

By all means for what you want the 425 head on the 472 will meet most of your goals. Hitting your 18mpg target might be tough. You have a lot of rolling resistance with the size tires you are using. Plus truck are not very aerodynamic. However I don’t think that you should miss your target by much.

I have two R&D engines going together as of this writing. Both are based on "smaller" Cad engines. I am a firm believer that the make the better street engine for a majority of projects. The problem is that it’s very tough to break the bigger is always better way of thinking. For now the 472/425 engines are getting overlooked and under used.

According to the factory shop manuals, the cams look like this:

for the years '68, '69, '70

IO 18 BTDC
IC 114 ABDC
EO 71 BBDC
EC 58 ATDC

intake lift .440
exhaust lift .454

ln '71 the opening and closing numbers given make no sense. lt
must be a misprint. But the lift numbers match the '68 - '70.

'72 and '73

IO 34 BTDC
IC 100 ABDC
EO 78 BBDC
EC 58 ATDC

intake lift .490
exhaust lift .490

'74 and '75

IO 21 BTDC
IC 111 ABDC
EO 73 BBDC
EC 55 ATDC

intake lift .457
exhaust lift .473

l don't have access to a manual from '76, but l doubt it's any
different than a '75. The shop manuals make no mention of any
difference in cam specs between the 472 and the 500. Nor do they
make mention of any difference in cam specs between the
Eldorado and anything else, much though the dealers liked to
claim the Eldorado was designed for more "performance",
whatever that means. The carburetors were calibrated a little
differently, but not enough to account for that claim.

The shop manuals state that these cam timing numbers were
taken at .001 of lift, which does not compare to anything today. lt
makes the duration numbers look very long. Using a degree wheel
and a dial gauge, l measured a stock '68 cam. At .001 lift my
measurements match the shop manual specs, within production
tolerances. l also measured it at .006 and .050 of lift. Here is what
it looks like:

at .006

IO 12 BTDC
IC 78 ABDC
EO 62 BBDC
EC 20 ATDC

intake dur. 270
exhaust dur. 262

at .050

IO 17 ATDC
IC 36 ABDC
EO 34 BBDC
EC 13 ATDC

intake dur. 199
exhaust dur. 227

The exhaust lobe is about normal for a stock cam. But the intake
lobe is very strange. At the .050 level, it doesn't open until 17
AFTER TDC (l didn't mistype that). That is extremely late. lt badly
chokes the cylinder for air and fuel on the intake stroke. The 36
degree closing figure doesn't look too bad, but at .006 it's 78
degrees ABDC, which is also very late. Late opening and late
closing on an intake lobe really clobber low rpm torque. The cam
specs for all 472/500 engines reflect these same characteristics,
as do the cam specs for the 390/429 engines from '63 to '67. And
the cars these engines were in always felt sluggish and
unresponsive at low speeds under part throttle acceleration. These
stock cams are absolutely terrible. Even if you're rebuilding an
engine stone stock, use Al's MT3 cam; it will really wake up these
engines compared to the way the factory delivered them by letting
them breathe better.

Other seemingly unrelated side effects of this bad cam are that it
screws up the fuel curve in the carburetor. The fuel curve can't be
made correct under all throttle positions and rpms, no matter
what is done to the carburetor. l've tried it, and it's impossible.
Only when a well designed cam is used can the carburetor operate
the way it was designed to and provide a correct fuel curve under
all conditions. The other side effect of the bad stock cam is that it
makes the transmission shift weird, which is really only noticeable
if a shift kit has been put in it. Right before a shift when rpms are
high the power starts to feel pretty good, but after the shift the
power output drops so far that it makes the transmission feel like
it lurches and slams into gear. But put in a well designed cam and
suddenly the transmission shifts completely differently.
Transmissions from Cadillac were calibrated to shift very softly
and it nicely covers up the power output drop from one gear to
the next. But the cars are left feeling very lethargic.

Have l answered your question yet? l also tried to explain what the
stock cams are all about.

