Hypereutectic pistons are an aluminum/silica/magnesium and several other mineral alloy. The melting point is actually higher on the alloy than it is on forged pistons.

The cost difference between forged or alloy was very little.

My reason for using them was heat resistance.

Ceramic coated pistons more than doubles the cost per piston. Since I was milling them down to lower compression I would have paid a small fortune in shipping on top of the cost. I would have to ship them here, machine them to what I wanted, then ship them to be coated and ship them back here. I guess if I ran forged pistons I would have gone that route, but I have also heard a few bad things about ceramic coatings. Some local hot rod guys have had problems with the ceramic coating flaking off the pistons and scaring the cylinder walls of their high dollar race motors.

Power Strokes are running hypereutectic pistons and boost numbers close to 30 PSI without problems, should be fine in my IDI.

At the fuel settings I am running right now my max EGT is just a bit over 900 degrees at a bit over 20 PSI boost. So I don't have to let off.
I have 4000 miles on the engine now and was going to turn the fuel up a bit more last weekend, but it rained all weekend. Possibly this weekend I will have time to do it.

When I get everything set to where I want it, the thing that is going to tell me I have to let off is going to be oil temp probably way before the EGT says time to let off. I just switched back to synthetic oil last evening when I did my second oil change on the new engine. Now it can stand a little more heat than before.

When the timing advance is on in the morning, yes I have a Power Stroke rattle, as soon as the engine is warm and the advance kicks off there is no rattle. Timing is about 8.5 BTDC or just a tad more, with the fuel I normally run, it is as fast as it can be set at.

 

Dave, I've never heard of hypereutectic pistons before, thankyou for explaining them to us...next question-where do you get them? And how much? And what and or how do you increase your boost to 20 lbs.? Again thankyou for your patience.