Page 1 of 1

mahle 3 ring piston convert to reed?

PostPosted: Sat Jun 29, 2019 8:43 am
by DaveTomo
After a few years of various kits, I've decided to go back to basics and run a iron barrel.Nothing fancy stage 4 Indian barrel,porcupine head,delly 30,Ron Moss exhaust ,Indian webs and a jap conrod .The piston I'm using is a 3 ring Mahle with the bottom ring left off.I'm quite pleased with how it runs and at £35 a piston seems to be good fun ,having before now spending £120 on a piston .I am wondering though to improve the fuel consumption,about fitting a reed valve ( either the mb shorty or the scootrs type).So to my question , is the Mahle piston up to the job of being cut to suit a reed? Is anyone else running a similiar set up with a reed.I know I could get it rebored and get a piston to suit,but to be honest I don't want the ball ache of running in again,my present bore size is 66.2.Appreciate any help/feedback

Re: mahle 3 ring piston convert to reed?

PostPosted: Sat Jun 29, 2019 12:16 pm
by Scooterslag
I'm intrigued by this myself, someone I know made a 150 reed valve kit using a indian piston and a modified malossi carb kit ( think it was off a small frame) he only uses for blasting around and to my knowledge - hasn't gone bang yet . Don't know about the long time reliability of it and if the Mahle piston is weakened by cutting windows in it. Paul :)

Re: mahle 3 ring piston convert to reed?

PostPosted: Sat Jun 29, 2019 1:14 pm
by Warkton Tornado No.1
To answer the question, in a roundabout manner, I have fitted pattern pistons where a rebore is not necessary, just a hone, & they have been fine.

I have even used GOL pistons (which are cast) in reed valve engines & although they are frowned upon, to my old eyes, they look as well made as others, such as Asso. Let's face it, the cost of them is so cheap, you can buy two & have one as a spare, compared to some 'specialist' pistons, though out of all available, I prefer to use motorcycle pistons if the geometry allows. Having said that, I also think the thin ring SR pistons are underrated for those of us on a budget..... ;)

Re: mahle 3 ring piston convert to reed?

PostPosted: Sat Jun 29, 2019 2:51 pm
by Scooterdude
Warkton Tornado No.1 wrote:To answer the question, in a roundabout manner, I have fitted pattern pistons where a rebore is not necessary, just a hone, & they have been fine.

I have even used GOL pistons (which are cast) in reed valve engines & although they are frowned upon, to my old eyes, they look as well made as others, such as Asso. Let's face it, the cost of them is so cheap, you can buy two & have one as a spare, compared to some 'specialist' pistons, though out of all available, I prefer to use motorcycle pistons if the geometry allows. Having said that, I also think the thin ring SR pistons are underrated for those of us on a budget..... ;)


Just been on SR for a look at the 70mm pistons, one made me smile.......manufactured by ‘KAC’ of India, says it all really lol.