Lynn


In Reply to: Re: Stock Cams, GREAT Info for we uneducated! posted by Steve on January 28, 2004 at 14:14:20:

Those of you who have been trying to calibrate a carburetor on
top of a stock motor and haven't been able to get the results you
want, and those of you who put a shift kit in a transmission
behind a stock motor and didn't like the way it shifted, you know
what l'm talking about when l describe these strange side effects.

l have a '68 Cadillac convertible that l had for many years thought
was sluggish and unresponsive at part throttle. l'd step down on
the gas, l could hear the engine load up, and not much would
happen. l had the impression the engine couldn't breathe very well
and blamed it on the carburetor. l had been using an air/fuel ratio
gauge and a vacuum gauge to calibrate my carburetor and for two
years l chased around a bad spot in the fuel curve. lt was either
too rich somewhere or too lean somewhere else and no matter
what l did to the carburetor l couldn't get it straightened out.
Frustrated, l put the carburetor on another car on which l also had
an air/fuel ratio gauge installed and suddenly the carburetor was
fine. l put the other car's carburetor, which had been fine, on this
one, and suddenly it had the same problem. l was amazed to
realize the problem was not with the carburetor but it still took a
while to figure out what it was. l had also noticed a habit of
stepping down farther on the gas just after each upshift of the
transmission to compensate for the car feeling like it was slowing
down, but l still blamed this on the carburetor not flowing the
right amount of fuel when the air velocity through it changed.

Some 15 years ago l tried a shift kit in the transmission. l used
B&Ms kit at the stage one level. The transmission shifted so rough
and harsh that it wasn't long before l took it out.

About four years ago l finally got around to putting together a 472
with an MT10 cam l had bought from MTS about 10 years ago.
When the block was on the stand was when l measured the specs
of the stock cam and also the MTS cam. When l got it together and
in the car, l realized how much differently the engine ran, even
with an as yet unmodified carburetor and transmission. The
engine didn't feel sluggish at all; it felt like it had unlimited
energy. l could see on the air/fuel ratio gauge that the fuel curve
was operating completely differently, and it didn't take very long
to calibrate the carburetor and get what l wanted out of it. l
modified the transmission to shift even more firmly than B&Ms
stage one. lt's still comfortable and l may yet go even farther with
that. Just after the shift at the lower rpms the engine still pulls just
as hard as it did right before the shift, rather than feeling like it
slows down, and this completely changes the feel of the shift. The
difference is incredible. l realized that it was getting rid of the
stock cam that made all the difference. l don't know what the idea
was behind the intake lobe design. lt's very strange. lt doesn't
make any sense even from an emission controls standpoint. The
stock cam does nothing but cripple the motor badly.

One might think at first that a late opening and closing intake lobe
just means that the cam is ground several degrees retarded, but
that's not the case here. The point of peak valve lift is in a fairly
normal place, and it's not anywhere near the midpoint of the valve
opening and closing numbers. The opening ramp is late and fast
and the closing ramp is late and slow, which makes a lopsided
cam lobe, about like an egg that's flat on one side. lf the opening
and closing ramps had been designed correctly, the stock cam
probably wouldn't be too bad. The cams in the 390/429 motors
from '63 to '67 are the same way, which is why l asked Al in an
earlier post if he had considered making cams for that engine.
Give those poor engines some help!

Any well designed aftermarket cam from any manufacturer will fix
the problems created by the stock cam. l like Al's MT series the
best because they have appropriate valve timing figures, and they
have the most lift for a given amount of duration compared to
some others l've looked at. Even the small MT3 cam will run better
than the stock one and it will idle as smooth as glass because the
duration is short and valve overlap area is so small.

l wrote all that to say that those of you who have been driving a
'68 to '76 Cadillac (or even a '63 to '67) with a stock motor can
relate to the car feeling like this, even if you haven't realized there
was really a problem, and even if you have never tinkered with the
carburetor or the transmission. lt's easy to blame the slow feel of
the car on its weight. Those who talk about this engine having
good performance even in stock form, at the risk of being
insulting, don't know much about performance and were probably
used to the power levels of a smallblock Chevy. The only reason
the Cadillac engine had any performance at all stock is because of
its massive displacement. To those who have never driven one of
these engines in stock form, all this information is fairly worthless.
You put in an aftermarket cam and get all the benefits without
even realizing all the problems you eliminated in the process.

