When I get round to rebuilding my Li150 S2 engine, I'm going to upgrade to a 175 kit, but which one do I go for and why? A cast one, or an alloy one?
Help and advice please
Get one of the alloy 175 kits from AF Rayspeed, they've already had the "tidying up" done. Plus it'll have been checked out that the liner is actually in line and the head matches.
1) piston to bore clearance is OK (on a steel lined alloy, I've gone down to 3 thou with no problems)
2) The inlet and exhaust ports are reasonably tidy (I use a Black and Decker band sander believe it or not!!)
3) all studs are "studloked" in place
What I've started doing is get hold of just the steel lined alloy cylinder and then got a 200cc piston (66mm) - Scooter Restorations around £30
Give this to your reborer and ask him to bore and hone to suit (I ask for 3 thou as above on these set ups)
Widen the exhaust port to approx 65% of bore. Raise port by 1mm.
Source a 175/185 head and get this reprofiled to the 66mm piston crown
I've used a cheap 22 mm Jetex jeted as for a GP200 (123 main jet etc)
Finally a 42mm Clubman
Correctly set up and jetted I've had them cruice nicely at 65.
The whole lot is not a lot of cash compared with other kits available such as Casa and Mugello, plus you've got the satisfaction of doing your own thing. Please note that in no way am I some sort of tuning "guru"- I just like having a play to see what can be achieved- if it doesn't work, you've not lost a lot.
harry barlow does a very nice kit for around £180 and its been sorted and that inc a head reprofile porting etc plus some jetting advice
use the search function for his details
We sleep soundly in our beds because rough men stand ready in the night to visit violence on those who would do us harm
shocky wrote:harry barlow does a very nice kit for around £180 and its been sorted and that inc a head reprofile porting etc plus some jetting advice
use the search function for his details
thats excellant value! And you know if HB's been involved its good
http://www.proporting.com/contact.htm
might take some time he doesnt answere his fone much but when he does be prepared to listen and listen and listen
We sleep soundly in our beds because rough men stand ready in the night to visit violence on those who would do us harm