460 and 660 work saws double build

[CHEVYTOWN13]

I take it the polishing is only done to slow down/stop carbon build up?

Slow down for sure. When I pulled the cylinder head from the L6 I had ported and polished for the C10 to fix a rocker arm stud that broke, the polished exhaust ports had a layer of carbon build up. And I'm running a TBI too. But in the case of a two stroke, I would imagine it is a simple fix by removing the muffler and cleaning up the port with a solvent?

Some have even gone as far as to coat the exhaust port in ceramic, to aid in flow and retard buildup.

Sounds like a F1 technique. Very cool.

 

[Metals406]

Slow down for sure. When I pulled the cylinder head from the L6 I had ported and polished for the C10 to fix a rocker arm stud that broke, the polished exhaust ports had a layer of carbon build up. And I'm running a TBI too. But in the case of a two stroke, I would imagine it is a simple fix by removing the muffler and cleaning up the port with a solvent?



Sounds like a F1 technique. Very cool.

I spoke to the owner/inventor of a ceramic product on the phone... He said car racers have coated ports, and orifices in their cars with his product for a long time. He also sells to NASA.

 

[scotclayshooter]

Build up, and to improve flow. You don't have to worry about mixing air and fuel once combustion has completed... But you do want improved flow, thus the polishing.

Some have even gone as far as to coat the exhaust port in ceramic, to aid in flow and retard buildup.

I thought that the majority of the flow was in the middle of the port and the sides were not so important?
I remember big debates on polishing or not on car engines years ago.

I bet what we think is polished aint too smooth under a microscope.

Wouldnt chroming work better? I gather the plater could do the whole jug?

I havnt polished the exhaust port on my 262XP yet but if its worthwhile i will put in some more effort.
Cheers

 

[CHEVYTOWN13]

Time for a cerveza...

He said car racers have coated ports, and orifices in their cars with his product for a long time.

Old timers, gotta love 'em.

When I first heard about it back in the mid 90's or late, can't remember, Mercedes was dominating anything and everything in Formula 1. The FIA then banned their uses of ceramic coatings in their cylinder walls and went down hill from there for sometime until recent years. That was their bread and butter.

Sounds like a must do.

 

[Metals406]

I thought that the majority of the flow was in the middle of the port and the sides were not so important?
I remember big debates on polishing or not on car engines years ago.

I bet what we think is polished aint too smooth under a microscope.

Wouldnt chroming work better? I gather the plater could do the whole jug?

I havnt polished the exhaust port on my 262XP yet but if its worthwhile i will put in some more effort.
Cheers

As far as results I've heard from builders... They don't polish the intake side. It has to do with the rough surface swirling the air and fuel.

If you wanted to try your saw unpolished, and then polished, you would be able to see any gains or losses.

LOL, I just realized you were speaking of the exhaust side. I don't think they chrome due to it being cost prohibitive. If you wanted it super smooth, I would say use a ceramic coating. Ceramics have a higher heat resistance than aluminum or steel, and a smoother surface.

 

[Metals406]

Old timers, gotta love 'em.

When I first heard about it back in the mid 90's or late, can't remember, Mercedes was dominating anything and everything in Formula 1. The FIA then banned their uses of ceramic coatings in their cylinder walls and went down hill from there for sometime until recent years. That was their bread and butter.

Sounds like a must do.

Yeah, the ceramics are pretty awesome. According to this inventor, his product can be used to 'replate' a cylinder wall. I have a ceramic hybrid 14" metal cutting blade for my chopsaw... It cuts through steel like butter.

Ceramics and hybrid ceramics are the cats @ss.

 

[scotclayshooter]

As far as results I've heard from builders... They don't polish the intake side. It has to do with the rough surface swirling the air and fuel.

If you wanted to try your saw unpolished, and then polished, you would be able to see any gains or losses.

So do those builders think polishing the exhaust port is worthwhile?

Any builders get good results without doing it?

What % better if there is a measurable diff?

 

[Metals406]

So do those builders think polishing the exhaust port is worthwhile?

Any builders get good results without doing it?

What % better if there is a measurable diff?

Timberwolf polishes his ex. ports... Knowing his rep for testing things... I'd follow his lead.

 

[scotclayshooter]

Timberwolf polishes his ex. ports... Knowing his rep for testing things... I'd follow his lead.

If its good enough for TW Time to get the Dremel out again!

 

[Metals406]

See how smooth it is in his picture?

 

[scotclayshooter]

See how smooth it is in his picture?

Ok so finer and finer grades of paper and finish with a liquid polish?
I have polished aliminium with Tcut car paint polish before and it works real well.
Before i got a vibratory cleaner for my bullets i used Tcut and a Lee chuck in a cordless drill to clean the cases.