My suggestion is to pull the stock cam out, tie it in a knot (cartoon
style), and toss it in a creek, even if you don't like modifying
Cadillacs and want leave the rest of the car stone stock. Hey Al, if
your cam sales go up this month do l get any kickback? Just
joking. Not serious.

l also did all the other usual stuff to warm up the engine. Next
summer l want to put it on a chassis dyno and see just what it's
making. We have one in town where l live. Yes, l have been
rewarded by having a rather fast '82 Coupe. ln the stoplight wars
no one ever even inches ahead of me unless l'm not trying. The
worst that ever happens is that someone keeps up with me, but
even that is uncommon. Usually they get a good look at the
taillights of a Cadillac.

Lynn

http://www.cowboyseven.us

A much better Caddy performance board using the yabbse (pirate) format.

got a 455 pontiac in my truck and its a torque monster

most of these big engines didnt get abused much in their lifetimes so they still have alot of life left in them used, to get to the point for about 2 grand i`m making 576 ft lb`s on pump gas and knocking down 14mpg with 38`s.

kinda funny that everyones talking Caddy, I would have thought the cheaper and better approach would be an Oldsmobile engine.
the reason I say is because the majority of the 5.7 diesel trucks are still creeping around , and if you pull the engine then the Olds Gas engine is a straight bolt in. the bell housings the same(on Buick, Olds and Caddy) and the TH350 trans will hold up just fine. I have done the Caddy swaps in the past and they were pretty easy. just pulled out the old 5.7 diesels. but the one thing I wondered. how do find the power of the caddys? given that they are all road based engines designed for low rpms and tall highway gears.
I think dollar for dollar you could build 5 Olds for every caddy, and still be ahead.

My 500 Caddy cost me $150 fully dressed but no dist. I've still got to adapt it to the turbo 400 GM (fresh reman) in the 1-ton and work out the engine mounts. I figure with 37's to 44's the Low grunt of the Caddy motor should be just about right with the stock gears. 4.11:1 with 37" Goodyears should put me at about 2500 RPM at 60 MPH, Right in the meat of the Caddy's torque curve..

I figure I can get the Caddy in the truck running for $500, and maybe swing the MT-3 cam and Sanderson headders + running in the truck for $1k. (including all exhaust work and consumables)

The 1976 Hurse only had just under 40k and it was a comercial Non emissions set up.

The early 70's Buick 455 had impressive torque numbers at fairly low RPM's.

The numbers I have are as follows:
1970 455 355hp 510 tq

If memory serves me, I believe it reached that torque rating at around 2700 or 2800 RPM
I forgot, weight of engine is 600lb

kinda funny that everyones talking Caddy, I would have thought the cheaper and better approach would be an Oldsmobile engine.
the reason I say is because the majority of the 5.7 diesel trucks are still creeping around , and if you pull the engine then the Olds Gas engine is a straight bolt in.

AFAIK, the only 5.7/350 diesels in trucks were in '79-'81 C-10s (1/2 ton 2wds). And I've only seen a handful of them.

Pete

I'm running a 74 Caddy 500 in my 74 chev 3/4 ton and i have to say even in stock form this motor is amazing. the numbers i have are 250 HP with 550 lb of torque. I'm going to run a dyno later on and see how close those numbers are. The earlier engines (1970ish) were higher compression (10:1) and had a lil more HP but the 74 i have 8.5:1 likes pump gas more.

Who thinks these engines are expensive? I found mine in an el camino bought the car for $450 took out motor and trans and then sold the rest of the camino for $600. I made out like a bandit since there was absolutly nothing wrong with the engine except for a cracked flexplate and a bad power valve on the Holley Carb.

A caddy 500 is an awesome engine for crawling. I've been rolling up hills with 4:10 gears under 1000 RPM with no bog, no lack of power or torque, and i can still hit the gas on the road and eat imports alive. I came by the engine more or less by accident but I'm glad i have it now.

