507 Cadillac - Build

CanadianC10

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Well as you all know my 68 472 no longer lives, and for a few weeks there I was unsure of what to do next, 383 stroker was popping in and out of my head and maybe another cadillac, but I've decided to go with another cadillac, this time not cut corners to save cost, seeing as I have just started a career in the royal Canadian airforce and have some money to play with, I'm looking for a 10:1 450 to 500 horse cadillac, so far I have 2 sets of 76cc heads, MTS springs, Edelbrock Intake, pertronix ignition, #10 Cam. I will go as far as forged rods and pistons but I don't plan on spray so I might cut out the forged pistons, tell me where to start, 72 5200 block, any input would be great, this thread will move slow
 

yellowroket

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Re: Another cadillac build

Your biggest focus needs to be in the heads and valve train. Going to need oversized valves,some decent porting and probably an mts15 or equivalent cam. Will need a set of roller rockers too. I dont believe you can run enough cam to get those numbers with the stockers atleast not with any kind of reliability.

Robbie
 

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Re: Another cadillac build

My 68 472 wasnt quite 450 to 500 horse, but it certainly got up and went. Id say it wasnt far off. That was a stock bottom end with ARP rods, and cast pistons. MTS #15 cam, cloyes timing roller set, ARP main studs and head studs, stock 76cc heads with MTS SS springs, and the old MTS econo shaft rockers. Edelbrock intake, and edelbrock 750cfm carb. Holley Black electric fuel pump, with 1/2" fuel line everywhere. If the head gasket hadnt blown, that was a very competent engine. And if I didnt have a 500 laying around and an itch to try new build ideas, I would have just rebuilt it as is. My favorite part about this engine was it was almost impossible to hear the lopey cam, or to tell that anything was out of the oridinary in the engine. But once you got past 2000rpm it would want to rev to the moon.



If I were to do my actual rebuild again, I would take Robbie's comments to heart. HEADS AND VALVETRAIN!

Figure out what you need for those, and build the rest to stand up to the punishment. If you can afford, I would recommend starting with a roller camshaft and roller rockers. The benefits of a roller cam are littered all over the internet. Its the "have your cake and eat it to" kind of part and the price isnt far off from what the BBC guys pay.

Then if you can still afford it, a set of CNC ported aluminum heads. Another option is ported 76cc heads. MTS ported my 76cc heads for a decent price. Not cheap, but not nearly as much as the aluminum heads. Its a conservative ported head, with higher flow numbers and zero compromise in port velocity for high efficiency.

I think you're SOL for skimping on the pistons. Unless you want to use 120cc heads, you will need the forged pistons (or hypers) to get the proper compression ratio.

Youre looking at probably $4000 worth of parts here, plus machining costs. Bore and hone. Line bore the mains to high side of spec (DO NOT CUT THE CAPS BEFORE DOING THIS), throw some bearings and gaskets at it, and have at it.







Failing those two options, wait for someone looking to get out of the hobby or offload the parts on this site, and swoop in and scoop it up at a CSOB kinda price! lol :bolt:
 

CanadianC10

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Re: Another cadillac build

Just bought a running 72 500 for a base engine, from an elderado, and the pan looks to be in good shape so that's a bonus, I have to try and pull the motor from the car sometime before next week but a hurricane is supposed to land here on the weekend, ill have to physically confirm but I believe this year has the 76cc with the soap dish pistons for the 8.5 to 1 CR.

yellowroket and frankenregal,
Roger on the heads and valvetrain, as for Cnc ported heads I don't think there in the budget for this build, since it will be spread out over a period of time I like the idea of dropping money on a roller cam, and everything to support it, I would like to see what kinda of numbers I can get with home ported heads, with some input from everyone on the board, I might try to tackle that, but if its impossible, MTS would be the next step, a 2.19 valve should help much, and leave the exhaust valve alone, last time I checked it was 375 plus 100 dollars shipping to do a valve job about 5 hours away from me [ closest place ]

For the bottom end I was thinking if the crank turns fine on disassembly then the mains wouldn't need a hone, but Im not 100% sure on how that works and if it is beneficial
From your guys past experiences what rpm am I looking at and is balancing necessary?
Thanks :beer2:
 

CanadianC10

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Re: Another cadillac build

Was looking at combos and ets and I like how Cadillacs R Us engine worked, the 509 that is, he dynoed 488/582 which are in the range I'm looking for, and His et showed with traction it will put me into the low 13s where I want to be with some traction work, as he stated there was much port work done to his 76cc heads by potter.

