Wondering if anyone has tried a 4.125 bore on a iron 6.0 block that's been filled with hard blok to the water pump holes and is using a 200 to 300 shot of N2O.

 

No street driving, or cruising around, strictly a track motor

 

That would be interesting. Is there enough material in the bores to go out that far would be the question. It's .063 off each side of the bore so it's likely there is enough. That block would be heavy as hell with a full pour on each side. What kind of a cooling system would be needed for cooling just the heads and very little of the water jacket vs. how long would it be run for at a time. Do it….

 

Is the block filled to the water pump holes considered a full pour?

I ran a Pontiac 455 with a pour to the bottom of the water pump holes with an oil cooler on the street all day long. As long as you have good flow to the heads, I would think that you would be good on the street.

And if you have .185 cylinder wall thickness you can bore it out to whatever you want, but you might want to sonic check your cylinders before taking it that far. You need the most meat on the thrust side if the piston, which is opposite of each other on each side of the block.

 

It would be run long enough in the pits to get it up to 150 to 160 degrees. Towed with a 4 wheeler up to the line and ran long enough to do a burn out and make a pass. Maybe 5 minutes tops. I'd use a Scirococo? radiator (pardon spelling errors) with a small cooling fan. Maybe 2 gallons total capacity. I would also be running it on methanol. N2O on race gas. I don't think it would be an issue to cool it off.

 

Just on the absurdity of the block weight, full cooling system capacity is what 4gallons?
Let's say you replace half that water with concrete and just for argument's let's use the specific gravity of regular concrete which is 2.37 times heavier than water(highest number I found on Google)Using those number we are talking about adding 23lbs when you deduct for the displaced water.
This is added to a 216lbs block.
Next we will discuss boring the block for the weight savings.......

 

IMO having found plenty of weak links w/NOS over the years that the nasty cylinder pressure will split the less than ..100" thick cylinders. I know the rock will help, but I doubt the deck is thick enough to support the top 1.5" of unsupported casting which will be subjected to the same forces kicking the slugs. I'd fill it @ 4.065 and still have freshen ups of .070 and .080. If you are dead set on the large bore, perhaps talk to someone @ a performance diesel shop that could install ultra strong sleeves meant for boosted applications. They may be able to get you to a strong 4.100" which would probably require a custom piston and just the machine work on the block would be pricy.

 

The block is already .065 over and no issues yet with a 250 shot and no concrete. I didn't bother sonic checking. I was just curious if anyone had tried a bore that large with one of these blocks. I guess I can be the guinea pig lol

 

Widest I've seen on here is a 4.07 w/o a hard block