Porting help don’t need/want #’s

[TexasJohnny]

Hey y’all. Don’t want anyone’s secret numbers or theories, etc. just need general porting advice.

I’ve ruined two cylinders so far and what always gets me into trouble are the upper transfers. The right angle hand piece I have is one of the Amazon cheap ones. I’ve tried the double cut burrs but I’m jumping out and scoring the crap out of the cylinder.

I’ve figured out finally that lower rpm’s and a lighter touch is best - you think I could raise the upper transfers with a diamond burr instead? Or should I go less aggressive with like a sanding drum.

If y’all suggest diamond burr what shapes work for y’all? I’m working a CS590 and a 501p if that helps knowing the size of the uppers. Any other tips would be helpful and much appreciated!

Edit to add: I’m using the now junk cylinders for practice as well.

 

[singinwoodwackr]

Hey y’all. Don’t want anyone’s secret numbers or theories, etc. just need general porting advice.

I’ve ruined two cylinders so far and what always gets me into trouble are the upper transfers. The right angle hand piece I have is one of the Amazon cheap ones. I’ve tried the double cut burrs but I’m jumping out and scoring the crap out of the cylinder.

I’ve figured out finally that lower rpm’s and a lighter touch is best - you think I could raise the upper transfers with a diamond burr instead? Or should I go less aggressive with like a sanding drum.

If y’all suggest diamond burr what shapes work for y’all? I’m working a CS590 and a 501p if that helps knowing the size of the uppers. Any other tips would be helpful and much appreciated!

Edit to add: I’m using the now junk cylinders for practice as well.

Keep practicing.

 

[EFSM]

The ramped intake side transfers on those cylinders are weird. Some people square them up and turn the roof into a normal flat profile but I use a flat ended diamond burr in a dremel to evenly grind the roof to maintain the angle. As far as right angle hand pieces, I found that high speed actually benefits me because there is less time for chatter. The key is to take it slowly.

 

[srcarr52]

Single cut burrs will chatter less.

I use this in large dual ports when it will fit.

SE-51

Buckeye Carbide

www.buckeyecarbide.com

Then I use something similar to this for smaller transfers.

SE-53

Buckeye Carbide

www.buckeyecarbide.com

 

[tree monkey]

i use old dull hogs in the transfers so i can puy some pressure on them

 

[TexasJohnny]

Thanks for the suggestions y’all, I’ll keep at it - got two new echo cylinders coming in the mail - won’t touch my Stihls until I get consistent results with the cheaper echo cylinders.

Again, thank you for the responses!

 

[drf256]

Try a block of paraffin wax also. Grind into that before grinding upper.

Do you have a motor that has fwd/rev?

 

[TexasJohnny]

Sorry guys been working turn arounds and projects - whelp I got my 501p back together last night finally and pretty sure I hung a ring on the exhaust. She’s stuck like chuck. Sounded good for a few seconds though.

yalls tips helped me a lot and I appreciate it. Next cylinder I’m just going to set the squish to .020 and see how she does. Maybe scuff up the intake and try the exhaust again (less is more).

As a newb it is hard not to grind way too much. It’s kind of like trading stocks, you know when you’re getting emotional and chasing but you’ve got to learn to deny the urge to pull the trigger and wait or you’ll just lose.

I’ll try to tear it down sometime this next few weeks and post pics of my attempt so yall can have a good laugh.

 

[TexasJohnny]

Small piece of piston ring left in the crankcase made its way through the lowers and embedded itself in the piston and squishband. I’m gonna clean out the crankcase again, slap her back together and run it. It’s just a hobby and first attempt, I’ll order another piston and cylinder and try the porting again. I’ve been practicing on another cylinder with the diamond burrs and less is definitely more.

 

[TexasJohnny]

Pic didn’t attach.

 

[EFSM]

Pic didn’t attach.

Where did the piece of ring come from?

 

[legdelimber]

Make sure the ring locating pins are accounted for also.

 

[TexasJohnny]

Where did the piece of ring come from?

From the original rings on the piston. I was heavy handed taking them off.

 

[dangerousatom]

The above advice is all spot on.
Like drf256 mentioned wax the burr while using it will help keep chips from forming on the back sides of the edges and clogging it. There are lots of high temp cutting wax sticks out there even a toilet bowl ring will work in a pinch. A cheap spray lube works well also. Apply it on the uphill side of were your removing material and let it flow down to were your working. A cheap trigger oil can with WD40 in it or used thinned out ( acetone or paint thinner ) trans fluid.

I have found that speed is your friend when cutting with the single cut burrs, but a very light pass & controlled firm hand grip on the tool is key. Using one had to move the tool and the other to brace helps with avoiding chatter/kick out. Another trick to do if you go a while between port jobs is keep an old shot cylinder on deck to start on. A few passes on that and you'll get your rhythm back before diving into the good cylinder.

PRACTICE practice PrAcTiCe!
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.
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[Sloughfoot]

Little cut off wheels on a Foredom is what I use on uppers. Can't always get the optimum shape I want but can raise them and widen toward the intake just fine. They're cheap, don't hurt anything but cosmetics if they jump out and are surprisingly fast. I believe 5/8 is what I've got.

 

[Sloughfoot]

From the original rings on the piston. I was heavy handed taking them off.

Admit, I'm bad to brake rings. Was anyway. What do you think caused the ring to hang on the exhaust port?

 

[EFSM]

Admit, I'm bad to brake rings. Was anyway. What do you think caused the ring to hang on the exhaust port?

From what I understood, the replacement rings are intact. There was a piece of old ring in the crankcase.

 

[Sloughfoot]

From what I understood, the replacement rings are intact. There was a piece of old ring in the crankcase.

Post #8 is what made me ask.

 

[EFSM]

Post #8 is what made me ask.

He assumed a ring had hung because it was locked up, but it was a piece of ring jammed in the squish band.

 

[TexasJohnny]

He assumed a ring had hung because it was locked up, but it was a piece of ring jammed in the squish band.

Yes. Correct. I originally thought I hung a ring in my crappy port job. When I first took it apart (pre-porting) I broke one of the original rings and a small piece must have found its way into the case - I flushed the case and thought I was good. My eyes aren’t what they used to be.

I ordered a new cylinder, piston and rings today.