Ported saws

[RogerD]

Nice to see this has devolved into a pecker measuring contest. If a piece of equipment wears out, then repair it. Costs less to repair than to replace most of the time. Must be true with commercial duty equipment. Either do it yourself or find a competent mechanic. From what I see here at work the older units are built much better than newer throw-away type units. As far as modding goes, the more extreme you go with port timing, compression, etc the less life you will have. There is no catch-all porting mod that works on every engine. You cant just go in and raise exhaust ports and think the the thing is now a racer. Lots of math involved to do things correctly, a flow-bench helps as well.

 

[North by Northwest]

You ever logged? I'm betting not as it's a little more involved than a couple mile nature walk with a saw.. for starters 6 hours is a partial day. Ever did body work in 3 feet of snow or while dealing with swarms of mosquitos and black fliea?

Ever try loading 2000 110 lb bales in 10 hrs .

 

[bwalker]

Ever try loading 2000 110 lb bales in 10 hrs .

I have loaded small squares many times.

 

[bwalker]

Nice to see this has devolved into a pecker measuring contest. If a piece of equipment wears out, then repair it. Costs less to repair than to replace most of the time. Must be true with commercial duty equipment. Either do it yourself or find a competent mechanic. From what I see here at work the older units are built much better than newer throw-away type units. As far as modding goes, the more extreme you go with port timing, compression, etc the less life you will have. There is no catch-all porting mod that works on every engine. You cant just go in and raise exhaust ports and think the the thing is now a racer. Lots of math involved to do things correctly, a flow-bench helps as well.

Another guy that's never done it dispensing advice...

 

[camel2019]

You ever logged? I'm betting not as it's a little more involved than a couple mile nature walk with a saw.. for starters 6 hours is a partial day. Ever did body work in 3 feet of snow or while dealing with swarms of mosquitos and black fliea?

Done body work in 120 degrees fahrenheit while the sun was beating on me all the time.
Also washed cars that have to come into the shop while it’s freezing while the heaters quit working in the shop.I know what’s involved in logging and most of it ain’t done that way anymore. Ever work a frame table that’s more work then anyone would want.

 

[bwalker]

Done body work in 120 degrees fahrenheit while the sun was beating on me all the time.
Also washed cars that have to come into the shop while it’s freezing while the heaters quit working in the shop.I know what’s involved in logging and most of it ain’t done that way anymore. Ever work a frame table that’s more work then anyone would want.

You haven't a clue what's involved in timber falling with a chainsaw.
What kind of auto body shop is outdoors exposed to the sun?

 

[RogerD]

Another guy that's never done it dispensing advice...

Never done what? logged, no. Rebuilt 2 strokes, damned straight. I could show you the math involved if you like. You're a logger, good for you. I repair small equipment for a living. Here is box of parts, lets see you assemble them. You need to calm tf down.

 

[link]

Never done what? logged, no. Rebuilt 2 strokes, damned straight. I could show you the math involved if you like. You're a logger, good for you. I repair small equipment for a living. Here is box of parts, lets see you assemble them. You need to calm tf down.

Thats pretty bold but I like it, you think mr.b is a scout boy or what

 

[Czed]

Well, haven’t got mine back yet. Not hoping for a forever saw, but would like to get a good 5 years out of it. I don’t think a woods ported saw will last as long as a stock saw, all things equal. But I don’t think I care either, I run a saw 5 days a week and I want to enjoy the feel, sound, power, and let those chips fly

Dunlap ported this 272 about 4 year's ago I have 4 saws he ported and I've got him porting a 2171

I have 25-35 66cc+ saws most of them ported and have never seen a disadvantage of having a saw ported or much more fuel usage.
The performance over stock is exceptional
But of course I switch off saws every so often but this one has a lot of time on it.
I forgot what did you have him port?

 

[link]

Dunlap ported this 272 about 4 year's ago I have 4 saws he ported and I've got him porting a 2171
View attachment 1019365
I have 25-35 66cc+ saws most of them ported and have never seen a disadvantage of having a saw ported or much more fuel usage.
The performance over stock is exceptional
But of course I switch off saws every so often but this one has a lot of time on it.
I forgot what did you have him port?

