Not trying to win anything. I’ve followed misinformation before and it cost me a lot of money and headache. Just trying to prevent the next guy from thinking he has a race saw just because he bought high octane fuel.
Up the compression or big bore
- Thread starter Joseph W Santora
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Capitalist
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In reality you are a dumbass that just cant accept you are wrong and try to make arguments out of nothing.
Like I said A HIGHER COMPRESSION (HIGH PERFORMANCE) ENGINE REQUIRES HIGHER OCTANE FUEL TO CREATE MORE POWER.
You just cant let it be.
If you up the fkin compression you up the gd octane or you are pissing in the wind.
The op asked if he should increase compression or increase the bore.
Nothing I said was wrong and yes you are trying to win a little pissing match of intelligence.
Higher perfomance/higher compression/higher octane!
You can argue with the others about other crap but nothing you said was even related to the op's post.
You must be a fkin euro
lead farmer
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Who's this guy ?
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You’re changing your story. You’ve been Googling
Huskybill
Addicted to ArboristSite
It’s not the size of the dog in the fight, it’s how much fight is in the dog. Smaller cc engines like screaming at higher rpm’s. Not torque but running wot. Example, a stock ported, Honda 125 cc cr dirtbike ported to the max eats 250’s. There higher raving.
Any saw under 60 cc’s count on running at a higher rpm. Now a big bore kit may slow it down unless the crank assembly with flywheel is rebalanced. I think that max porting is the way to go.
My dealer told me to use nothing but high test gas in my newer huskys.
In the old days with the late 60’s muscle cars with high compression engines we raced with Sunoco 260.
In a drag race you are right on dirt bikes. You can run any high rev 2 stroke on a tight technical course of your choice and I will eat your lunch on a low rev 4 stroke high torque bike of smaller size any day and every day and twice on Sunday. It simply comes to usable power. You can have all the power you want, but if you can't control it or use it, it's almost worthless.
We seem to be getting side tracked here.
My engine builder that builds 40% of the national ATV and dirt bikes in the country tells me if you only do one mod you get more power with higher compression then you do in boring it bigger. Of course you can combine mods and go even farther. But if you doing one mod only, I would go with higher compression first.With a high rev 2 stroke that is getting a single mod, I would start with the simplest and easiest mod and do higher compression, then later do a simple muffler mod then if you want more do the next easiest part and port, bore size would be the last mod. Or just do all the above and let'er rip. Oh! Don't forget tuning, timing, and jetting. Then let'er rip!!
cuinrearview
Red saw lover
I can tell you've ran a lot of high compression chainsaws. From what you've posted here and on other threads.
Now boys and girls,,,,,, lets think about it. The more you compress an explosive, the more energy it will give off.
Joseph W Santora
ArboristSite Operative
Shame on you. That was action to be used, NOT abused.
We seem to have covered a lot of ground here. I just wanted some info/opinions. Getting back into saws after a looong while. My last( and first) saw was a 262xp and we were a good team. Unfortunately it got stolen and I didn't get a replacement till my GF got me a 572xp for christmas. I cut my teeth tuning 2 strokes while living and racing in japan in the 70's. Think CR250's and RG500's . Spent the mid 80's building race motors on the east coast so I know how to massage motors but I don't know how well that knowledge (however much of it is left
) transfers to our saws. One big plus in tinkering with saws is that I don't have to worry about expansion chamber lengths or converging cone angles. Joe
cuinrearview
Red saw lover
Depends on the explosive no?
cuinrearview
Red saw lover
These ****ers forget what they're tuning.Shame on you. That was action to be used, NOT abused.
We seem to have covered a lot of ground here. I just wanted some info/opinions. Getting back into saws after a looong while. My last( and first) saw was a 262xp and we were a good team. Unfortunately it got stolen and I didn't get a replacement till my GF got me a 572xp for christmas. I cut my teeth tuning 2 strokes while living and racing in japan in the 70's. Think CR250's and RG500's . Spent the mid 80's building race motors on the east coast so I know how to massage motors but I don't know how well that knowledge (however much of it is left
Joe
Capitalist
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Well sonofabitch there it is!
Not smart enough to post that without first getting in an argument with a bunch of youtube commentors.
