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Posted: Mon May 21, 2012 9:46 pm
by dave.owen
Here is a link to Harley Pistons via an EBay dealer
http://www.ebay.co.uk/itm/320599680568? ... 1423.l2649
Dave
Posted: Tue May 22, 2012 1:00 am
by nevhunter
That is the high top one which I don't recommend. You will have to go aftermarket as the ariel standard size is a harley oversize of about .050" ( Don't quote me).
The price is not good either. They are cheap in the USA at the moment. The motor you reference is the 1,000cc Sportster, which was last produced in 1984 or therabouts. There is a low compresion piston( which still has a dome) which is very suitable. The " standard" piston(shown) has too high a crown though you may be tempted to want to run it, the Harley is a full hemisphere head and a bit deeper that the Ariel. Nev
Posted: Wed May 23, 2012 12:09 pm
by john.whiting
I have cut apart a 9.1 piston.The dome flat is 7mm thick at centre to 8.5mm thick at the outer edge radius,ditto the valve flats of the dome.The curved outer part of the dome is 10mm ,back to 8 at deck height.There is a rib from one boss under the dome to the other boss,about 6mm thick by 6 deep . 3mm could easily be machined from the outer edge radius of the dome ,and all sharp edges given curved surfaces. I havent seen any low compression pistons at cheap prices,but I was quoted by a local supplier $39 for two pistons and rings for the[9.1].The deck height of the Harley piston is 30mm, the Ariel height of a dished piston from my bike 1 1/4 or 31.8mm.,weight is very similar[few grams].My suggestion to anyone contemplating manufacture of pistons is to look at getting a lc piston JCC 10775[ HD no. not known] before spending a fortune on moulds[which would be a fraction of the price if made in china.] Regards John.