Supercharged CBR250 build
Moderator: DLRA
- gennyshovel
- Posts: 866
- Joined: Tue Mar 29, 2005 10:10 am
- Location: Broken Hill
Re: Supercharged CBR250 build
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)
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)
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering
Postiebike Racing , created & funded by TwoBob Engineering
Re: Supercharged CBR250 build
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
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
Chris
- gennyshovel
- Posts: 866
- Joined: Tue Mar 29, 2005 10:10 am
- Location: Broken Hill
Re: Supercharged CBR250 build
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.
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.
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering
Postiebike Racing , created & funded by TwoBob Engineering
- Greg Watters
- Posts: 760
- Joined: Mon Sep 27, 2004 8:57 pm
Re: Supercharged CBR250 build
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...
Re: Supercharged CBR250 build
Yeah Viton is the GO, there is a more expensive material thats even more durable but thats for space shuttles.
Chris
Chris
Chris
-
- Posts: 1315
- Joined: Tue Jul 05, 2005 11:23 pm
- Location: Right behind you Chief !
Re: Supercharged CBR250 build
gennyshovel wrote: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
...few understand what I'm trying to do , but they vastly outnumber those who understand why..
- gennyshovel
- Posts: 866
- Joined: Tue Mar 29, 2005 10:10 am
- Location: Broken Hill
Re: Supercharged CBR250 build
Get outside Doc, I don't care if it's raining,,,,,,your losing the plot mate,,go indulge in some LSR therapy.
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering
Postiebike Racing , created & funded by TwoBob Engineering
- gennyshovel
- Posts: 866
- Joined: Tue Mar 29, 2005 10:10 am
- Location: Broken Hill
Re: Supercharged CBR250 build
Getting there.
Fresh and ready
Fresh and ready
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering
Postiebike Racing , created & funded by TwoBob Engineering
- gennyshovel
- Posts: 866
- Joined: Tue Mar 29, 2005 10:10 am
- Location: Broken Hill
Re: Supercharged CBR250 build
More eye candy
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering
Postiebike Racing , created & funded by TwoBob Engineering
Re: Supercharged CBR250 build
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
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
- gennyshovel
- Posts: 866
- Joined: Tue Mar 29, 2005 10:10 am
- Location: Broken Hill
Re: Supercharged CBR250 build
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 ?
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 ?
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering
Postiebike Racing , created & funded by TwoBob Engineering
Re: Supercharged CBR250 build
Last Minute Racing
DLRA #928
2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF
-
- Posts: 34
- Joined: Thu Feb 15, 2007 8:56 pm
- Location: Perth
Re: Supercharged CBR250 build
Try these guys
chaingangchainsandsprockets.com.au
Freecall 1800 806 857
07 3376 8488
Cheers
chaingangchainsandsprockets.com.au
Freecall 1800 806 857
07 3376 8488
Cheers
The Cups half full!!
- gennyshovel
- Posts: 866
- Joined: Tue Mar 29, 2005 10:10 am
- Location: Broken Hill
Re: Supercharged CBR250 build
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.
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering
Postiebike Racing , created & funded by TwoBob Engineering