A BIT OF SIL 200 TUNING

Post your Lambretta dyno graphs here! But graphs & spec info only, keep the chat in the 'dyno chat' section ;o)
Darrell Taylor
Dealer
Posts: 818
Joined: Wed Apr 06, 2011 8:43 am
Main scooter: LAMBRETTA
Location: Doncaster
Contact:

Tue May 29, 2012 12:16 am

Recently had a sil 200 cylinder and head in to tune for touring use with a reed valve conversion running on a 30mm carb the brief was for excellent tractability with a low rpm peak
The cylinder was coupled with an asso 1.5mm ring piston so the port widths were kept mild so nothing extreme in its layout which comprised single exhaust port 2 transfers and a single boost port was added
the porting layout is very simple in appearance but accurate in respect to port durations ,areas and angles its exhaust port/inlet port and base gaskets are all to standard gasket sizes.
Image
feel free to use this link to contact me on facebook and like it(if u like it)
https://www.facebook.com/pages/Taylor-T ... 8819767924

Darrell Taylor
Dealer
Posts: 818
Joined: Wed Apr 06, 2011 8:43 am
Main scooter: LAMBRETTA
Location: Doncaster
Contact:

Tue May 29, 2012 12:22 am

the barrell fins were cut away to suit the mb reed assembly that runs the great little derbi reed block that i reccomended (its not minarelli as advertised) and the 30mm pwk that i run on my zip and derbi race motors matches the reed size really well
Image

I matched the reed box to the inlet port initially with a fine finish then returned to rough it up

Image
Image



the cylinder head was standard so machined it up to a slightly higher compression ratio
Last edited by Darrell Taylor on Tue May 29, 2012 1:48 am, edited 1 time in total.
feel free to use this link to contact me on facebook and like it(if u like it)
https://www.facebook.com/pages/Taylor-T ... 8819767924

Darrell Taylor
Dealer
Posts: 818
Joined: Wed Apr 06, 2011 8:43 am
Main scooter: LAMBRETTA
Location: Doncaster
Contact:

Tue May 29, 2012 12:26 am

had to trim out a corner of the reed box to allow full petal lift and stop the petal from breaking its tip where it touches down too early
Image
feel free to use this link to contact me on facebook and like it(if u like it)
https://www.facebook.com/pages/Taylor-T ... 8819767924

Darrell Taylor
Dealer
Posts: 818
Joined: Wed Apr 06, 2011 8:43 am
Main scooter: LAMBRETTA
Location: Doncaster
Contact:

Tue May 29, 2012 12:31 am

heres the piston window i added
Image
feel free to use this link to contact me on facebook and like it(if u like it)
https://www.facebook.com/pages/Taylor-T ... 8819767924

Darrell Taylor
Dealer
Posts: 818
Joined: Wed Apr 06, 2011 8:43 am
Main scooter: LAMBRETTA
Location: Doncaster
Contact:

Tue May 29, 2012 12:35 am

top view of the simple port layout
Image
feel free to use this link to contact me on facebook and like it(if u like it)
https://www.facebook.com/pages/Taylor-T ... 8819767924

Darrell Taylor
Dealer
Posts: 818
Joined: Wed Apr 06, 2011 8:43 am
Main scooter: LAMBRETTA
Location: Doncaster
Contact:

Tue May 29, 2012 12:39 am

view from base
Image
feel free to use this link to contact me on facebook and like it(if u like it)
https://www.facebook.com/pages/Taylor-T ... 8819767924

Darrell Taylor
Dealer
Posts: 818
Joined: Wed Apr 06, 2011 8:43 am
Main scooter: LAMBRETTA
Location: Doncaster
Contact:

Tue May 29, 2012 12:41 am

ex port
Image
feel free to use this link to contact me on facebook and like it(if u like it)
https://www.facebook.com/pages/Taylor-T ... 8819767924

Darrell Taylor
Dealer
Posts: 818
Joined: Wed Apr 06, 2011 8:43 am
Main scooter: LAMBRETTA
Location: Doncaster
Contact:

Tue May 29, 2012 1:25 am

The results from dyno testing was ok as the power when fitted with a temporary af clubman was quite good/promising and for a sil 200cc fares quite well against a few of the off the shelf kits
15.66 bhp 13.4 torque
Image
feel free to use this link to contact me on facebook and like it(if u like it)
https://www.facebook.com/pages/Taylor-T ... 8819767924

Darrell Taylor
Dealer
Posts: 818
Joined: Wed Apr 06, 2011 8:43 am
Main scooter: LAMBRETTA
Location: Doncaster
Contact:

Tue May 29, 2012 1:37 am

a return trip with a new pipe fitted (ads3) had the motor running lean so richened it up and running a rich 11.5-1 afr showed some better results
21.7bhp and 18 torque

power range
4k 6.7bhp
5k 12.3bhp
6k 20.3bhp
7k 21.7bhp



Image
feel free to use this link to contact me on facebook and like it(if u like it)
https://www.facebook.com/pages/Taylor-T ... 8819767924

mickdale
registered user
Posts: 549
Joined: Tue Aug 04, 2009 8:40 pm
Contact:

Sun Jun 03, 2012 12:06 pm

hello darrell,
would you recommend a 30mm pwk on a non reed converted SIL200 top end?

cheers
mick

Post Reply Previous topicNext topic
  • Information
  • Who is online

    Users browsing this forum: No registered users and 0 guests