48 HP dyno chart for stock stroke 500 domni racer
- Thread starter jseng1
- Start date
hybridracer
MEMBER
- Joined
- Feb 2013
- Messages
- 395
Very nice,but mixture looks very weak up to 7000. Is that accurate?
What is the camshaft?
What is the camshaft?
johnm
FULL MEMBER
- Joined
- Feb 2008
- Messages
- 2,065
Yes. Assuming it's petrol around 12.5 is best for power.
hybridracer
MEMBER
- Joined
- Feb 2013
- Messages
- 395
Sorry, , I looked too briefly and it was 2hrs past my be time.
I will havet to check how the JS2 compares with the 4S I used in mine for a few races.
johnm
FULL MEMBER
- Joined
- Feb 2008
- Messages
- 2,065
Nice result.Brians 500 with all the JS internals and some mild porting.
About 20 years ago now I dynoed my 500 after a couple of years of tuning.
the plot is on here somewhere.
Best I got was 51 bhp rear wheel at 6100 rpm. But I still had megaphonitis very bad under about 4200 rpm.
This curve is much better lower down and also continues well over 7000 whereas mine was flat from 6500. I didn't have a Lambda meter back then. This engine would be much more ridable than mine especially if the rules said a 4 speed box. A very nice result.
My bike had a PW3 cam and 10.25 :1 GPM pistons. Mk1 30 mm Amals, home made exhaust, porting by a NZ guy who did a lot of speedway cars and bikes. Pump gas.
Funnily enough my bike is sitting in my garage with a 50 % assembled engine with JS cam and lightened pistons etc fitted. And a intertial dyno is parked in my garage. But I'm not much into racing these days.
Last edited:
jseng1
MEMBER
- Joined
- Nov 2009
- Messages
- 3,501
Those are excellent results. Anything over 50 HP is one hell of an achievment with a 500 twin. Brian has a couple more ideas to get him over 50 HP - the next piston design with 11 CR should get him there. I have another 500 twin customer in Canada who got 57 HP with a short stroke 500 and 12+ CR
johnm
FULL MEMBER
- Joined
- Feb 2008
- Messages
- 2,065
Above 40 bhp from 5,500 and on to 9000 rpm. That would be one quick bike.Those are excellent results. Anything over 50 HP is one hell of an achievment with a 500 twin. Brian has a couple more ideas to get him over 50 HP - the next piston design with 11 CR should get him there. I have another 500 twin customer in Canada who got 57 HP with a short stroke 500 and 12+ CR
Interesting looks like that dyno is the same as the one in my shed - Dynojet series 100.
Running on Dynojet software. A very good friend passed away recently and the Velo IOM team inherited his dyno. I got the task of converting it over to new Yourdyno software and firmware. We matched runs on the old software and new to calibrate results. If you get a chance tell your Canadian friend I can recomend the Yourdyno product if he wants to upgrade. I'd never run a dyno before and sorted it in a few hours.
YourDyno Dynamometer DAQ - YourDyno.com https://share.google/DWyk3oCLGSkFuL9pe
johnm
FULL MEMBER
- Joined
- Feb 2008
- Messages
- 2,065
cliffa
FULL MEMBER
- Joined
- May 2013
- Messages
- 4,687
Is that this bike ?
Nice chatting to you today John. As mentioned here's a couple of pics of the 500 Velo taken yesterday at St.Ninians crossroads at the top of Bray Hill.
It's a real shame about the weather.
It's a real shame about the weather.
johnm
FULL MEMBER
- Joined
- Feb 2008
- Messages
- 2,065
Yup that's the bike.Is that this bike ?
Nice chatting to you today John. As mentioned here's a couple of pics of the 500 Velo taken yesterday at St.Ninians crossroads at the top of Bray Hill.
It's a real shame about the weather.
Actually packing the crates this weekend for them to return to the IOM for this year's races. There will be the 350 and 500 DOHC girder fork bikes built entirely in NZ and also a new 350 KTT bike built in cooperation with ABSAF in the Netherlands.
Peter Lodge is also taking the ES2 back. The bike that won last year.
Spent the last couple of weeks sorting paperwork, carnets etc.
