Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: SquareFile on December 21, 2014, 08:51:09 am

Title: Husqvarna 2100 performance upgrade?
Post by: SquareFile on December 21, 2014, 08:51:09 am

Will a 395xp piston help performance on 2100cd?

If so, what modifications need done for the piston to work?
Title: Re: Husqvarna 2100 performance upgrade?
Post by: bloodontheice on December 21, 2014, 09:22:09 am
I think the 395 is slightly taller only a mil or two from what I can remember.

I lucked out and picked this NOS thin ring piston and rings up off ebay a few weeks ago.

(http://i6.photobucket.com/albums/y244/CaleSigas/_57_zps88c3c92a.jpg) (http://s6.photobucket.com/user/CaleSigas/media/_57_zps88c3c92a.jpg.html)
Title: Re: Husqvarna 2100 performance upgrade?
Post by: SquareFile on December 21, 2014, 09:38:48 am
I currently have a thick ring piston with a few scratches on the skirt in my saw. Its useable. If a 395xp piston is a little taller from the wrist pin I can face it off. Do you know if I'd gain performance? I know I've read that some builders like the 395 piston but I cant find in my searches.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: man of stihl on December 21, 2014, 10:04:04 am
If your tightening the squish with a taller piston there will be performance gain. I don't know any thing about the 395 piston but If it was me I would find a thin ring 2100 piston and machine the cylinder to desired squish. That's what I did with mine. Its extremely torquey. I love that saw....
Title: Re: Husqvarna 2100 performance upgrade?
Post by: man of stihl on December 21, 2014, 10:06:40 am
If I remember right the stock squish was .050. Now its .025
Title: Re: Husqvarna 2100 performance upgrade?
Post by: srcarr52 on December 21, 2014, 10:55:23 am
Yes, it can be used but you have to machine the squish band of the cylinder to make it swing. 
Title: Re: Husqvarna 2100 performance upgrade?
Post by: SquareFile on December 21, 2014, 12:00:24 pm
If I machine the squish band for proper clearance, wouldn't the port timing be effected with the taller piston?

Would it increase performance?
Title: Re: Husqvarna 2100 performance upgrade?
Post by: 660magnum on December 21, 2014, 01:42:36 pm
Some people take a little rim cut on the deck of the taller pistons in the squish area and this minimizes the timing difference.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: srcarr52 on December 21, 2014, 05:56:32 pm
If I machine the squish band for proper clearance, wouldn't the port timing be effected with the taller piston?

Would it increase performance?

Yes, it does alter the port timing and the exhaust and transfers would have to be raised up to get the performance you want.

Some people take a little rim cut on the deck of the taller pistons in the squish area and this minimizes the timing difference.

You could do a pop-up on the piston to make it clear which would leave the exhaust and transfer timing alone.  I'd personally still change them to get more performance though.  Here is a 2100 with a 395 piston I did.  It also has a 394 carb and a custom made v-stack. 

https://www.youtube.com/watch?v=QNZIirUijBc
Title: Re: Husqvarna 2100 performance upgrade?
Post by: SquareFile on December 21, 2014, 07:07:33 pm
If I machine the squish band for proper clearance, wouldn't the port timing be effected with the taller piston?

Would it increase performance?

Yes, it does alter the port timing and the exhaust and transfers would have to be raised up to get the performance you want.

Some people take a little rim cut on the deck of the taller pistons in the squish area and this minimizes the timing difference.

You could do a pop-up on the piston to make it clear which would leave the exhaust and transfer timing alone.  I'd personally still change them to get more performance though.  Here is a 2100 with a 395 piston I did.  It also has a 394 carb and a custom made v-stack. 

https://www.youtube.com/watch?v=QNZIirUijBc

Sounds like its holding some crazy RPM's. Great job

I don't have porting tools, degree wheel or knowledge of good numbers. So I think I'm just going to cut a popup on a 395 piston.

Thanks for all the help
Title: Re: Husqvarna 2100 performance upgrade?
Post by: Al Smith on December 21, 2014, 09:14:28 pm
You go to jacking the compression on that thing you'd better have the arms of a gorilla .That's one of the hardest pulling SOB's ever made .
Title: Re: Husqvarna 2100 performance upgrade?
Post by: SquareFile on December 22, 2014, 06:33:26 am
Thanks Al, I will keep that in mind. It definetly doesn't pull over easy stock.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: man of stihl on December 22, 2014, 09:05:26 am
I have a big stock Sachs 143 thats more of a bear to pull over than the 2100 with jacked up compression. I have a D handle on the 143 and you can not drop start it..... the foot in the rear handle is a must.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: SawTroll on December 22, 2014, 10:31:45 am
You go to jacking the compression on that thing you'd better have the arms of a gorilla .That's one of the hardest pulling SOB's ever made .

