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Title: Hi comp pistons, Where? Post by: oppet on July 16, 2008, 12:07:39 PM Whats a good place to buy "drop in" hi comp pistons? And Do I notice difference with 12:1 pistons in my 900 with fcr:s, otherwise its original thou from SS
T Title: Re: Hi comp pistons, Where? Post by: teddy037.2 on July 16, 2008, 01:05:42 PM picked mine up from fast by ferracci
Title: Re: Hi comp pistons, Where? Post by: oppet on July 16, 2008, 01:11:44 PM Jup, ive seen them in ebay... and read here that they arent really good to make business.
I live in finland, cant go and pick them up Title: Re: Hi comp pistons, Where? Post by: ducpainter on July 16, 2008, 01:26:16 PM How about ca-cycleworks?
I think Chris sells an 11 1/2:1 drop in. Title: Re: Hi comp pistons, Where? Post by: Speeddog on July 16, 2008, 02:34:26 PM Ducati Kaemna?
Title: Re: Hi comp pistons, Where? Post by: clubhousemotorsports on July 16, 2008, 05:11:22 PM Ducshop
in GA. sells pistal pistons, they may have a hi-comp drop in. probably one of the best pistons you can buy. Title: Re: Hi comp pistons, Where? Post by: printman on July 17, 2008, 02:53:59 AM IMO anything over the 11.1 : 1 will have problems detonating. With 93 octane, you still need to change the base advance 2 degrees BTDC to keep it from pinging
Title: Re: Hi comp pistons, Where? Post by: oppet on July 17, 2008, 08:31:02 AM we have 95 as lowest octane, 12:1 should go.
I think cycleworks will have my invoice soon Title: Re: Hi comp pistons, Where? Post by: supertjeduc on July 17, 2008, 08:44:05 AM Don't think it will work with 95
You will have to go to 98 And is 12:1 not a bit to much for a street bike I think your old monster won't like it in the long run (or is it for a racebike?) Title: Re: Hi comp pistons, Where? Post by: clubhousemotorsports on July 17, 2008, 09:24:15 AM This is a question best left to those who have been installing the pistons you have been looking at. Often times the advertised compression ratio is optimistic at best. I am running 11:1 (cc'd and calculated) on 89 with 0 problems(dual plugged). If you want the higher compression ratio dual plug your heads and I bet you would be fine on 93.
I would check with chris kelly and see if he has measured the compression ratio on his pistons or if he has had problems running them on pump gas. same with mark at the ducshop. Title: Re: Hi comp pistons, Where? Post by: supertjeduc on July 17, 2008, 01:49:38 PM 83 in the US is not the same as 83 in Europe
I had a alfa romeo with high comps and used 85 (normal in the netherlands) And had to replace the cilinderhead after 4000 km Than used super 98 and no problem Title: Re: Hi comp pistons, Where? Post by: brad black on July 18, 2008, 02:50:13 AM i've used the je in a couple of bikes. we machined 3mm off the crown (straight side cut of the top 3mm, not an angle cut) of the first set and it ran fine (ssie), the next one we didn't and it does ping a little with the std ignition map on our premium (98 unleaded). i checked one with 3mm machined off and it was 10.8 from memory.
my 750 is running ferraci 12:1 pistons that have been modified a bit (a bit lower, i didn't check it) and it doesn't ping even with quite a lot of timing on our 95 octane (std 89). i epxected it to. some people don't like the je, but they seem ok in my experience. there's been some pretty cheap ones on ebay lately. Title: Re: Hi comp pistons, Where? Post by: Norm on July 18, 2008, 07:31:11 AM I've never had a problem with JE, but also use a lot of other brand pistons as well. VeeTwo and a couple of others can give you a 12:1 but most of the others will be around 11.2. I've never had a problem with 12:1 but I also use carbs & aftermarket ignitions. The more compression you can stuff in there, the more HP and torque you'll get. It is the foundation for most other mods.
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