Reply to "Reinforcing with "Hard Block""

Info:

The original purpose of grouting was to reduce cylinder wall flex in drag race engines, which improves ring seal and makes more horsepower. There is no doubt that grouting accomplishes this. The original purpose of grouting was never to prevent cylinder wall cracking.

Grouting has not caught on in road racing or dirt track circles to my knowlege.

Some guys who have run grout on the street say they'll never do it again. Others who are currently running it say "no problem". The guys running it on the street all advise to fill to the bottom of the water pump discharge holes. They also all advise to make sure the cooling system is in top shape, and most advise to use an oil cooler. The oil temps WILL run hotter.

Nobody running it on the street ever mentions making more horsepower (which is the purpose of grouting). Of course, nobody mentions cracking cylinder walls with a grouted street block, but how can they prove the block would have cracked without grouting? So the jury is still out, and will always be out, in regards to the benefit of grouting a street motor. Its a religious thing, a matter of faith, you're either a believer or you're not.

My opinion:

The owner of an average "street performance" Cleveland does not need to worry about cylinder wall cracking ... if the motor has been assembled with the usual precaution and precision. I purchased my first Cleveland powered vehicle in 1976, and have never been without one since. I've never cracked a cylinder.

Those who are serious about avoiding cylinder wall cracking can do 4 things:
(1) Use the stock stroke crank for the best rod length to stroke ratio possible
(2) Index the cyliner bores during boring
(3) Use pistons with floating pins
(4) Use fully round skirt endurance racing pistons

To think it is possible to pour similar strength inexpensively from a bottle and avoid the cost of this machine work and the cost of these parts is dreaming. Supplementing these things with grout would seem reasonable however, that's how the guys who originally thought of using grout used it, as a supplement to all the other machine work and parts. They were in search of every possible last horsepower.

However if I were building a powerful street or road racing motor, and felt the 4 steps I mentioned earlier weren't enough, I'd use a NASCAR block for additional strength. I wouldn't grout. In my opinion its a drag racer trick. One thing I have learned over the decades, drag racers get away with a lot of stuff you can't get away with in other types of motorsports.

Grouting tips:

If you're going to grout use Embecco 885 or the suff Moroso sells. You'll need two bottles of the Moroso stuff.

Grout before you have the block machined because things are going to be moved & distorted by the grout.

Grout one side at a time and let one side set-up (harden) before you grout the other side.

Grout needs to cure for 28 days to be completely cured. In a week it is only cured about 50%.

Level the block front to back, and level each deck side to side before filling.

Torque the main caps in place before grouting.

Bolt a head with a gasket on each bank immediately after pouring, and leave them there while they are curing.

-G