Do you like torque or RPMs?

[blsnelling]

There are enough woods ported saws out there to support that there's not enough added stress to the bottom end to be a real concern. Ask Terry for example. His 372XPW is about as fast as they get in a woods ported saw, yet he uses it daily for production falling. True race saws are another story. Some make enough heat that they have to be let cool after cutting three cookies. A woods ported saw isn't anywhere close to that level.

 

[NORMZILLA44]

So the modified saw's I see, almost always have a rpm increase, and significant so woods port how much? And what is done to relieve the strees? Crank re-balance? Wood size, and type is a factor in logging. I learned from guys in my two pic's I just posted, and the pros around my area. We have run togehter since 87. I have seen alot of trial, and error, including in myself. I have always tried to learn from it.

 

[blsnelling]

Nothing is typically done to the bottom end on a woods port. Balance is not an issue. For example look at this 440/460 I just built. It's now wearing a larger/heavier piston, yet is not an issue. This isn't like a SBC where you have multiple cylinders that must be balanced. It's just not a big issue.

 

[NORMZILLA44]

Not yet, to new I guess the hig rpm any way. Though not a v-8 alot of thory still applies, for such rpm increse. Alaways took alot of low end work to get there, and remeber the d-stroke engines more rpm same displacment, shorten the stroke. With the same lower end, and stroke such a rpm increase, the life expetancy will drop. That is a guarantee, ps those big trees here were cut with stock saw's that werent worthless LOL! I like you Brad, but I do need proof in the pudding before I will buy it. My only argument is stock saws are not worthless, and ported, and modified are great!, as long as Rpm's stay in a reasonable range. Much higher is still experimental. Hope we can agree on that little buddy! Like I said I am open minded, and always trying to learn.

 

[blsnelling]

In no way do I actually mean stock saws are worthless. When I say they suck, that's just my way of saying they're boring You really do need to run a good ported saw Why settle for a Yugo, when you can turn that Yugo into a Porsche!

 

[WoodChuck'r]

High revvy RPMs mean absolutely nothing. I've said it in the past - a saw that cuts at 2k in the wood cuts a lot faster than a saw that's turning 16k out of the wood.


Holding good RPMs in the wood under load is the result of a well built saw. A saw that turns 16k should be holding 15,500 in the wood - not 11-12k. Saws that turn 16k are race saws, ones that turn 16k and drop to 11 or 12 are race saw duds.

Good work saws are built to run at factory RPM. They drink more fuel and combust it smoothly and properly so the saw holds it's RPMs under a strong load. Super high revvy "work saws" that turn 16k and drop down have a lot of air going into them. Fuel makes power, not air.

Getting the saw to eat a lot of fuel makes power and keeps it cool.


My 681 runs fat as hell but watch the vid I posted with me cutting. Under load it cleans right up and runs like there's no tomorrow. Doesn't cut as good or as fast in the other vids when the motor isn't loaded right - that's cuz she's gotta drink! And she ain't drinkin' unless she's workin'!

 

[mdavlee]

A real popular builder in oregon said he tuned all the 372xp and xpws to around 13800 when he sent them out. He didn't like the limited coils even on the stock ones. The fallers would use it for one season and buy another and use that one for a backup saw. Terrys xpw is the hottest 70cc work saw I've ever ran. If it has survived for around a year without bottom end problems then I don't think it's an issue.

 

[WoodChuck'r]

My point is good work saws do not need to turn high RPM. Leave the RPMs for the race saws.


I run both my 372 and 681 in the woods all the time. What's the need in worrying about crank case and bearing problems when the saw is at factory RPM....

 

[blsnelling]

My point is good work saws do not need to turn high RPM. Leave the RPMs for the race saws.


I run both my 372 and 681 in the woods all the time. What's the need in worrying about crank case and bearing problems when the saw is at factory RPM....

