Dominant piston v4 tight squish

[Yotaismygame]

$110 plus shipping so let’s say $120 per piston. $120 x 2 = $240. That’s what I charge. I didn’t mean the price was expensive for what it is. But expensive for what you get especially when there’s cheaper alternatives that are potentially better. I can buy a whole oem top end for $110 shipped. Cool idea from the guys who make it but the cost is too much. Anyone who’s informed enough I bet is not interested in a $110 piston. I am still curious about its specs though. The ops pic makes it looks like it’s modified to change port timing.

 

[blsnelling]

The 268 piston is .060" taller. What do you do with the other .020"?

 

[Yotaismygame]

The 268 piston is .060" taller. What do you do with the other .020"?

In order to fit it you need to run a stock base gasket and make a .035 pop up. That will net a .020 squish. However you can safely take .040 off the crown.

 

[Leerod83]

I believe they have started to bevel the exhaust side like that. I think the intake side skirt is shorter also. Reason I say that is a guy on YouTube has a deal going with dominant and the pistons he was showing were like that. Ironhorse is his channel.

 

[Matt93eg]

Wonder why they don't make a piston for a 390XP?

 

[Andyshine77]

So the point of these pistons was to obviously get compression up, but you still have to machine them to get them to work? And cutting the skirt, even though you will have to drop the cylinder which will increase intake duration even more? What exactly is the advantage of these pistons in anything other than potentially a race saw?

 

[Yotaismygame]

Andy are you talking about the Dominant piston?

 

[huskihl]

The metal used in Wisecos is a whoooooole lot better than any standard oem or AM piston

 

[Yotaismygame]

The metal used in Wisecos is a whoooooole lot better than any standard oem or AM piston

I don't doubt the quality one bit.

 

[Andyshine77]

Andy are you talking about the Dominant piston?

Yes.

 

[Andyshine77]

The metal used in Wisecos is a whoooooole lot better than any standard oem or AM piston

Machined not cast, if I remember correctly, also a bit heavier?

 

[Matthew Steingass]

If I'm understanding you correctly, you're saying that you only have a couple thousands clearance with a factory gasket?

Yes a sheet of paper on either side of the piston locks it up.

Send it back, drop in a 268 windowed piston with a .040 pop up machined on it. Way cheaper and it'll turn a stock saw into a beast with 190 comp.

I actually have one on hand. I mail it to you for $55. Its a meteor with caber ring. These dominant pistons crack me up.

Idea behind this saw was drop in parts readily available. No machining. No porting. Burn something up, Have it running the same way in a few days. I like dominant as a company and where they're from. Also weisco is pretty cool too.

That piston looks to the eye to be a lot higher from wrist pin to top and front edge looks to be sloped down, is that the case or just illusion from picture? Also looks like a thinner ring than those stock 1.2mm's. Maybe @blsnelling can enlighten me. I am not a porter, just a saw hack.

It's like they tried to get the squish closer to .018 with an oem gasket. Seems to be taller than that though. Exhaust side is sloped. Who knows it might go to snelling to get 17 thousands off the squish band but then it's not a drop in cylinder.

Crank is a 2007. Case is a 2004. Any problems there?

 

[huskihl]

Machined not cast, if I remember correctly, also a bit heavier?

The piston itself is lighter. But with stronger metal, I'm sure they could get away with using less of it

 

[Andyshine77]

The piston itself is lighter. But with stronger metal, I'm sure they could get away with using less of it

That's good, I always thought the machined pistons had more weight. Never personally played with any of them.[emoji111]

 

[Andyshine77]

If it has a true .018" of clearance you're 100% good to go.

 

[Matthew Steingass]

If it has a true .018" of clearance you're 100% good to go.

More like .0018

 

[Andyshine77]

More like .0018

Yeah that would be a little too close.[emoji44]

 

[huskihl]

Could add another gasket. Or maybe they intended it to be used with a thicker gasket? Not sure if there is such a thing or not

 

[Deleted member 117362]

Could you cut one from a copper sheet?

 

[blsnelling]

IIRC, these are lighter than OEM pistons. They were designed as a direct, drop-in replacement. I would highly recommend you get in contact with Dominant. I have not seen these issues.