Vintage hemi block identification

Discussion of the 426 Street / Strip HEMIs.

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MaxCuda
Posts: 3
Joined: Thu Jan 08, 2009 10:45 am

Vintage hemi block identification

Post by MaxCuda »

I'm trying to identify a 426 Hemi block I acquired back in the early 80s. The sides have been shaved ( no part #s ), and it has 1/2" head bolts and 9/16 " mains, drilled holes for oil drain back in the valley (no cast in holes above the cam) and has a very high nickel content. I was
told by the seller that it was a special mopar block, modified by Keith Black in the early 70,s but was never used because aluminum blocks became available, and then was used at Logghe.s shop as a mock-up block. Block is new ( never run} , standard 4.250 bore. Any ideas on what racing series (Top Fuel/Pro stock.ect) this block would have been used in ?
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MaxCuda
Posts: 3
Joined: Thu Jan 08, 2009 10:45 am

Re: Vintage hemi block identification

Post by MaxCuda »

I'm trying to identify a 426 Hemi block I acquired back in the early 80s. The sides have been shaved ( no part #s ), and it has 1/2" head bolts and 9/16 " mains, drilled holes for oil drain back in the valley (no cast in holes above the cam) and has a very high nickel content. I was
told by the seller that it was a special mopar block, modified by Keith Black in the early 70,s but was never used because aluminum blocks became available, and then was used at Logghe.s shop as a mock-up block. Block is new ( never run} , standard 4.250 bore. Any ideas on what racing series (Top Fuel/Pro stock.ect) this block would have been used in ?
Nil1
Posts: 1
Joined: Sun Dec 16, 2018 12:44 pm

Re: Vintage hemi block identification

Post by Nil1 »

I once asked former chief engineer Willem Weertman about the claimed "fuel/high nickel blocks" of the 70s.
I got a long reply that in short said that there were two "fuel blocks". The first one was what later became the reinforced standardblock in 1970, the second had siamese cast cylinders and was later reproduced as the Mopar Megablock.
The foundry used for the aftermarket blocks at that time used a slightly better material but still within tolerances of the Chrysler material standard. A stronger alloy would be to hard and time consuming to machine.
It looks like your block has siamese cast cylinder walls, can you confirm?
Do you have a picture of the crankcase and the main bearing webs? It would be interesting to see whether there is a difference to the 1970 standardblock.
Have you done a hardness test to confirm the nickel content?
In an old Direct Connection handbook there is mentioned a heavy duty block with thicker cylinderwalls and reinforced main webs like the 1970 block, part no P3690010. However, at least later blocks with that part no did not have siamese cast cylinders.
MaxCuda
Posts: 3
Joined: Thu Jan 08, 2009 10:45 am

Re: Vintage hemi block identification

Post by MaxCuda »

I will check if it has siamese bores ( I don't think it does) and get some pictures of the bottom end.
It does not have siamese bores. I-D pad has the large W - T and an E in the same size and font.
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