Basic Porting and Polishing Techniques

[Gypo Logger]

Now that I have ported a few saws, namely 020 (2), 044 (1), 026 (3), 372 (2), 262 (1), 980 (1) and a 385 which I finished today, I wanted to share with you some of the basic tricks of the trade that will help you with the gains you have all been looking for.
Firstly, lets talk about the cutting of the port. Clean the cylinder as best you can with lacquer thinner and then hot soapy water and rinse and dry.
Then spray the inside of the cylinder walls with machinist Dikam, which is basicly a blue ink. Then mark the cyl. to the specs you want.

Carbide cutters are the best for rough cutting. Using the shortest shank cutter possible for the job will ensure more control. Port flow is just as important as the amount of material you move, so try to make steady and precise cuts as possible.
It's best to leave about .5 mm for clean up, leveling and polish work. You can always remove metal, but you can't put it back on.
Using slower cutting speeds is best so that the aluminum doesn't heat up and develope hard spots that will be hard to even out later.
In our next discussion of porting we will detail how best to accomplish basic leveling of the rough cutting.
Yours to Happy Porting!
John

 

[04ultra]

Teacher can we see some pictures and movies..






Please no singing in the movies

 

[jokers]

Clean the cylinder as best you can with lacquer thinner and then hot soapy water and rinse and dry.
Then spray the inside of the cylinder walls with machinist Dikam, which is basicly a blue ink. Then mark the cyl. to the specs you want.

Carbide cutters are the best for rough cutting. Using the shortest shank cutter possible for the job will ensure more control. Port flow is just as important as the amount of material you move, so try to make steady and precise cuts as possible.
It's best to leave about .5 mm for clean up, leveling and polish work. You can always remove metal, but you can't put it back on.
Using slower cutting speeds is best so that the aluminum doesn't heat up and develope hard spots that will be hard to even out later.
In our next discussion of porting we will detail how best to accomplish basic leveling of the rough cutting.
Yours to Happy Porting!
John

Nice work John! Now you`re plagiarizing the inside back cover of the C&C Specialties catalog. I guess that no low is too low when you start at the bottom and then attempt dive deeper.

Russ

 

[Kenskip1]

Porting Gypo

Gypo,Your technique is very harsh with little specifics. I am porting a 55 with a 12 volt drill and some emery paper. Have you ever thought about working for NASCAR? Jack Roush is looking for a few good men! Ken

 

[Gypo Logger]

Russ, is right, alot of the jargon come from a great bunch of people in Lawrenceburg Tennessee . Particularly Debra Hagen who works there who completed my order. The place has all these porting tools you'll need and you can contact Debra at:
www.ccspecialtytool.com
KD hotsaw sent me the original catalogue.
Anyway, if you want to talk hotsaws call Ken at 530 589 2744.
John

 

[Gypo Logger]

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

 

[Gypo Logger]

Here's the modified version of the above saw. He seems to be about twice as fast after my work, however the saw is still tight and will loosen up after a few gallons of fuel have been run thru it.
I can't stress enough how important the polishing procedure is to the air flow and therefore the resultant power of the finished motor.
We will be dealing later with polishing after we discuss basic leveling of the ports.
John

 

[Andy1234]

A good start.
When I used to port aluminum heads and manifolds, I used a makita straight electrical die grinder with high speed steel bits.
The steel bits were cheaper and worked almost as fast as the carbide bits.
There are many different cutter profiles to choose from. By a few different ones and experiment on a junk part first.
Use a coarse tooth for the roughing, and a medium tooth for the finish, followed by a 200 grit silicon carbide sanding roll to give a smooth finish.
Also, when using the cutters, smear some liquid dish soap on the port, it acts as a lubricant and helps prevent the cutter from clogging.
FWIW.
Andy1234

 

[Gypo Logger]

Hi Andy, thanks for your most informative post. I'll try your dishsoap idea.
Thanks
John

 

[Marky Mark]

Gypo Logger keep up the good work it's the only way you'll learn. I guess if you don't try what did you learn. I learned if you want to make money as a trapper you better start with a little. But life over Snuffies Bar and Grill ain't always easy. I was skinning a skunk in my one room that acts as my make believe house and you guessed it I hit the scent gland. So now I am looking for a new plave to live at. I never knew I had to wait for internet at the library. Be back on line once the line goes away.
Regards,
Pal

 

[Chainsaw Master]

Gyppo you say " Then spray the inside of the cylinder walls with machinist Dikam, which is basicly a blue ink. Then mark the cyl. to the specs you want."
How did you figure out where to put the marks, that you cut the ports too? What are the rules for figuring out the specs?

 

[whatsnext]

Gypo, Is this done before or after you cut the intake side of the piston skirt?
John..

/or was it the exhaust side?

 

[timberwolf]

So John, Transfer ports. Do you polish them up or not. Some things I have read say no just knock off any casting bumps and some how the texture adds to the surface area, wetted surface and evaporation of any persipitated fuel..., Other info points to making nice smooth surfaces to minimize the thickness of the layer of lower velosity air near the walls of the port.

What ya think???

 

[bwalker]

Gas flow through a pipe is greatest at the center. The gas next to the pipe walls tumbles and is lower in velocity than that in the center.
With that said the surface finish of a port isnt going to do much for you. Some guys polish the exhaust port to lesson carbon buildup, some dont. I have even seen some guys polish the transfers and intake to a mirror finish.
I once asked noted motor cycle tuner if it was worth it to polish ports and he said no. I also have not had polished ports on any of the cylinders I have had done.

 

[Kneejerk Bombas]

Ben, your avatar is very distracting.















He must work out.

 

[jokers]

John,

I`m proud of you to be actually using real tools for a change! Keep it up!

 

[Gypo Logger]

Chainsaw Master, as an alternative to the ink and scribe method, you can also invert a ringless piston into the barrel and take measurements that way.
With an old piston you can cut the skirt after measuring and use it as a template to arrive at the actual height of the port.
As far as the specs it is not an exact science however, experiment with small amounts like .5mm- 1.5 mm. You want to raise the exhaust and transfers while lowering the intake. With some saws I simply lower the intake 1mm and raise the exhaust .5 mm, while not touching the transfers.
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.
Brian, I have started polishing the ports as opposed to leaving them unfinished because like you I heard there are two schools of thought, but the finished product looks much better when polished, plus Tommy Fales told me to polish.
Ben, that's a good point about the carbon.
Russ, I still use my trusty fingernail file on occasion
John

 

[Marky Mark]

John that's a nice cut off head. When did you start cutting off heads for your saws??

 

[bwalker]

John that's a nice cut off head. When did you start cutting off heads for your saws??

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

 

[Simonizer]

Hi Andy, thanks for your most informative post. I'll try your dishsoap idea.
Thanks
John

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.