Here are a few good caddy websites:

Caddy BB Forum:
http://www.cadillacforums.com/forums/forumdisplay.php?f=77

Maximum Torque Specialties: http://www.500cid.com/

Caddy Shack: http://www.geocities.com/MotorCity/Pit/9364/guide/preface.html

Cad Company: http://www.cad500parts.com/

Lots of good Cadillac Stuff!

I ran a 75 cad 500 in a 74 K10 short bed w/4 spd. I now run a FI 454 in a 77 Blazer w/4spd (TBI from 89 K30). For driveability, the Cad was quiter, smoother and pulled better. It was a pleasure to drive. However, I drive a Chevy for parts availability. I would trade off some of the Cad benefits for a simple and lower cost maintenance routine.

According to the factory shop manuals, the cams look like this:

for the years '68, '69, '70

IO 18 BTDC
IC 114 ABDC
EO 71 BBDC
EC 58 ATDC

intake lift .440
exhaust lift .454

ln '71 the opening and closing numbers given make no sense. lt
must be a misprint. But the lift numbers match the '68 - '70.

'72 and '73

IO 34 BTDC
IC 100 ABDC
EO 78 BBDC
EC 58 ATDC

intake lift .490
exhaust lift .490

'74 and '75

IO 21 BTDC
IC 111 ABDC
EO 73 BBDC
EC 55 ATDC

intake lift .457
exhaust lift .473

l don't have access to a manual from '76, but l doubt it's any
different than a '75. The shop manuals make no mention of any
difference in cam specs between the 472 and the 500. Nor do they
make mention of any difference in cam specs between the
Eldorado and anything else, much though the dealers liked to
claim the Eldorado was designed for more "performance",
whatever that means. The carburetors were calibrated a little
differently, but not enough to account for that claim.

The shop manuals state that these cam timing numbers were
taken at .001 of lift, which does not compare to anything today. lt
makes the duration numbers look very long. Using a degree wheel
and a dial gauge, l measured a stock '68 cam. At .001 lift my
measurements match the shop manual specs, within production
tolerances. l also measured it at .006 and .050 of lift. Here is what
it looks like:

at .006

IO 12 BTDC
IC 78 ABDC
EO 62 BBDC
EC 20 ATDC

intake dur. 270
exhaust dur. 262

at .050

IO 17 ATDC
IC 36 ABDC
EO 34 BBDC
EC 13 ATDC

intake dur. 199
exhaust dur. 227

The exhaust lobe is about normal for a stock cam. But the intake
lobe is very strange. At the .050 level, it doesn't open until 17
AFTER TDC (l didn't mistype that). That is extremely late. lt badly
chokes the cylinder for air and fuel on the intake stroke. The 36
degree closing figure doesn't look too bad, but at .006 it's 78
degrees ABDC, which is also very late. Late opening and late
closing on an intake lobe really clobber low rpm torque. The cam
specs for all 472/500 engines reflect these same characteristics,
as do the cam specs for the 390/429 engines from '63 to '67. And
the cars these engines were in always felt sluggish and
unresponsive at low speeds under part throttle acceleration. These
stock cams are absolutely terrible. Even if you're rebuilding an
engine stone stock, use Al's MT3 cam; it will really wake up these
engines compared to the way the factory delivered them by letting
them breathe better.

Other seemingly unrelated side effects of this bad cam are that it
screws up the fuel curve in the carburetor. The fuel curve can't be
made correct under all throttle positions and rpms, no matter
what is done to the carburetor. l've tried it, and it's impossible.
Only when a well designed cam is used can the carburetor operate
the way it was designed to and provide a correct fuel curve under
all conditions. The other side effect of the bad stock cam is that it
makes the transmission shift weird, which is really only noticeable
if a shift kit has been put in it. Right before a shift when rpms are
high the power starts to feel pretty good, but after the shift the
power output drops so far that it makes the transmission feel like
it lurches and slams into gear. But put in a well designed cam and
suddenly the transmission shifts completely differently.
Transmissions from Cadillac were calibrated to shift very softly
and it nicely covers up the power output drop from one gear to
the next. But the cars are left feeling very lethargic.

