Search found 768 matches

by Darrell Taylor
Fri Jan 26, 2018 2:49 am
Forum: Lambretta Tech
Topic: How Many CC’s
Replies: 32
Views: 14990

Re: How Many CC’s

a basic acu method of calculating cubic capacity is bore x bore x stroke x 0.785 so 64 x 64 x 60 x 0.785 = 192.92 cc that's wrong! use this https://lambretta-images.com/tuningh/port-timing-calculators/cc-calculator/ :) or this https://www.scooterhelp.com/tuning/defs.ccs.html or this https://www.ica...
by Darrell Taylor
Mon Jan 22, 2018 1:37 am
Forum: Lambretta Tech
Topic: How Many CC’s
Replies: 32
Views: 14990

Re: How Many CC’s

a basic acu method of calculating cubic capacity is bore x bore x stroke x 0.785

so 64 x 64 x 60 x 0.785 = 192.92 cc
by Darrell Taylor
Sun Jan 21, 2018 5:58 pm
Forum: Lambretta Tech
Topic: Casa 225 engine
Replies: 26
Views: 8374

Re: Casa 225 engine

pair of cowlings af heavy duty black powder coat £45

RT £4533
by Darrell Taylor
Sat Jan 20, 2018 11:57 am
Forum: Lambretta Tech
Topic: Casa 225 engine
Replies: 26
Views: 8374

Re: Casa 225 engine

£200 mikuni pre jetted 35mm best clearance and good size at 250cc

running total £4000
by Darrell Taylor
Fri Dec 22, 2017 7:09 pm
Forum: Lambretta Tech
Topic: Detonation, lean seizure, or....?
Replies: 33
Views: 11770

Re: Detonation, lean seizure, or....?

can you calc out the rpm back from the gearing , i dont think 24 at 4000 is correct id expect 13 to 18 bhp at 4k so possibly an rpm error that would also throw the ign curve if based on same rpm measurement most dyno runs start at 3k so be at 4 almoststrsight away no extra increase in stinger size w...
by Darrell Taylor
Tue Dec 19, 2017 1:09 pm
Forum: Lambretta Tech
Topic: Detonation, lean seizure, or....?
Replies: 33
Views: 11770

Re: Detonation, lean seizure, or....?

Forgot to mention the exhaust port side failure of the piston eroding away around the ringland ive only seen in situations of small stinger diameters ,although other contributing factors like high compression or over advanced ignition timing will make matters worse im not too familiar with the origi...
by Darrell Taylor
Sun Dec 17, 2017 1:03 pm
Forum: Lambretta Tech
Topic: Detonation, lean seizure, or....?
Replies: 33
Views: 11770

Re: Detonation, lean seizure, or....?

if you look at pics of piston head and plug you can see theres a good dark base layer of carbon but on the piston see that the layers are build up over the top of the eroded alloy so id say this failure started long ago and kept on running until the final fail on the dyno that i wouldnt blame in any...
by Darrell Taylor
Thu Dec 14, 2017 2:42 am
Forum: Lambretta Tech
Topic: Detonation, lean seizure, or....?
Replies: 33
Views: 11770

Re: Detonation, lean seizure, or....?

id check on the stinger size and have that as the failure ,at 300cc id have 26mm as absolute minimum size up to approx 30mm as about right check the vent size on the baffle cone and the stinger tube , mount plate , silencer baffle tube and that it hasnt collapsed ,, 1 more possible is have you short...
by Darrell Taylor
Tue Dec 12, 2017 9:24 pm
Forum: Lambretta Tech
Topic: Cubes, cubes, I want more cubes!!!
Replies: 51
Views: 14590

Re: Cubes, cubes, I want more cubes!!!

Darrell, What are the rod specs (length, weight)? And piston weight? I never weighed my 125mm rod or 76 mm piston. Just wondering so that I might have a baseline comparison if it ever becomes an issue. Thanks! Its a development spec so not available ,not an answer but didnt want u thinking i was ig...
by Darrell Taylor
Mon Dec 11, 2017 1:04 pm
Forum: Lambretta Tech
Topic: Cubes, cubes, I want more cubes!!!
Replies: 51
Views: 14590

Re: Cubes, cubes, I want more cubes!!!

To analyse bmep and make comparisons from different sources can be difficult ,there are lots of variables to consider 1 simple one is that of method of dyno measurement be it rear wheel or engine,then the industry standard that is applied eg sae isa as correction factor used plus the barometric adju...