Basic Porting and Polishing Techniques

[Gypo Logger]

Use a front-exhausting CP mini-die-grinder. Put about 3 cc's of ATF in the inlet for each port you cut, it will lube the carbide burr as you work. Here is another tip for you junior; cut the head off a 1/4" X 2" capscrew. Slice it down the center 1". You can now tear a 3" long piece of emery cloth roll and install it in the slot twisting it clockwise to give you a very nice polishing tool. I use 240 grit. The nice thing about this set-up is as follows: it is aggressive at first allowing you to profile and perfect your surface, as it plugs up with aluminum, (and ATF), it effectively becomes 400 grit, 600 grip and almost crokus cloth at the end. Your finish will be mirror-like. Cheers.

Thanks for the tip Simon. I have one of those, it's called a slotted mandrel and works great. I also bought some sanding roles as well.
Did you see my 385 video above? How would it compare to yours? Red Maple is about the same hardness as Alder.
John

 

[Simonizer]

Thanks for the tip Simon. I have one of those, it's called a slotted mandrel and works great. I also bought some sanding roles as well.
Did you see my 385 video above? How would it compare to yours? Red Maple is about the same hardness as Alder.
John

I cannot say how they would compare without putting them side-by-side. I know I an getting ~7.7 HP right now with the 385. I have built and sold 108 385's as of today. I test run my saws with a 32" bar in a 4 foot diameter hemlock log. I want to give you another tip. If you are extremely careful you can chamfer your ports with a 1/2" diameter spherical carbide burr. Keep the RPM very low and be extremely gentle. With practice it will look like the work was performed by a CAD machine. Chamfer width should be 0.040" on a 60 degree angle.

 

[Mr.]

crokus cloth

The first one here to now what it is

Fred

 

[Mr.]

Marky, Your looking at the bottom of the cylinder in that pic.

Marky was correct.

Fred

 

[bwalker]

Marky was correct.

On second look you right. I didnt see the transfer off to the left and thought it had the same style jug as a 044 or a 395.

 

[timberwolf]

Simons numbers?????

385 is claimed to be 6.3 hp stock, so 7.7 is about a 20% gain. Opening up the muffler and a little exhaust work should give that kind of gain alone.

 

[skwerl]

I suspect Simon's work is very similar to Walkerized saws. Just a muffler mod and a light cleanup of the ports, nothing more.

 

[timberwolf]

That and may be a bit of hokuspokus window dressing, lots of little things can be done insided the saw that dont add up to much of anything but giggle time with a dremil.

Easy to get caught up id doing such things, I know! It's fine if your tinkering on your own saw, but just driving the price up and production volume down if your selling your work.

 

[Gypo Logger]

Although blown up at least 2X, here's the spiral mandrels that can be used while porting and the spiral rolls that come in 5 different grits from 50 to 320.
Shank dia. is 1/4" and 1/8". The ones pictured are 1/8". All available at CC Specialties. 1- 800 - 762 -5165.
John

 

[Simonizer]

I suspect Simon's work is very similar to Walkerized saws. Just a muffler mod and a light cleanup of the ports, nothing more.

Not even close.

 

[woodsjunkie]

So anyway, here's a vid of the 385 straight out of the box, expect I used a 9 pin sprocket as that is what I used on the moddified version.
Here it is cutting a 16" block of Red Maple with an 18" bar. The cut looks like about 5 secs.
John

Hey gypo you sawed of runt kudos to ya.
Saw looks good I bet it will run with'in a few thousands of a ported 088?
__________________

 

[Gypo Logger]

That's what I was thinking too Eric!
The modd worked out good. I copied a KD 385 barrel I had. Although my work is no where as good as Kens, the only thing I couldn't reasonably replicate was the upper transfers so I simply beveled them on an upward angle.
Regardless, It's some of my better work.
John

 

[04ultra]

Gypo more pictures please..

 

[whatsnext]

It's a fun learning thing and you won't screw up your saw if you don't go overboard. I'm not sure what you mean Whatsnext.

John, Well, a couple of weeks ago in this thread: http://www.arboristsite.com/showthread.php?t=27921, you were explaining how to improve the performance of our saws via piston skirt work but now you're suggesting port work. I'd like the best performing saw possible so I'm just asking you where we should start.
Thanks, John..

 

[Gypo Logger]

It depends on the saw and the figures you are working with. Obviously taking it off the piston skirt of the intake side is much easier than lowering the intake port.
Also if the intake port looks restricted and not symetrical then by all means work the port over.
John

 

[SWE#Kipp]

keep up the good work

thanks for a very interesting and informative thread !! just love to read about this stuff

/The little swede

 

[046]

Use a front-exhausting CP mini-die-grinder. Put about 3 cc's of ATF in the inlet for each port you cut, it will lube the carbide burr as you work. Here is another tip for you junior; cut the head off a 1/4" X 2" capscrew. Slice it down the center 1". You can now tear a 3" long piece of emery cloth roll and install it in the slot twisting it clockwise to give you a very nice polishing tool. I use 240 grit. The nice thing about this set-up is as follows: it is aggressive at first allowing you to profile and perfect your surface, as it plugs up with aluminum, (and ATF), it effectively becomes 400 grit, 600 grit and almost crokus cloth at the end. Your finish will be mirror-like. Cheers.

Simon sure seems to know the little details....

here's my porting setup with assortment of carbide bits, forward exhaust die-grinder and rear exhaust snap-on die-grinder

prefer grinding off all the ruff casting marks, then polish smooth.

 

[jokers]

John,

Where did you get this picture? Is this some of your work?

Russ

 

[johnb]

Porting

Thanks Gypo for all the info keep it coming! I'm starting my third 066 project saw and was looking for someone who would open up! HA Ha about the porting process. I recently ported and polished a 2.3 ford 4-stroker head and intake manifold for a friends pulling garden tractor, what an improvement in Horse power! You can also get a good porting kit from Eastwood company at www.eastwood.com. I was always a little un easy about modifying 2 cycle ports. I feel better now! thanks The Hoosier!

 

[046]

yup, good thread!

most of my porting has been done on british sports cars. mostly cleaning up intake ports, intake manifolds, matching up ports etc.

have not done much two stroke work, except to clean up exhaust ports and match to muffler. so this information is really helpful.