Have l answered your question yet? l also tried to explain what the
stock cams are all about.

Lynn


In Reply to: Re: Stock Cams, GREAT Info for we uneducated! posted by Steve on January 28, 2004 at 14:14:20:

Those of you who have been trying to calibrate a carburetor on
top of a stock motor and haven't been able to get the results you
want, and those of you who put a shift kit in a transmission
behind a stock motor and didn't like the way it shifted, you know
what l'm talking about when l describe these strange side effects.

l have a '68 Cadillac convertible that l had for many years thought
was sluggish and unresponsive at part throttle. l'd step down on
the gas, l could hear the engine load up, and not much would
happen. l had the impression the engine couldn't breathe very well
and blamed it on the carburetor. l had been using an air/fuel ratio
gauge and a vacuum gauge to calibrate my carburetor and for two
years l chased around a bad spot in the fuel curve. lt was either
too rich somewhere or too lean somewhere else and no matter
what l did to the carburetor l couldn't get it straightened out.
Frustrated, l put the carburetor on another car on which l also had
an air/fuel ratio gauge installed and suddenly the carburetor was
fine. l put the other car's carburetor, which had been fine, on this
one, and suddenly it had the same problem. l was amazed to
realize the problem was not with the carburetor but it still took a
while to figure out what it was. l had also noticed a habit of
stepping down farther on the gas just after each upshift of the
transmission to compensate for the car feeling like it was slowing
down, but l still blamed this on the carburetor not flowing the
right amount of fuel when the air velocity through it changed.

Some 15 years ago l tried a shift kit in the transmission. l used
B&Ms kit at the stage one level. The transmission shifted so rough
and harsh that it wasn't long before l took it out.

About four years ago l finally got around to putting together a 472
with an MT10 cam l had bought from MTS about 10 years ago.
When the block was on the stand was when l measured the specs
of the stock cam and also the MTS cam. When l got it together and
in the car, l realized how much differently the engine ran, even
with an as yet unmodified carburetor and transmission. The
engine didn't feel sluggish at all; it felt like it had unlimited
energy. l could see on the air/fuel ratio gauge that the fuel curve
was operating completely differently, and it didn't take very long
to calibrate the carburetor and get what l wanted out of it. l
modified the transmission to shift even more firmly than B&Ms
stage one. lt's still comfortable and l may yet go even farther with
that. Just after the shift at the lower rpms the engine still pulls just
as hard as it did right before the shift, rather than feeling like it
slows down, and this completely changes the feel of the shift. The
difference is incredible. l realized that it was getting rid of the
stock cam that made all the difference. l don't know what the idea
was behind the intake lobe design. lt's very strange. lt doesn't
make any sense even from an emission controls standpoint. The
stock cam does nothing but cripple the motor badly.

One might think at first that a late opening and closing intake lobe
just means that the cam is ground several degrees retarded, but
that's not the case here. The point of peak valve lift is in a fairly
normal place, and it's not anywhere near the midpoint of the valve
opening and closing numbers. The opening ramp is late and fast
and the closing ramp is late and slow, which makes a lopsided
cam lobe, about like an egg that's flat on one side. lf the opening
and closing ramps had been designed correctly, the stock cam
probably wouldn't be too bad. The cams in the 390/429 motors
from '63 to '67 are the same way, which is why l asked Al in an
earlier post if he had considered making cams for that engine.
Give those poor engines some help!

Any well designed aftermarket cam from any manufacturer will fix
the problems created by the stock cam. l like Al's MT series the
best because they have appropriate valve timing figures, and they
have the most lift for a given amount of duration compared to
some others l've looked at. Even the small MT3 cam will run better
than the stock one and it will idle as smooth as glass because the
duration is short and valve overlap area is so small.

l wrote all that to say that those of you who have been driving a
'68 to '76 Cadillac (or even a '63 to '67) with a stock motor can
relate to the car feeling like this, even if you haven't realized there
was really a problem, and even if you have never tinkered with the
carburetor or the transmission. lt's easy to blame the slow feel of
the car on its weight. Those who talk about this engine having
good performance even in stock form, at the risk of being
insulting, don't know much about performance and were probably
used to the power levels of a smallblock Chevy. The only reason
the Cadillac engine had any performance at all stock is because of
its massive displacement. To those who have never driven one of
these engines in stock form, all this information is fairly worthless.
You put in an aftermarket cam and get all the benefits without
even realizing all the problems you eliminated in the process.

