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Re: 495cc Big Bore Kit
Posted: Fri Jul 24, 2009 5:10 pm
by whizzo944
TTS used to do a 500cc conversion but he doesn't do it any more because it's too much hassle.
I went to see him (Richard Albans) about the possibility of doing the conversion without using
liners, just boring the block and using Nikasil on the bores. The JE pistons weren't very good
either, they were FAR too heavy.
Dave.
Re: 495cc Big Bore Kit
Posted: Sun Jul 26, 2009 7:56 am
by L.Svedberg
cal44walker wrote:I've got a set of the G-force pistons and I'm just waiting for the carillo rods to arrive. Cost around $3400 and with the exchange rate for Danish kroner that works out to about £1700.
If you think about what a full system plus PC costs for most bikes today, it's cheap hp.
428 cc high comp cosworth pistons (+3mm pin hieght)
+3mm Carillo rods
Balanced standard crank.
Should give over 80 hp at the back wheel without any other mods. The peak stesses on the crank/rods if anything should be lower as the forces are greatest at TDC on the exhaust stroke. The pistons alone wiegh about 20gr less than standard. Reliabilty and power I hope.
Just curious; but how on earth can you expect an over 20 bhp increase from just adding 28cc (or, I would guess, 50cc) of capacity??? Certainly you must have done a whole lot more motorwork for this?
Cheers/Lasse
Re: 495cc Big Bore Kit
Posted: Mon Jul 27, 2009 10:32 am
by cal44walker
Because the pistons are short skirt 2 ring designs that drastically reduce friction in the cylinder. The compression ratio also goes up to 13.5 to 1 and the longer rods mean the piston spends more time around TDC which gives more at the top end. Thats how.
Matt