Hello all...I have a '73 Coupe deVille. I am getting my 472 rebuilt soon. The place that I have selected to do the work is asking me if I want any performance modifications/accessories/dressing the engine. So I'm asking for your opinion. Pretend money is no object (ha ha). If you had a stock 472, what would you do? She already has dual exhaust. Other obvious mods would be removing the smog pump and switching to HEI, but beyond that...? What's your fantasy 472 and why? Thanks!!
Me being me, I would absolutely get the heads ported/polished and spec out the right cam for making some extra power. Anything that isn't necessary but stealing power away would get tossed. HEI definitely. Turbo? Twins? The possibilities are endless. I would also get a FI kit for it too - but that's based on "money no object" haha
Cat,
You have quite a range of choices. You can go full out and end up like my 73 which is just barely street able, though 12 second quarter mole times are assured, or since you are rebuilding the motor you can go to 10:1 forged pistons and an MTS #5cam. That combination will get you just about as much HP as the stock rear end can put to the ground without a continuous one tire fire. Of course if you go to a much bigger cam with the valve train it will require, some head work will help.
I would suggest you contact Paul at MTS and talk about your expectations with him.
Just for reference I have attached the U-tube link for my motor.
https://youtu.be/3FyiMlsIdr8
Let us know how it works out.
Greg Surfas
I am currently rebuilding my 68 472cui - you can follow me here: http://forums.cadillaclasalleclub.org/index.php?topic=130360.180 (http://forums.cadillaclasalleclub.org/index.php?topic=130360.180)
Here is what I am planing on doing so far:
1) replace the 8.5:1 pistons with 10.5:1 from egge.com
2) moly rings
3) Cam #5 from MTS (or similar lunati or comp cams)
4) Maybe slightly larger valves, but only if I put hardened valve seats in
5) fresh timing chain
6) rebuild distributor HEI
7) light cleanup of the manifold and intake (no real porting)
My engine already has the 76cc camber.
I think this combination will work good for me, I use it as a nice cruiser.
@Greg: What "light" modification would you recommend?
Best regards,
Nicolas
Actually, if it is performance you are after, convert it to a 500.
The next best thing you can do after all the machining is done is a good balance job.
Bruce. >:D
Quote from: DeVille68 on November 21, 2017, 03:59:06 PM
I am currently rebuilding my 68 472cui - you can follow me here: http://forums.cadillaclasalleclub.org/index.php?topic=130360.180 (http://forums.cadillaclasalleclub.org/index.php?topic=130360.180)
Here is what I am planing on doing so far:
1) replace the 8.5:1 pistons with 10.5:1 from egge.com
2) moly rings
3) Cam #5 from MTS (or similar lunati or comp cams)
4) Maybe slightly larger valves, but only if I put hardened valve seats in
5) fresh timing chain
6) rebuild distributor HEI
7) light cleanup of the manifold and intake (no real porting)
My engine already has the 76cc camber.
I think this combination will work good for me, I use it as a nice cruiser.
@Greg: What "light" modification would you recommend?
Best regards,
Nicolas
. The 68 472 had 10:1compression oe. I could see going down to use regular, but something's odd about that piston change.
Dave,
Going to a performance designed forged piston would be a natural if increased performance is what you are after.
Greg Surfas
Forged pistons are not required for street. Clearances required for Forged make for added noise, till the engine gets to the required operating temperature..
Bruce. >:D
Depends what you want to do with the car. Call MTS and discuss it with them.
I was referring to the plan to move up to 10:1 pistons from 8.5:1, when it already has 10:1, agreed, forged pistons are a poor choice for a relatively stock low rpm engine.
With all due respects, the OP stated he wants suggestions for performance improvement which I would interpret as he is going to put his foot in it. Forged pistons if nothing else act as a bit of safety when somehow the octane of the gasoline is below the posted numbers or you have a bit too much advance.
Greg Surfas
I would buy as much as possible or maybe even everything from a place like MTS. They have the experience to know what is the good stuff and what is junk and there is a lot of junk out there today. I made the mistake of letting my shop get some of the stuff and it turned out that was the stuff that caused all the problems. I didn't get any sort of warranty out of them because they didn't do the final assembly. When I did compare prices they always seemed to be competitive on the stuff you could get anywhere so I just got it from them to help them out and make it easy on me too. There are tons of vendors now that don't actually stock anything but imply that they do so you can run into lots of delays or even find out they can't actually get the part.
