Why Toss A Perfectly Good OEM Cylinder Just Because It's A Little "Smaller", A "Simple" Build From The Junk Pile

weimedog

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"Bob goaded me now for a couple of years on the merits of the closed port 48mm Husqvarna 365 Special Cylinders. They are "original" edition pattern, NOT X-torq. So I built one last year or the year before on Aftermarket cases. Great saw to run...but I wanted an ALL OEM build and also wanted it in the "red" side of the Husqvarna Jonsered family. No real "technical" reason other than I happen to like the Jonsered's of that original edition pattern more than the Orange ones and any of the "X-torq" versions regardless of color. Also a "path" to take a blown up X-torq should someone like the concept. SO here is the "intro" to that build. The goal is simply to match the performance of a stock 50mm 372/2172 X-Torq saw with a saw a little lighter with less inertial forces making if easier to handle. Sound goofy? maybe. But those little 48mm OE cylinders respond really well to a simple compression increase. And rather than follow the "herd" online be it to Aftermarket "Big Bore" top ends, or the conventional tried and true performance build configurations with "decked" ( Lowered ) cylinders, machined squish bands to both reduce combustion chamber size promoting efficient combustion along with corresponding port modifications and timing numbers. A typical 50mm 372 build after grinding will have numbers like an intake timing 80-81 degree's BTDC, Exhaust 98-100 ATDC & Blowdowns in the 18-20 degree range, timing numbers depending on other "particulars" AND a concept often regurgitated/copied , been there done that! Great running saws no doubt which is why folks fork out money to have them built. BUT requires either cash to have some one replicate that concept or machining and porting to the transfers which requires expensive tools for those closed port with no transfer caps cylinders. ( Why 372 X-Torqs ARE a great place to learn that porting game along with saws like Husqvarna 359 & 350s ) Nope, going my own way. A focus on "Tools From Lowes" ( NO machine tools ) , "Bolt" on parts like a "popup" piston, and simple changes that make a different anyone can accomplish, A focus on compression therefore efficiency. BUT I really don't expect anyone to want to follow this path. So why watch? Because while building this saw, I mutter about things from theory to actual experience relative to assembling this type of saw.. :) Really about the trials and tribulations of a junk pile build "

 

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