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I am building my avant into what I hope will be my ideal type engine for my series 1, I am hoping for a clean economic tourquey and lazy ride, I have converted to lth reed and am now after a bit of advice, has anyone run an otherwise standard avant with 60mm stroke ?, I am happy to match casings and have already increased the inlet timing with a scalloped and windowed piston, i didn't really want to start hacking about with the cylinder, so questions are 58/110 or 60/110, I have 26 28 and 30 Pugh ?, I also have a b race stealth and mb clubman, I know I will need to trim fins etc to fit the clubman, any advice would be appreciated, ta!

Oh yeah forgot to mention, I have Italian li150 late pacemaker and Italian to gears as options, and am about 12 and a half stone, only occasionally 2 up on the Lambretta.

Sorry about my predictive kicking in, I know it's avanti not avant, and I have ltalian li150, late pacemaker and Italian gp gears, doh!

It all do-able but by fitting the longer stroke and/or longer rod you may have clearance issues with the cowling/head hitting the frame.

There's 4 of us running Avanti's and the clearance's are different on all the scoots.........mine being the worst with barely a cig papers clearance between the cowling and frame. This is a frame/casing issue rather than the kit.

The Avanti works fine with a 58/107 but it's always nice to experiment.

Thanks Mick, I ran the avantii top end in on my gp frame and it's Indian casing using 57/110 without the reed conversion, when I fitted the reed to the cylinder on the empty case I intend to use I found the 3mm packer helped with clearance between the lth casting and engine mount,. Cowling Clearance before the reed on the gp chassis was good,. But I will do a dry build on the series 1frame, the main reason for considering a 60/110 was that it seems god cranks from either gt or harry Barlow are readily available in that configuration, I was really hoping that someone on here had done the same without too many cylinder modifications. And could confirm it will not ruin the avantii performance. As I am aware it was designed for straight fitting as 58 stroke.

I knew someone was doing something similar viewtopic.php?f=7&t=2842&hilit=captain

If the Captain's reading this ......is there an update ?

Just finished a build with an Avanti on a 'welded' 60mil BGM crank. 3mm packer plus 0.75 base gasket to get squish right. Piston is below the exhaust port at BDC but not by much. First ride was yesterday, and it was sweet as!

Thanks Davey, any updates as you put some miles on it wold be appreciated.

Hey Runiman,
This is really interesting as its exactly the kind of set-up I would like to use for My S2 project, will you be able to use your B-race Stealth on the Avanti without much adjustment?
THANKS
Mark

Raveydavey wrote:Just finished a build with an Avanti on a 'welded' 60mil BGM crank. 3mm packer plus 0.75 base gasket to get squish right. Piston is below the exhaust port at BDC but not by much. First ride was yesterday, and it was sweet as!

I'm doing very similar Avanti and my exhaust port is similar, 1.3 squish so don't want to go any higher with base gaskets. Glad your getting results you're happy with, looking forwards to getting mine in a frame.

I could take cylinder off and lower port, but it's only like .5 mm. I'm undecided.......