Supercharged CBR250 build

[gennyshovel]

Thanks Greg, I've had a rethink on blowing it up.
It almost seals , still a slight leak past the "O" ring caused by air getting under it.
I glued it in place , which helped, but I think if I machine the other side, leaving a 2mm raised section in the sealing ring area, and use some viton sheet between the 2 faces, the added PSI in the raised section, compared to the same load spread over the 8mm ring surface should sort the slow leak problem, just leaving the fine tuning of the spring pressure.
Speaking of springs,,I bought a selection of 16/17 & 18 guage springs of varying lengths, all which proved to be too light, so I've stuck with the FZR valve springs, with 8mm preload, which let go @ 15 psi.
The exhaust nightmare might be next, plus a seat tail/ fuel tank combo (baffled)

[momec3]

Tiny,
O'Rings are the best option but on a flat plate against a flat plate requires a receiver groove on one side or the other.
There is a chart for correct groove depth for any given O ring dia but its almost common sense. Glue or silicone will not work.
O Rings are designed to be assembled with proper O Ring grease or vaseline, nothing else. Never use silicone and glue will fail without a groove and be unnessasary with one.

For custom O Rings or sizes you can't get from your local supplier or advise on groove depths, materials etc call Derick at Sealing Motion. 07 3809 0499. This is not an add just a specialist supplier many might not no exists.

Chris

[gennyshovel]

Thanks Chris, Iv'e machined the back side of the plate, leaving a thin raised section and plan on using Viton sheet to look after the sealing.
I had a test run using 3 for $3 teflon cutting boards (hard and ever so slightly textured) and the leak slowed to something resembling crab farts @ 20psi when coated with detergent, so I'm confident the Viton will finish the job.

[Greg Watters]

Backing up Chris's comments If the o ring is not secured in a groove, any pressure that causes the plate to move may also displace the o ring,esp with a backfire ... happened to me with a common BOV , now permanantly capped...

[momec3]

Yeah Viton is the GO, there is a more expensive material thats even more durable but thats for space shuttles.
Chris

[Dr Goggles]

Thanks Chris, Iv'e machined the back side of the plate, leaving a thin raised section and plan on using Viton sheet to look after the sealing.
I had a test run using 3 for $3 teflon cutting boards (hard and ever so slightly textured) and the leak slowed to something resembling crab farts @ 20psi when coated with detergent, so I'm confident the Viton will finish the job.

good price on Viton sheet...I notice though that they spell it a little differently

[gennyshovel]

Get outside Doc, I don't care if it's raining,,,,,,your losing the plot mate,,go indulge in some LSR therapy.

[gennyshovel]

Getting there.


Fresh and ready

[gennyshovel]

More eye candy

[BONES]

Hi Tiny,
There is a story in a recent 'Two Wheels' mag about a guy sprouting off about having the fastest posty bike.
I thought you had the fastest posty.
It isnt you in the article cause he's not nearly as good looking and lives up the north coast.
I'll find the article before I sprout off any more.
Looking forward to seeing and hearing the 250 at 17000rpm
cheers Bones

[momec3]

That looks fully sick Tiny.

Chris

[gennyshovel]

Things are still flat out in the creation station, final assembly,,,,,



The plan is to do some testing minus blower to sort out the jetting on gas the 'ol fashioned way, full noise and throttle chop, plug reading 'till I'm happy with the "feel" and the plug colour, as the only Lambda I know is a builder, the rejet for fuel, fit blower and have some fun.



I'm getting the rough end of the pineapple treatment with a brisvegas sprocket supplier, can anyone suggest someone who might have 428 -47t sprocket blank in stock ?

[RGV]

http://completedrives.com.au/home.htm

They might be worth a try Tiny

Looking good BTW.

[Jeff lemon]

Try these guys

chaingangchainsandsprockets.com.au

Freecall 1800 806 857

07 3376 8488

Cheers

[gennyshovel]

Thanks Jeff & Dave, the pineapple has been removed, and the sprocket will be here this week, or,,seeing as I now have the contacts for the supplier, if it's not here this week, I'll have a new home for a slightly used pineapple (I don't care if his local shop is struggling to pay the bills) I'll deal direct , as I should have in the 1st instance, 4 weeks ago.