Ported Dolmar 7900 vs Ported 372xp aftermarket or OEM cylinders

[banditt007]

Dolmar 6400 series any cylinder
Husqvarna 372 series (x torq or not) any cylinder

Ok to clarify I'm not talking pop up pistons and running race fuel. I'm talking what a guy with grinding/polishing tools, a timing wheel and possibly cutting the jug down to reduce squish can achieve between these two saws. Running pump fuel. NOT a cookie cutter, NOT a full time logging saw, but a good reliable work saw setup with a good power band and some serious nuts.

I see there are numerous aftermarket kits for both saws and also the OEM cylinders of course. I have found its not just the 54mm big bore kits for the aftermarket for the Dolmar, there are also 52mm kits and 47mm kits. For the Husqvarna I see 50 and 52mm kits available.

Looking for what setup, and how much more power you could achieve compared to a 6400 with 54mm NWP BBK.

 

[Termite]

Good questions 007, but not many answers or opinions.
The lack of response is about like I started this thread.

 

[wde_1978]

For the Dolmar 64xx/73xx/79xx saw family a OEM 79cc P&C kit is deemed top shelf!
The original PS-7900 kits are NLA, but PS-7910 P&C conversion kits are available - they are direct bolt on.

The AM P&C kits, regular 52mm and 54mm BB, are said to lack proper factory pre-set squish and feature low manufacturing quality (low cast quality, bad port beveling, questionable plating - these issues relate to cylinders and may not be evident on all AM kits).
Also the 54mm BB kit is said to sport more grunt but not truly noticeably more power then the OEM 79cc P&C - it has supposedly something to do with insufficient crankcase volume to properly feed the 54mm cylinder.

If cost is a issue then a AM P&C kit is acceptable, but it should be looked at and reworked thoroughly before assembly and squish must be checked too.
It is recommended to replace the AM kit piston ring with an OEM or Caber one.
The AM kit circlips also recently caused some turmoil in form of ears braking off and seizing the P&C.

The above is my understanding of the topic and is only information I read from within AS!

I can not comment on the 372 kits, they are not nor ever were of interest to me!

 

[blsnelling]

Stick with the OEM 71cc topend on the 372.

BTW, if you can turn the cylinder base you can turn a pop-up piston. Only takes a couple minutes.