LCGB Forums

The ability to post messages is restricted to LCGB members. Any questions contact us at lcgbadmin@googlemail.com

Work out CC

Technical help for Series one, two and three Lambrettas. Models include the Li, Li Special, TV, SX, GP, Serveta and API/SIL models

Work out CC

Postby Hughieboy » Sun Jun 09, 2019 8:08 pm

Anybody know how to work out cc...??

I have a GT186 with a 116mm conrod, 58mm stroke.

8mm of packers and gaskets at the base and a 2mm head packer plus regular thickness gasket. I just wondered what the calculation is?

Cheers!
User avatar
Hughieboy
 
Posts: 163
Joined: Tue Jun 17, 2014 7:15 am

Re: Work out CC

Postby MickYork » Sun Jun 09, 2019 8:15 pm

Your cc wont change.

cc = stroke x area (barrel radius squared x pye)
MickYork
 
Posts: 1476
Joined: Sun Jun 01, 2014 8:37 am

Re: Work out CC

Postby Hughieboy » Sun Jun 09, 2019 8:25 pm

So when a 60mm stroke increases the capacity, is that because it’s travelling 1mm further either way? Meaning that with mine you discount the packers, ie it just pushes everything away a bit but doesn’t increase capacity?

That would make sense if I’m thinking correctly.... therefore it doesn’t matter how thick the base/head packing, if it’s a 58mm stroke it remains 186cc?
User avatar
Hughieboy
 
Posts: 163
Joined: Tue Jun 17, 2014 7:15 am

Re: Work out CC

Postby MickYork » Sun Jun 09, 2019 8:36 pm

Yup, you've got it :)
MickYork
 
Posts: 1476
Joined: Sun Jun 01, 2014 8:37 am

Re: Work out CC

Postby Hughieboy » Sun Jun 09, 2019 8:41 pm

Brilliant, thanks! :D
User avatar
Hughieboy
 
Posts: 163
Joined: Tue Jun 17, 2014 7:15 am

Re: Work out CC

Postby dscscotty » Sun Jun 09, 2019 10:23 pm

try this-0.785 x bore x bore x stroke so for gt 186 with 60mm stroked crankshaft- 0.785 x 64 x 64 x 60 = 192.9cc
dscscotty
 
Posts: 718
Joined: Fri May 30, 2014 7:42 pm

Re: Work out CC

Postby Feersum Injun » Mon Jun 10, 2019 11:17 pm

^^^ this ^^^
User avatar
Feersum Injun
 
Posts: 215
Joined: Tue Apr 26, 2016 11:21 pm
Location: Wirral


Return to Series 1, 2 & 3

Who is online

Users browsing this forum: No registered users and 18 guests