Dominant saw V4 371 build

[Ronie]

Well sent them an email, hopefully this can get straightened out. Same issue with 2 cylinders I have which are built some 20 years apart. Do you mind going into a little more detail about you knowledge on the fitment issues? Thanks Brad

Have you heard back from them? I'm curious about what they say about it.

 

[Funky sawman]

Nope.

 

[Ronie]

Nope.

I'd give them a call. 802-526-4729

 

[Funky sawman]

Will try again tommorow, left a voice mail

 

[Ronie]

I emailed them a link to this thread. Maybe they will come on here and discuss their piston.

 

[Funky sawman]

Ok, I've made the decision at this point to clean my kitchen floor and put the saw back together with oem single ring piston, and no base gasket......like the 50 or more others I've built like this. Stick to what I'm good at. Living in a trailer house and a saw tore apart inside for weeks is not something to keep the wife happy

 

[blsnelling]

So does this mean were seeing a .020 difference in deck to crank centerline in these series of saws?

No way.

 

[Funky sawman]

That's what I figured. I have never ever seen squish very more than .010 in all the year of working on 372's. Started working on them when it was the 371 in 99, then quit wrenchen on them daily in 2013

 

[Funky sawman]

What i find interesting is even with the 0.00 squish, and that dominant piston with a new ring, not the ring from the other cylinder, is that i was only blowing 145 psi with an oiled cylinder. I have a feeling that the thin ring doesnt seal well at cranking speed and possibly even at idle. No doubt that it would seal good at 14,000 rpm. Got that saw put together tonight, and its got a pile of compression with stock single ring. Guessing 165 plus.
Kitchen floor will be cleaned up lol clean kitchen, happy wife.
At least it didnt take me 24 hrs to assemble this time

 

[Funky sawman]

That dominant piston......its sure purty ta look at

 

[Dub11]

What i find interesting is even with the 0.00 squish, and that dominant piston with a new ring, not the ring from the other cylinder, is that i was only blowing 145 psi with an oiled cylinder. I have a feeling that the thin ring doesnt seal well at cranking speed and possibly even at idle. No doubt that it would seal good at 14,000 rpm. Got that saw put together tonight, and its got a pile of compression with stock single ring. Guessing 165 plus.
Kitchen floor will be cleaned up lol clean kitchen, happy wife.
At least it didnt take me 24 hrs to assemble this timeView attachment 211857

Man I'm tellin!!!!!

I can't believe they'd sell taters that ain't from Idaho there lol.

 

[drf256]

They were pretty good about returns with me.

Nice guys at Dominant, but they don’t have a good knowledge base. I believe they get mislead by manufacturers and sell products they don’t even know aren’t any good.

 

[blsnelling]

They've been good to me as well. However, I think this piston has significant design flaws.

 

[Funky sawman]

Man I'm tellin!!!!!
View attachment 211876
I can't believe they'd sell taters that ain't from Idaho there lol.

Well, go figure..... an idaho resident cannot buy idaho spuds in idaho.......?..true story

 

[Funky sawman]

Not to bash anyone...... talked with Dominant saw. Very nice guy caught between a rock and a hard spot.. a fellow andy wellman designed these pistons, said they worked, then bailed on him. He is taking the piston back.
I feel for this company, people set out to try and make a product and crap happens but folks that have the tools of knowledge pull the plug on him. Times are tough enough as is let alone having issues like this arise.

 

[Funky sawman]

Is that andyshine? Sorry if im completely out of line

 

[Funky sawman]

I know its not a chainsaw, but here we go. Was talking to one of my old fart buddies about chrome rings with nikisil bores. He owned a dirt bike shop for 50 years, and built custom race 2 strokes. I mentioned my situation with low compression despite a new cylinder, tight ring end gap, "0" squish and pop up piston. He stated that in his many builds he tried chrome rings alot, but always went back to cast due to poor sealing and or excessive time to get chrome ring to properly seal.. he also said that any little variance in bore, weather it be out of round, has spots that expand more than other spots along the ring travel path and cross hatch pattern all have very major rolls to play when dealing with chrome faced ring in Nikisil bores. He perfers chrome bores with cast rings. Maybe thats why stihl went this route. Not saying Husqvarna is any less superior.

 

[Funky sawman]

He stated if he was building a dirt circle track bike, he liked chrome rings because they stay seated with repeated high rpm use, these motors almost never idle, so low speed comp or idle quality is not an issue

 

[Funky sawman]

Anyone have the address for Dominany saw? I lost the packing. Please pm me if possible

 

[Funky sawman]

I need a saw to have very stable idle. Dont want to start it with every cut, sometimes I go up to 5 minutes between cuts, such as hiking to next tree to fell.