Re: Hardblock?
 

and at over 3K

Re: Hardblock?
 

Any special preparation needed before HardBlok? Is the standard hot tank good enough, or does it need special rust removal to get a good bond to the iron? I'm thinking muriatic acid inside with a water flush. Maybe follow with Evap-o-rust or is all of that overkill?

Found this online.

http://dalhems.com/f/d/808c931833604...str-022005.pdf

Re: Hardblock?
 

The muriatic acid cleaning is an excellent idea. I don't use anything after that except a flood of good clean water.

I bolt a head to the opposite side of the block, and torque the main caps. Then I pour the first side, and immediately install a cylinder head and torque it. I let it set one week. Then remove the head on the other side, pour that side, reinstall the head, and let it set another week.

Re: Hardblock?
 

This guy found the same thing I found out.

Re: Hardblock?
 

If you want the best, use MasterFlow 885, formerly known as Embeco 885.

MasterFlow 885 has a metallic aggregate, it is non-shrinking and way stronger than HardBlock or the Moroso product after cured.

Re: Hardblock?
 

My rule of thumb if you have to fill the block your using the wrong block,


Cylinders change during heat cycles and and never come back to the original machined size.

Re: Hardblock?
 

So every combo that can not get an aftermarket block should just stop building engines. That is what you are basically saying

Re: Hardblock?
 

Which engine wòuld that be?

Re: Hardblock?
 

go look at the replacement blocks listed by the nhra, and try to find some of the rarer combo's. This idea having to run a replacement block and spend vast amount of money to compete will be the nail in the coffin for many people.

Re: Hardblock?
 

I have never experienced any of the out of round problems.
Over the last 30 years I have filled blocks for Circle track, Drag and mud racers as well as boat racers. A few years ago I took a late mod 305 and filled it and bored it to std. 283 for a boat race class. Freshened it once and I think it is still going.
I use a Machine grout and I let it harden at least a month before doing any machine work. I also increase the Piston to wall clearance by at least 40 -50 % . I always test piston growth before deciding on the final cold bore clearance. A water block cylinder moves, a filled block does not and the pistons still grow with the hot oil and combustion heat on them.
Allow for it. On the circle track Applications I only fill to the oil galley holes in the lifter bores. My theory on that is still have water in that part of the cylinder to pull heat out of the oil going through the lifter galleys.
Seems to keep oil temps in check.