Supercharged CBR250 build

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momec3
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Re: Supercharged CBR250 build

Post by momec3 » Mon Jul 25, 2011 7:10 pm

Make the escape area bigger than you think is nessasary! Lessens damage.

Chris
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gennyshovel
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Re: Supercharged CBR250 build

Post by gennyshovel » Thu Aug 11, 2011 12:04 am

Chris, the biggest I can go is 2" , hopefully,,that'll shite it in .
Ive been busy in the creation station , with SFA to show for my time.
Those fiddly little jobs that usually rear their ugly head at the end of the build are happening NOW !
More pics,,,
Image

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Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering

momec3
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Re: Supercharged CBR250 build

Post by momec3 » Sun Aug 14, 2011 4:13 pm

Your the Hot Rodder from Hell Tiny, if it don't fit cut a bigger hole!!!!!!! :lol: :lol: :lol:

Chris
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Dr Goggles
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Re: Supercharged CBR250 build

Post by Dr Goggles » Mon Sep 05, 2011 9:48 pm

That's a Zoidberg manifold isn't it?
...few understand what I'm trying to do , but they vastly outnumber those who understand why..

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gennyshovel
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Re: Supercharged CBR250 build

Post by gennyshovel » Thu Sep 08, 2011 3:09 pm

Dr Goggles wrote:That's a Zoidberg manifold isn't it?
Nope,,,it's (been) a pain in the freckle, that's what it is.
I remember giving myself a talking to once, self , I said , NO MORE FIDDLY PROJECTS !
This has been the most frustrating project Iv'e ever done , things like FIVE sets of blower mounts made before I got it just right, and multiple just about everything else too.
The problem has been Iv'e had to work backwards, get things close, then work forwards again,,then backwards, until the bits were where they were wanted / needed to be .
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But finally,,today has been forward steps only.

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I recon my next build will be a Ladies wristlet watch, it'd be less fiddly, although not near as satisfying when done.
I'm not looking forward to fitting 32 pissant valve colletts when its engine freshen up time :roll:
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering

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ROSS BROWN
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Re: Supercharged CBR250 build

Post by ROSS BROWN » Thu Sep 08, 2011 9:38 pm

gennyshovel wrote:I recon my next build will be a Ladies wristlet watch, it'd be less fiddly, although not near as satisfying when done.
Funny you say that.
Once you asked me what I did in my spare time... :shock:
Just so happens that this quaint little piece.. 1949 ... 25jewel Waltham ladies wristlet,after a little tweeking started ticking again :D :D
Your looking at it through a 10x loupe
these little tools are super helpfull when doing valve collets the tenth of the size of your finger nail
This one on ebay is the pick of them , ussually sell for around ten dollars and if you unscrew the front lense of it takes it from a x20 to about a x10
http://www.ebay.com.au/itm/20X-JEWELRY- ... 2a13c4dbb0

and simple enough to switch it over to your good eye

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ALSO in the watchmakers tool section of ebay is sets of plastic tweeseers ,they come in
.super helfull as well .that wooden powerpole looking thing in the picture is a toothpick.

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AS USUALL TINY
U got some interesting shit happening 8) ..
IT IS ALL A RACE AGAINST TIME.
TIME WAITS FOR NO ONE.

HOW FAST CAN YOU GO ?

S/UF 925

grumm441
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Re: Supercharged CBR250 build

Post by grumm441 » Tue Sep 13, 2011 9:11 am

Tiny
Make sure the blow of valve exits away from the rider
blow off valves and wastegates were apparently covered by 7.B.20 Exhausts, however, it wasn't clear in the rules so it wasn't enforced

http://www.landracing.com/forum/index.p ... cseen.html

I have it on good authority that this incident will bring a rule clarification
G
They make it
I make it work

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gennyshovel
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Re: Supercharged CBR250 build

