427 Race info

[Clois Harlan]

I have a friend who has recently purchased a Nationally known Drag Racers inventory of 427 engines with a large inventory of exotic parts. Of the dozen or so engines blocks he bought a few of the blocks have had CEMENT POURED INTO THE WATER PORTS ABOUT HALF WAY UP THE CYLINDER WALL. Has anyone ever heard of this before? Randy tells me the cement provides stability around the cylinders and that it still allows coolant to move through the block.

I have never heard of such a thing. Are these blocks boat anchors now?

Clois

[Ron61]

Clois,

I never heard of that and I asked a couple of the local drag racers if they had and they said no. I suppose if you are just running the engine 1/4th mile and then cooling it down that is a possibility, but I don't think you could drive it that way very long. It will be interesting to see what some of the knowledgeable drag racers have to say about this.

Ron

[1962SuperStock]

It's common to fill blocks this way for drag-race applications. Of course, the cooling is compromised. Doesn't mean they couldn't be used on the street (I know people who do it), but it's an unknown that would make me choose another block for my project.

Somebody with more experience might be able to tell you that the filled blocks definitely CAN'T be used in a streetcar, but I doubt anyone could tell you definitively that they won't overheat on the street. Wildcard.

[Clois Harlan]

I talked to an old drag racer here and he said they once did this and it helped the engine stay together. He also thought that the cement could be "COOKED OUT" in a oven after pulling all the freeze plugs.

I had just never heard of such a procedure. Personally, I would not be comfortable buying one of the blocks that had the cement treatment done to them.

Clois

[ItBites]

This practice is still very common with drag race motors. Modern racers use a product called HardBlok, among other products. I have heard of folks using partially filled blocks on the street, but I think you've got to try some out to determine how much fill you can get away with. Also if there is not enough fill, the results in cylinder wall stabilization will be minimal. Usually, this is considered a race-only mod.

See www.hardblok.com

The blocks you refer to are likely great for drag racing. May be OK for road racing. You could contact a reputable 427 builder to discuss how much block-fill is still streetable.

BTW, I doubt a cement-based product can be cooked out, but you could try it.

My $.02

[Hotfingrs]

I've never heard of anyone using cement in a block. My block is half full of the Hardblok. The Hardblok stabilizes the crank and bottom end. I drive on the street all the time, on the freeway engine stays at 170 with no fan, when I'm in the city, temp might hit 200 with the fan on....Don't see any need for it, if you're not turning some high RPM's

[ItBites]

Hotfingers,

Hardblok is mostly cement, with some Iron granules added to get the CTE to match the block better.

I suspect the filler in the blocks in question is similar, unless they were filled a long time ago, and then it might be just cement (?). If they've been run that way and the filler is not cracking away from the walls, its probably OK.

[Clois Harlan]

Son of a Gun,

I seem to learn something new every day. I had never heard of this procedure.

Clois

[SCOBRAC]

A good vinegar soak will eat the cement paste. It is hard to get out but it can be done.

[Excaliber]

I've heard of it many times, but never actually seen it. Seems to me the last person I heard make reference to it was DV, Double Venom. He is a drag racer after all.

[griffinzein]

filling blocks is common practice where im from. a friend of mine has created what he call his secret mix, its a compound that i wanna get my hands on, it allows complete cooling.he wont tell anyone what it is. i think hes just scaming, i think mabey he filled the block a little with water then put wax in on the water and so on untill the had the block layered then poured the water out after the wax cooled, filled then poured the hardblock in and heated it and melted the wax out allowin quasi cooling tubes to be formed in the hardblock. just my 2 cents, and i wouldnt run a half filled block on the street.

[RICK LAKE]

Clois There was an article in Hot Rod or Car Craft about filling a block with hardbokt. You can run a block on the street if the fill is below the freeze plug level without an problem. The higher the fill the less coolant needed. The heads and the top 2" of he bore in the block are the most important. You can get that stuff out with a dremel tool if you have the time. A local racer told me he drills holes in it down the passages and sends the block to a vibration table place that causes the hardbloc to fall apart without damage to the block. I would check these block for how much cylinder wall is left first, if 30 over it might not be worth it. If stock bore or 10 over, buy 2 and you have a winter project. Hope to see you at R&G in Sept. Rick Lake