I've heard the 298 is worse - and that adds up, as long as it has the original smaller diameter starter.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: Cut4fun . on December 22, 2014, 10:45:18 am
I know one of my 166 had just 190psi stock piston and used to kick my butt even with a decomp. The hard plastic T handle snapped in to one time on a start on a kick back, stung my hand big time. I thought oh heck no never again. Stihl 460 rescue handle went on that saw from there on.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: SquareFile on December 22, 2014, 11:00:37 am
I took the cylinder off this morning. Squish @.050 as a member stated his was. What I thought was scratches ended up being barn find grime and carbon streaks. The saw was stored for a long time without a muffler. I'm going to try a 395 piston. I can always go back to the original. I was surprised how large the chamber is dished on this cylinder.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: Cut4fun . on December 22, 2014, 11:19:16 am
I'm quicker here then text.

2101 with half wrap 20.3lbs  so  2100 with full wrap more.

084 20.7lbs

088 21.8lbs

Title: Re: Husqvarna 2100 performance upgrade?
Post by: Cut4fun . on December 22, 2014, 11:36:25 am
So do you guys think there is anything to be gained by the window design of the 395 piston compared the the stock thick ring 2100 piston windows?
Title: Re: Husqvarna 2100 performance upgrade?
Post by: Cut4fun . on December 22, 2014, 11:41:58 am
this style 2100 http://www.ebay.com/itm/like/150842324112?lpid=82

to this 395 http://www.ebay.com/itm/METEOR-BRAND-Chainsaw-piston-kit-fits-HUSQVARNA-395-395XP-56mm-/291229484660?pt=LH_DefaultDomain_0&hash=item43cea14674

Then there is this 2100 aftermarket piston I seen in search.  ?   http://www.ebay.com/itm/HUSQVARNA-CHAINSAW-2100-2101-1100-PISTON-RINGS-56MM-NEW-BOX2300-/351169037424?pt=LH_DefaultDomain_0&hash=item51c34e4470


Then you got the top dog for race 2100 thin ring piston.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: neil on December 22, 2014, 05:37:19 pm
I think the 395 is slightly taller only a mil or two from what I can remember.

I lucked out and picked this NOS thin ring piston and rings up off ebay a few weeks ago.

(http://i6.photobucket.com/albums/y244/CaleSigas/_57_zps88c3c92a.jpg) (http://s6.photobucket.com/user/CaleSigas/media/_57_zps88c3c92a.jpg.html)


Other way round, I'm sure the full skirt 2100 piston is higher than a 395, I have both on the shelf, I could measure.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: neil on December 22, 2014, 05:41:48 pm
You go to jacking the compression on that thing you'd better have the arms of a gorilla .That's one of the hardest pulling SOB's ever made .

hahahah yes they do take some pulling over, my 3120 hot saws have the decomp removed as I had one fail in a final once so it had to go and have plugged them ever since. can be interesting sometimes and do break starters at times.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: mdavlee . on December 22, 2014, 07:33:22 pm
To install a 2100 piston in a 395 you have to cut the chamber or a popup.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: Cut4fun . on December 22, 2014, 08:03:00 pm
To install a 2100 piston in a 395 you have to cut the chamber or a popup.

He is wanting to put a 395 p in a 2100. 

Anything gained in the windows of 395 compared to that thick ring 2100 p in ebay pics?
Title: Re: Husqvarna 2100 performance upgrade?
Post by: mdavlee . on December 22, 2014, 10:15:43 pm
To install a 2100 piston in a 395 you have to cut the chamber or a popup.

He is wanting to put a 395 p in a 2100. 

Anything gained in the windows of 395 compared to that thick ring 2100 p in ebay pics?
Right. It will be way short I believe. If I remember right you have to knock .040" or so OT of the chamber or a popup to clear the 2100 in a 395. So with that much difference and squish at .050" squish may be .090".
Title: Re: Husqvarna 2100 performance upgrade?
Post by: SquareFile on December 23, 2014, 03:34:01 am
My current 2100 thick ring piston measures .868" from the top of the piston to the top of the wrist pin. If anyone knows that measurement on a 395 piston I would appreciate that information.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: 660magnum on December 23, 2014, 04:36:34 am
27 mm or 1.063" for the 395
Title: Re: Husqvarna 2100 performance upgrade?
Post by: SquareFile on December 23, 2014, 05:48:08 am
Thanks Jim
Title: Re: Husqvarna 2100 performance upgrade?
Post by: mdavlee . on December 23, 2014, 11:23:35 am
There's more stroke in the case of the 2100 then. I knew in a 395 the 2100 piston is too tall.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: srcarr52 on December 23, 2014, 12:15:20 pm
He is wanting to put a 395 p in a 2100. 

Anything gained in the windows of 395 compared to that thick ring 2100 p in ebay pics?

There is a reason why Husky went from the original full skirt windowed piston to the most current bridged pin support piston found in the 272/288/394/395. They dabbled with other windowed piston designs like in the 2100 but as everyone knows they didn't have the same performance as the large windowed piston. The problem lies with the stock lower transfers. They majority of the flow has to go through the piston windows as the full skirt closes off the transfer when getting closer to BDC, effectively neutering the time area of the transfers. So the large window was the ticket. Now when you remove the full skirt and keep the piston pin supports high on the piston, like the 395, it never impeads the flow into the transfers and you get to utilize much more of the time area that the transfers are open. 

