Author Topic: abrasive porting cones (Read 6034 times)

turboguzzi · « **on:** March 07, 2019, 09:59:36 AM »

well as you can guess im proceeding to finish the porting work...

A bit taken aback by the price of these kits!

Anyone has a reasonable priced ebay/amazon source NOT in the USA?

adding shipping and taxes from USA to italy will make it even worse...

one of those "free shipping" solutions would be grand, not in a hurry

MessnerMoto · « **Reply #1 on:** March 07, 2019, 01:34:48 PM »

https://www.aliexpress.com/item/10-30-50Pcs-Cone-Abrasive-Sandpaper-Grinding-Head-Mounted-Point-Flap-Sanding-Wheel-1-8-Shank/32972781379.html?spm=2114.search0104.3.49.2d53556eu8lyju&ws_ab_test=searchweb0_0,searchweb201602_8_10065_10068_10843_319_10059_10884_317_10887_10696_321_322_10084_453_10083_454_10103_10618_10304_10307_10820_537_536_10902,searchweb201603_70,ppcSwitch_0&algo_expid=9fc9af2f-c540-4b88-af90-91c192cce007-7&algo_pvid=9fc9af2f-c540-4b88-af90-91c192cce007

and many many more

https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20190307133622&SearchText=Cone+Abrasive+Sandpaper+Grinding+Head+Mounted+Poin

turboguzzi · « **Reply #2 on:** March 08, 2019, 01:20:30 AM »

close but not exactly the ones im looking for, too big diameter to work on a 500's small exhaust port,

they also look rigid, for port work they need to be flexible cartridges

was really looking for those that are modular like in my picture

PeWe · « **Reply #3 on:** March 08, 2019, 03:27:38 AM »

So this is enogh for improve the ports? I thought that rotating files were used first for removal of the major amount of alu without creating additional ports

https://www.eastwood.com/engine-porting-kit.html
Here one guy complained about cheap imported stuff that did not last. The Eastwood kit however do.

turboguzzi · « **Reply #4 on:** March 08, 2019, 04:38:55 AM »

hei peewee

of course the main cutting was done with carbide bits, i am now in finishing stage

yes, that link would be the stuff, even if for a 500 i'd need smaller diameter stuff,

got some are where the roll needs to be no more than 10mm 3/8" diameter

most kits i see in ebay are for big american car V8 ports

in any case between 35$ + 30$ shiiping to italy + customs here it gets expensive

that why i wrote NOT from the USA....

MessnerMoto · « **Reply #5 on:** March 08, 2019, 05:45:40 AM »

https://www.aliexpress.com/item/SI-FANG-10-50Pcs-3mm-Shank-Sandpaper-Conical-Flap-Wheel-Grinding-Head-320-Grit-Polishing-Cone/32974682162.html

this are 10mm

maybe paper is not good

Don R · « **Reply #6 on:** March 08, 2019, 09:22:25 AM »

I've been known to unroll and tear off a little grit paper to change the OD.

turboguzzi · « **Reply #7 on:** March 08, 2019, 11:00:38 AM »

good idea!

still, i'd need to find someone in europe that sells those cartridge kits as the shipping and customs from USA multiply the cost for me...

those single use cones from aliexpress dont convince me too much

info is also a bit erratic, Mirko's last link says it's 320 grit, (too fine for porting, maybe for last polish pass..), but close up picture looks like 60 grit....

been today to my tuner friend flavio and he has a nice DIY solution, so might try that too.

jgger · « **Reply #8 on:** March 08, 2019, 07:17:28 PM »

Back in the day when I was playing with 2 stroke dirt bikes we would just cut a slot in the end of a rod that fit the grinding tool. Then wrap the rod with emery cloth of what ever grit or width we wanted and grind/polish away. The nice part about doing it like that is the diameter and length of the "bit/pad" was totally custom to what fit the situation. You might be very pleased with how easy and versatile that is .

turboguzzi · « **Reply #9 on:** March 09, 2019, 01:12:34 PM »

yep, thats also what flavio recommended
so just built the holder and it works like a charm,

but also gave a try to do my own cones, gluing the small end with super glue and stick them on a a dremel polishing pad mandrel with left hand thread at the end.

your idea seems to work better at the entry exit side of the ports, the cone on mandrel better for the bowl area near the seat, approaching from the combustion chamber

jgger · « **Reply #10 on:** March 09, 2019, 02:29:51 PM »

And the price is right!

754 · « **Reply #11 on:** March 09, 2019, 08:34:48 PM »

Look up cratex rubber cones.

turboguzzi · « **Reply #12 on:** March 11, 2019, 03:23:05 AM »

interesting, never heard of those,

surely expensive for a non-pro like me.... but its a 100 pcs kit after all...

