New maincaps question.

[Hans Olsson]

What is the proper interference fit between maincaps and the register in the block?
Ford 351 C motor.

Thank you.

[Mike Taylor 3601]

you want cap to fit tight enough that you have tap the cap down into register and you have to work it back out if using bolts,I pull them up near top of hole and push sideways to remove cap,I have brass hammer with plastic handle that I use to remove and install caps i use the plastic handle.
I measured some blocks here in shop they had .002-.005 interference fit on cap and block.
Do you have loose caps or installing new ones?
Mike Taylor3601

[Jim B]

It also goes without saying you don't want to do anything to change the interference fit once the main bores have been finish align bored/align honed. The parting line diameter (cap side) will change if the 'squeeze" is altered......

[Hans Olsson]

Originally Posted by Mike Taylor 3601

you want cap to fit tight enough that you have tap the cap down into register and you have to work it back out if using bolts,I pull them up near top of hole and push sideways to remove cap,I have brass hammer with plastic handle that I use to remove and install caps i use the plastic handle.
I measured some blocks here in shop they had .002-.005 interference fit on cap and block.
Do you have loose caps or installing new ones?
Mike Taylor3601

The thrust cap (center) was 0.0008 interference fit and moved after a few runs.
We are installing new Pro-gram fourbolted caps on the three center positions.

Thanks.

[Hans Olsson]

Originally Posted by Jim B

It also goes without saying you don't want to do anything to change the interference fit once the main bores have been finish align bored/align honed. The parting line diameter (cap side) will change if the 'squeeze" is altered......

Thank you!