Make sure the shop doesn't mix up the sensors on the corners of the heads. They look the same but are very different and at this age you may not be able to read any numbers. Just label them front behind alternator and rear brake booster. Also keep bolts sorted there are some that are only like 1/8 different in length or have or don't have a washer that will bite you if they get messed up like the ones that hold the cam sprocket on. You get a guy that has Chevs memorized it may just be used to throwing all the bolts in one pile. On final assembly remind them that the cylinder numbering is basically flipped from typical GM with the odd bank on the right.
If you are staying with stock covers I would spend the time cleaning the original hardware and re using it. IF you are not going stock don't get typical bolts and washers, they won't stay tight especially on things like oil pan. Find a hardware set that is like the OE where most of the bolts have the built in washer.
Have your shop weld nuts on the back of the timing cover for the small 1/4 water pump bolts. They originally just threaded into the 'tin' cover and are easily damaged. The nuts are totally hidden and don't interfere with anything. The way to do it is thread a spare bolt into the original hole then spin the nut down on the back. This will hold it for welding plus align it with the existing threads assuming they are still there.
Have your shop carefully inspect the oil pan. At this age there are often thin spots in the bottom from moisture being trapped. Usually its pretty easy to braze up any thin spots they find. Also make sure the threads for the drain are in good shape and its not bent up.
Make sure the shop takes extra time to knock all the crap out of the oil pickup tube/ screen.
Rocker arms can be a problem. Apparently someone is making replacements but I have not heard good things about the quality. You hate to put sometimes questionable used rockers on a motor you spent a ton on making everything else like new. There are decently priced shaft rocker sets now but they require you to go with new valve covers for clearance so keep that in mind when it comes to the budget and appearance. Some rocker options require machining of the guides which cold also give you more/better seal options.
Most people would be ditching the smog pump at this point. MTS has a pulley set so you don't have to search junkyards. You can use the same brackets, the alternator hides most of the pump part of the bracket or you can just cut the smog part off if you want. MTS has the plugs for the smog holes in the heads. If you don't currently have working AC you can go to the later single groove setup for the AC/PS belt. This leaves plenty of clearance for the HEI cap. The single belt works on the dual PS pulley but looks a little odd since it rides high and has the empty groove. The later single groove press on pulley pump setup is pretty common and easy to find. Bolt on single groove was pretty rare since it was only a partial year thing.
Get your exhaust manifolds cleaned up and surfaced at the same time and put them together with no gaskets like the factory did.
New cam is a decent idea. GM cams from the 70's were a little soft so its likely showing some wear and they were doing strange things with the design to try and cope with low lead and emissions. The cams like the #5 don't seem to hurt the idle so seem to be a good performance boost without wrecking the Cadillac style.
A 73 should have come with the 76 cc (small chamber high comp) heads. To get the lower ratio they went with a massive dished piston. Lots of guys look at those pistons and scratch their heads wondering how that engine could run as clean and smooth as it did with that design. It must have had issues because they only did it for 3 years before they changed the head design so they could use a more traditional piston. 74-76 was the 120cc head.
My research was a few years ago and for a 500 so things could be different today and for a 472. If you want to stay low compression you may want to look into getting the later heads. There may be medium compression options with your existing heads like something in the 9's which is a decent way to go. You get a little more power but it should not be as tricky to tune or sensitive to the gas you use. High compression with your existing heads should be the easiest to do but then locks you into premium gas and a the tune is a little more critical.
Changing to a 500 should not be a huge deal with the motor apart either, difference was just crank and pistons. A place like MTS could likely send you a rebuilt 500 crank ready to drop in.
Once you get an idea what you want to do ask about what pistons and such may be in stock and if anything is on sale. When I did my motor MTS had some 20 over pistons for like a 1/4 the price of the more common 30's. Sadly I think it took 40 to clean up my block.
I've gone through this twice now. The engine just got re-assembled last week and put back in the car. I'm not home, so can't comment on how its running, but this is what I did and here are some of my observations.
First, while MTS can be a source for a lot of parts, they are EXPENSIVE. RockAuto, Jugs, & Summit should have most or all of the parts you would need, Except for a crankshaft - that will be Hard To Find if you need another or want to go to 500 CI. Even amazon has some of the parts needed.
Pistons: I wouldn't go higher than 10:1, its just too high for the gas that's available unless you have access to 100 or 110 octane fuel to mix in. I have Keith Black # 395 pistons (I think) for 10:1 while my original was 10.5:1. The heads were shaved slightly in 2005 so actual compression is a tad higher. I used KB moly rings as well
Cam: I had a comp cam cam put in, don't know the model #, but I can look it up when i get home.
