building an engine with a series 1 case

Anything related to Lambrettas... ask tech questions, post helpful info, or just read and learn.
Dryballs
registered user
Posts: 362
Joined: Fri Jan 16, 2009 10:02 am
Location: Stockwell, London
Contact:

Thu Mar 05, 2009 4:05 pm

Hi guys,

I'm about to start building my engine for my series 1 framebreather

I'm going to build a gt206 engine
I want to use the original case from the scooter but was wondering what the differences are?

I know the mag flange is different, but it seems to be different around the main bearing

I was thinking of machining (with my dremel) around this area to make it the same as a s3 casing... Any thoughts on this? And is there any other differences?

Thanks in advance,

Dryballs

User avatar
Knowledge
Dealer
Posts: 1116
Joined: Sun Jan 11, 2009 12:49 am
ebay user ID: knowledge62
Main scooter: GP
Location: Ipswich
Contact:

Thu Mar 05, 2009 5:04 pm

I wouldn't risk a tuned engine in a SI engine without upgrading certain components, especially the mag flange. I don't think there is anything stopping you using an SIII flange and a decent crank, so why not do it. Can anyone confirm this?

On SI engines, there is no dished oil thrower behind the front sprocket, but as no one has explained to me what this oil-thrower does (apart from "throw oil" :shock: ), I wouldn't worry too much.
Martin

martints1
registered user
Posts: 39
Joined: Mon Jan 12, 2009 9:34 am
Contact:

Thu Mar 05, 2009 6:19 pm

...I used a GP-crank an a GP-maghouse in my s1-engine...no problem...

User avatar
Special X
registered user
Posts: 483
Joined: Wed Jan 07, 2009 9:38 am
Main scooter: Lambretta 125 special 230cc
Location: Wakefield
Contact:

Thu Mar 05, 2009 9:52 pm

Wellerchap's done this with his Mugello, if you give him an IM on WKFASC He'll tell you what he did.

Robi D
registered user
Posts: 164
Joined: Thu Jan 29, 2009 9:08 pm
Location: Amherstburg, Ontario, Canada
Contact:

Thu Mar 05, 2009 11:58 pm

i have dione it too, tameni gp crank and ser. 3 mag, i did take the dremel tool to where the oil throw washer goes, i would only think that it helps the oil lubricate the main bearing far better and easier. i run a deanspeed 190.

User avatar
mawso
registered user
Posts: 468
Joined: Wed Jan 07, 2009 8:47 pm
Location: Harrogate
Contact:

Fri Mar 06, 2009 10:25 am

Yes I have a GP Mag housing and crank, 5 plate clutch & chaincase on an S1 case with no problems....pretty much just the casing & gearbox is S1 now.

Someone also told me S1 rear hubs were pretty good for tuned engines anyway as they are a thicker cast than the S3 or new patterned ones..I used one anyway because I had one.

Apologies to jump this thread...but will using S1 150 gearing give you a different ratio to S3 150 gearing? Anybody?

Thanks Stu

Ian Hepworth

Fri Mar 06, 2009 11:28 am

mawso wrote:
Apologies to jump this thread...but will using S1 150 gearing give you a different ratio to S3 150 gearing? Anybody?

Thanks Stu
Same.

User avatar
dapper
registered user
Posts: 1008
Joined: Tue Jan 27, 2009 5:30 pm
Main scooter: The Biriani Bullet
Location: Brighton (well Hove actually)
Contact:

Fri Mar 06, 2009 5:27 pm

If I remember correctly the Series 1 chaincase cover doesn't have the strengthening webs around the kickstart exterior and are prone to breaking on tuned engines. Adults please :roll: ;)
Compact Toolbox Flywheel Holder

Dryballs
registered user
Posts: 362
Joined: Fri Jan 16, 2009 10:02 am
Location: Stockwell, London
Contact:

Fri Mar 06, 2009 8:26 pm

dapper wrote:If I remember correctly the Series 1 chaincase cover doesn't have the strengthening webs around the kickstart exterior and are prone to breaking on tuned engines. Adults please :roll: ;)

Thats cool... It wont affect the rest of the engine tho

Although if anyone has a spanish side case they want to sell me let me know!

Alternatively can you use a series 3 side case?

Robi D
registered user
Posts: 164
Joined: Thu Jan 29, 2009 9:08 pm
Location: Amherstburg, Ontario, Canada
Contact:

Sat Mar 07, 2009 3:04 am

Alternatively can you use a series 3 side case?
yes they are all interchangable.

Post Reply Previous topicNext topic
  • Information
  • Who is online

    Users browsing this forum: Majestic-12 [Bot] and 11 guests