Post by gennyshovel » Tue Sep 13, 2011 9:17 pm

Yeah Grumm, I thought there would be repercussions after that incident.
The fuel shutoff valve operated without removing hands from the 'bars rule is in place to minimise fire incidents like that, but even with fhe fuel shut off, the fire will still burn while theres fuel in the bowl, and the blower is still blowing.
My blowoff will be located under the plenum, and due to the shape of the crankcase, any flames will be blown out the L/H side of the bike, and hopefully , by the time it reaches my left leg, it will have lost most of its ferocity ?
Here's a class question for you , this bike is all honda, although from completely diferent models, the frame has been raked.
Would M=BF be stretching things a tad ?
A=BF also has a few requirements that differ from M in regards to "stock" appearance (off the top of my head)
There are'nt too many "stock" VT250, or CRB250 parts used in its construction, and definitetly is'nt a combination Honda ever threw together.
class designation wont change the builds direction, but A will give me more footrest choice, and open more choices for 2013, if this actually works.
The fuel (methanol) is controlled by a solenoid(normally closed) mounted directly to the fuel tank, and shut by either turning ign off, operating the thumb operated kill switch, or the lanyard switch.
Steering lock is limited to 15 degrees either way, and has positive stops.
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering

grumm441
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Re: Supercharged CBR250 build

Post by grumm441 » Tue Sep 13, 2011 11:19 pm

gennyshovel wrote:Yeah Grumm, I thought there would be repercussions after that incident.
The fuel shutoff valve operated without removing hands from the 'bars rule is in place to minimise fire incidents like that, but even with fhe fuel shut off, the fire will still burn while theres fuel in the bowl, and the blower is still blowing.
Yep
And it probably would've worked if he had used his hand to turn off the fuel and not cover the blow off valve
He got yellow tagged and was sent back to tech. He showed us a glove which didn't look like it had been burned and a hand that did
Coincidentally, the proposed SCTA rule "clarifications" arrived in my inbox at 12:17 pm today
Included was the blow of valve proposal
Looking at it, it may not be enough that it just exits the left side

I'm looking at your bike and looking at the rules and looking for reasons that it can't be "M"
Apart form the wheelbase?
G
They make it
I make it work

momec3
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Re: Supercharged CBR250 build

Post by momec3 » Wed Sep 14, 2011 6:52 pm

Tiny,
your projects remind me of '04 when I turned up with the Ute with a full size G bottle of Nitrous mounted securely in the tray. The poor bloody scruiteniers looked at the bottle, then they looked at the rule book then they looked at the bottle. Then they said to me "we can't see where it says you can't run a size G bottle of NOS so we can't stop you but please don't bring it back next time. :lol:

Chris
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ben james
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Re: Supercharged CBR250 build

Post by ben james » Wed Sep 14, 2011 8:18 pm

04 what a year that was at the salt. salt was dry & rock hard. the 1st year i went & the last year that it was a small event.
didn't we have some fun dr goggles
ben james dlra#389
moriwaki monster.

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Dr Goggles
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Re: Supercharged CBR250 build

Post by Dr Goggles » Thu Sep 15, 2011 10:29 am

Aye......

sleepin on those stretchers for the first two nights under the starts while it blew a gale of grit sundown to sunrise...gee I miss that members camp.

But yeah, we had a ball, that was what started all this Benny, expensive mistake goin there :roll:
...few understand what I'm trying to do , but they vastly outnumber those who understand why..

grumm441
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Re: Supercharged CBR250 build

Post by grumm441 » Thu Sep 15, 2011 4:42 pm

Yep
Expensive mistake alright
G
They make it
I make it work

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gennyshovel
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Re: Supercharged CBR250 build

Post by gennyshovel » Fri Sep 16, 2011 5:20 pm

The BOV is finished, except for testing.

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I plan on plating the open ends, one with a spark plug installed, then pressurising till it'll hold 20 psi.

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Then filling the plenum with start ya bastard, then spinning the 'ol Howard maggy while hiding 'round the corner

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I have a feeling I'll have to replace the springs with some lighter ones ?
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering

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Greg Watters
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Re: Supercharged CBR250 build

Post by Greg Watters » Wed Sep 28, 2011 8:00 pm

Tiny just cap it and use a regulated air supply to see what the cracking point is, it should have no prob blowing off with a backfire but you also want to be sure it holds enough pressure to be usefull :D

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