Head and block mix

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Head and block mix

Postby Cavansbh » Tue Oct 13, 2020 8:45 pm

Hi I was wondering if I can put a 1l head on a 1.3 block and if so what parts I have to change to 1.3 parts or 1l parts like head bolts, gasket etc thanks in advance
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Re: Head and block mix

Postby viva les vegas » Tue Oct 13, 2020 9:32 pm

I seem to remember something about the HA head gasket having smaller bolt holes than the HC, but I’m not sure. If that is the case, then I think that the 1256 head bolts probably wouldn’t fit through the holes in the head. I’m sure someone more knowledgeable will be along soon to correct me.
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Re: Head and block mix

Postby bluevanman » Sat Oct 17, 2020 4:19 pm

Early 1056 blocks had 3/8 head bolts not sure if they changed later.1257 engines had 7/16 bolts it is possible to mix but it needs sleeves in the 1257 heads to reduce the holes for the head bolts to 3/8 as the bolts locate the head on the block
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Re: Head and block mix

Postby pbottomley » Sun Oct 18, 2020 8:37 pm

The above is correct in principle that there will be a bolt size difference, that will make the 1256 bolts impossible to get throw the smaller holes in the head.

even if you overcome that issue, with heli-coiliing the block to take a smaller bolt, you may find the oil gallery doesn't line up.

Some of the 1256 blocks have the main oil gallery slightly off line to the 1057 / 1159 heads, and other 1256 engine blocks have the oil gallery starring the same hole as an engine bolt. so beware.

I used to run a 1057 block with a ported and polished 1159 head which has 7/16th holes and yes the advice above to use a sleeve to locate the head square is correct, but you are doing this the other way around so it's not possible to fit a 1057 head to a 1256 for the two reasons above.
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