Anyway, work is finished with DIY polishing solutions, results much better than any other porting job i did, will post some pics soon.

when there's a need there's a way

754 · « **Reply #13 on:** March 11, 2019, 08:53:05 AM »

They are rubberized abrasives, they make a wide range.
I bet used extensively in mould polishing for die casting..

The rolled paper ones, man they would have to be very bouncy... I bet the Cratex are far smoother to use.

turboguzzi · « **Reply #14 on:** March 17, 2019, 02:42:42 PM »

went at the end the DIY way and everything was easier than expected.

first, what made a huge difference in productivity was buying this 50$ 750W die grinder in ebay with a speed controlled dial. unlike the air grinders in which rpm is totally unpredictable, or punny dremel, this one sits at the exact speed you set it, even at lower rpm/heavy cutting and being long it gives a lot of control and steadiness.

A must have is pedal activation so you are not turning it on/off outside the port and destroy seats.... I attached it to the same pedal that i use for my roller starter and that makes a huge difference.

did three "flag type" holders with a slot on a rod, two with 6mm shaft for the die grinder and one 3mm shaft for fine work with a dremel.

then discovered i had in one of those cheap chinese kits polishing kits a 6mm holder with left thread so tried my hand at making my own cones, and they work great! not bouncy at all. they become soft with use and really let you go into tight crannies and smooth out things.

used on them with everything from 80 grit for heavy smoothing to 600 grit for mirror finishing the exhaust. intake was left at 80 grit finish.

so easy to make that it'a a no brainer. Just use protective glasses as these throw up a lot more stuff than the carbide cutting tools. So do try it at home kids

754 · « **Reply #15 on:** March 17, 2019, 04:17:51 PM »

Now try the rubber ones..
I am curious what M Reick uses..

bwaller · « **Reply #16 on:** March 17, 2019, 04:43:41 PM »

I think Mike works by hand with long skinny fingers!

dragracer · « **Reply #17 on:** March 17, 2019, 07:32:41 PM »

Glad I read the statement on the die grinder you used. I decided to order one just now.

Don R · « **Reply #18 on:** March 17, 2019, 09:37:18 PM »

I use a regulator/filter drier on my air die grinder. I never try to throttle the speed with the lever.

turboguzzi · « **Reply #19 on:** March 18, 2019, 04:36:39 AM »

Quote from: Don R on March 17, 2019, 09:37:18 PM

I use a regulator/filter drier on my air die grinder. I never try to throttle the speed with the lever.

Hi don
I sure used a regulator and filter, but at least in my case it was hard to make the air grinder work at low-medium revs while still giving good torque for carving.
not to mention the fact that you need a very serious compressor to feed it over long jobs, mine was almost on 80% duty cycle.
try an electric one, youll see what i mean in terms of control...

PeWe · « **Reply #20 on:** March 18, 2019, 04:52:15 AM »

Any good procedure with toolings how to clean the old oiled, carbonized ports and chambers?
That must be the first step before grinding, sanding.

turboguzzi · « **Reply #21 on:** March 18, 2019, 06:32:24 AM »

I guess there are other ways but nitrocelluse thinner works for me... The solid stuff rotary wire brushes

gschuld · « **Reply #22 on:** March 18, 2019, 07:16:50 AM »

Speed control is big for porting.

Pops Yoshimura used a basic heavy aluminum framed high speed drill to port a LOT of fast heads back in the dark ages😉. I’m guessing the heft of the drill helped damped the tendency of the long carbide bits to pull to the side. It certainly wasnt because he was a brute of a man who liked to wield heavy stuff around for fun🙄. The shape of the drill was also convenient as the handle gave him a great and ergonomically comfortable and stable grip for his left hand (and trigger) and the right hand was free to grip the body. This technique is great for porting assuming all the cutting is downward (like it should be) allowing the weight of the drillbitself to apply the pressure. Turn the head as needed to keep cutting/sanding “downward”. Can’t argue with success👍

Oh, and the biggest secret... the best porting happens when you have a lit cigarette clenched in your lips.😀

George

bwaller · « **Reply #23 on:** March 18, 2019, 07:57:16 AM »

Well of course all the best port magicians smoke.

I thought Pops was a tremendous guy, know this first. However after a while, they did so many heads there was no time to waste and most ports were "less than beautiful".

Mind you they worked very well, but looked like they were hogged out by a guy with a 1/2" drill and a ciq in his face!! LOL

turboguzzi · « **Reply #24 on:** March 18, 2019, 11:18:31 AM »

good ones george!
i think there's not much difference, in fact the first job port i did was with my bosch drill.
the die grinder just gives you much better control at the front end from what ive seen, and higher rpm when you need it.

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Author Topic: abrasive porting cones (Read 6034 times)