Nitrous 93.4cc 139qmb

[hocastroka]

Hey everyone,

I posted a few weeks ago in the Lobby to introduce myself. Once again thanks for the welcome. I decided to make a build thread to keep data for both myself and anyone interested in a setup like mine. If anyone has questions or seeks advice on using a stroker crank with bigger bores feel free to ask.

I'll start uploading pictures once I get them all synced with my computer.

I use a wideband on everything I tune so if anyone has questions about jetting at ~550 feet elevation or anywhere near it feel free to ask. I'll also share my jetting and timing adjustments when running on motor, nitrous, and the different fuels I run.

Everything is built in house by myself. I do my own portwork and also have access to a flow bench with the orifice adapter for these heads. I have flow tested stock, the chinese big bore heads, and the current head on my scooter in both its stock form and after I had gone through it.

The data, fuels, nitrous, timing adjustments, engine modifications will be included in upcoming posts because I'm going to try to keep it organized.

If anyone has any questions about what I've mentioned, my setup, other things being built at the moment, or questions about things I haven't mentioned please feel free to ask.

Thanks again for looking and I hope you stay tuned in for the build and aftermath when I decide to put too much of the bottle to it.

[gsx600racer]

Aftermath ? Are you expecting something to blow up ? LOL

[hocastroka]

Yeah haha,I expect it to eventually take a toll on the ring lands or the crank because I'm going to attempt to spray it to 70mph to hang with the 2 stroke fellas.

[Deleted]

Awesome!

Bill

[hocastroka]

ENGINE:

139qmb
Hoca 44mm crankshaft
Scrappydog 52mm dome piston
Scrappydog 52mm cylinder
Hoca 52mm base and head gaskets
Hoca 52mm big valve head
-ported intake and port/polished exhaust
Port matched 150cc intake
Intake matched 24mm carb
Port matched Scrappydog exhaust
A9 camshaft
Stock stator
NGK CR8HIX
Currently experimenting with different CDI curves

VARIATOR:

Naraku drive face
Polini variator
4.5gr Dr. Pulley slider weights
Naraku drive belt
Stock rear pulley
Stock torque sheave and spring
Stock clutch engaging at 7500rpm
Hoca 16/42 secondary gears

[Deleted]

Depending on what factory actually made your crank, I'd put a Jackson says it torques the first time you hit the go juice.

[humanshield]

Yeah, I'd agree there's a high probability of very low miles outta that motor. Make sure you have VERY good oil pressure is all I can say.

[190mech]

Not a 4T guy,but I gotta agree with humanshield,,better "think out of the box" for keeping a thick film of oil on the loaded parts,,High volume pump,spinning the stock pump much faster,stacked pumps,pump from bigger motor,,etc..
Also gotta remember when the bottle runs out the flashing blue lights will catch up with you!!

[hocastroka]

Thanks for the advice and interest I appreciate it. I've had the oil pressure and volume idea in mind for a while now before I go spraying a bunch at it. I've been toying around with the idea of spinning the stock pump faster. I don't really trust the oil pressure and volume in these things in the first place. I'm currently looking into getting gears machined to increase pump rotation.