The end of the Lambretta crank as we know it ???

[soullad]

Hmmmmm remember that thread the other week about that red scruffy S2 TS1 that made 30+ HP on JB's dyno. Now that had a trememndous amount of work done on enlarging the transfer areas, esp on the crankcase. Even JB said he was amazed at the results.
I believe some of this work had been started by Jerome, but either way by attempting to copy modern 2 S engine design and enlarge the transfer areas have they stumbled upon the need to lower PC?
The only way is a back to back dyno Dan .........come on son get yer finger owt .....

[drunkmunkey6969]

The only way is a back to back dyno Dan .........come on son get yer finger owt .....

Leave it with me, i'll do my best.

[RinB]

But remember here its not just about increasing the volume in the casing, transfers, inlet ect

It is also about getting the gas round and out
So the key thing to me is the Exhaust its no good doing back to back and get a like to like
system as the exhausts will prob need be to be different.

For example
HPC with a TS1 of x timings & 34 mm carb and a JL4
When you come to do LPC with the same TS1 of X timing & 34mm carb the JL4 might not work !!!!

To me the removal of metal is the simple bit ,but to develop an Exhaust to work ????

[drunkmunkey6969]

When you come to do LPC with the same TS1 of X timing & 34mm carb the JL4 might not work !!!!

Maybe.....maybe not. But JL4 is a nice fat revvy pipe, and a long way from the 1.65:1 box pipes of old.......so on the other hand, maybe a JL4 will work very well?

Maybe the JL4 complements a TS1 cylinder and a standard crank very well, but will compliment a TS1 and tuned crank even better??

Of course nothing works as well as a 'tune specific' developed pipe......but not having £500 to spare, i'll just have to try what we've got.

[fishi]

I think, the JL4 was developed at a time, when nobody was thinking about Low Compresion in the crankcase.
I can not imagine the Jim Lomas was told to build an exhaust for LC engines, more for engine with padded cranks, like they were used until a few years before the first full circle cranks were available.

But the JL4 is still, IMHO, the best aftermarket exhaust, you can get.


fishi

[Avantone]

So the key thing to me is the Exhaust its no good doing back to back and get a like to like
system as the exhausts will prob need be to be different.

Except then you wouldn't really know what made the difference.

Running a motor exactly the same but with the LPC crank would either increase power, reduce power or do absolutely nothing - at that point irrespective of the result you'd have learnt and established FACT............. THEN you could try a range of exhausts to again confirm or dispel the assumptions and see if the power delivery can be improved on the baseline.

This is how motors are developed, and why the people that invest 1000's of hours doing it aren't likely to offer up their findings lightly (or may even throw a few herrings in)

[sean brady scooters]

jl and others have for a very long time,been making expansion chambers that work with LPC engines..................
VESPAS................

[snoghound]

The only way is a back to back dyno Dan .........come on son get yer finger owt .....

I would like to see all of the top tuners build a group 4 race moter. And then have a dyno day somwhere to see who has created the most power!

[Juan]

That would be excellent although somehow I doubt it would happen.

[Avantone]

The only way is a back to back dyno Dan .........come on son get yer finger owt .....

I would like to see all of the top tuners build a group 4 race moter. And then have a dyno day somwhere to see who has created the most power!

I've been misquoted! - he's too old to be my son