Dominant V4 Piston for the 372

[XP_Slinger]

Got a short video of the first cuts. I'm going to richen the high side up some, it's 4 stroking at wot but not much. I think it ran pretty good. Later today I'll try and get a better tune and post another video, I've got babysitting duty for the next couple of hours.

Sounds good. Did you check squish by rotating with a drill like Al suggested? Just curious, it makes a difference

 

[Ronie]

Sounds good. Did you check squish by rotating with a drill like Al suggested? Just curious, it makes a difference

No, I rotated it by hand.

 

[BonScott46]

Would be interesting to see one of these against a 268 pop up.

 

[Ronie]

Would be interesting to see one of these against a 268 pop up.

When I get some more wood I'll compare it to the one I have with a non windowed 268 popup. That's the last piece of wood I have to test saws with at the moment. I think the chain speed is higher with the Dominate but he one with the 268 piston has more torque. That may change when I richen it up some.

 

[huskyboy]

I have to wonder if the impact of the piston hitting the soft solder at high speeds with a drill flattens it more than it actually is realistically. Not arguing docs claim, he is a smart man and I have learned a lot from him. Just thinking from a different standpoint. Now something I think would actually be really interesting, is to check squish after a long hot cut vs cold. To see if the piston expanded any...

 

[Marshy]

Having solder closest in diameter to the final squished thickness is probably a larger factor.

 

[BonScott46]

When I get some more wood I'll compare it to the one I have with a non windowed 268 popup. That's the last piece of wood I have to test saws with at the moment. I think the chain speed is higher with the Dominate but he one with the 268 piston has more torque. That may change when I richen it up some.

If it is even close i don’t see how the dominant piston is worth the cost IMO.

 

[Ronie]

If it is even close i don’t see how the dominant piston is worth the cost IMO.

Yea, there's cheaper ways of getting the same results.

 

[Funky sawman]

Well the way I see it, the dominate saw piston is worth the price if its indeed a plug and play piston. Not all of us has resources for machine work, and shipping cost from were i live is the highest cost in the nation, not to mention the drive it takes me just to ship a powerhead.

 

[BonScott46]

Well the way I see it, the dominate saw piston is worth the price if its indeed a plug and play piston. Not all of us has resources for machine work, and shipping cost from were i live is the highest cost in the nation, not to mention the drive it takes me just to ship a powerhead.

266/268 piston is a pop up drop in. Buy a meteor from dave have him ship it to a member who can cut a piston and have them ship it on to you.

 

[huskihl]

266/268 piston is a pop up drop in. Buy a meteor from dave have him ship it to a member who can cut a piston and have them ship it on to you.

It costs less to ship the cylinder to have the base and squish cut. Then you can adjust the port heights or leave them. Either way will work better than a popup that shoots the incoming charge up into the spent exhaust.

 

[Ronie]

Well the way I see it, the dominate saw piston is worth the price if its indeed a plug and play piston. Not all of us has resources for machine work, and shipping cost from were i live is the highest cost in the nation, not to mention the drive it takes me just to ship a powerhead.

I was speaking for myself. If you or anyone else feels it's worth it, then it's worth it to them.

 

[Funky sawman]

It costs less to ship the cylinder to have the base and squish cut. Then you can adjust the port heights or leave them. Either way will work better than a popup that shoots the incoming charge up into the spent exhaust.

Well fine and dandy if your not dealing with a particular powerhead like mine with .040 difference in deck hight. My saw gotta be worth alot cause it's a factory high compression model lol

 

[Funky sawman]

I not saying that a windowed 268 piston is going backwards, but in my personal experience, with a 372 built by dean at washington hot saws that used a oem 266/268 windowed piston was lacking alot of torque. Was really peaky. The guy I sold it to was also a saw builder, he put a factory 371 piston in it and cut the pop up to match the 268 piston. It regained the torque and made a useable torque curve, similar to running a 372 XT

 

[huskihl]

Well fine and dandy if your not dealing with a particular powerhead like mine with .040 difference in deck hight. My saw gotta be worth alot cause it's a factory high compression model lol

Yeah somethings up with that one. I’m guessing someone before you milled the case rather than turning the base on a lathe to increase compression. I’ve only seen them vary a few thousandths

 

[Funky sawman]

Nope, it was a one owner new saw. I bought it from a guy that I know personally.

 

[BonScott46]

It costs less to ship the cylinder to have the base and squish cut. Then you can adjust the port heights or leave them. Either way will work better than a popup that shoots the incoming charge up into the spent exhaust.

I am not trying to say a 2 series pop up is going to run as well as a ported cylinder, I am saying that IMO the dominant piston is not worth the money as a drop in performance increase if the saw with a 2 series pop up runs close to it.

 

[huskihl]

I am not trying to say a 2 series pop up is going to run as well as a ported cylinder, I am saying that IMO the dominant piston is not worth the money as a drop in performance increase if the saw with a 2 series pop up runs close to it.

Yeah true.
I have ground a little bit on a few of the Wisecos and the metal is definitely a harder alloy than standard pistons. I’d imagine because of that, they probably last quite a while under normal circumstances without wearing out the skirts

 

[Funky sawman]

If I had to start over again, I think i would have been better off sending off my whole powerhead for a squish band cut and port job. I was hoping that dominate saw piston would get me at least half way there as compared to a full on build.
If i was to design a new piston for 372, the squish band portion of the piston i would have shortened by .015" and use a 1.2 mm single ring. Keep the popup and remove that cut on the ex side of piston.

 

[beaglebriar]

They shoulda quit while they were ahead. The version 1 piston is quite good. My saw with that piston flat out rips but it is ported as well.
My only complaint was the false claims about weight savings. Which in hindsight, a super light piston wasn't really what I needed in this saw.