Sbc up to LT1:

When does it have to be filled?

If it is half filled, can it be streetable (ie overheating)?

Thanks.

 

No simple answer to the first question, but blocks with partial fill can certainly be used on the street. I do it.

rich

 

Thanks very much for your quick reply.

 

Rich, how much fill do you put in? What brand do you prefer? Electric or mechanical water pump?

 

I have used the stuff from Moroso and Hard Blok, both seem to work fine. Obviously, for a street motor you want to do a "short fill" - to below the level of the water pump holes. I have used both a mech and an elec WP with partially filled blocks. There is very little heat in the lower part of the block. However, OTOH I am not sure how much stability is added with a short fill. So, this begs the question of "should I do it?"

Rich

 

I'm sure it's not a perfectly linear relationship, but I would have to imagine that if Block Fill helps at ALL, then a half fill will give somewhere around half the stiffness.

I have nothing to base that on of course, but I can't imagine that a half-fill wouldn't have a significant effect, even if it's nowhere near what a full fill would.


You'd think someone would have done some testing on this by now...

 

No kidding.

Does block fill just help stabilize the cylinders, or does it make the bottom end (mains) more rigid too?