Valves: new valves with original size and hardened seats. No porting of heads or manifolds, but they were cleaned out and the manifolds were ceramic coated this time in 2017.
New timing chain and gears both times
FelPro gasket sets. They have the better quality valve guide seals
I used the original oil pump in 2005 but with the 2017 problem i wrote about on this forum, I got a new pump for the 2017 rebuild. Thoroughly cleaned the pickup and it was fine.
I used all the original bolts in 2005 but got new rod ARP bolts, and a set of ARP main bearing studs and head studs for 2017. You have to have the rods "reconditioned" as well.
I went with the 1970 pulleys to completely eliminate the AIR pump nonsense. I put in a Delco 12SI based Powermaster 150 amp alternator - chrome of course.
I kept the original distributor in 2005 but it was too loose by 2017 so it was replaced. Still points & condenser and when it's running right, a cold start takes about 1/10 of a second.
I kept the 3 port thermal wax switch and have a couple spares as well.
I put in a Crane Cams adjustable vacuum advance kit in. They have them for both points and HEI ignitions.
AC copper plugs, you CANNOT run platinum plugs in a P&C ignition, New Delco 508D wire set.
If you want to keep your climate control, you have to run the factory intake and should run the proper QuadraJet. The Q-Jet is no slouch, when it's properly cleaned and set up. These were rated at 750CFM.
Get someone who knows what he is doing on the climate control R134 will work correctly if it is properly set up ans you can keep the original condenser and evaporate, just the POA / ST needs replacing along with a thorough flush. I had my lines stainless braided.
Get yourself about 5 cans of Hirsch Cadillac Dark Blue engine enamel for the painting.
Here's my engine just installed the day before I went on vacation:
Engine looks great!
I'm ready to see Greg's write up on his ride in the Self Starter............
;)
Working on it Chris. Trying to get a couple of meaningful photos and captions. It is kind of hard to condense a whole lot of activity down to 1500 words. Should be soon.
Greg Surfas
Is 1,500 the max word limit on a submission? You can always go a bit over, because it WILL be edited.
I never wrote about my cars, i need to, at least the 1968 and 1996, and their predecessors.
Quote from: Dave Shepherd on November 21, 2017, 08:56:35 PM
. The 68 472 had 10:1compression oe. I could see going down to use regular, but something's odd about that piston change.
Dave, don't forget that Nicholas is located in Switzerland and the cars GM imported at that time had low compression pistons.
Quote from: cadillacmike68 on November 22, 2017, 09:04:31 PM
Here's my engine just installed the day before I went on vacation:
Nice Job....... ;)
Bobby
Quote from: Bobby B on November 23, 2017, 10:52:30 AM
Nice Job....... ;)
Bobby
. Your are correct, missed that completely!! :-[
+1 on the engine-- Beautiful!
Have the shop actually measure the rockers and pedestals.
I had an issue with mine. They were made in the US and brand new but they each had so much slop they ticked like crazy. I chased my tail all over the place until I found it by accident. I am running the original set now and they are still better than the brand new crap the shop put in.http://forums.cadillaclasalleclub.org/index.php?topic=143600.msg351510#msg351510
TJ is correct on the bolts. They put the wrong bolts my cam sprocket which caused the cam to move forward and back for the 10 seconds it ran before we shut it off. Find out as much as possible about the shop and who will be doing the work. As it turns out the guy who built mine was sick at the end and I think he rushed to get it done. I had to get it out of there quickly before things turned messy when he got sick. He died shortly after I got the engine out so I really had no recourse with the problems I had. Not being cold hearted but just telling it like it is.
Good luck
Jeff
Chiming in here and adding the customary 2 cents, where my goal is a mostly original look, but improved perfromance:
1. Modified stock intake manifold from MTS, where they machine interior of it, gets more torque
2. Modified cam - your choice - this heavy car will never be a racer, would go for the mid performance upgrade, not extreme, as normal driving will not be as nice
3. Modified exhaust manifolds, smoothed out on interior.
4. Stock heads modified by MTS with larger intake and exhaust valve sizes
5. 10 to 1 pistons, that is on my 1970 and it never knocks
6. Get the 1970 pulley set up to eliminate the air pump (MTS sells a kit)
7. Of course, standard stuff, like timing chain, and etc.
I have done the performance intake (item 1) on my 1970 Cadillac RWD 472only (and of course already have items 5, 6 and 7 done). If I ever tear into the engine again will do items, 2, 3, and 4.
Also, I doubt the snorkel allows full air flow the carb will manage, so would install it upside down for normal running and right side up for shows only.
