Early custom forged pistons

[Nashfan]

For earlies, off the shelf piston options these days are regular cast pistons, and they dont handle high boost levels for very long. Actually, with aggressive timing, they wont handle stock boost levels for very long. I've pounded out the ring lands really badly and broken rings doing that. Years ago, Clarks offered the Hitech pistons for earlies, and this is what I've been running since 2004 and found they work really well at the boost levels that I run- 20-22. In 2018, during a tear down to replace a toasted cam, one of the center cylinder pistons was found to have some minor scuffing and the wristpin seemed to be sticking a little, so it was decided to replace it. Clarks didnt have Hitech pistons for earlies anymore, and I couldnt find any early forged (tried really hard to find some) so, eager to get my car going again, held my breath and put stock cast pistons in on the 2 center cylinders. Yes, I know, a far from ideal way to take care of it, and knew that it was going to have problems at some point and planned on getting a complete set of custom forged pistons before that bad thing happened.
The engine now has approximately 30000 miles on it and has been up around 20-22psi a few times without issue, until my knock sensor died and I sorta forgot about getting it fixed. Hit it really hard and got some bad pinging and then a HUGE gusher of oil shot out the dipstick. Never ever have I had anything like that happen before, so knew I likely did something bad to one of those 2 cast pistons. This was a year ago, and I ordered custom forged pistons from Ray Sedman at American-Pi . In the meantime I found I could calm down the blow by by driving it easy and slightly increase the oil viscosity. I have been driving the car as is while waiting for the pistons. Finally, here they are!

[doug6423]

[fred bagnall]

Definitely custom pistons with drilled oil return holes and some kind of friction coating on them ?

[Nashfan]

Yes, the pistons have been hard anodized and some sort of "slippery" stuff is infused into the anodizing, and will NOT come off!. They also have a thermal barrier coating on the top surface. Super trick for me is how LIGHT these pistons are compared to stock early pistons. These custom pistons weigh 406 grams vs the stock cast pistons at 520(!) grams. Its well over a lb total weight savings. Much easier on the bearings that way and probably enough to noticeably rev quicker. There was a lot of addition machining done on these that normally isnt done, because the wristpin is normally much closer to the wristpin. Additionally the ring set is much improved compared to standard early pistons in that the rings are a lot skinnier, which is really good for ring life. In the 1980s, Nascar still ran "fat rings" that had the same dimesions as in the 1960's and were thoroughly shot after a 500 mile race. Now that they run skinny rings, they get 1500+ race miles out of them!