Husky 372XP "Big Bore" Kit Build Piston Question

[BING38RT]

Hi,
I recently bought one of those husky 372 XP kits of the internet that I'm trying to build. I didn't like the shape or the quality of the head that came with it so I bought a Hyway Big Bore Kit that came with the pop-up piston ( 52mm ).

Now after reading a bunch, doing research, and talking to others I realize that using a pop-up piston isn't a good idea for the longevity of the saw especially if I were to have it ported.

I'd like to put a meteor piston in it but it doesn't seem like meteor makes a 52 mm Big Bore piston specifically for the 372XP "Big Bores", they do however make one for the 272. I was wondering can I use the 272 piston from meteor in my 372XP ?? Or am I stuck having to buy a 52 mm generic non pop up hyway or other aftermarket brand piston ??

If anybody knows if this would work I would appreciate your input or if there's another piston that's 52 mm that's made by meteor that would fit I would love to know.

Thank you in advance for all your help. I'm new to pro saw building as I've mainly only built clamshells.

 

[J D]

The problem with those kits isn't the piston it's the kit as a whole. The ports & timings are far from optimal & you can only remidy them so much. Generally speaking a well ported big bore kit will perform about the same as the standard OEM C&P

 

[BING38RT]

The problem with those kits isn't the piston it's the kit as a whole. The ports & timings are far from optimal & you can only remidy them so much. Generally speaking a well ported big bore kit will perform about the same as the standard OEM C&P

****. So should I just bail on it then ? I already have 6 saws, a MS 250, 3x MS 390s, a MS 391 and a Husqvarna 460 Rancher. I just wanted a 70cc plus saw to use for bigger trees and possibly milling.

I want a 440 or 460 maybe even a Holzfforma G660 but I'm not sure about that brand.

 

[Bjorn T]

****. So should I just bail on it then ? I already have 6 saws, a MS 250, 3x MS 390s, a MS 391 and a Husqvarna 460 Rancher. I just wanted a 70cc plus saw to use for bigger trees and possibly milling.

I want a 440 or 460 maybe even a Holzfforma G660 but I'm not sure about that brand.

Do you have a lathe?

 

[BING38RT]

Do you have a lathe?

Yea it's an old one from the farm over at my uncle's house bc I don't have the room here and it weights a ton. .

My thing is I don't want that crappy Hyway pop-up piston in it because I purchased an aftermarket Nikasil big bore head so I'd need a 52mm piston.

I wonder if the windowed one Meteor makes for a Husqvarna 272 will work on the kit I got ?

 

[Bjorn T]

Yea it's an old one from the farm over at my uncle's house bc I don't have the room here and it weights a ton. .

My thing is I don't want that crappy Hyway pop-up piston in it because I purchased an aftermarket Nikasil big bore head so I'd need a 52mm piston.

I wonder if the windowed one Meteor makes for a Husqvarna 272 will work on the kit I got ?

 

[Bjorn T]

The 272 piston is higher then the 372 so you can make a good pop up if you have a lathe. I made a pop up and full circle crank for my race saw. I used the dukes cylinder. But a hyway is ok. I jb weld the intake, so its open at 76 degrese btd center.

 

[sean donato]

It wasn't the best choice to grab a big bore kit, but the saw will run just fine with the pop up piston. I wouldn't be worried about longevity either. It's either going to work, or blow up. Same as anything else.

 

[BING38RT]

It wasn't the best choice to grab a big bore kit, but the saw will run just fine with the pop up piston. I wouldn't be worried about longevity either. It's either going to work, or blow up. Same as anything else.

Thanks guys I ended up sending it out to a guy who builds these kits professionally, I had him get rid of the big bore kit and use the stock oem head. He ported and polished it for me, added a real Walbro Carb and machined the head down on a lathe for me because my original squish with the base gasket was .035 and now with the gasket it's .022.