J-Madd

Good luck finding used 33 PWKs. I had to buy new just this week. If they are out there, I couldn't find them.

I know almost nothing about how to port or exhaust port shape. But if the cut out in the middle actually allows the port to open that is now the beginning and end of the duration. Not the flat area. And that is when the sound wave exits. The actual charge may not exit at the same crank degree as the sound wave, I dunno. I think you want the entire charge to exit quickly and completely. It could also be a last microsecond attempt to stuff the return pulse from the pipe back into the cyl before the port is completely closed. I'd like to hear opinions from those who know why that port is funky as well.

I have a 24 Mil Twister Sniper motor. It's ~ 850 cc. Complete motor, Mattoon billet cases, 12 plate clutch and side covers, billet transmission. Can probably save you quite a bit and should make more power than a 24 mil DM.

I have a chassis like that. I'd build a Twister motor if you're gonna spray. I've heard they love the nitrous. Hell I'd build a Twister anyway if you can get a hold of one. 78 x 70.

MR12? Any good power adding race gas is gonna be way more $$$$ than alky and more of a headache, IMO.

Good carbs. Someone will come along wanting then.

Fair enough!! Due to quality or weight?

We only run ATF. I've honestly never looked for a lighter oil. Hmmmmm.

Would the drag of the extra oil offset the (perceived) benefit of a cooler transmission? Most of my experience is with drag racing and some tend to run as little oil as possible for weight savings and reduced drag. I'm not in that group, because I don't want to have a missed shift and bent fork or lose a race over a few ounces of oil.

I can't answer that, but I think another "bottleneck" in porting is how wide you can make the Exhaust port before it eats rings.

There ya go. I was very sure it was but didn't want to mislead anyone. I've only had Packard Alky needles.

Just place the order. Then Jeff will call you with the total and you can discuss this. Your credit card won't be charged until he calls. ...Or just call them.

All you have to do is change the needle to go from gas to alky. Sometimes people drill out the "main" orifice on alky but I think you can still get gas to work with a needle change. I've never tried it. Those don't appear to be the typical Packard PE1 needles but Lectron makes their own alky needle too. I'm not sure what it looks like. If OP can take a better pic of the needle or read the numbers in it that would answer it.

Get that bitch done! Let's see those LEDs!

That's because you were probably a negative dick to them and OP is probably a nice guy!

Good. We'll just throw that theory away then. I've wondered if it even matters, but Menz always shut the fan off during the dyno pulls. I didn't know why at the time.

Sleeper06 will take care of ya.

Maybe have them discount the piston? The damage is probably miniscule unless near the ring land. You could lightly sand down the burr and be on the way with your project. I've ran pistons with small pits on the top before and they had zero effect on performance. I understand you want a new build perfect, but if you can get some money back on that piston and still run it thats more funds for other stuff. Bad business deal though for sure. Puts the dealer in a tough spot when it's not their fault. But they should just eat the shipping cost, or try to pass it on the wiseco if it was damaged from the beginning.

Is it possible the fan cooled the pipes during the run?

[This is not a post to start any shit whatsoever, but just some things that come to mind] Is there a fan on during any of the dyno runs where pipes are compared? (In this thread or the one Ayesully referenced). Tyrelz mentioned that Snipers liked more fuel. Do they like a higher temperature? Up to a point, more fuel = higher pipe temperature (not to be confused with combustion chamber temp). Now if the motor is pumping out raw fuel like during clean out with alky, of course that will cool the pipe down. Sound waves move faster through a hot pipe. The faster they move, the faster the wave returns the mixture in the pipe back through the exhaust port. Faster sound waves = shorter tuned length and higher target rpm. Things that increase combustion chamber temp (timing, compression, moderately lean condition) decrease pipe temperature. Knowing some of this it's easier to see why a pipe may not perform as intended without knowing how much heat an engine will put into it. This would also make sense regarding stinger diameter and the heat of the pipe. Where do you put AFR probes in a 2 stroke? I don't know because I've never seen it done. I also don't know how it can be reliably done, and it's not just because of the oil. There is no place from piston to stinger where the gases are representative of what was burned in one cycle.??? Its always moving back and forth and takes several cycles to exit. I must be wrong because I've seen AFR mentioned here and on other dyno sheets but I don't see how. Very interested in others opinions/facts on this...and feel free to point out any errors in my rant. Move this to a new thread if you want.

I'm done. I couldn't find a popcorn emoji.

If you can't feel any big grooves throw new pistons in it and go. Can maybe clean that dome up with scotch bright as well. Edit: looked back at the pic. Piston may be usable too.

Then what Ragun said would be the concensus.

Depends on the motor. I dynoed a 200* exhaust port 10 mil Cub and the BB CPIs came on sooner and pulled longer in the rpms.