Wiseco Piston and Hybrid Ceramic Bearings from Dominant Saws for 372XP
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Chainsaw Jim
CJ Saws, LLC
I wouldn't expect an extreme compression number with a single thinner chrome ring.
I do have a question after reading the instructions where it say use only on nikasil and not chrome plated bores.
Is a nickel ceramic coating covering a chrome plate or is the entire plating solution a nickel ceramic material?
I do have a question after reading the instructions where it say use only on nikasil and not chrome plated bores.
Is a nickel ceramic coating covering a chrome plate or is the entire plating solution a nickel ceramic material?
I might be a little late but, you should ask Wiseco! Can't stress that enough.
It survived it's maiden voyage! There appears to not be a mark on the piston, much unlike the 660 Wiseco piston I tried before. This one must be engineered and sized correctly. I'm waiting for it to cool off to get a good compression number. I'm then going back in it to cut a taller popup like I normally would.
I have it tuned a little on the rich side here to 13,000-13,200 for break-in.
I have it tuned a little on the rich side here to 13,000-13,200 for break-in.
I turned an additional .035" of popup on it. Squish is not at .018". It has to cool back off before I can test the compression again. BTW, after cooling off from the video above, compression was 148 PSI. As pointed at, this is a single and very thin ring piston. It's not surprising that static compression is down a little. With pressure on it during combustion, that ring will create a lot tighter seal, yet having much less drag and parasitic loss to friction.
It's now pulling 182 PSI.
Big_Wood
westcoast dweller
it's pulling 182 psi but what the rest of us want is for it to be a performance advantage over OEM as a drop in piston like dominant saws claim. i consider what you did significant work. really cool to finally see the outcome of this thread but i think i'll stick with meteor or OEM. i don't build race saws though so maybe this piston was meant to lure in the race crowd. i was tempted to buy one of these pistons a while back at the start of this thread but glad i didn't cause i would have been pissed if .017 needed to be taken off the base just to make squish acceptable and then see less then a gasket delete stock saw even after machining. dominant saw seem to be blowing smoke with their claims. i have used wiseco many times in dirtbikes and love them for that but that's where they're gonna stay for me. thanks for the follow up brad.
Chainsaw Jim
CJ Saws, LLC
Unless my eyes deceived me it looks like he only removed the .017 to get the squish down to .020 and maintain the use of an oem gasket. The same thing would be necessary with an oem piston.
Jon1212
Riff Raff Fart Knocker from other Forum's.
That's a considerable gain. I need to make some shekels........
Do you think the purple shirt helped in the saw "waking up"?
For what these pistons cost, they absolutely target the race/enthusiast crowd. No one else is going to pay that kind of money for a piston. I think that's understood and expected.
There's a lot more to saw performance than static compression. However, I think Dominant Saw isn't quite satisfied with the compression they're getting with these either. The second batch of these are not only lighter, but have a taller dome. These pistons will evolve as they gain more experience with them.
It's been a long time since I ran a stock 372, but this saw is quite impressive for only having a muffler mod and set squish. I think the static compression reading is deceptive.
For me, the biggest performance advantage is the single thin ring. Most guys under estimate how much parasitic loss there is due to friction from the rings. It's significant!
To me, the slightly less weight is only a nice bonus. I could be wrong. It certainly doesn't hurt! Every little piece of the pie helps.
The forged part doesn't mean a lot to me either. I don't see an issue with stock pistons breaking. But, who else are you going to get to make you a quality piston to your specs? Wiseco is an obvious choice, and forged pistons are what they do, and they do them very well.
Bottom line, I've yet to find any fault with these. Yes, they're expensive, but it is a custom made, higher performance, high quality piece. You're going to pay for that. I like the direction they're headed with the changes...just more of a good thing. Of they could get 180PSI with a drop in piston, they'd be the cat's meow, IMHO.
There's a lot more to saw performance than static compression. However, I think Dominant Saw isn't quite satisfied with the compression they're getting with these either. The second batch of these are not only lighter, but have a taller dome. These pistons will evolve as they gain more experience with them.
It's been a long time since I ran a stock 372, but this saw is quite impressive for only having a muffler mod and set squish. I think the static compression reading is deceptive.
For me, the biggest performance advantage is the single thin ring. Most guys under estimate how much parasitic loss there is due to friction from the rings. It's significant!
To me, the slightly less weight is only a nice bonus. I could be wrong. It certainly doesn't hurt! Every little piece of the pie helps.
The forged part doesn't mean a lot to me either. I don't see an issue with stock pistons breaking. But, who else are you going to get to make you a quality piston to your specs? Wiseco is an obvious choice, and forged pistons are what they do, and they do them very well.
Bottom line, I've yet to find any fault with these. Yes, they're expensive, but it is a custom made, higher performance, high quality piece. You're going to pay for that. I like the direction they're headed with the changes...just more of a good thing. Of they could get 180PSI with a drop in piston, they'd be the cat's meow, IMHO.
Did you ask Dominant if they expect their pistons to have increased performance as a plug and play replacement piston or do they expect some level of cylinder porting/squish cutting to unlock the potential performance gains? Seems like a large investment in a part that is "evolving" and appears to be marketed as plug and play power adder.
Also, did you request any specific specs for the piston (i.e. custom piston) or are these just their AM performance product for this saw?
Also, did you request any specific specs for the piston (i.e. custom piston) or are these just their AM performance product for this saw?
Chris-PA
Where the Wild Things Are
That's a really cool saw, and looks really good too. The piston is neat, and I'm interested to see what advantages it might have.
As I've said before I think people associate way too much meaning on low rpm pressure readings on a gauge. It's really a diagnostic tool for determining cylinder/ring condition, and does not tell you all that much about performance or cylinder pressure under combustion conditions.
bikemike
loud pipes save lives
Why do a ceramic hybrid bearing. They are still standard races might as well spend the money and buy full ceramic bearings they can handle some crazy loads and rpm and temp. You can also run the dry and cause no harm to them
Chainsaw Jim
CJ Saws, LLC
I just looked at parts tree and they list three oem Pistons from $89-$117. This wiseco piston is listed for $119.99.
I don't think I'll be buying an oem next time.
I don't think I'll be buying an oem next time.
What jerk sold you a saw with a messed up case and crank?
Big_Wood
westcoast dweller
I realize that compression isn't everything. Hell even a 372 with 140psi runs pretty dang good. All I was saying is for the average hack it would still be a better route to stick with OEM or meteor if there is no advantage with the wiseco. If they could make them so squish is acceptable and compression is stout around 180 like you say just as a drop in I'd have to try one.
I consider Meteor to be OEM quality. They're like $40-$45.