Around here marine diesel engines at 2k rpm does 60 years of impeccable service.
You say a ported chainsaw gas engine at 15k rpm presents the same reliability ?

 

[link]

I like your new avatar dude.

 

[Parkerpusher]

Dunlap ported this 272 about 4 year's ago I have 4 saws he ported and I've got him porting a 2171
View attachment 1019365
I have 25-35 66cc+ saws most of them ported and have never seen a disadvantage of having a saw ported or much more fuel usage.
The performance over stock is exceptional
But of course I switch off saws every so often but this one has a lot of time on it.
I forgot what did you have him port?

I had him port a 562xp

 

[camel2019]

You haven't a clue what's involved in timber falling with a chainsaw.
What kind of auto body shop is outdoors exposed to the sun?

One that doesn’t fit 5 and 10 ton trucks inside because it’s full.

 

[bwalker]

One that doesn’t fit 5 and 10 ton trucks inside because it’s full.

Sounds like a hillbilly outfit to me.

 

[camel2019]

Sounds like a hillbilly outfit to me.

Nope just busy as heck and had to do the tow trucks for one of the bigger companies here.

 

[Lightning Performance]

Nice to see this has devolved into a pecker measuring contest. If a piece of equipment wears out, then repair it. Costs less to repair than to replace most of the time. Must be true with commercial duty equipment. Either do it yourself or find a competent mechanic. From what I see here at work the older units are built much better than newer throw-away type units. As far as modding goes, the more extreme you go with port timing, compression, etc the less life you will have. There is no catch-all porting mod that works on every engine. You cant just go in and raise exhaust ports and think the the thing is now a racer. Lots of math involved to do things correctly, a flow-bench helps as well.

Mines bigger than yours
Raising compression too high does kick the tar out of bearings but who cares, right?
Makes a good bandaid though.
RPMs beyond 11k in the cut might wear out your piston faster but who cares, right?
Hell the about oh 40%, sounds like a cool number, yes?... isn't in the actual port work but who cares, right?
New stuff is always built better, right?
Math eh

The flow bench is about worthless on a piston ported simple chainsaw cylinder unless your just testing bolt on parts or the intake port or other intake parts. The fact is you can't test dynamic flow and wet flow on a common dry flow bench. Don't believe me go study the facts for yourself. Wet flow occurs from the popoff valve to the transfer port exits and up to a full fresh intake charge is captured then cut off by the piston. Anything before or after is dry flow and maybe or maybe not dynamic flow. The exhaust starts out supersonic and goes sonic shortly after leaving the cylinder exit window. Down stream is only dry flow on the entire exhaust cycle after combustion occurs. Once you have all the wet flow modeling worked out you can try to figure out your sign waves and your dynamic flow on the dry side. Oh one small note the flow bench is about worthless on exhaust port testing because you can not easily recreate supersonic or sonic flow on any bench type apparatus, fact. Most people really have no clue about what is actually going on inside the engine at 6K let alone 10K or more. Even the best will admit you don't know what you don't know unless you have bottomless pockets. Quote that.
Forget all those pesky bits like measuring stuff, lighter parts, bevels, chamfors, pumping losses, burn rates, parts swapping, improving flow, what not to do, stuff not related and a whole host of other interesting facts that may make or break your build commonly overlooked.
Going to port my pocket now, enjoy.