Great post.
Capitalist
Addicted to ArboristSite
Nope. Now you are trying to deny E=mc2.
Capitalist
Addicted to ArboristSite
They make decomp valves for you.
Never used one but I hear they are nice brother.
That was a joke.
I have no disrespect for you.
henry r
ArboristSite Operative
Well, if thats your background, Joseph, i expect nothing less than a full house build.
I'm sure if you hunt around you will find some decent (sucessful) recipies for timing figures to go with and suggested max port widths to prevent ring damage.
There are 357xp/359 muffler mod suggestions all over the internet.
The base gasket delete is dead easy.
A timing advance needs nothing more than filing the flywheel key.
As it is a work saw not a race bike it is probably better if you don't take it right to the edge... so no need for a parts consuming trial and error process.
I'm sure if you hunt around you will find some decent (sucessful) recipies for timing figures to go with and suggested max port widths to prevent ring damage.
There are 357xp/359 muffler mod suggestions all over the internet.
The base gasket delete is dead easy.
A timing advance needs nothing more than filing the flywheel key.
As it is a work saw not a race bike it is probably better if you don't take it right to the edge... so no need for a parts consuming trial and error process.
Ok I'll argue with myself. What about the 3 rules of fire. You have to have 3 components to make fire. Heat, fuel and oxygen. If you run out of any of them the fire will go out and the energy will stop with it. Crazy!!
Capitalist
Addicted to ArboristSite
Dont say that.Ok I'll argue with myself. What about the 3 rules of fire. You have to have 3 components to make fire. Heat, fuel and oxygen. If you run out of any of them the fire will go out and the energy will stop with it.
Someone will argue with it.
drf255
BAD CAD
Compression adds potential energy in the form of heat to a fuel charge. It does nothing more than that.
Energy is never lost or created. It simply changes form.
So the kinetic energy from the crankshaft revolution is converted to potential energy. So one loses power to create it in another place. The key is to compress it enough so it’s on the brink of burning, then the timed spark adds that extra amount that puts it over the threshold to burn completely
Too much compression in a saw will make it run hotter, so long cuts will cause the tune to change more than it would in a lower compression saw. Too much compression will rob too much kinetic energy that the saw will fight itself and not make more rpm (power/time).
Kevin is correct. The higher the compression, the more heat one is adding to the chamber. Preignition (knocking) occurs when the mix is compressed so much that it can ignite before the timed spark. One needs to either lower compression or add a fuel that burns slower to prevent that.
Even hopped up saws with 220 psi + are only in the 7:1 compression range. Plus, at the high operating rpms saws run at, the dynamic compression is much lower. There is simply not enough time to fill the swept volume. Accordingly, there is no need for high octane fuel in a chainsaw (in general). Using a slower burning fuel can result in less complete combustion and therefore less conversion of the fuel to heat/gas expansion.
To the OP, the big bore kits have time and time again been shown to make less power than there smaller bore OEM counterparts. Stick with your oem cylinder and play with your squish.
Energy is never lost or created. It simply changes form.
So the kinetic energy from the crankshaft revolution is converted to potential energy. So one loses power to create it in another place. The key is to compress it enough so it’s on the brink of burning, then the timed spark adds that extra amount that puts it over the threshold to burn completely
Too much compression in a saw will make it run hotter, so long cuts will cause the tune to change more than it would in a lower compression saw. Too much compression will rob too much kinetic energy that the saw will fight itself and not make more rpm (power/time).
Kevin is correct. The higher the compression, the more heat one is adding to the chamber. Preignition (knocking) occurs when the mix is compressed so much that it can ignite before the timed spark. One needs to either lower compression or add a fuel that burns slower to prevent that.
Even hopped up saws with 220 psi + are only in the 7:1 compression range. Plus, at the high operating rpms saws run at, the dynamic compression is much lower. There is simply not enough time to fill the swept volume. Accordingly, there is no need for high octane fuel in a chainsaw (in general). Using a slower burning fuel can result in less complete combustion and therefore less conversion of the fuel to heat/gas expansion.
To the OP, the big bore kits have time and time again been shown to make less power than there smaller bore OEM counterparts. Stick with your oem cylinder and play with your squish.