I want to consider options for improving the blocks oiling system, this thread will be as in detail as possible with many pictures once I get my computer back, typing on this iPhone is driving me up the wall
 

CanadianC10

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Re: Another cadillac build

Was looking at combos and ets and I like how Cadillacs R Us engine worked, the 509 that is, he dynoed 488/582 which are in the range I'm looking for, and His et showed with traction it will put me into the low 13s where I want to be with some traction work, as he stated there was much port work done to his 76cc heads by potter.

I want to consider options for improving the blocks oiling system, this thread will be as in detail as possible with many pictures once I get my computer back, typing on this iPhone is driving me up the wall
 

PROSTOCKTOM

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Re: Another cadillac build

CanadianC10 said:
I like the idea of dropping money on a roller cam, and everything to support it
If you're not going to use CNC ported Iron Heads or MTS aluminum heads I would not even consider spending money on a roller cam.

I would build a solid foundation right now. This means a balance short block with good rods and pistons. You also should plan on buying

MTS rockershafts with any cam over a MTS10 from the start.

It's kind of like building a house, you can change the counter tops and the carpets later on, but it's damn hard to pour a new foundation

once the house is on it. Take your heads and have big valves installed along with your home port job and an MTS 20 cam. You'll get a good

bang for your buck. Don't worry what kind of power and torque it makes your seat of the pants dyno will tell you it's strong and healthy.

Later on if feel the need to spend a lot lot more money to gain a 100 HP then add the roller cam and nicer heads. Odds are if you get what

I described above built you'll probably have a lot more engine than you ever imagined you would.

Tom
 

Darius

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Re: Another cadillac build

PROSTOCKTOM said:
CanadianC10 said:
I like the idea of dropping money on a roller cam, and everything to support it
If you're not going to use CNC ported Iron Heads or MTS aluminum
heads I would not even consider spending money on a roller cam.


I would build a solid foundation right now. This means a balance short block with good rods and pistons. You also should plan on buying MTS rockershafts with any cam over a MTS10 from the start.It's kind of like building a house, you can change the counter tops and the carpets later on, but it's damn hard to pour a new foundation once the house is on it. Take your heads and have big valves installed along with your home port job and an MTS 20 cam. You'll get a good bang for your buck. Don't worry what kind of power and torque it makes your seat of the pants dyno will tell you it's strong and healthy.

Later on if feel the need to spend a lot lot more money to gain a 100 HP then add the roller cam and nicer heads. Odds are if you get what I described above built you'll probably have a lot more engine than you ever imagined you would.

Tom
I agree with Tom's approach and advice.

Best,

d
 

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Re: Another cadillac build

Tom has a solid approach.

Just keep in mind, Cadillac had some high precision and tight tolerances when they built these brutes back in the day. Line honing isn't always necessary (especially if the main bores are to spec), but a 40+ year old engine with multi miles on it may not have all the bores 100% concentric. This is why I chose to have a line hone done. If you do this, do not cut the caps! chances are the bores will be within spec, and Cadillac held the bore spec to a better tolerance than you will achieve at the machine shop. Its round and square and true and usually doesn't need the caps cut.



With new pistons its a good idea to have it balanced. A lot of guys can get away without doing so because they don't turn the engine that high in revs, but there are harmonics and forces you are introducing without it. The factory had a bit of tolerance between rotating assembly weights from cylinder to cylinder. I say if you are outside this tolerance you need balancing.
 

hertzdaddy

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Re: Another cadillac build

My 514: Dynoed 496HP/560TQ (with a very leaky valve seal)- hand ported Iron heads, flat tappet hyd cam, bulldog single plane intake, Holley 850DP, 1 3/4" headers, MTS shaft rockers. You can reach your goals without a roller cam.
 

