Supercharged CBR250 build

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gidge348
Posts: 122
Joined: Sat Mar 07, 2009 12:50 am

Re: Supercharged CBR250 build

Post by gidge348 » Fri Nov 20, 2015 11:34 am

Ewww in my day that was called a "Triple M"..............Monumental Mechanical Malfunction.

I saw a Ferrari engine with valves like that, 32 valves at $400 a piece plus other assorted carnage.

Ian...

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gennyshovel
Posts: 819
Joined: Tue Mar 29, 2005 10:10 am
Location: Broken Hill

Re: Supercharged CBR250 build

Post by gennyshovel » Fri Nov 20, 2015 11:42 am

The bit that hurt, was the fact that those valves were new, and made of almostunobtanium, @$888 a set,if ya lucky,,I got REAL lucky, and found 10 x intake & 10 x exhaust on gaybay (in a weird section), buy now of best offer, I offered $200, and got 'em :D
I just used the last of 'em :roll:
As for pistons,,absolutely NO OEM pistons available, anywhere, especially .05 mm o/s , as Honda never thought anyone would ever need 'em ?
I have 15 Chinese units left in stock @ $20 each, with rings !, although I wouldn't use their pins in anything other than a model massey ferg engine, OEM's are $100 / set :roll:
Tiny
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering

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gennyshovel
Posts: 819
Joined: Tue Mar 29, 2005 10:10 am
Location: Broken Hill

Re: Supercharged CBR250 build

Post by gennyshovel » Fri Aug 19, 2016 3:06 pm

When is a hole. not a hole ?
https://youtu.be/v205ISys5o4
This is a rather late post Speedweek 2016 update, yup, we did it again,,,,
NEXT year will be year #5 , and with a bit less boost, a bit fatter mixture, a bit more piston crown thickness (stock C/R) a bit more cam overlap, a bit less gearing, & a LOT more weight (I'm riding 1st) we should get a record , after all , all I have to do is make it to the 2 mile maker, piece of pi** ? :shock:
Tiny
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering

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gennyshovel
Posts: 819
Joined: Tue Mar 29, 2005 10:10 am
Location: Broken Hill

Re: Supercharged CBR250 build

Post by gennyshovel » Wed Dec 07, 2016 7:16 pm

It's almost full steam ahead with the engine reassembly, the head should be home within a week, with a valve job that actually seals , although Iv'e knocked up a jig to hold shims while diamond grinding the thickness down (I was down to the 1.2mm minimum size before the seats were recut), & have a plan B, just in case,,,,another $700 worth of almost unobtanium OEM valves
Iv'e been filing my fingertips down all year so I can get the o/head gear oil line, and intake hose clamps on while moving the unbolted plenum & blower back as far as possible (about 10mm)
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering

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