 

[bwalker]

Mines bigger than yours
Raising compression too high does kick the tar out of bearings but who cares, right?
Makes a good bandaid though.
RPMs beyond 11k in the cut might wear out your piston faster but who cares, right?
Hell the about oh 40%, sounds like a cool number, yes?... isn't in the actual port work but who cares, right?
New stuff is always built better, right?
Math eh

The flow bench is about worthless on a piston ported simple chainsaw cylinder unless your just testing bolt on parts or the intake port or other intake parts. The fact is you can't test dynamic flow and wet flow on a common dry flow bench. Don't believe me go study the facts for yourself. Wet flow occurs from the popoff valve to the transfer port exits and up to a full fresh intake charge is captured then cut off by the piston. Anything before or after is dry flow and maybe or maybe not dynamic flow. The exhaust starts out supersonic and goes sonic shortly after leaving the cylinder exit window. Down stream is only dry flow on the entire exhaust cycle after combustion occurs. Once you have all the wet flow modeling worked out you can try to figure out your sign waves and your dynamic flow on the dry side. Oh one small note the flow bench is about worthless on exhaust port testing because you can not easily recreate supersonic or sonic flow on any bench type apparatus, fact. Most people really have no clue about what is actually going on inside the engine at 6K let alone 10K or more. Even the best will admit you don't know what you don't know unless you have bottomless pockets. Quote that.
Forget all those pesky bits like measuring stuff, lighter parts, bevels, chamfors, pumping losses, burn rates, parts swapping, improving flow, what not to do, stuff not related and a whole host of other interesting facts that may make or break your build commonly overlooked.
Going to port my pocket now, enjoy.

I agree with your comment on the usefulness of a flow bench when it comes to 2 strokes. Guys that don't know what they are doing think in terms of bulk flow. Guys that know what they are doing realise that gains are in the timing and bulk flow is pretty much meaningless.

 

[Hermio]

walking a couple miles carrying a saw then running it 6 hours is physically easier than body work. lmk when you spend all day welding in panels, cutting sheet metal by hand then grinding it back only to spend hours blocking it back out. Ever tried holding a full quart paint gun arm extended straight out for 20 minute intervals all day wearing a tyvec suit and full respirator in a 90+ degree booth? It turns you into a sealed in liquid coated sausage. Heaven forbid you get exposed to clearcoat fumes and your head throbs for two days. I know a 70 year old body man that can break your hand like a vice during a handshake from blocking/painting and holding panels for decades
Hell I know a lady that ran her own shrimp boat for 20 years as captain, shes built like a gorilla from pulling lines all day. She was the county boxing champ for a few years and known to break a jaw or two in local bars.
Both are very sweet people with hearts of gold and the world needs more people like them.

You don't necessarily get strong from doing a lot of work. If it worked that way, bricklayers would be stronger than powerlifters, as they lift more every day, 5 lb at a time, than a powerlifter does in a week. Strength is built primarily by doing low reps with heavy weight, to momentary muscle failure. Many top powerlifters workout 2-3 times per week, and sometimes only one workout is to failure. The workout generally takes about 30 minutes.

 

[bwalker]

You don't necessarily get strong from doing a lot of work. If it worked that way, bricklayers would be stronger than powerlifters, as they lift more every day, 5 lb at a time, than a powerlifter does in a week. Strength is built primarily by doing low reps with heavy weight, to momentary muscle failure. Many top powerlifters workout 2-3 times per week, and sometimes only one workout is to failure. The workout generally takes about 30 minutes.

All that is true, but a bit off topic.
I'm still betting an auto body guy would about die packing a saw up and down hills all day falling timber.

 

[camel2019]

walking a couple miles carrying a saw then running it 6 hours is physically easier than body work. lmk when you spend all day welding in panels, cutting sheet metal by hand then grinding it back only to spend hours blocking it back out. Ever tried holding a full quart paint gun arm extended straight out for 20 minute intervals all day wearing a tyvec suit and full respirator in a 90+ degree booth? It turns you into a sealed in liquid coated sausage. Heaven forbid you get exposed to clearcoat fumes and your head throbs for two days. I know a 70 year old body man that can break your hand like a vice during a handshake from blocking/painting and holding panels for decades
Hell I know a lady that ran her own shrimp boat for 20 years as captain, shes built like a gorilla from pulling lines all day. She was the county boxing champ for a few years and known to break a jaw or two in local bars.
Both are very sweet people with hearts of gold and the world needs more people like them.

My points exactly.