Project: Hawk Stage II - Head Work and Nibbi

Baskt_Case · 05-20-2020, 09:01 AM

Quote:

Originally Posted by Megadan

This is the first bike where somebody decided they were going to go all out.

Well, this project sure didn't start out that way, but things kinda got outta hand and now I'm just goin with it!

If the weather cooperates, today is Nibbi day.

OneLeggedRider gave me the fantastic idea to check port volume on the Brozz head before I ship it off. Has anyone checked port volume on a stock Hawk head, or can they? I'm gonna grab a big syringe and some ATF this morning.

And I just found these incredibly helpful calculators this morning. Calculate HP from E/T, Speed, and Weight. Need to find a good app that logs speed vs. time better. My current app only has 1.0 second resolution.

http://www.wallaceracing.com/Calculators.htm

OneLeggedRider · 05-20-2020, 11:18 AM

Glad I could be of assistance Basket_case. It's actually pretty common to check head and port volume with a graduated buret and ATF in high performance cylinder head work, especially on multi cylinder engines, besides Flo-bench testing.

Do you need dyno testing to tell if you're making more power? No. But it's the only accurate way to measure gains. When I lived in Florida I had regular access to one thanks to becoming very good friends with Don, my former high performance instructor who had worked for some of the biggest name drag racers. That taught me you can't always go by "feel", which is often inaccurate.

And you gave me an idea on weighing the rotating mass before and after on the trike project. And it got me to thinking about selling the 200X rear end and buying something newer that came with 12" rims because of parts availability and the ability to buy much larger aftermarket rims that I can mount DOT approved tires on.

I haven't been posting much because of being sick for 3 weeks and working on my cabin. And also I'm a little aggravated with this site and uploading pics. Even on poor service days I can upload multiple pics to FB in less than a minute, but on here one pic might take a half hour or not at all, which seems screwy to me.

**JerryHawk250** · 05-20-2020, 12:42 PM

Quote:

Originally Posted by OneLeggedRider

I haven't been posting much because of being sick for 3 weeks and working on my cabin. And also I'm a little aggravated with this site and uploading pics. Even on poor service days I can upload multiple pics to FB in less than a minute, but on here one pic might take a half hour or not at all, which seems screwy to me.

I was just about to text you to see how you wee doing. Hoping you're doing better.
Yeah, uploading pictures to this site takes longer because it resizes the picture. Even on high speed internet it takes time to process it.

Baskt_Case · 05-21-2020, 02:22 AM

Was finally able to at least get the Nibbi mounted and briefly run the motor before I ran out of daylight. Lots of loose ends to tie up tomorrow. Throttle cable was too short, carb touches frame, barely got air filter on it. I sent the Nibbi intake to the builder so I'm using the shorter generic rubber Amazon one. At least the rubber filter adapter is now cushioning the carb against the frame. Longer Nibbi intake will put the bowl on the frame. Not sure what I will ultimately do. Also need to stretch out the spring on the idle knob, or add a star washer. The knob vibrates a ¼-turn either way.

Initial jetting is 40 slow, 115 main, clip in middle, 1½ turns out, 700 feet elevation. Have not been on the road yet. Snap throttle off idle has a tendency to kill it. It'll pop occasionally on come down. Plan to install 45 and 120 and methodically work each. I had not started the bike in a week. Pulled plunger, hit starter, instantaneous light-off. She runs. Would probably get to town in an emergency. I'm tickled for the moment.

Head is on its way to California. Now I wait. Dont ask how long, were just not gonna talk about that right now. However, I did get a chance to measure port volume before I packed it up...

Intake = 51 cc
Exhaust = 24 cc

05-20-2020, 11:18 AM	#2
OneLeggedRider Join Date: Nov 2018 Location: Stockport, Oh. Posts: 1,442	Glad I could be of assistance Basket_case. It's actually pretty common to check head and port volume with a graduated buret and ATF in high performance cylinder head work, especially on multi cylinder engines, besides Flo-bench testing. Do you need dyno testing to tell if you're making more power? No. But it's the only accurate way to measure gains. When I lived in Florida I had regular access to one thanks to becoming very good friends with Don, my former high performance instructor who had worked for some of the biggest name drag racers. That taught me you can't always go by "feel", which is often inaccurate. And you gave me an idea on weighing the rotating mass before and after on the trike project. And it got me to thinking about selling the 200X rear end and buying something newer that came with 12" rims because of parts availability and the ability to buy much larger aftermarket rims that I can mount DOT approved tires on. I haven't been posting much because of being sick for 3 weeks and working on my cabin. And also I'm a little aggravated with this site and uploading pics. Even on poor service days I can upload multiple pics to FB in less than a minute, but on here one pic might take a half hour or not at all, which seems screwy to me. __________________ ~ Don't poke the bear ~ M.M.I. Dean's List graduate class of '95 and Specialty welder 2020 Ice Bear Terifecta 150cc Trike 2011 Honda Foreman 500ES 4x4 2001 Polaris Scrambler 400
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