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Discussion Starter #1
I wanted to build a 472 that was capable of running NOS, but also a capable engine without it.
I was figuring on getting:
1. Edelbrock intake
2. Stainless Valves
3. New cast stock .040 over pistons w/ rings
4. New rod, cam and crank bearings
5. Cam, springs and lifters
6. Carb tuning kit from Cad. Co
7. Crank scraper from Potter
Heres my question though; can I use a 510-520 lift cam on stock pushrods with stock springs? I want a huge cam, but only up to the point that new rockers are necessary. Also, are Maddog valves any good? I think they're 2.00 and 1.62 stainless. I don't really want to mess with the valve seats. Any other suggestions or does that look okay? Eventually I will also fab up some headers but I don't have a car for this motor yet.
 

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1976 Eldorado project
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No, you can't.

But pushrods and springs aren't much man, and pushrods are included most of the time with the new rockers, from most of the vendors, at least.

Potter sells 2.11/1.77 stainless swirl polished valves for $240 I believe. I'd go with those instead. He can also hook you up with your springs, pushrods, and rockers that will all work with each other. His company is Cadillac Performance Parts

Other vendors include Al @ MTS (Maximum Torque Specialties) and Flashcraft/Cadco
 

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1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
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I'd say a cam in that range would be OK with stock rockers. No way you could get away with worn out weak ass stock springs though.

The valves Maddog sells are pretty much stock replacement. If the valves you have in your motor need to be replaced which is fairly common then they're probably a good choice. 2.11/1.77 valves are oversize, you won't see too much of a gain if you just throw them in without porting a bit.

If you can get away with a hone, do it that way, keep the stock pistons, since it's probably a higher mileage motor have the rods resized and run ARP rod bolts and call it good. I wouldn't hesitate to spray a 200 shot.

If you have to bore it, I'd reccomend using the Olds forged rods and some cheap forged pistons if you want to cheap out on the rods. Olds rods are gonna be around $150 or so, which is nice compared to $500 for aftermarket forged. If you're spraying it, you may as well go for the gold and run forged pistons, they might be a couple hundred over cast but then you can spray it harder and it'll live longer.
 

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1970 Sedan deVille hardtop
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davesdeville said:
If you have to bore it, I'd reccomend using the Olds forged rods and some cheap forged pistons if you want to cheap out on the rods. Olds rods are gonna be around $150 or so, which is nice compared to $500 for aftermarket forged.
What are the little details about running those though? Aren't they a bit longer than the Caddy rods? What about the big end width and rod side clearance?
I'm not trying to criticize at all, I'd like to run Olds rods, but I've heard about Olds rods needing a bit of work to fit a Caddy motor, just haven't seen what the details are.
 

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I'm not too sure, but I'm pretty sure there are some just a tad longer, and then the Olds 7" rods which are a lot longer. Not sure on the details though.
 

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1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
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Olds forged rods are .015" shorter than stock Caddy rods. So mill the deck .015." Yes the 7" are way longer but will work with some of the aftermarket forged pistons such as the ones Al/MTS sells.
 

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Well, I was trying to post, but the 'net took a dump on me and it lost everything I had typed.
So, here's the gist of what I had found. Caddies have a larger wristpin diameter than Oldses, so an Olds rod would have to have the small end honed out slightly.
Anyone know about the rod width though?
I seem to recall the rod journal needs to be turned down as well.
 

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Discussion Starter #9
What'd I need to get if I wanted to get the 270H cam from Comp. Cams? (516/516) lift. Would I really need pushrods or would springs be enough?
 

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1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
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I'm not totally up on Olds rods, they're good for being from a stock motor, but once you're over 600hp they can be a risk. I'm sure the CB7 board has all the info you could ever want on them.

7.0 said:
What'd I need to get if I wanted to get the 270H cam from Comp. Cams? (516/516) lift. Would I really need pushrods or would springs be enough?
With a reduced base circle cam you need longer pushrods. The cam lobes stick up from the "base circle," when the lifter is on the base circle it's not opening the valves. To make bigger lobes, the base circle is made smaller so the lobes essentially stick out more so the valves open more. With a reduced base circle cam and stock length pushrods, the pushrods won't make it all the way from the lifter to the rocker arm.

Springs keep the valves closed when they're supposed to be closed. If you use a bigger cam, it needs bigger springs to return the valve to the closed position. If you use too weak of a spring you'll encounter "valve float" where the valve isn't closing quick enough.

...That answer your question?
 
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