looking for people interested in top end performance modifications

**axa** · 04-26-2015, 09:33 AM

http://www.harborfreight.com/media/c...mage_13065.jpg

**Zorge** · 04-26-2015, 11:25 AM

"Old school".

Here's abrasive mesh I mentioned in action - https://www.youtube.com/watch?v=r8MZbYQHtz4. Maybe it'll come handy on some of your next projects.

**axa** · 04-28-2015, 04:50 AM

I might say that in the video is old school using home made tools, and my way is new school as the cartridge rolls surely came more recently

for sure if doing work like in this video, you must be prepared to do more work.
as you can see he makes many contacts with the valve seats and valve stems are already removed.
for sure he need to take head to pro machine shop, or at least use pro tools to cut new cable seats and insert new stems.

by the way you might be interested in this article about intense modification of 167fmm:

https://rideapart.com/articles/how-t...200-motorcycle

**Zorge** · 04-28-2015, 07:28 PM

In my part of the world, "old school" would be stones of different hardness, conical, cylindric, spherical - you name it. An I hate them all - blue, red, and f.... white ones.

I like this trick with abrasive mesh because it seems to me you can not screw things in a second, as you can with other abrasives, plus you don't have to have a steady and "artistic" hand in order to get decent looking port. It is certain that I'll try something like this when I get a chance. Finally I have some use for the old "Peugeot" motor head.

You mentioned valve seats cutting. Do you have experience with a hand cutters? With which is easier to do the job - carbide tipped or those classical, made of tool steel?

A propos "Ride Apart's" article: I'm interested to see that camshaft with a new lobe, more than anything else they did. I think (but do not rule out the possibility that I'm wrong) that no one in China has offered to the market modified camshaft for CG clones. Looking for one?

**axa** · 04-29-2015, 01:50 AM

never seen any custom cam for sale on cg engine. I never cut valve seats. iy require more tooling than I have, must be very precise.

OK so when u use this kind of flap abrasive let us know how it goes.

**axa** · 05-24-2015, 10:39 AM

so through a series of mistakes I ended up blowing my head gasket. a combination of under torqued head bolts, low octane gas, sharp edge left from head deck caused hotspot detonation.

I didn't oil the head bolts when assembling, I didn't re-torque after first use, after disassembly i found them very loose.

I was using 87 octane with the 10:1 compression, this caused a distinct high frequency ping I could hear but not recognize as detonation...

and disassembly i was very suprised to find i left newly created sharp edges created when the shaved head brought the edge of the larger intake valve closer to the surface.

also excessive after fire should have been looked into.

needless to say I fixed these issues as well as resurfaced the head removing .007" more for a total of .042 or approximately 1mm total head reduction.
I have not calculated final compression ratio yet so I won't speculate now. so far so good

**Zorge** · 05-24-2015, 02:42 PM

With so much "shaving" of a head, maybe you should fit injector pump and convert it to diesel.

**axa** · 05-24-2015, 04:17 PM

that's crazy talk :p:eek:

**Zorge** · 05-24-2015, 05:04 PM

Spare parts available for order.

**axa** · 09-22-2015, 07:56 PM

"About carbie: I think that some CV carbie would do better job (for everyday riding) than plans slider type with acceleration pump.

But, IMO, there is one big thing that limits you significantly - this pushrod design with only one lobe and, as you realized earlier, non existing tuning cams.

Everything else you've already done....

BTW, did you tried to measure compression (not compression ratio, which is anyway just arithmetic mean)? You know... gauge, hose, spark plug hole, cranking... and result in... what you use in your part of the world - PSIs? On dry and with few cc of oil inside cylinder?

As you can see, my English limits me a lot, so I would mention few things for you "to think about". I'm not regular in this thread, so I'm sorry if I missed some mods on your bike.

If you already experiment with low octane gasoline and increased compression, you could think about buying adjustable or programmable CDI unit. Those adjustable are available at "Aliexpress". It could be handy to have possibility to adjust ignition angle and smooth engine's running.

Another thing is oil cooler. There are some kits with engine head cover with oil inlet and outlet, set of hoses and radiator, and what is important, it is "bolt-on" solution.

I believe that adjustable ignition and oil cooler could, if not prevent, than at least reduce, engine surges you mentioned half a year ago."

I did measure cr sometime ago, but didnt take note becuase it was on a freshly honed cross hatched cylinder, so it couldnt get any better...

Can you point me to a programmable (variable) CDI, preferably one i can get easy in US like on ebay.
When i looked into it there i couldn't find enough information to know which will legitimately adjust the timing and will work with the 167fmm.

Yes i still have the strange surging mainly when loading the engine, but also generally when approaching opening throttle.
To figure out if it is the air fuel mix, Ive started to ride with small main jet and replace filter with velocity stack, and i will work my way to larger jet and closed filter."

But something tells me this surging is not mix problem because ive had mix issues before that did not result in strange engine surges.

Also an oil cooler might also be a useful item, but its hard to know if i have a heat problem and if the unit for cg engine is effective. I have my doubts to its design
Do you notice there is no pump and this engine has lower oil pressure, so im skeptical if the oil flows well through.

PS. your english is fine. no need to conciser it