Scot, what MTS does means ? I tried with google, without a good result.
MTS's site is http://www.500cid.com/
Maximum Torque Specialists. I started using 'them' when it was AL in Wisconsin in the early 2000's. I think it goes back to the 90's at least maybe even before Al. I don't think Al was much more than a shop that really liked these engines. AL sold to Marty who was a big time enthusiast in the mid 2000's who moved the operation to CA and really grew it. He took it from enthusiast to a full blown operation with a warehouse and staff and everything. I believe within the last few years they even bought out or merged with the machine shop that was doing a lot of the work so now its all under one roof. So they are pretty much one stop shopping. They distribute new and used parts as well as full rebuild machine shop. They also work with the 'big' names to get or keep parts for these engines coming as well as design and commission their own parts. Marty was the key and usually the one you got if you called. He was the kind of guy that if you just needed to order a nut you could spend a half hour chatting if you wanted to so pretty much everyone felt like they knew him and I would imagine gave him great insight to the customers too. Marty got hit with what now seems the typical not the worst cancer that should be manageable for a while that suddenly turns and you are gone. Marty's brother Paul had work with him the whole time and has kept things going. I have not needed anything the last several years so I have not really been keeping up on what the current status or offerings are but they do seem to still have a good rep on the forums.
MTS Stands for Maximum Torque Specialties, now known as 500CID. http://www.500cid.com/
Greg Surfas
Thanks Greg for the right name!
Quote from: Scot Minesinger on November 26, 2017, 09:07:53 AM
Chiming in here and adding the customary 2 cents, where my goal is a mostly original look, but improved perfromance:...
Also, I doubt the snorkel allows full air flow the carb will manage, so would install it upside down for normal running and right side up for shows only.
That's true. Another possibility is drilling some holes along the bottom of the housing to let more air in. But then you are cutting an original part. You could also get a chrome cap that only covers the air cleaner and then put your regular one on for shows. This would keep your original cover from getting all scratched up when it it is installed upside down...
Hello all! Work on the 472 is progressing nicely. I've attached a few pics.
One question about removing the smog pump...is there a conversion kit of some kind for that?
Thanks for all of your help with this project.
C
Hi Cat, as mentioned above, Cadillac High Performance (used to be MTS) sells a kit to eliminate the smog (A.I.R.) pump.
https://cadillachighperformance.com/collections/big-block/products/chp-bl49-smog-pump-removal-kit
Not cheap, I bought one for my '73 a few years ago and it fits and works well. You can also get some pulleys off a 1970 472 (again as mentioned above) and use those --- no smog pump that year which is what I did on my other 472 engine.
Geoff N.
First please make sure the shop has experience with these engine family 472/500/425. Talk to the man who is working the tools, not the owner of the shop who sells you the job. Their are countless bone head stories about mechanics who mess up these engines on this forum, such as but for sure not limited to switching bolts that hold on oil pick up with cam sprocket (oil pick up are longer and will not tighten correctly). The late 1970's is when many engines became more similar and in this era they were still unique to each GM division. I cannot emphasize knowing the person who will actually do the work enough. Highly recommend you pull the engine and re-install, otherwise count on your climate control messed up among other inconveniences. Then while the engine is out you can clean up the engine bay.
This will never be a racer and it will never be super valuable as an original, and frankly these Cadillacs are already powerful enough, but if it were me at a minimum I would:
General: Keep it so it is a smooth running nice car that you could take your wife out to dinner in.
1. Make the intake a performance type, where the original intake manifold is re-machined.
2. Go with a mild cam improvement, not one that lopes at idle.
3. Of course timing chain set must be replaced
4. Use the MTS modified heads where they re-machine the original heads with larger intake and exhaust ports.
5. Make the compression ratio higher, yet still bale to run on unleaded premium pump gas.
6. Remove the air pump (MTS sells the kit)
7. Remove any heat riser apuratus.
8. Best to utilize used rockers and stands, not new - the new are made very poorly.
Come to think of it, I would probably pay the money and send it to MTS in CA, it ill be worth it to have it rebuilt by them - that is all they do.
The rear end is a 2.93, try to find a Fleetwood that is 3.15 and that will give a little more snap. You can use same case and just replace pinion and ring gears, which would make remote shipping a possiblity (those are left handed bolts I think so be careful).
I just wrote what I would do and it is all a matter of opinion.
Most important, have fun and enjoy your Cadillac!