CanadianC10

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Re: Another cadillac build

Eric, at what rpm?? And what size valves?

Thanks for the input everyone

Tom, what size valve do you think would be best? Does the exhaust valve need to be larger?

Started unbolting the 72 500 today, I can take anything off the car and it looks to be all there so if someone needs something let me know ASAP cars a eldorado, and I'm gonna be selling the exhaust manifolds too I have 2 sets as it is, I just hope the bolts aren't seized solid and will have to be drilled out.

I'm glad I found a block with a good oiling system, apparently this motor has no miles but they all say that, antifreeze was dark green and looked brand new so I can't see it being cracked, said he coated the cylinder walls in oil before be layed it up. Will have the motor out this weekend and stripped.
 

PROSTOCKTOM

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Re: Another cadillac build

CanadianC10 said:
Eric, at what rpm?? And what size valves?

Thanks for the input everyone

Tom, what size valve do you think would be best? Does the exhaust valve need to be larger?

Started unbolting the 72 500 today, I can take anything off the car and it looks to be all there so if someone needs something let me know ASAP cars a eldorado, and I'm gonna be selling the exhaust manifolds too I have 2 sets as it is, I just hope the bolts aren't seized solid and will have to be drilled out.

I'm glad I found a block with a good oiling system, apparently this motor has no miles but they all say that, antifreeze was dark green and looked brand new so I can't see it being cracked, said he coated the cylinder walls in oil before be layed it up. Will have the motor out this weekend and stripped.
If you just going to street drive it I would use 2.11"/1.77" Pontiac size valves. If your going to race it or hard street drive it with a MTS 20 in it

I'd use a 2.19"/ with the 1.77" or a 1.84" if you really feel the need, but for my money I would stay with the 1.77"

Tom
 

dave brode

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Re: Another cadillac build

There will be much less hand work needed in the bowls with 2.11/1.77 valves. [45* for RAIV/edel heads]
 

dave brode

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Re: Another cadillac build

CanadianC10 said:
I'm glad I found a block with a good oiling system,


Better than 68/69, yes. However, some passages on the early 5200 blocks are smaller than on later 5200 blocks. When did the changes occurr? I don't know, but a '71 and a '76 block are different for sure. There are threads on the subject. That said, a 5000-5500 rpm 500h/600t engine would probably be fine either way.
 

CanadianC10

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Re: Another cadillac build

Good to know, thanks Dave

Is there much detail into porting heads in the MTS tech guide?
 

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Re: Another cadillac build

Tom is dead on on all points. There are many threads here with pictures of quality sensible head porting for all three style of Cadillac heads. The search button is your friend.

Maddog
 

dave brode

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Re: Another cadillac build

CanadianC10 said:
Good to know, thanks Dave

Is there much detail into porting heads in the MTS tech guide?
I doubt it. Ditto Maddog.

I would first ask your choice of shops how close they can get the valve tips when cutting the seats for larger valves, with NO trimming on the tips. They need to be +/- .005". If they aren't willing to do that, find another shop.

In some cases, a ready to run ported head is not a bad deal. Do the math on all the machine shop costs, and figure 30-40 hours of hand grinding. And, the risk of screwing stuff up.

Dave
 
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Re: Another cadillac build

Ditto what Dave said. I went through the hassle with different valve stem height between in/ex. Requires different keepers to adjust spring height and different length pushrods to get the proper lifter preload. Then the geometry of the rocker is still different between the in/ex and there is no way to adjust that on individual cylinders between the intake and the exhaust. If you are planning on doing much work on the head see if they will rough in the seats and then do the final work later. That way if you slip with the die grinder hopefully the seat can be finished without recessing the valve. May cost extra with another trip to the machine shop but one slip is all it takes.
 

dave brode

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Re: Another cadillac build

And it you slip badly, you are talking a seat insert, or cutting all of the seats way lower to fix it

I'm not pro, but some of the work that I've seen shops actually charge for is terrible.
 
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