Stock Appearing Race Saws

[Chopwood]

it seems to me that in a 3 cut race, a larger flywheel would be nice.
1. you get to store energy as you come down on the first cut.
2. the stored energy covers a few screw ups mid log.
3. you get stored energy in changeover.

it does take some to accelerate it up, but it seems like there is plenty of time as you lift the saw to spin it up.
i've never raced though, so am listening to my elders.

Not being a smart azz, here we go.

1. The RPM drops slowly over the peak rpm range through the cut, thus no energy is being stored. It is being used up, so to say.

2. There is no way to account for screwing up in a cut, if you drop a real pipe racesaw 300RPM off the peak, it's gonna fall on it's face. No matter how much weight you have on the flywheel.

3 yes, there is engergy being "put back" into the flywheel on changeovers. This energy is gone an inch into the cut as the RPM goes back down to peak.

As far as having plenty of time to spin the saw up on the cold start. You do not want the saw to over-RPM before you get to the wood. Not only will that cause parts to go flying, but an alcohol saw will go lean if you take too much time. I have "beaten" my saws to the wood before. That happens at about the .7 second range for the cold start. When that happens, the race is over. I have also been slower, about 1.5 seconds, and the saw dies in the first cut. Just my observations over 15 years of racing and being hard-core for about 8 years. I'm sure Dennis and Helsel will have some thoughts on this. Dennis was racing before I was born, Helsel knows his crap.

 

[timberwolf]

Doug, Drop it, Both Fred and I did.

You very post is the epitome of all examples. You hack up a post because you can't stand me personally. You chime in late after the dust has settled then try to direct the thread back into turmoil.

Happy trolling....

Anyone out there adding weights to their racesaw flywheels? Though it may be so, I have not seen one such saw yet. I know they add them on bikes when they are looking for good power down low.

 

[drmiller100]

chopwood, what you say makes sense.

i guess i'm still thinking that a heavier flywheel isn't all bad though. sure, it adds weight to the saw, which isn't great.

but it DOES store some energy, maybe offsetting the overall weight increase.

in any case, it sure doesn't seem to me like you are going to find a tenth of a second in a race by cutting your fins off the flywheel.

 

[Al Smith]

.

but it DOES store some energy, maybe offsetting the overall weight increase.

in any case, it sure doesn't seem to me like you are going to find a tenth of a second in a race by cutting your fins off the flywheel.

I'm not in the fray,just an observation regarding flywheel weights ,fins etc.


By changing to a heavier flywheel on the old antique tractors,in praticular the "war years" John Deere B's,you can get about 15 to 20 more feet of pull,using the potential energy stored in the flywheel.This potential energy is turned into kinetic at the point the rpm's drop off.Newtons law of pysics,ya know. A body in motion,tends to stay in motion blah,blah.In the case of a hotsaw,it wouldn't spool up as fast,making this detrimental to the overall performance,old Newton haunts us again.

In the case of the fins,the power required to move air is not liniar in nature but rather almost logarithmic.By using a "Baker fan" which is an early crude dynamometer,it may take twenty horse power to spin one a 200 rpms.To increase to 300 it may take 40,400 it may be 80 etc..It is progresive as the amount of air ,cfm's , is moved,thus rpm's is increased.That old trick of shaving a flywheel is old as the hills,it was used by the go karters even back in the 60's,worked then,will work now.

 

[drmiller100]

That old trick of shaving a flywheel is old as the hills,it was used by the go karters even back in the 60's,worked then,will work now.

gokarts are trying to accelerate out of corners.

chainsaws however are trying to maintain a nearly constant rpm.

all this is probably mosquito testicles. in other words, it doesn't amount to much probably.

 

[Al Smith]

gokarts are trying to accelerate out of corners.

chainsaws however are trying to maintain a nearly constant rpm.

all this is probably mosquito testicles. in other words, it doesn't amount to much probably.

Just facts DR,take them how you wish,you usually do.

Try this for a little documentation of fans and the power required to move air.

Get a W W Grainger book and look up a 9.5 iinch squirrel cage fan.Note the power requirements and speed for the certain cfm outputs. Draw your own conclusions on the results.When you've digested all that pertainent information,then talk to me whose pet mosquito has the biggest cahoonas.

 

[Crofter]

What is the maximum displacement cyl and crank combination that goes in the 61 Husky crankcase?

 

[Chopwood]

As far as I know frank, it's the 272 stuff. I may be wrong though.

 

[Jacob J.]

That's pretty much it unless you machine a 288 crank down and throw a 288 crank, cylinder, and piston on the smaller chassis. It's a lot of work for what you get out of it though.

 

[Mr.]

What is the maximum displacement cyl and crank combination that goes in the 61 Husky crankcase?

Frank, you're looking childish and your innuendo is tired.

Fred

 

[Mr.]

That's pretty much it unless you machine a 288 crank down and throw a 288 crank, cylinder, and piston on the smaller chassis. It's a lot of work for what you get out of it though.

Jacob,

It would be much easier to stroke a 61/266/272 crank than to machine down a 288 crank. When you have two apart it is easy to see the complication of machining down a 288. There would be obvious weak spots.

Fred

 

[Al Smith]

Earth to Fred,it's not the easiest thing in the world to stroke any engine,ya know.

 

[Cut4fun]

I thought I recognized that husky 61 from Chardon, but wasn't sure till the other day. 52mm piston, stock stroke of 34mm suppose to be run in 5ci

 

[Mr.]

I thought I recognized that husky 61 from Chardon, but wasn't sure till the other day. 52mm piston, stock stroke of 34mm suppose to be run in 5ci

Sounds like you are telling people you have been inside this particular saw???

BTW are you trying to open a dialog where both of us unburden ourselves of any knowledge of "large" saws. I know of a couple from up your way......

Fred

 

[Mr.]

Earth to Fred,it's not the easiest thing in the world to stroke any engine,ya know.

Easier is a relative term, but you know that Al.

If you take a look at the two saws and come up with a different outcome, then tell me.

Fred

 

[Mr.]

Here is the pic of the carb. It's at a weird angle and looks rough, but is not.

The carb was built by MVP for a 181 that latter got a 3120 carby.

Fred

 

[Mr.]

Here's a few pics of the 272. I haven't cleaned it since I bought it.

Fred

 

[Cut4fun]

Sounds like you are telling people you have been inside this particular saw???

BTW are you trying to open a dialog where both of us unburden ourselves of any knowledge of "large" saws. I know of a couple from up your way......

Fred

Nope I have no dialog for you.
I was just stating that 61 turned out to be the same saw I looked at Chardon. I was interested in buying the 61 at one time and have also posted the same pics of the saw for sale for the true owner.

 

[Mr.]

Way to not answer the question/:monkey:

If you have "the same pics," post them.

Fred

 

[Cut4fun]

If you have "the same pics," post them.

Fred

Why dont you just go over at the race place and look at the pics of the same saw I posted for the MI guy in the trader section.
OH, thats right, here is the pics off my puter for now.

I also think the owners initials are on my pics in the beginning eh.