This was the best fit that I could find for what I’m trying to do. I had to factor in wrist pin size, and compression height and needed them close enough that I could make them work.Wow that pistons pretty big why dont ya start using mower pistions they can be pretty large
I did.Probably start a diffstorm saying this, but if you remove metal take it from the piston, not the rod.
Thanks for the heads up, I’ll keep an eye on it.That little threaded hole on the side cover might leak oil. It did on mine. Took me a minute to find out where it was coming from.
View attachment 130394
You may have gotten one that was attacked by a rouge drill press operator, lolI pointed out the wrong hole. Its this one. It looks like yours doesn't have it.
They may have stopped doing that hole, because its literally drilled all the way through so oil leaks out.View attachment 130445
I see you are adjusting your redline down by the engine speed - longer stroke at less RPM's gives you the same piston speed. Have you factored in piston weight? How much heavier is the 96mm piston than the stock 88mm? I think you see where this is going - a heavier piston can weigh the same (and stress the rod the same) at 7200 as a lighter one at 7500. Even 10 grams can make a difference, especially when a different crank may not be balanced for the new combo.According to the math on mean piston speed I should be safe at 7500.
You’ve nailed my whole reason behind doing this with the RPM. My thought is that if I can make enough torque that I won’t have to rev the engine nearly as much, so it should last better.
I blew up 3 really nice small blocks this year and I believe that it was because we have to turn them 9-10k rpm to get the job done.
The 96mm piston is significantly lighter than the stock piston. I haven’t weighed them, but you can feel the difference when you hold them in your hand.I see you are adjusting your redline down by the engine speed - longer stroke at less RPM's gives you the same piston speed. Have you factored in piston weight? How much heavier is the 96mm piston than the stock 88mm? I think you see where this is going - a heavier piston can weigh the same (and stress the rod the same) at 7200 as a lighter one at 7500. Even 10 grams can make a difference, especially when a different crank may not be balanced for the new combo.
Not trying to be a smart Alec here. We used to mix-n-match parts in small engines for pulling tractors 40 years ago, with varied results. Some worked out well - ran smooth with good power. Other combos were miserable, expensive mistakes, that either would shake your fillings out or grenade quite impressively. Just trying to respectfully ask a couple questions, and why I'm asking. Sounds like it will be a neat build. Willie
I’m just gonna send it.The underside of the piston looks like a pretty “rough” casting. Are you worried about stress risers or are you going to polish it out? Or maybe even shot peen it?
Once I get the head back I have to get the o ring grooves cut, I still need to get the gead gaskets cut, pushrods made, there quite a bit to do still.How long before we hear it go Vrroom or Boom? Can’t wait to see what it’ll do!