A Tale of Three Saws

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The 390xp is low on compression stock, about 150psi on the average. Reducing the squish/quench to .020-.025, plus a .020-.030 popup really wakes them up.;)
 
You can by Australian made ones Al, probably about 30 bucks...

Yeah mate, there are some really nice oil skins available. I'd only loose them!

The 390xp is low on compression stock, about 150psi on the average. Reducing the squish/quench to .020-.025, plus a .020-.030 popup really wakes them up.;)

Matt's 390 is only running gasketless if I remember correctly.
 
The 390 I'm running is around 175 lbs with just a shaved cylinder. The 660 is around 150 after 5 tanks.
 
I haven't measured compressions yet but the 660 with pop up will be up there once it's properly run in I think :)
 
Must be a Aussie thing, every site I found was in Australia:laugh: I guess wearing shorts and work boots isn't as popular over here, thats to bad.

Frank...

I'm gonna petition to have your Hillbilly permit revoked.:hmm3grin2orange:

Lop the last 8" off of the sleeves of an old windbreaker with elastic in the wrists.
Boom! Instant black jack flaps(Gaiters).

If ya insist on bieng all citified about it, REI has 'em.;)

Stay safe!
Dingeryote
 
Frank...

I'm gonna petition to have your Hillbilly permit revoked.:hmm3grin2orange:

Lop the last 8" off of the sleeves of an old windbreaker with elastic in the wrists.
Boom! Instant black jack flaps(Gaiters).

If ya insist on bieng all citified about it, REI has 'em.;)

Stay safe!
Dingeryote

I've said this one before. ;)

Cut the last 6" off the bottom of your old tracky dacks with elastic bottoms, turn em upside down...instant gaiters!
 
So in the end what compression did that 660 end up with the popup, and was there any pics taken of the popup ?.

Cheers all

Hi Andrew.
Compression isn't silly on this 660 and from memory was about 180psi - standard was around 155psi. The Makita that I had with the popup was about 200psi. 180psi certainly isn't excessive and stock untouched pro saws such as the Dolmar 7900 are commonly 170-180psi. I don't think Brad took any photos of the work he did. I reclon I asked him earlier in the thread.
 
The tale goes on

The Tale Of Three Saws goes on for one of them anyway.
Matt has very kindly sent down the 2rd one of those 660s the Brad modded,for me to play with.
So what do you do,put it up against a stock ozzy (dual port muf,h/output oiler) 660 and for interest a stock ozzy 880.
The firsts cuts are the stock 660 (blue tape on chainbrake handle)

Stock 660
Dual port muf
2009 mod done a fair bit of work
8 pin rim
25'' bar
Fuel is Caltex Vortex 95 Mobile 1 T2 @ 40;1
w/o 12800 rpm

Snellerized 660
Muf mod dual port
Woods ported,cylinder machined lowered
Popup piston
8 pin rim
25'' bar
Fuel BP Ultimate 98 Mobile 1 T2 @40;1
w/o 13800 rpm

stock 880
2010 modle
8 pin rim
36'' bar
Fuel is Caltex Vortex 95 Mobile 1 T2 @ 40;1
rev limitted

All have Stihl semi chisel chains of the same roll
[video=youtube;8NLuAaoA7B0]http://www.youtube.com/watch?v=8NLuAaoA7B0&nofeather=True[/video]
 
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Great job Andrew.

Softwood going by the blue stain?

Wood looks a little yellow in the vid for pine...........Oregon/Douglas fir?

I got-

stock 660 - av 8.8
Worked 660- av 8.6
880 - av 7.4

Hardwood, say Stringy twice the size would spread the times some!
 
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Yeah Al I was talking to Andrew via email and I think if he dropped the rakers a bit you'd see the modded 660 (and the 880 of course!) really start to kick butt over the stock 660 due to the extra torque. I know that when I was running it you could get pretty aggressive with the raker height and it just kept on pulling...hard...

It was a very difficult saw to stall or slow down, just like my 3120.
 
I totaly agree with you Matt about dropping the rakers,but what i was trying to do was keep everything that i can control the same to get a fair comparison between them.
 
I totaly agree with you Matt about dropping the rakers,but what i was trying to do was keep everything that i can control the same to get a fair comparison between them.

Hey I agree Andrew, I would have done exactly the same as you - you need to set a standard to start with which you've done nicely :)

Now get angry with those rakers! You'll see your stock 660 lag behind, the modded 660 will pull away, and the 880 will kick all their arses - mark my words. No matter how good somebody mods a 660 it ain't gonna fill a 28 odd cc torque gap!
 
Its real hard to say just listing and watching videos but it "sounds" like both 066's are being loaded about the same (good job of running them) you can here them both pull down in the power band about the same.
I'm curious what would happen if you do take the rakers down.
personally "I" think you make be going the wrong way. Try filing the chain back some and leave them where they are and try it on the 066.
 
No matter how good somebody mods a 660 it ain't gonna fill a 28 odd cc torque gap![/QUOTE]

I here what you are saying cc s are everything,i put the 880 in there for my own interest.I suppose deep down i am trying to find out if i can live without it or not,but i have a soft spot in my hard for it,dont know why,its heavy,hard to handle,likes a drink but gee it sounds good but.:laugh:
I would love to send it to Brad,get it modded and throw away that rev limitter,know that would be a weapond.:rock:
 
Unless Im way off on my math then you have a gain of 2.27% from stock vs. modded on your 660. The times i got were as follows
Stock 9.60 & 8.13
Snelleriized 9.34 & 7.78

Thats not much in the way of gains at all. Am I missing something here? Shouldnt a modded saw get atleast about 15% more?
 
In defence of the mooded 660 is old habbits die hard in that im not familier with high torque modded saws,and i didnt realy know how hard to lean on it.The big differance is the torque and holding rpm in the cut.Modded one holds 10000 rpm no problem,the stock one is around 8 to 9000 rpm.
What Matt and Al are saying is drop the rakers and it will still have the torque to hold the rpm but cut farster.:msp_smile:
 
Unless Im way off on my math then you have a gain of 2.27% from stock vs. modded on your 660. The times i got were as follows
Stock 9.60 & 8.13
Snelleriized 9.34 & 7.78

Thats not much in the way of gains at all. Am I missing something here? Shouldnt a modded saw get atleast about 15% more?

In that size wood and being softwood the benefit of porting can't shine. Double the size and make it hardwood would increase the difference. As Matt said when he was running it, it had the grunt in larger wood. My 365BB with 166° Ex would whip the butt of my 395 in that size softwood. Alot bigger wood and hardwood, the reverse would happen.
 

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