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Discussion Starter #1
There is a guy local to me with a 4 bolt main .060 over 502 block for sale fresh from the machine shop. I know nothing about these blocks. .060 over sounds like a lot to me but it may not be because I am used to small blocks so I have no clue how thick the walls of a big block are.

1. Is .060 safe for a 502 block?

2. How much HP can the block handle reliably?

3. Any known issues with these blocks?

4. Is it a tall deck or short deck block and which one is better?

5. How far can the factory 502 block be pushed (how many cubes can it be stroked out to?)


I have always wanted to build a 540+ cube engine and this may get me started if the block isnt a hunk of junk.
 

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I am not sure about the 502 blocks, but I can tell you the MKIV 427/454 is good to +0.100 some go 0.120. But The block should not be machined without the piston that are going to be used. So your +0.060 bore may be to big for a +0.060 piston, now if is smaller that 0.060 you should be Ok as it can be honed to size depending what the actual bore measures.
 

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You could have the block sonic tested to see what the bore thickness is. :yes: That's really the ONLY way you'll know if it's OK..:yes:
 

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Discussion Starter #4
I am not sure about the 502 blocks, but I can tell you the MKIV 427/454 is good to +0.100 some go 0.120. But The block should not be machined without the piston that are going to be used. So your +0.060 bore may be to big for a +0.060 piston, now if is smaller that 0.060 you should be Ok as it can be honed to size depending what the actual bore measures.

The guy told me the only thing it needs is a final hone to match the bores to the pistons so I assume it was slightly less than .060. He told me he bought it from a machine shop that had it sitting due to a non paying customer.
 

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Discussion Starter #5
You could have the block sonic tested to see what the bore thickness is. :yes: That's really the ONLY way you'll know if it's OK..:yes:

Yeah I thought about that. I know a friend of mine has a .100 over 454 stroked to something like 512.
 

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The guy told me the only thing it needs is a final hone to match the bores to the pistons so I assume it was slightly less than .060. He told me he bought it from a machine shop that had it sitting due to a non paying customer.
Veno's been eyeballing one here at a VERY reputable shop in Houston.:yes: Just waiting for the shop to make the call on letting it go.:devil:

It might be a virgin....:yes:
 

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I bought a brand new std bore block & had it machined .030 over to turn it into a 540ci fuel injected 750 hp pro street motor :D
The paper work says the block is good for 700 hp. My engine builder told me the weak part of this block is the main webbing.
Hope it stays together:confused:
 

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Discussion Starter #8
The paper work says the block is good for 700 hp. My engine builder told me the weak part of this block is the main webbing.
Hope it stays together:confused:


Hmmm now im not sure. I guess I will have to pay my machinest a visit and deiscuss this with him and see what he thinks. I was thinking about stroking it and everything to get max cubes out of it and if it has weak webbing then that might not be a good idea. My ideal engine would be a 632. Someday :devil:
 

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You can go a lot more than 700 HP with a 502 block. They are stout.

There are basically two types of 502 blocks, Gen V and Gen VI. Gen V blocks do not have provision for mechanical fuel pumps or a clutch pivot. The coolant holes and head bolt holes are different from a Mark IV 454 so head choice is somewhat more limited. They quit making the Gen V blocks in 1995.

The Gen VI has better cooling and can use Mark IV style heads. The Gen VI blocks can also be had with and without provision for a mechanical fuel pump and has an undrilled clutch pivot boss. Gen VI is by far the more-desirable block and are still made today.

I have a Gen VI 502 that is designed to produce an excess of 1,000 HP with aftermarket heads and internals. I was told by the tech guys at Wieand that people are taking bone-stock Gen VI 502 long blocks with the stock hydraulic roller cam, bolting-on 8-71 superchargers and getting 800 HP.
 

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in my research.. the 502 should handle 1500hp......it is no weaker than any other 4 bolt bbc MK4 block..... there are many 496 making 700 to 900 hp in a stock 4 bolt 454 block.... I dont ever think I have ever heard of the main webs ever failing on a bbc.... I know of one 40 ford with a blown 871 468 making a verified 1500 blown hp.... so I should think a 502 block would be well capable of such levels.
 

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Discussion Starter #12
Thanks so much for the info guys! Really appreciate it. I may pull the trigger on the block.
 

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Hmmm now im not sure. I guess I will have to pay my machinest a visit and deiscuss this with him and see what he thinks. I was thinking about stroking it and everything to get max cubes out of it and if it has weak webbing then that might not be a good idea. My ideal engine would be a 632. Someday :devil:

Due to a couple class rules there's a lot of folks pokin-n-strokin the 502 blocks out to 588". With the times they're running, I would say build it however you want. The block won't be the reason for any failures down the road.:no:
 

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Hello---
Can't seem to find a 502 block with a mech. fuel pump boss anywhere on the 'net........???

Did I overlook it???

Thanks in advance-
ktownkid :)
 
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