Author Topic: billy's racer  (Read 4643 times)

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Online camman3

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Re: billy's racer
« Reply #120 on: January 26, 2016, 11:44:47 AM »
Strewff Bill :o, you really are going to town on this one :)
Fantastic work and fascinating to follow.
Graham
1957 C12
In sunny (sometimes) Christchurch, Dorset, UK

Online Owen

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Re: billy's racer
« Reply #121 on: January 26, 2016, 09:30:01 PM »
Now being a real numpty in the tuning dpt.
Could someone fit one of your racier cams into a standard C11 and get much improvement in the running/power or would you need to do the porting & flywheel balancing as well to achieve a significant power gain e.g. +2Hp?
1940 C12 (350cc)
1945 C10 & C11
1953 C10 & C11

Offline BillyF

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Re: billy's racer
« Reply #122 on: January 27, 2016, 11:16:49 AM »
hi owen
making these cams up is very labour intensive and needs a high compression ratio, but there are other things you might want to do first.
here is a list of what i think would help :-
cut off the perforated end of the exhaust pipe and use a burgess type silencer, or an open pipe ending at the rear spindle, it is not too loud - probably need to go up a jet size.
the inlet length is far too short - you could make an angled flanged  spacer between the carb and head.
the inlet port could be opened out a size and the port and valve fettled then go up a size in carb diam.
i have seen the imp piston used but you could very easily spoil a barrel by breaking through at 68mm.
i have used the 66mm wiseco honda k4 piston - you would need to make a small end bush and skim a bit off the barrel. (bore it nice and slack to avoid nipping).
make a head gasket with 0.9mm annealed copper.
all that can be done without taking the engine out and make a noticable difference in performance.
then you could machine the flywheels a bit which would help with throttle response and acceleration in the lower gears.
then fit a racier cam
cheers bill

Offline BillyF

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Re: billy's racer
« Reply #123 on: April 03, 2016, 02:57:00 PM »
hi folks
still messing with the c11 on the rolling road dyno (it's a great thing - on a 10 second run say you can glean all the info immediately after on the lap top with graphs and reports and everything in between - intake temperature, cylinder head temp. exhaust gas temp. air fuel mixture ratio, revs, horsepower and torque)
on the first engine with the standard crank and honda piston- 273cc i have squeezed 21hp at 6250 revs, now i am in the process of testing the second engine with the short stroke crank and big beefy big end and home made rod with honda piston 248cc and i am up to 19.5hp at 6750 revs with the rev limiter set at 7500 revs - i have still got more things to try
i have just ordered 20l of methanol to get a back to back test against 95 octane petrol, if it is good i have a high comp. piston to try (about 12.5:1).
based on my experience out on the road with the first racer i am in the process of building another with a whole lot of refinements - there should be photos attached.

my arthritis has got me pretty fckud, but next week i am getting my right hip done and as soon as i can after get my left one done then hopefully i will be able get my leg over the saddle and if that all works i would like to get a semi modern v twin, but i have no idea what to look for -- i am open to suggestions.
cheers again bill

Offline BillyF

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Re: billy's racer
« Reply #124 on: April 03, 2016, 02:59:35 PM »
more pics

Online donkey

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Re: billy's racer
« Reply #125 on: April 03, 2016, 03:23:57 PM »
Looking GOOD billy i was going to have a run up soon but i will wait a bit till you get sorted with the Hip i hope all runs smooth i will give you a call in a cpl of weeks.
Kev

Offline Paule

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Re: billy's racer
« Reply #126 on: April 04, 2016, 05:40:50 PM »
Very interesting, Billy! In the last pic, i see you've modified the gearbox plates as well. Next to the plates, what are the two steel bars for? That bolt in the middle, is it your "memory" for adjusting primary chain?
Wish you all the best with your hips and good recovery!    Paul

Offline BillyF

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Re: billy's racer
« Reply #127 on: April 05, 2016, 09:15:14 AM »
hi paul
as the joint at the rear of the gearbox plates is probably the weakest and wobbliest part of the bike but is critical to stability of frame and rear chain tension i have tried to beef it up as much as i can.
the side plates are to put that part in a double shear, i have also welded a strip of flat bar along the length of the underside of the drive side gearbox plate.
the whole mod. has very effectively strengthened and stiffened up assembly.
there should be some close ups to help explain.
cheers bill

Offline BillyF

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Re: billy's racer
« Reply #128 on: April 05, 2016, 09:16:31 AM »
more pics

Offline spaceraver

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Re: billy's racer
« Reply #129 on: June 12, 2016, 02:06:12 AM »
Absolute madness. I love it all the same.

Offline BillyF

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Re: billy's racer
« Reply #130 on: June 12, 2016, 05:05:34 PM »
hi all
i've made a wee bit headway since then here are a couple of photos
cheers bill

Offline BillyF

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Re: billy's racer
« Reply #131 on: June 12, 2016, 05:07:40 PM »
more photos

Offline BillyF

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Re: billy's racer
« Reply #132 on: June 12, 2016, 05:09:20 PM »
two more

Online camman3

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Re: billy's racer
« Reply #133 on: June 12, 2016, 07:14:55 PM »
Absolutely cracking work Bill.....a proper wolf in sheeps clothing you have created :)
Graham
1957 C12
In sunny (sometimes) Christchurch, Dorset, UK

Online Owen

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Re: billy's racer
« Reply #134 on: June 12, 2016, 07:17:35 PM »
Looks fantastic.

Meant to ask why does increasing the inlet tract help increase power?
1940 C12 (350cc)
1945 C10 & C11
1953 C10 & C11