Hot SAW WANTED in New Jersey!~!~

[THALL10326]

I guess it's interesting, but just very basic physics. HP is 2*pi*rpm*torque/33000.

So the more rpms the more torque?????

 

[Freakingstang]

I guess it's interesting, but just very basic physics. HP is 2*pi*rpm*torque/33000.

You are throwing formulas out there without explanations.

so say the average guy knows his saws turns 13,800 can he figure the TQ if the HP is known? No, because you don't know where the horsepower figure was made. So goes back to Fred wanting to see Torque ratings published like advertised HP numbers are. So, without a dyno or some inside information from the company, it is highly unlikely you will ever find the corrected torque of a stock saw, let alone a modded one

 

[Simonizer]

You are throwing formulas out there without explanations.

so say the average guy knows his saws turns 13,800 can he figure the TQ if the HP is known? No, because you don't know where the horsepower figure was made. So goes back to Fred wanting to see Torque ratings published like advertised HP numbers are. So, without a dyno or some inside information from the company, it is highly unlikely you will ever find the corrected torque of a stock saw, let alone a modded one

You are 100% correct. You need to know the torque at a specific rpm to calculate the HP at that point. That is how the very accurate torsion beam dyno's work.

 

[Simonizer]

So the more rpms the more torque?????

????? no. HP is a function of torque and rpm. A 3 HP winch turning 60 rpm has the same power as a 3 HP two-stroke engine turning 14000 rpm. The torque developed however is very different. (and is proportional to the inverse of the rpm)

 

[THALL10326]

You are 100% correct. You need to know the torque at a specific rpm to calculate the HP at that point. That is how the very accurate torsion beam dyno's work.

Good point there Simon but doesn't the length of how far the piston travels in the cylinder or stroke play a major part in measuring torque? I mean the longer the stroke the more torque, correct?

 

[Simonizer]

Good point there Simon but doesn't the length of how far the piston travels in the cylinder or stroke play a major part in measuring torque? I mean the longer the stroke the more torque, correct?

You are correct buddy. Remember this though, if you have a long stroke, ie. a diesel engine, at a given rpm the piston must travel furthur. When we talk about mean piston speed, a large diesel engine running at 1600 rpm can have a higher piston speed than a chainsaw engine running at 13000 rpm. Ever wonder why diesels don't rev too high? Think about going to your kitchen and back every 5 seconds vs. going to the grocery store and back every 15 seconds.

 

[THALL10326]

????? no. HP is a function of torque and rpm. A 3 HP winch turning 60 rpm has the same power as a 3 HP two-stroke engine turning 14000 rpm. The torque developed however is very different. (and is proportional to the inverse of the rpm)

Awwwwwwwww ok, I see whatcha mean, makes sense to me. I was wondering about that because a ole Briggs 5 hp only turns 3600 rpms to get the 5 hp where as a 038 mag turns around 12,500 to get 5 hp. Of the two engines there which one has the most torque on a dyno at max rpm even if the horsepower for both is 5 hp. As I said before this is a interesting subject.

 

[THALL10326]

You are correct buddy. Remember this though, if you have a long stroke, ie. a diesel engine, at a given rpm the piston must travel furthur. When we talk about mean piston speed, a large diesel engine running at 1600 rpm can have a higher piston speed than a chainsaw engine running at 13000 rpm. Ever wonder why diesels don't rev too high? Think about going to your kitchen and back every 5 seconds vs. going to the grocery store and back every 15 seconds.

I see whatcha mean there. Seems there are many ways to measure hp and torque on different engines. Quite amazing to me. While I was down at Va Beach in trianing the instructor showed us a pistion out a nitro fuel funny car engine. He said beleive it or not this one piston in a funny car engine puts out more hp and torque than a entire Nascar V8 engine. I was quite amazed one 5 inch piston could put out over 800 hp.

 

[Simonizer]

Awwwwwwwww ok, I see whatcha mean, makes sense to me. I was wondering about that because a ole Briggs 5 hp only turns 3600 rpms to get the 5 hp where as a 038 mag turns around 12,500 to get 5 hp. Of the two engines there which one has the most torque on a dyno at max rpm even if the horsepower for both is 5 hp. As I said before this is a interesting subject.

Yes, the Briggs in question would be developing 7.3 lbs.ft of torque at 3600 rpm and the Stihl would be developing 2.1 lbs.ft of torque at 12500 rpm yielding the same HP.

 

[Simonizer]

I see whatcha mean there. Seems there are many ways to measure hp and torque on different engines. Quite amazing to me. While I was down at Va Beach in trianing the instructor showed us a pistion out a nitro fuel funny car engine. He said beleive it or not this one piston in a funny car engine puts out more hp and torque than a entire Nascar V8 engine. I was quite amazed one 5 inch piston could put out over 800 hp.

Yes, he was right ha ha, but they have a short and terrible life. The brake mean effective pressure on a nitro-methane, blown engine is incredible. That piston alone uses 4 liters of fuel in 4.2 seconds. They are kinda thirsty engines.

 

[04ultra]

You are correct buddy. Remember this though, if you have a long stroke, ie. a diesel engine, at a given rpm the piston must travel furthur. When we talk about mean piston speed, a large diesel engine running at 1600 rpm can have a higher piston speed than a chainsaw engine running at 13000 rpm. Ever wonder why diesels don't rev too high? Think about going to your kitchen and back every 5 seconds vs. going to the grocery store and back every 15 seconds.

Could you explain this in more detail please .. Thank you

 

[stihlatit]

My grocery store is closer to me then my kitchen.

EMkitchen=diesel squared.

 

[Simonizer]

Could you explain this in more detail please .. Thank you

Where are you getting tripped up? This is a relatively lucid analogy.

 

[Simonizer]

My grocery store is closer to me then my kitchen.

EMkitchen=diesel squared.

Then you have a diesel chainsaw.

 

[04ultra]

Then you have a diesel chainsaw.

Now I get it.. Thanks

 

[THALL10326]

Now I get it.. Thanks

ya get it do ya,whatcha gettin???????????

 

[stihlatit]

Glad I could bring that out for you Ultra but now seeing as I have a diesel saw do I have to change my mix and should I use amsoil.

opcorn: opcorn: opcorn:

 

[04ultra]

ya get it do ya,whatcha gettin???????????

I had to set down my Jack & Coke to see the relatively lucid analogy..

 

[stihlatit]

I had to set down my Jack & Coke to see the relatively lucid analogy..

Look through the bottom of the glass to see my diesel saw.

 

[THALL10326]

I had to set down my Jack & Coke to see the relatively lucid analogy..

Well I'll tell when I was a young buck I had way more hp and torque. Now that I'm a ole geezer my hp and torque ratings are much lower which would mean wear and tear and age also play a role in ratings of hp and torque. That Jack and Coke will surely bring your ratings down so fuel too has a effect although the more you drink it the less you will care about your ratings, hmmmmmmmm, that may be a good thing. We will have to get Andy(Lakeside) in here and see his view on this subjuct too....