Also when going to a 395 piston you can open up the lowers much more creating a larger funnel which can be done in a way to guide the charge into the cylinder better. In my opinion you are able to raise the usable RPM range this way without sacrificing any peak torque because you can stick with larger blowdown numbers, the loop scavenging is more efficient, and there is enough flow to keep the engine from chocking out until a higher RPM.

Another improvement in the 395 piston is ring pin location above the intake port. I'd prefer the skirt length of the 394 piston as it would help keep the intake duration under control but the pin locations on the 394 pistons are horrible being right over the side of the skirt, so you are really limited to your transfer shape or you have to run it backwards and keep the exhaust port smaller. 

I think in the saw that I posted before I just skimmed the base of the cylinder to make sure it was flat and I took 0.010" out of the squish to get the 395 piston to swing.  Which put the intake duration at 157 degrees without touching the port. 
Title: Re: Husqvarna 2100 performance upgrade?
Post by: SquareFile on December 23, 2014, 02:04:02 pm
Thanks Shaun, that helps me alot
Title: Re: Husqvarna 2100 performance upgrade?
Post by: 3000 FPS on December 23, 2014, 08:42:22 pm
Dang Shaun sounds like you know your 2100's.    If I ever decide to mod mine I know who I will send it to.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: Cut4fun . on December 23, 2014, 08:42:32 pm
Thats the info I was digging at. Thanks Shaun.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: srcarr52 on December 24, 2014, 11:52:48 am

Dang Shaun sounds like you know your 2100's.    If I ever decide to mod mine I know who I will send it to.

I kinda specialize in big cc huskys.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: Eccentric on December 25, 2014, 03:48:46 am
How about relocating the ring pins on a 394XP piston as an alternative to running it backwards or using a 395XP slug?
Title: Re: Husqvarna 2100 performance upgrade?
Post by: srcarr52 on April 30, 2015, 03:27:09 pm
How about relocating the ring pins on a 394XP piston as an alternative to running it backwards or using a 395XP slug?

I'd rather not relocate ring pins if I don't have to. There is no cast in boss on the 394 piston where you'd like to put the pins so you wouldn't have much material to hold them in.  With the 395 piston you can't take much out of the squish in order to keep your intake timing in check but they already have plenty of compression so cutting too much out of the squish isn't really necessary.

The hardest part I had forgot about. You have to cut a lot off the base because of the difference in piston crown heights. So much you'll have to massage the dividing wall to get the intake to sit nicely and the carb shelf will have to be dimpled for the carb.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: Eccentric on April 30, 2015, 03:32:49 pm
How about relocating the ring pins on a 394XP piston as an alternative to running it backwards or using a 395XP slug?

I'd rather not relocate ring pins if I don't have to. There is no cast in boss on the 394 piston where you'd like to put the pins so you wouldn't have much material to hold them in.  With the 395 piston you can't take much out of the squish in order to keep your intake timing in check but they already have plenty of compression so cutting too much out of the squish isn't really necessary.

The hardest part I had forgot about. You have to cut a lot off the base because of the difference in piston crown heights. So much you'll have to massage the dividing wall to get the intake to sit nicely and the carb shelf will have to be dimpled for the carb.


That's what JJ told me when we were discussing piston options a while back.  I can't remember how much he said had to be taken off of the base of the jug................but it's substantial...
Title: Re: Husqvarna 2100 performance upgrade?
Post by: srcarr52 on April 30, 2015, 05:08:24 pm
That's what JJ told me when we were discussing piston options a while back.  I can't remember how much he said had to be taken off of the base of the jug................but it's substantial...

It was substantial but well worth it. The one I built like this has a lot of power. The owner uses it for bucking and free hand ripping large oak logs and it usually runs a 36" full skip, square ground with an 8 pin driver. Even dogged in it is still hard to bog. 
Title: Re: Husqvarna 2100 performance upgrade?
Post by: aclarke on April 30, 2015, 05:45:21 pm
Why not put the pin in vertically and peen or weld over?
Title: Re: Husqvarna 2100 performance upgrade?
Post by: srcarr52 on May 08, 2015, 10:12:21 am
Why not put the pin in vertically and peen or weld over?

The 395 piston also has 1.2mm rings instead of 1.5mm on the 394.  It's all around a better piston. The skirt is a little shorter but both have the same crown height to you still end up cutting a lot off the base of the cylinder.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: aclarke on May 08, 2015, 10:46:44 am
Intake timing is ok after using the shorter piston (skirt ) AND dropping the jug?
Title: Re: Husqvarna 2100 performance upgrade?
Post by: srcarr52 on May 08, 2015, 11:54:27 am
Intake timing is ok after using the shorter piston (skirt ) AND dropping the jug?

With the squish cut about 0.010" the intake timing was just shy of what I wanted. So I was able to clean up the bottom lip and shape the port the way I wanted.

So you can't make a super high compression saw without the intake timing getting out of hand but at -0.010" on the squish it has plenty of compression for a saw without a decomp.
Title: Re: Husqvarna 2100 performance upgrade?
Post by: aclarke on May 08, 2015, 12:14:40 pm
Cool.  Thanks