Nut Up your Husky 365, 371, or 372

[Grande Dog]

Howdy,
There is an OEM cylinder and piston assm. available for these units that displaces 75cc's and really improves the torque. It'll set you back an extra $100.00 or so US compared to the stock top end, but if your replacing your top end anyways it's worth it. Husqvarna's part# is 503 97 59 02.

Grande Dog
Master Mechanic
Discount Arborist Equipment and Tree Care Supplies

 

[eyolf]

Wo...

So what's up with that...having a factory speed part in the books that nobody knows about?

Stock carb mounting boot works? How about muffler?

With a stack of bills for a stroker crank, a guy could have a saw able to eat 395xp's lunch , but only weigh 13#, huh?

 

[jokers]

It`s the top end from the 75cc cut off saw. I`ve heard that it doesn`t mod well and that a guy would be money ahead to have a reputable builder tweak his stock 371/372.

Russ

 

[Grande Dog]

We just strapped this on a stock 371 the other day and right off the bat there was a noticable difference in torque. When we get 30 hours or so on it I let you know. As far as I'm concerned there is no replacement for displacement.

Grande Dog
Master Mechanic
Discount Arborist Equipment and Tree Care Supplies

 

[glens]

And how are you going to get the saw to shed over one pound?

All you people using one of those saws and thinking they weigh what the literature says are like women who believe <i>this much</i> is 8 inches.

hahaha

Glen

 

[Crofter]

Jokers you might be right. The cutoff appplication has to govern rpm anyway to not overspeed the wheel. I would like to see the shape of the transfers. They might well not lend to high rpm.

Frank

 

[dozerdan]

372/375

Hi
Yes you can use that piston and barrel on the 365,371,372 chain saws. That will make any of those saws a 74.7cc engine as opposed to 70.7 for the 371,372. However the port timing figures on the 375 barrel are lower then that of the chain saws, they are designed to make top horse power at a lower rpm. I have ported a few of those barrels and they do work well but you have to be careful. Once you get the exhaust port up to where it should be the metal starts to get on the thin side.
The 372 has a 50mm bore.
The 375 has a 51mm bore.
Yes they are a direct bolt on.
Crofter
The ports are the same design as the 372 barrels.
Later
Dan

 

[jokers]

Dan,

What if you were to have your son Tig some extra material onto the outside of the port runners before porting/ That would give you some wiggle room wouldn`t it? Sounds like an interesting project.

Russ

 

[dozerdan]

Russ
I would have to get my son to weld it, because I sure as sheet cant do it. I failed tig and aluminum big time. LOL
I guess that I used a stick and a mig to many years, the tig and I do not get along very well.
I can finally weld up the thin metal for a pipe with it but I still cant weld aluminum.

Pm me your phone number again.

Later
Dan

 

[Jacob J.]

Russ- TIG welding extra material on the outside of a cylinder is an excellent way to give yourself more room to modify ports. I built up the transfers on Dan's 090 this way so I could drop them all the way down into the crankcase.

 

[Crofter]

Jacob J.

Would there be any problem with distortion to weld material on above to raise exhaust port. I'm thinking out of round.

Frank

 

[bwalker]

Dan, How does a pp375 compare to a pp372? Whats the cost over a standard pp job.

 

[Jacob J.]

Frank- you don't want to Tig directly above or below the exhaust or intake ports, because you might peel the chrome liner ( or nicasil ).

As far as making a cylinder out of round, I've never seen a chainsaw cylinder that was round. Almost all of them are shaped like oblong cones, getting narrower closer to the combustion chamber.

 

[glens]

Jacob, you reckon maybe that's so when they come up to (the inevitably variable) operating temperature, they're closer to a true cylinder?

Glen

 

[Bernard]

Crofter, I have welded flanges on my intakes and added material to my transfers, but if you get to much heat to fast you will warp the cylinder. I even heated the cylinder to 400 degrees and put in a steel plug, let it cool and then welded on the cylinder. Same result, didn't hurt the nicasil but made a high stop that couldn't be hone out. If you weld a quick pass, keeping the heat to a minimum it can work, but your taking a chance. Try a titanium putty or JB Weld stick putty for adding extra material around the outside of the tranfers or exhuast.
Bernie

 

[Crofter]

Thanks for info re distortion. The steel plug is a neat idea. I have done welded repairs on hydraulic cylinders and find that you always have to hone out some shrinkage in the weld area. Wasnt sure about how much permanent deformation there might be with cast aluminum.

Frank