Copper Pipe Customs - CL175 Build Thread - THE TIGER! (DONE..for now. VIDEO!)

Probably just perspective. They are PE24's.

I was considering buying a probe engineering FS-10G digital ignition...
I'm getting some work done on the heads and engine by Chris Schuman / Poor Bastard Cycle Works in Portland. I'm guessing it wont be a friendly daily rider.

I'm looking to ride it at the track. But I kept the lights and signals in the event I wanted to show it off.

...Since I haven't ridden this money pot yet (In its current form), I figured i would wait until it was alive and running to spend the money on the ignition.
 
PE24 is fairly large for a street motor. That said, we use PW26's on a 175cc race motor and it runs fine. What bore and what cam are you using, if you don't mind sharing?

Boretech/Probe comes with electronic advance AFAIK, so that shouldn't be a problem.
 
I had talked with them about different setups, they almost had me sold for a 240cc configuration. It will be 55mm bore, 198cc and the 122-x9 megacycle grind.

I was sold on the setup based on the availability of parts and seasoned conditioning. I should be able to wear it out on the track with good reliability and still purchase replacement parts in the event of a failure.

Hopefully ill be taking it to beaverrun this spring for some open track days.
 
That's a big cam. We tried all the Megacycle cams at one time or another - except maybe that one - and found the best one was .... much milder. Maybe with a big motor it might be able to use the extra duration. Which pistons and liners are they going to install?

We did a 240 conversion from scratch a few years ago and it needed the heads welding up and remachining etc. That one runs PW26mm Mikunis in AHRMA's 250GP class
 
We had talked about the cam /engine combinations and some of the engines that they've had on the track. From their testing, success varied in relation to a larger valve size, and if it happens to be a 'magic motor'. I had originally asked about a milder cam, I think the x9 was recommended because it was predictable. Ive got my fingers crossed for the head work and a bit of magic. I guess ill see what happens.
 
Not to say that the cam won't work in your motor, but much as I love magic, I know in my heart that there's no such thing. We believe in hard verifiable facts and dyno testing and lap times tell us a story that we work from.

Larger valves are necessary with bigger bores or else they are the limiting factor, but they can't increase much before they touch each other - even after they have been pocketed (sunk into the head). Big bores can work well with longer duration cams because they "suck" harder ie they need more air, and longer duration goes some way to compensate for lack of valve area.

I'm waiting to see a decent piston crown shape on a CB175/200. They are all too high and much of the fuel goes straight down the exhaust unburned even with ridiculous amounts of advance. I love flat chambers and good flame propagation, so we tend to machine lots off every available face and come up with a rather different compromise.

Did anyone suggest a HP number or RPM number for the build? Typically they peak at much lower revs than people think and bigger bores exacerbate that. The other interesting thing is that even stock, they flow more air than the engine could ever use, so they don't need a lot of intake flow. Our 250 flows enough air to support something like 40+hp at 15,000 and of course it barely makes half of that at much lower revs.

Flow is really interesting. We have had 4 or 5 heads ported and flow tested and on a 160, it's easy to get intake flows close to a 175 or 200 but they stop flowing at relatively low lift so that fitting a big cam doesn't help them. On a 175 &200 it's hard to get much more flow out of them - which is probably just as well - they flow enough, but they continue to flow at higher lifts and that's where a big lift cam may work. 160 exhausts on the other hand are terrible and are hard to improve, but 175 and 200 exhausts are easier to improve. That is the restriction in those small motors.

The problem with the intakes is that the Critical Port Diameter is around 24.5mm and that's too large. That would work with a 31mm valve and 27mm carb!!!! Or the ports need to be reduced in size in certain places. That's enough secrets for one day....
 
Sounds like you've built some pretty wild machines. I've got another engine in the garage- maybe you could build me a 240cc? i wouldn't mind having two. ;) They've dyno'd a few of the engines with the same parts package at 24-26 hp @12,000. I think the magic came in into play with some of the engines that exceeded their expectation from the same setup.
I like working with hard facts too.

So from your experiences would you say that you'd recommend a milder cam even on a head with oversize valves? Or at least have another one to do some real world testing on?
I appreciate the conversation. --thanks again.
 
Re: Copper Pipe Customs - CL175 Build Thread - Paints done.

Very excited about how the paint turned out. Very.
 

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Paint looks good. BTW we managed to get just over 21 out of 175cc at 11,250. That 12k number is interesting - must be a 180 degree crank and better control of the cam chain.

What tank is that?
 
Slapped it together real quick. Realized I should go back and put the oem fender back on-- looks pretty suitable. Im regretting splitting it apart.

The tank is an aermacci from Bret at glass from the past, the rest is an avon race fairing, and some common seat.
I'm still waiting on the engine. It cant come soon enough.
 

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Longest project ever...

Heres my engine finished. Not very exciting.

As soon as the weather warms up, it will be time to plug it in!

Hah-- Almost one year since the last reply.
 

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