Turning an ebay CNC 12cc head into a 7cc powerhouse.

[Risk Man]

Where is the "speed clock"?

 

[Jayraye39]

Where is the "speed clock"?

Lol just past the last road on the left

 

[Jayraye39]

Gonna do another clock run tomarrow got just enough brake pad left to do another. I wanna see what I can get now my head is down to 7cc.

I put it back together and rode it for an hour today. I can feel the added compression its allaround more responsive and it sounds better for some reason too.

Im tryin for 40 on the clock. Ill try to get a clearer shot. It will be hard since it dont own a GoPro. I just ziptie my phone to my helmet. Lol

 

[Street Ryderz]

This is what your modified engine speed should look like! Watch to the end, 58 mph 3/4 throttle!

 

[Chainlube]

There are 6cc heads on the market, mill down .5 and have a 5.5cc head. Doesn't really do anything for go fast but at least shows you can do it.

 

[Jayraye39]

Gained very little uptop but My torque got improved a good deal When the bike is in the air and I try to pedal start. The clutch slips just a tad that's what tells me i got more compression.

Ive also read some of Gordon Jennings writings on compression. From what I gather, he was more focused twards case psi being more performance driven

Wondering if since I upped the compression in the cylinder if i combine that by stuffing the case if that will impove my top?

Case stuffing and balancing my crank for higher rpm vibes is the only modds i have left to do. My crank came as a BETTER BALANCED CRANK. But what the hell does that mean? Better than what exactly? Lol

I have yet to split the case on one these girls and by alot of my readings sounds like i dont want too. Does anybody know what thinkness of plate would be best for a moderate psi increase. Just like my cylinder, I dont wanna over compress the case

 

[Jayraye39]

While im in their ill prob replace my bearings with top $ ones

 

[Street Ryderz]

Gained very little uptop but My torque got improved a good deal When the bike is in the air and I try to pedal start. The clutch slips just a tad that's what tells me i got more compression.

Ive also read some of Gordon Jennings writings on compression. From what I gather, he was more focused twards case psi being more performance driven

Wondering if since I upped the compression in the cylinder if i combine that by stuffing the case if that will impove my top?

Case stuffing and balancing my crank for higher rpm vibes is the only modds i have left to do. My crank came as a BETTER BALANCED CRANK. But what the hell does that mean? Better than what exactly? Lol

I have yet to split the case on one these girls and by alot of my readings sounds like i dont want too. Does anybody know what thinkness of plate would be best for a moderate psi increase. Just like my cylinder, I dont wanna over compress the case

Read the Two Stroke Hand book by Jennings, https://www.amrca.com/tech/tuners.pdf
Stuffing the case increases the pumping pressure and if the transfers are not corrected in shape and angles along with the insufficient blow down period you'll just blow the charge right out the exhaust.
If you were to correct those and, resetting the big end first balanced and trued the crank then slip fit it so as to be able to slide the case half's on and off easily with the bearings pressed in square, shims allow you center it and then you use clay or play dough or whatever in each half and squish it together leaving a measurable imprint as to how thick you can go, every one is just slightly different but you can gett 1.5 mm in there.
You should see some gains but not where you think.

 

[GW's Motorized]

This is all beyond me. The only performance mods I'm going to do to my current engine are exhaust and intake and some port matching. I'll look in to high performance mods when and if I do a saw highbrid engine.

 

[furweider691]

Man , I hear and feel what you are saying about your creative process , and I'm sure many of us would never throw shade on your fabrication skills . That being said , the motor and tuning stuff is a whole other thing , processes need to be done in a more left brained way . I have been using these rooms for nearly 4 years and I have never seen street riderz give any advice that wasn't based in proven past results.. I don't think to target you , just pointing out some practices are done for a reason ... Because they work .