 

[Metals406]

Ok so finer and finer grades of paper and finish with a liquid polish?
I have polished aliminium with Tcut car paint polish before and it works real well.
Before i got a vibratory cleaner for my bullets i used Tcut and a Lee chuck in a cordless drill to clean the cases.

In rough in, I believe (?) he uses a medium like beeswax, or something like this, so his bits won't clog with aluminum: click picture



Ive used Lenox LUBE TUBE, and like it.

Then I believe he uses different grit bits (not sue what kind?) I could be wrong... But I know other guys go this route.

You could search TW's posts or PM him, and I'm sure he would tell you his technique.

 

[scotclayshooter]

Cheers for the info im away studying some of TWs posts here and somewhere unmentionable lol

I was using WD40 on my bits and it didnt really stop the aluminium from bonding but will try the wax now.
I used paraffin when doing car heads but it was no better than the WD40

 

[Metals406]

Cheers for the info im away studying some of TWs posts here and somewhere unmentionable lol

I was using WD40 on my bits and it didnt really stop the aluminium from bonding but will try the wax now.
I used paraffin when doing car heads but it was no better than the WD40

No problem.

You should see if you can get Lenox Lube Tube in Scotland, or somewhere in the UK... I think you would like it.

It's good for bandsaw blades, drill bits, etc, too.

 

[scotclayshooter]

No problem.

You should see if you can get Lenox Lube Tube in Scotland, or somewhere in the UK... I think you would like it.

It's good for bandsaw blades, drill bits, etc, too.

No joy on internet other than 5L liquid in the UK
I was given a tube of solid lube for sawblades years ago and wondered what it was for.
So i will find it tommorrow and see if it will do.

Found a great thread on Blowdown Saves me asking lol

 

[drmiller100]

leave it a little rough on the intake to create a decent boundary for best flow.

on the exhaust, there are 3 factors towards smoothing it out.
smoother means less surface area, which means less heat transfer into the aluminum.
smoother means less carbon build up.
smoother means less heat transfer into the aluminum, which means more heat is carried out in the exhaust, so the exhaust moves faster out the muffler.

 

[timberwolf]

Just got power back on, been out with a wind storm.

I don't think it's going to be possible to see the gains of polishing or not on the ports. The difference between any two cuts in a log is going to be greater than the % gain/loss from such subtle changes. Need to trust technical reasoning and studies done by others working bigger motors on dynos ect.

Overall if you want a fast saw you can't start discounting small gains here and there.

Likely more important than polished smooth is getting the walls flat, getting all the humps and bumps out makes a significant difference to flow. A good smooth exhaust port helps keep the carbon off.

A polished aluminium surface might not do as well at blocking heat where exposed to direct flame as one would think. I did a little testing on heating aluminium finished in different ways with a dirrect flame. The aluminium sample that failed first was the pollished one, well before the dirty oxidized aluminium. I'm suspecting this is due to a reduced boundry layer held near the surface by surface texture and also the lack of a protective aluminium oxide coating likely also plays in.

406 hit the nail on the head, I start with carbide burs, then a light go with stones to take out any chatter marks from the carbides, then sand paper on a small drum or mandrill and polish with beeswax and pumice or rottenstone on a felt bob.

 

[Carlyle]

Finally got a couple videos of 460 up. First is stock as it came set up from stihl tuned just to 4 stroking. 7.15 seconds

Second video is ported, with a 9 pin gear. It's a bit too much for it in this sized wood, but should be ok in 8x8. 3.63 seconds so just shy of 100% faster.

Hey Brian,
With the idea of this saw(460) being a firewood(work)saw, would you recomend an 8 tooth gear for normal cutting. I have a couple 9's but had intended on an 8 with a 20-28 inch bar.

Also what are you using for race chain if you don't mind sharing your secrets, or "better chain" as you call it? It appears that you have gained 30% by using a 9 pin and better chain over stock set-up. I have a couple loops of RSLK that I was waiting to use for something, but I don't hear many talk about that chain here. I am not much of a square cutter guy so I am waiting for the Vallorbe guide to sharpen them.

Carlyle

 

[timberwolf]

It will run well with 8. If you get into heavy cutting with 28 inch bar then the 7 will likely be nicer to use. Think I sent it with an 8 pin gear on it.

9 Would only work cutting small wood with good chain, then depending on the chain 8 may be better.

Race chain is a topic onto its self, I can make some not bad chains, but find I spend more time on saw motors. Doing up chain is tedious work. Even just an ok chain is a full day of filing and grinding. Real thinned out race chains are much more time yet to build.

 

[CHEVYTOWN13]

I'm assuming the talk of a smaller gear on the drive, 7, will spin the chain faster like a smaller pulley would?

So will a bigger gear drive 8-9 give you more torque?

After reading the last post, I think I have it backwards.

This stuff is complicating...