My suggestion is to pull the stock cam out, tie it in a knot (cartoon
style), and toss it in a creek, even if you don't like modifying
Cadillacs and want leave the rest of the car stone stock. Hey Al, if
your cam sales go up this month do l get any kickback? Just
joking. Not serious.

l also did all the other usual stuff to warm up the engine. Next
summer l want to put it on a chassis dyno and see just what it's
making. We have one in town where l live. Yes, l have been
rewarded by having a rather fast '82 Coupe. ln the stoplight wars
no one ever even inches ahead of me unless l'm not trying. The
worst that ever happens is that someone keeps up with me, but
even that is uncommon. Usually they get a good look at the
taillights of a Cadillac.

Lynn


IM NOT MUCH OF A DODGE FAN BUT ONE OF MY BUDDYS OWNS A PLACE HERE IN PHX CALLED RELIABLE DIESEL AND FOR ALL THE THINGS THAT YOU ARE WANTING THAT BIG TRUCK TO DO YOUR BEST BET WOULD BE TO STUFF A 24 VAVLE CUMINGS DIESEL IN IT. WITH A FEW MODS WITH THE TURBO AND EXHAUST AND A CHIP/PROGRAMER GETTING THAT THING TO RUN 14'S ON 37'S WOULD BE A LITTLE CLOSER TO REALITY AND LESS WORK, PLUS BETTER MILES PER GALLON. IM THINKING SERIOUSLY ABOUT PUTTING ONE IN MY 2000 C2500 CREW CAB SHORT BED FOR TOWING, MY BUDDY SAID HE CAN DO THE COMPLETE SWAP WITH MOTOR IN CLUDED AND INSTALLED FOR AROUND $6,000. AND I GUESS WIRING THEM IN ARE EASY ITS ONLY LIKE 4WIRES SO IM TOLD.
ROWDY

68-69 472 ci 375hp@4400 525torque@3000 compression 10.5:1


1970 472 ci 375hp@4400 525torque@3000 compression 10.0:1

1970 500 ci 400hp@4400 550torque@3000 compression 10.0:1

1971 472 ci 345hp@4400 500torque@2800 compression 8.5:1

1971 500 ci 365hp@4400 535torque@2800 compression 8.5:1

1972 472 ci 220hp@4000 365torque@2400 compression 8.5:1

1972 500 ci 235hp@3800 385torque@2400 compression 8.5:1

1973 472 ci 220hp@4000 365torque@2400 compression 8.5:1

1973 500 ci 235hp@3800 385torque@2400 compression 8.5:1

1974 472 ci 205hp@4000 365torque@2400 compression 8.5:1

1974 500 ci 210hp@3600 380torque@2000 compression 8.5:1

1975 500 ci 210hp@3600 380torque@2000 compression 8.5:1

1976 500 ci 190hp@3600 360torque@2000 compression 8.5:1

472= 4.300 bore 4.060 stroke
500= 4.300 bore 4.304 stroke

I know this is an old thread but still a great topic

Cad 500 is an awesome mill if you can find one. 472 is no slouch either. The blocks were excellent castings and usually they last a very long trouble free life.

Folks use them a lot down here on airboats because of their great torque and relatively light weight. They do pretty good running the propeller right off the crank, but when you add a gear reduction they turn into a monster.

Only things that really need to be changed is the intake manifold, exhaust manifolds, and the cam.

Stock intake is a sunken-in design and you can save weight by switching to aluminum

Cams are usually smog freindly which means they suck. Get a new cam and some headers

Top with your favorite carb and you have a mega torque monster

Wish I could find one down here cheap but most in this area know they are great airboat motors and want a lot for them

Potter Automotive in Soddy Daisy, TN makes a lot of great stuff for these motors and really knows how to get a lot of power out of them