Supercharged CBR250 build

[gennyshovel]

Thursday night in the creation station,,converting new pistons into old pistons, with a file or 2, and wet 'n' dry



Busy couple of weeks ahead, plenum, head work and assembly, blocks to bore (again) and a week of night shift


Valve grind tomorrow, pistons are being coated, go go go !

[Stayt`ie]

i see that ya have applied the soft head theory to them there pistons, ,,

[ChrisACT]

The one on the right looks a bit cold.

[ROSS BROWN]

[gennyshovel]

More progress pics,
Mk 2 plenum build

[dplecko]

Looks ok. Judging by the can of beverage there is at least 10:1 plenum to cylinder ratio if not more. I am still worried about the mixture distrubition?

[gennyshovel]

A bit of AC/DC magic

[gennyshovel]

[gennyshovel]

Holy smoke Batman there's a hole innitt

[Greg Watters]

Hope you have a blast shield between that and you

Looking good ,

[gennyshovel]

Hope you have a blast shield between that and you

Yeah Greg, I'll breathe it in, and blow it outa my dot, added thrust, ya know

Seriously, I have a duct plan in mind, using the spring retaining bolts to hold it on, then exit a 2" pipe down low, and to the left, ending somewhere near the blower belt housing, exactly where is yet to be determined, but the potential invisible fireball will have to miss my left calf, while being directed away from the salt,
ANIMAL, if you are about, the ECTA need a "colorful" voice with knowledge to help with the "Bonneville live" broadcast, I'm sure YOU could entertain the Yanks ?
Tiny

[gennyshovel]

The shiney bits are arriving,,

[gennyshovel]

Collector fab.

[gennyshovel]

My new plenum is finished, not the prettiest creation, but function comes 1st,it can be fitted (just) with the engine in the frame,and it holds pressure (20 psi) so once I stop the air sneaking out of the BOV bolt mounting threads (loctited and curing now) I'll adjust the spring pressure (Cibbie valve springs, of course) to get the BOV to let go over 15 PSI to stop any backfire explosions(they WILL happen) from bursting the plenum, and/or damaging the blower.
The thermocouple bungs are welded into the header pipes, the collector and tail pipe are marked ready for cutting/welding, but I'm thinking of bolting the tailpipe (with Lambda sensor bung in it) using the 3 bolt double flange aka stock, out of stainless as the 02 sensor will have to be removed before running on petrol after methanol, 'cos the gauge has been calibrated for methanol, switching the gauge and removing the tailpipe would be the easiest way .
I also bought a new Mikuni that's jetted for petrol, so that'll be swapped over after I'm finished racing, or testing to run the engine to clear out any methanol residue, whis , if left in the system, will result in the dreaded "white death" attacking all the aluminium while it sits. WD40 will be the last thing it burns before being stored (yup, it'll run on WD40 !)
The additional instrument cluster had also been welded, that'll contain the 4 EGT gauges, Wideband fuel/air guage, the gear position indicator, and switches for the new fuel pump (5 amp 4psi,and twice the flow I need) and the 02 gauge, the fuel pump will be switched off, after priming, while the engine is fired, to reduce the demand on the battery while cranking, 'cos we all know how much the CDI's enjoy voltage drop, don't we ?
The block has been in Mildura getting it's 2nd rebore for 2 weeks, so that will return soon (.005mm UNDER the maximum "cleanup" bore size)
The head sits in an airtight box shimmed up with its brand new valves I managed to score (oem), for the princely sum of $400 for 10 of each !, ready to bolt up.
I'm gonna be REAL busy soon,,,,,,,,,
Tiny

[gennyshovel]

The plenum in its unpolished form, leak free and with a functioning BOV (escape plan for the gasses is in my head)