The only reason your 681 isn't turning those higher RPMs, is because it's tuned so fat. Tune it where it wants to be and you'll see RPMs similiar to that of your other saws. Also, I'm not buying a properly tuned saw only loosing 500 RPMs in the cut. That's just not happening. The only way a ported saw is going to turn factory RPMs, is to tune if fat pig rich.

 

[NORMZILLA44]

Good reply's Brother's, and that I know. My point was alot of the ported, and modified one's I have seen talked about in alot of threads lately, and are not race saws. Just ported, and modifed ones, but claiming 14,000, 14,800 etc. I dint see any problem with 13,800, thats pretty close to stock. Im just talking such a big jump say over 14,000. Any kind of porting, and or polishing will benefit that has been around for year's, and I agree on that. Flow= H.P, and toeque. More flow, = more of you know what.

 

[Mastermind]

A real popular builder in oregon said he tuned all the 372xp and xpws to around 13800 when he sent them out. He didn't like the limited coils even on the stock ones. The fallers would use it for one season and buy another and use that one for a backup saw. Terrys xpw is the hottest 70cc work saw I've ever ran. If it has survived for around a year without bottom end problems then I don't think it's an issue.

And there you have it. Michael just nailed this down in a few words. Terry's XPW is a beast. It's been killing trees daily for about a year now.

My ms460 is a heck of a strong work saw, holds about 12,500 in the cut. Is that over revving it?

 

[NORMZILLA44]

Cool, good deal glad they work for Terry sound like great saws. When I speak of rpm to hig. I am talking say from going from stock 13,500 no load, to 14,000 or 14,500 and so on no load on a saw.

 

[WoodChuck'r]

The only reason your 681 isn't turning those higher RPMs, is because it's tuned so fat. Tune it where it wants to be and you'll see RPMs similiar to that of your other saws. Also, I'm not buying a properly tuned saw only loosing 500 RPMs in the cut. That's just not happening. The only way a ported saw is going to turn factory RPMs, is to tune if fat pig rich.

But I like'er to be fat and fulla fuel.

And the 16k - 15,500 comment I made was about race saws, not work saws. I went back and looked and I really didn't specify that comment very clearly....

I was more or less addressing Norm's talk about high high revvy saws in general. To me, it's not necessary for a work saw to be revving as high as 15k, 16k, ect.... Saws that turn that high are (or should be) race saws and they drop very very little RPM when in the wood - it's pretty insane to hear very little change in the motor once a race saw is under load.....

 

[Chris J.]

I like whatever














HILLBILLYREDNEC recommends :msp_lol: :biggrinbounce2:.

 

[WoodChuck'r]

I like whatever









HILLBILLYREDNEC recommends :msp_lol: :biggrinbounce2:.

Now THERE'S a dude who's got his **** together!!

 

[NORMZILLA44]

I only wish Brad, and Randy could be good friend's as well as sponsors, and say send me a demo saw. Im not picky 288xp, 390xp!

 

[NORMZILLA44]

P.S I bet sales would go up LOL!:msp_tongue:

 

[wigglesworth]

Physics,

you can run a saw on the ragged edge and cut real fast, but if you err a bit you will score the piston,or worse.

I would like to take some of these cookie cutters and strap them on my mill. I would bet dollars to donuts I could kill them,,,,,,,,,,pretty fast.

I milled quite a bit with my ported 044/046 hybrid. Never had a problem. I do keep it tuned a bit rich, 13.5k or less. Does fantastic on my small grandberg.

 

[wigglesworth]

I milled quite a bit with my ported 044/046 hybrid. Never had a problem. I do keep it tuned a bit rich, 13.5k or less. Does fantastic on my small grandberg.

I would also like to add, that I've done extensive testing with this saw in timed cuts in uniform wood all across the rpm range. This particular saw will still 4 stroke hard out past 15.5k, but will cut quite a bit faster in a timed cut set at around 14.5k wot.

It takes fuel to make power.

 

[Mastermind]

I only wish Brad, and Randy could be good friend's as well as sponsors, and say send me a demo saw. Im not picky 288xp, 390xp!

We are good friends. :msp_thumbup: