What Does Porting Really Mean?

[MasterBlaster]

I understand about modding a muffler to let it breath, but exactly what does porting mean? What gets done and what does doing that do?

 

[Al Smith]

It's a generic term .You are basically souping up the engine by changing the porting scheme .

Plain statement of facts ,it takes fuel to make power .You are in essence causing the engine to consume more fuel in probabley a less effcient manner but resulting in a higher power output .Kind of like putting a racing cam shaft in an automobile engine only you do it by altering the porting parameters . --clear as mud .

 

[MasterBlaster]

Sounds good to me!

 

[NickfromWI]

Who wants to port mine!!


love
nick

 

[MasterBlaster]

Randy, for $250.

 

[Al Smith]

You'd probabley get better results by hiring a gent like Randy who knows what he's doing .

In this business of reworking saw engines the trend has changed .A few years back the trend was for high RPM saws,cookie cutters but lousey every day cutters .You want something that can run all day with increased power not something that can cut three cookies and give you nothing but bragging rights which certainly won't put beans on the table .

 

[NickfromWI]

I'd probably be best served by just taking the thing apart and cleaning lots of pieces. There's gunk all over it.


love
nick

 

[802climber]

Honestly, the "ported muffler" thing confused me for ages. When a saw builder ports a saw's engine they are modifying the intake/transfer/exhaust ports then advancing the timing... etc. They have earned their target porting "numbers" by experience which includes porting some saws too far. Then, they can really make out with a particular model of saw, aka build it for torque, or build it for RPMs, or best yet, achieve the perfect combination. The pro builders are giving you a great deal especially if your saw is already in need of any kind of tear-down/rebuild. One word of advice though, once you get used to working with strong, woods-ported saws, your stock saws will seem like gutless junk. Also, the newest models are being made increasingly difficult or impossible to modify, or just not worth it.

 

[mrdiesel]

Also, the newest models are being made increasingly difficult or impossible to modify, or just not worth it.

I have heard of some of the husky autotunes being ported but I'm not able to get my head around if it can produce any gains as the auto tune is always retuneing. Im wondering if a muffler mod is also a pointless because if the autotune

 

[Al Smith]

Truth be known you could probabley enhance the performance of anything .The question is ,is it worth 250 bucks to do it over a simple grind job on a muffler .You're going to have to answer that question yourself .

I've ran saws done by Ken Dunn ,Randy ,TW, Cliff H, ,Dan Henry and heavens knows how many others .They all ran good .Does it really make a difference if on three cuts of an 8 by 8 that some run a second or two faster .I think not .I've never seen an 8 by 8 growing with roots on it .

Randy is one of the very few that will actually show the porting work .Some of the others think it's top secret or something .

Mine are done simpley because I enjoy it and my only competiton is with myself .I like it that way .

 

[Raj]

At one time I rebuilt truck and car engines, and did some performance upgrades, on those engines the theory was to have a smooth controlled turbulence as the air mixed with the injected fuel. The more "mixed" the air and fuel was, the more of a burn would happen in the piston on the power stroke.

 

[FireFighterZero]

How is it that Randy has not found this thread yet?

 

[MasterBlaster]

Ha, me too. Perhaps he doesn't wanna release trade secrets...

 

[CurSedVoyce]

He's busy porting

 

[Jed]

Yeah, it'd be lovely to have the real saw builders chime-in here. I've ported four saws in my entire life. Two made really awesome gains, one not so good, and one exploded. Willie (SOTC, on the House. Where the heck's he been btw?) who has had some logging experience was the first guy who gave me the guts to just tear-in and go for it. He told me this anecdote about an old-timer who swore that you could port a cylinder with a round file, and it would actually run better. That gave me a laugh, and encouraged me to give it a go, because I really don't have the proper tools. I just hog-out the intake and exhaust ports with a carbide bit on a dremmel, and kinda just do what I can on the transfer ports, where a little goes a long way. Then I just hog-out the muffler any old, dumb way, which is probably why I blew-up my 395. I did one 440 a little bit of good, (I think) and did another 440 a lot of good, but my crowning achievement was turning a piece of junk Echo 360t into something that cut comparable to a 200t.

