Use of Hard Blok to reenforce bottom end

turbobob924

Member
Joined
May 28, 2001
I was reading an issue of Hot rod and saw an article about using product called Hard Blok" to reenforce the bottom end of blocks.

It is like concrete but specifically designed to be poured intot eh water jackets and setup the bottom end of high performance engines.

Apparently it is commonly used in big blocks.

Supposed to provide much better support of the clynder walls and crank.

Anybody tried it??
 
Hard Block

I would not do it again. If you drive on the street, it will overheat in the summer. That was my experience a few years back.
 
Re: Hard Block

Originally posted by Lee Thompson
I would not do it again. If you drive on the street, it will overheat in the summer. That was my experience a few years back.

Lee do you remember how high you filled the block? Bill at Champion has used Blok and he does not overheat in FL.I just put some of this in my stage 2 and I filled it up to about 3/4 up on the freeze out plugs. I do not use this car alot on the street and I do have a much better then average cooling system. I am hoping that I can avoid the issues with cracking between the freeze plugs.

Jeff
 
they have full and half fill avaliable, block must be empty no crank/cam etc. cylinders must be plate honed at least if not cut open. i had 377 with 1/2 fill in it ran True Street events and cruised the heck out of it with no cooling issues
 
Originally posted by turbobob924
I was reading an issue of Hot rod and saw an article about using product called Hard Blok" to reenforce the bottom end of blocks.

It is like concrete but specifically designed to be poured intot eh water jackets and setup the bottom end of high performance engines.

Apparently it is commonly used in big blocks.

Supposed to provide much better support of the clynder walls and crank.

Anybody tried it??
I have just completed a Stage II
street install with a half fill concrete job. So far no problems. Vehicle has a large Be Cool radiator & has not gone over 180 in traffic. Just make sure that the block fill has had ample time to harden before haveing any machine work done.
 
Bill filled the block in a specific way in which he found water flow not to be severely hampered. He also did some dremel work on the hard block through the water pump openings. I know cause i have seen this block:)
 
Check with Lonnie. He has been pouring some too. He had a 4.1 with hard block in it when I was there on a visit. Been too long, time to make a trip.
 
fill

Years ago, I filled an 85 block to within 1-3/8 in. of the top. I leveled one bank, both ways, used a piece of 3/4 in. rad. hose (90 degree ) and used sealant to finish closing the hole in the front of block. Mixed and filled, then torqued a head (with gasket) on block. Let sit 24 hours and did other side. I did not have the cooling system I have now (stock at that time ). The problem I had was, once the eng. got hot (180 range ) the oil temp. would start to climb and the water would follow.
Jeff, did you fill both sides of the cyl? Ron Taribori once told me to lay the block on an angle and only fill the needed area. In your case the outer side of cyl. I feel this would work OK. Best of luck in any case.
 
Originally posted by Louie L.
Bill filled the block in a specific way in which he found water flow not to be severely hampered. He also did some dremel work on the hard block through the water pump openings. I know cause i have seen this block:)

Louie, I waited about 10 hours after the fill was poured and then removed the tape covering the water inlet (at the front of the block) and created a passage way for the coolant. The Hard Blok was still workable with an utility knife.
Jeff
 
trick

I have a Stage II block that is thin on # 3 cyl. (intake side ) from underside of deck to bottom of water gacket. (.140 ) This is what I decided to do to save it. I used rope that goes around woodburning stove doors to make a STOP so Hard Block would be contained around intake side of # 3 cyl. only, Managed to place 2 strips of foam (long story) in the thin area (one at the top, one at the bottom) Hard blocked it, torqued a head with gasket on, let sit 24 hrs. then poured gasoline in through a predrilled hole to disolve the foam. Now I have a solid wall with 2 --3/16 X 3/4 in. water passages.

I used a long scrwedriver (going down through the holes in the deck) to CLEAN up some of the rough edges.

What do you think????
 
Someone on a thread about this said your water temps wont be the problem its the oil temp that will be getting hot. Might of been Lonnie?
 
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