Mileage/Reliability for an iron barrelled 225

[Dimitrios_231]

I have triple checked it,on your awesome port timing calculator
I'm not in a great hurry for this project,
Piston,crank,rebore can be found/done easily (they only cost money )
I can do all the porting work on my own but I don't have/use a lathe to reprofile the head.
I'll only start the project,if I first find a reprofiled head that suits.
I don't trust any of the local guys to reprofile the head.

[Dimitrios_231]

This is the start of my 245cc Kawasaki conversion.



It will go on this Lowline replica.

[Mr G in NYC]

Love a Lowline !!!!! Just blown the oil seals on this Ah well back
to the drawing board........or rather the garage......might swap out the Amal
for a flat slide dellorto 34mm......I've also soft seized it three times trying
to hit 75 with only 250 miles on the engine wonder why it
nipped up Stage 6 Stuart Owen lump in it .....its lovely when it runs
I'm learning to come off the throttle and take baby steps on running in an Iron
Barrell.......... Good luck with your lowline project G.

[Dimitrios_231]

Totally amazing Mr G
You are lucky that you didn't lock the rear wheel trying to hit 75 with only 250 miles

I have also soft seized a cast iron barrel which had clocked only few miles because I got too excited and used WOT for less than one mile
They need a lot of patience while running in.

[Mr G in NYC]

Locked this one up at 70+ on the long island express way a few months back.....
Full lock up and burning rubber !!!!!!!!! stayed upright and pulled it over
Stage four tuned..... not run it for a while .....shit petrol and a tad lean and
I think the drive side oil seal went on this also !! !! Note to self ......must ride
these on a more regular basis I'm building the GT200 kit on this with a
cyclone box , bgm pipe and 30mm dellorto, jap race bearings and Af race clutch
basket......and I have promised myself to BABY it for the first 400 miles

And YES they are two different scooters Supertune twins G.

[Dimitrios_231]

Ouch.
I'll post pics in the future, when I'll lock mine
I hope that this has nothing to do with black and white themed Supertunes,because this is my chosen paintwork scheme .

[Mr G in NYC]

Yes please post pictures......... hopefully not 'Locked' pics
look forward to seeing that project of yours good luck .

I'm gonna fit the old scored barrel once cleaned up on a SX200
that is stock paint ........it should be a 70+ bog standard looking
SX200. Just waiting on the pipe from the ceramic coaters....to
come back and thats my winter project

[Dimitrios_231]

I plan to finish it in 2016,I'm not in a hurry.
I'm collecting parts for it the last 3-4 years.It will have (hopefully) a vast amount of original parts.
I have many other projects (not mine) in between to do.

Your piston is fecked but the barrel looks OK,a rebore and will be fine.
Good luck with all the other projects

[Dimitrios_231]

Stormy weather last night

[Dimitrios_231]

Two barrels are better than one.







Piston to bore clearance 0.1mm or 4 thou.







The deck height is 32mm which suits better the 62/116mm crank.
At BDC it will be the same as it was with the 107mm crank and standard 39mm deck height piston,using a standard base gasket.
A thick head gasket will be used to set the squish as the piston crown will protrude the top of the cylinder.





I'll start to work with the ports later this year or early next year,
I'm still waiting for the crank,I'll have it next week.

[Eden]

you dont want to pack the head! you will be much better off packing the base, then you can lower the bottom edge of both the exhaust and transfer ports to match the piston crown at bdc!

[Dimitrios_231]

This is also an option.
I can do one of the two barrels like this.

I run without problems a 2mm thick gasket (and 3.5mm packer) on the Rapido 252.43cc that I have.
The piston crown also protrudes there.I use it with a 62/110 crank.

Theoretically,
on the Kawa project.
The timing in standard form,using a standard base gasket and 2mm head gasket, will be:

EX 152.89
TR 121.57
IN 155.26

Squish 1.2 to 1.5mm

If I raise 5mm the exhaust port,I'll get 172.42
If I raise 6mm the exhaust port,I'll get 176.17

In general, I don't plan to use larger than 180 degrees of exhaust and 160 degrees of inlet.
I intend to use a 48mm clubman exhaust with a 30mm or 32mm Amal MK1 plus SX200 gearing.

[Dimitrios_231]

I'm a little confused about the exact settings used on the Rapido,
I have the data somewhere stored but I cannot find it now.
The head gasket could also be 1.5mm and the packer 2.5mm sandwiched with two standard base gaskets,
I cannot remember clearly as it was done 3-4 years ago.

[Eden]

EX 152.89
TR 121.57
IN 155.26

will be really shit

[Dimitrios_231]

Υeah I know

These results are without raising the exhaust.

[Dimitrios_231]

I'll be able to talk about timing and other things when I get and fit the bloody crank
I can only assume now.
I'm really curious how this project will end.
I have ridden this untuned Autisa 200cc cylinder with standard exhaust and SH1/20 carb and it was feeling like a standard Li150.

[Dimitrios_231]

This is the Rapido at TDC

[Eden]

trouble is if you run it as you have suggested you will have to lift the exhaust by a lot and if you find its not what you wanted you cant then lift the barrel because your exhaust port will be far too high then. best to work the other way so you have the option later to run the barrel lower if you need to.

[Dimitrios_231]

Holy shit
Eden you are right.
On the previous theoretical calcs,I forgot to add the extra 2mm of the 62mm crank for TDC.It worked nice for the BDC though.
The total length will be 150mm (116+32+2) compared to the standard 146mm (107+39).4mm difference.
When I checked with the standard piston/crank the deck height was 0.5mm.
This means that I'll have 3.5mm negative deck,
I'll need a 3.5mm packer to get the piston crown level with the top of the barrel.
I calculated earlier for 1.5mm negative deck instead of 3.5mm,my mistake
This is the problem when someone tries to calculate timing without having the parts assembled.

[Adam_Winstone]

Don't let Eden convince you to raise the barrel too much though or your transfer timing will go too high. Eden does like porting that works well with a JL4, whereas, I know that you like a load more grunt.

I do agree that head gaskets are nasty though. In order to get rid of head gaskets, I normally reprofile the head with the recess that I'm looking for cut into the head. You'll need to dowel the head to the barrel so that they stay in alignment, however, you would be well advised to do that anyway with a 'floating' fat gasket.

I guess this all depends on what you want the end result to ride like. Decide what you want, then determine what port timings would deliver this, then see how best to achieve these timings.

A motor can be anything that you want it to be... it just can't be all things to all people.... make it yours

Adam

PS - I like to set my transfers first... but that's just me.