Improving a piston: porting, polishing...

[Fred_64]

I tried to search various ways of improving a piston on the forum, but I was not too succesful.

So far I have always smoothed egdes on the pistons I used; none ever broke (maybe I did not try hard enough!).

Could someone post some advice and probably nice pics of what can be done to a TS1 Asso piston??

On a previous 175 engine I did this on the piston:



This a kind of before / after picture on the same piston:


Any comments welcome !

[sean brady scooters]

thats great work matey
you must have really spent some time and effort on that,but what difference did it really make...?
cosmetically it looks fantastic,but who is ever going to see that again...?

the main thing i would have done to the 175 piston is to drill two oil feed holes into the gudgeon pin as per std pistons.

i,m pretty sure that your time and skills could be better spent on things that actually do make a difference.....
and i dont mean polishing ports to a mirror like finish.... :lol

[J1MS]

I use to clean up the standard pistons, just removing any rough cast especialy in the corners either side of the gudgeon pin boss, lightly buffing to prevent any cracks forming when the engine was revved hard, basicly what Webster recommended in his tuning manual.

Thing was the standard pistons were never really in long enough to crack, they usually lost a ring or nipped up well before they ever cracked. Got to say, I never polished a piston to that standard...

On standard TS1's pistons, I smooth the piston windows and cutaway a little, removing any light surface marks just to try and prevent cracks forming. In the past I have seen these pistons fall apart at the windows.

[red ghost]

Look here;

http://scooterotica.org/tempforum/viewt ... bead+blast" onclick="window.open(this.href);return false;

[dapper]

I likes that. Didn't someone post recently about sand blasting the inside of pistons? Seem to remember some photos being posted. I asked recently what could be done to lighten a piston, but got no replies At leat yours will be a few grams lighter

[dapper]

Thanks Red, beat me to it

[eibargum]

Ive a mate who knife edges the inside of the piston skirt, dont know why, i,ll have to ask .

[J1MS]

Ive a mate who knife edges the inside of the piston skirt, dont know why, i,ll have to ask .

Think its got something to do with turbulence and eddy currents, knife edging or cutting a chamfer on the back end of the skirt was or is supposed to reduce this... Done it myself in the past...dont know if it made any diffrence.

[Matty]

The piston in my Saxelby tuned Rapido 225 is flowed and lightened in places. Looks nice but I'm sure Ralph does it for a reason.

[jason frost]

http://scooterotica.org/tempforum/viewt ... f=6&t=3744" onclick="window.open(this.href);return false;