Catherine, just keep it stock, in good condition that 472 will give you plenty of stomp. Most any modification only ends up bumping up the overhaul price. I would, however, do the A.I.R. eliminator kit and the HEI, or maybe better a Pertronix electronic ignition kit. The HEI will create AC belt rubbing problems because the HEI distributor and cap is much larger around. The Pertronix will fit inside your original distributor.
Geoff N.
Catherine,
In general ANYTHING that you do to these motors to add more power results in the loss of something else. Idle qualit, fuel economy, smooth, low end torque, and sound quality.
I see from your pictures that your machine shop has bored the cylinders .030, and you are using replacement "soap dish" low compression pistons. That said AND if you want the qualities I described above, I would suggest your machine shop carefully examine your old cam shaft. If it is still within standard specs I would use it wit a new set of lifters. 73's are "special". If you need a camshaft replacement I would suggest and MTS #5 cam. Perfect idle and just a bit more low end power and torque.
If you are removing the AIR system be sure and have your carburetor re-jetted and set up appropriately. I used a set of 1970 pulleys (crankshaft and water pump. when I dumped the pump on my 73 and if you have any trouble finding a set PM me. I went crazy and bought a couple at the time.
Cadillac motors were intended to be slow speed torque monsters, and have a designed in weakness to limit the engine speed to something around 4600 RPM. To get to a higher engine speed takes a couple of grand worth of parts. Keep your rear end gears, cruise all day at 75 MPH at something like 2300 RPM.
What I have learned with these motors is you can't go half way, and going all the way really changes things.
Dress up is always an option.
Keep us up on your progress.
Greg Surfas
I like the look of nice clean engine parts. Sometimes I think I would have been happier just putting them on a shelf and just looking at them.
What happened to the front of the crank? In the mostly assembled picture I was thinking it had to be some sort of installation sleeve but then looking at the picture of it sitting on the bench it looks all chewed up there too. The hub is just a press fit on these, I would hate to think of how well its going to fit with that kind of damage.
Other tips from someone that has done one of these engines:
-don't buy one of those cheap or sometimes expensive general hardware kits with normal bolts and washers. They don't stay tight and will be a constant hassle. Clean up the originals or find new ones like the originals that have the built in washers.
-check the oil pump every which way possible. historically they have issues at the end of the pressure bypass valve bore and I had one where the idler gear sized onto its shaft. It made noise from the start but we could not figure out where it came from. A few hundred miles later we found out.
-looks like the timing cover is already on but even so I would consider taking it off to weld nuts to the inside for those bottom 2 bolts in the water pump. Way to common on these to have those strip and end up with leaks.
Thanks everybody, I will bring all of these concerns to the mechanic today.
I'm not changing to HEI; I'm familiar w/ points/condenser and don't want to invite the potential problems. I also think I'll just leave the smog pump on, and not worry about the few hp I might be sacrificing, because I don't feel like messing w/ the carb.
This car has been down over a year and I just want her back.
Thank you again, for all of your valuable input.
C
I second what Scot said about interviewing the actual mechanic. Just search posts under my name and you will see several headaches related to a VERY experienced and we'll recommended shop redoing my engine but not knowing what they were doing.
Also, don't lose control of the build. Have them contact you for everything he is spending. I had a bad piston and needed another. The shop decided it would be better to bore it over and buy a new set so they just did it (It was not badly worn and may not have needed it. They also put in new rockers and pedistals and a new oil pump all of which I didn't ask for and had to replace. Once the engine is buttoned up it is hard to have them pull those parts out.
Jeff
Hoping you can provide a couple clarifications to this HIGHLY useful thread.
Greg - you mention needing to do some carb work if the smog/A.I.R. pump is removed - what exactly? I've seen probably a hundred mentions of ditching the pump, but never once has anyone mentioned carburettor changes.
TJ - Re: welding the nuts on the backside of the engine front cover for the water pump bolts to thread into. This is a great tip...however I just discovered that one of my bolts can spin around in its hole because of a newly-discovered leak. Is there any alternative fix for such a leak, or am I gonna have to bite the bullet and re-remove the front cover and use your bolt fix?
Once again, this thread is a treasure trove of 472/500 info & tips. Since it is recent, I figured it better to add on than develop yet another separate posting.
I have been told that the metric equivalent to the 1/4-20 is slightly larger enough that you can carefully thread one in the damaged hole. I don't do enough metric to know that size off the top of my head.
I'm not sure what mods would be required from removing the smog pump since that is all happening after the exhaust valves. EGR can make a difference so perhaps that gets lumped in with 'all the smog emissions crap'?
This post was started over a year ago, are you enjoying the Cadillac regularly now? How does it run?