People in our area usually distinguish between what they call "woods porting," which I take to mean: getting some moderate gains using whatever tools you have to hand without polishing, and "race porting," which usually incorporates specialized tools, lots of experimentation, high polishing, and, ideally a solid working knowledge of Venturi (spelling?)

Woods porting, will always be more than good enough for me. Like Willie says, "I need a work-horse, not a cookie-cutter." I just like to beat my work buddies who are all content to just run bone-stock pigs.

I always tell people, "Just dive-in and take a crack at it. If nothing else, you'll always at least make the dang thing louder.

 

[Moparmyway]

I have heard of some of the husky autotunes being ported but I'm not able to get my head around if it can produce any gains as the auto tune is always retuneing. Im wondering if a muffler mod is also a pointless because if the autotune

When you port a saw, or do a MM, you are actually just increasing the volume of air the saw can pump through its internals, then the autotune is adding additional fuel to keep the fuel/air ratio in a state that allows more power without too much heat, so the piston/cylinder/rings do not get too hot. The autotune/Mtronic takes care of the fuel mix (which affects air/fuel ratio) for you and also changes the timing for optimal performance.

Make no mistake, the autotune/Mtronic saws take in all parameters (including muffler mods, porting, etc) and adjust their outputs so you make smoothe reliable power throughout all cuts in all conditions.

A muffler mod allows more air to exit, which allows more air to enter the saw ................. autotune/Mtronic adjusts the fuel delivery and finds the best timing for each and every cut.

Porting a saw does not mean the timing has to change ........ one could just enlarge the ports on the sides, and smoothe the openings for better air movement, modify the muffler and see real gains. Probably not as much gains as altering the port timing, but still - an improvement can be had if you move more air !!!

 

[MasterBlaster]

Excellent post.

 

[Jed]

Probably not as much gains as altering the port timing, but still - an improvement can be had if you move more air !!![/QUOTE]

Yeah, but (at least for us inbreads) it's still kind of a dodgy proposition.

 

[Moparmyway]

Yeah, but (at least for us inbreads) it's still kind of a dodgy proposition.

IMHO, that all depends on what saw you are talking about. Personally, I have opened up some ports without altering the timing numbers (except of course port time/area) and seen a HUGE gain in performance (like an 038 Magnum) ................ and I have done the same thing on a different saw and had close to no gain (early McCulloch).

I have yet to see a backwards move in performance by enlarging the sides and smoothing the air flow passages ................ but I definately havent seen everything.

Enlarging ports without changing numbers ............. I have done about 2 dozen this way, and so far, they all have woken up except those early McCulloch ones
Enlarging ports and changing numbers ................. I have done about 4 dozen, every one woke up
Enlarging ports, changing numbers, and cutting the squish and base ............... I only have about 4 that I have done (someone else doing the lathe work) and WOW - what a difference !!!

 

[Moparmyway]

Excellent post.

Thanks Boss ................. coming from you - that means ALOT !!!!

 

[MasterBlaster]

Hey, you're the chainsaw expert... not me. I just use em!

 

[woodworkingboy]

what a difference !!!

In the sound too.

 

[Al Smith]

You can crank some extra power out of a McCulloch you just have to use a different approach .

Because there is no easy way to increase the compression alterations done to the exhaust are the most beneficial as well as advancing the timing slightly .Problem being with a gutted muffler they are so loud they could wake the dead. Fun to run for a few cuts ,not something you'd care to do all day long .

 

[Moparmyway]

You can crank some extra power out of a McCulloch you just have to use a different approach .

Because there is no easy way to increase the compression alterations done to the exhaust are the most beneficial as well as advancing the timing slightly .Problem being with a gutted muffler they are so loud they could wake the dead. Fun to run for a few cuts ,not something you'd care to do all day long .

Sorry Al, cant hear ya !!!
Used to use a few "yellow turds" the whole summer as a teenager .................. my problem is that now, no matter what I am cutting - if I bring out any McCulloch saws, they make my vision blurry, even with ear plugs !!!

 

[Tucker943]

Id like to see what my old style 372 would act like with a port job and muffler mod. I bet it would be a weapon.