Author Topic: "barn find" (Read 15024 times)

Rgconner · « **Reply #100 on:** April 13, 2012, 09:34:09 pm »

Well, the power is ~12 horse stock if you have the 24mm carb and not the 10HP 20mm carb, 18HPish for me. 225 is the bike weight.

That is a 18:1 stock
and 12.5:1 where I am

These are honest, to the wheel HP measured on a dyno.

a CB550 is 425, with 50 hp,

so that is 8.5:1

If you go with the more conservative 38 to the wheel I have heard, but not tested, then 11:1

Without a doubt, the CB550 is faster once you hit second. The Vespa is just silly fast coming off the line, but loses steam after 2nd.

It takes some control not to pop a wheelie in first on the Vespa, and second will lift up too if you drop that clutch like a hammer. Mind you, that is with me at 250 on the bike, leaning forward... the torque is ungodly.

A friend of mine has in his rather extensive stable of Italian scooters a P200 with 2 carburetors on it. One is the stock rotary, the second is a reed valve. If you can keep them in sync, it is a poop-inducing 30HP!

Totally undrivable in stop and go traffic, but really amazing if you are out on the twisties or a track. These bikes can turn in 1.2 of their radius

grcamna2 · « **Reply #101 on:** April 13, 2012, 11:28:03 pm »

I'm curious what the numbers are (rear wheel) for the Stock CB750K2...power to weight ratio. I've read somewhere that the CB550K is like close to 70 lbs lighter than the CB750K.I plan on finding a CB550 in the future.

Rgconner · « **Reply #102 on:** April 14, 2012, 10:58:56 pm »

So some updates:

Little package arrived with a new CDI. My postman loves my bikes and has a Yamaha from the 70s, the 900 I think. All in parts right now so he does not like to talk about it much =). I was outside preping the cb550 for a ride tomorrow. Anyway, The original was cracked at the spark plug connector and I was waiting on this on to come in.

These newer "blue" CDIs do spark advance as there is no mechanical advance. It will also spark up to 12 k rpm. The older ones did not regenerate that fast and even new rarely got above 7k.

Engine runs smoother and stronger now. Still letting the sound dictate shifts. If it sounds like it is struggling to spin faster, I shift.

Still only 50 miles on the poor thing, I have been working too hard lately to put miles on it.

grcamna2 · « **Reply #103 on:** April 14, 2012, 11:15:01 pm »

I see it's getting some more revs to go with a proper break in

..I think it will break-in even nicer now considering the way you described about the old CDI compared to the new one.It should be broken-in to be "normal" for it to rev quicker & higher..and then w/ the tach./speedo unit when you get that...that little Vespa will be an excellent tiny HOT ROD of a street screamer

grcamna2 · « **Reply #104 on:** April 23, 2012, 05:54:51 pm »

Rg,
How many miles do you have on the engine now ?

Rgconner · « **Reply #105 on:** April 23, 2012, 07:24:00 pm »

About 150.

The flywheel spun off, taking the stator with it and ruining all my hard work on the rewiring. =(

I torqued it to spec, and the builder kinda sighed and told me I should use an air impact wrench on it next time. The stock spec is just too low with the amount of torque it can produce.

I have a new stator I need to refit, just waiting on some other bits before I put it back together.

Oh, and I am not sure I mentioned this, but he did a repair on the rotary valve, something that is generally considered "impossible", find yourself another set of cases.

Well, now that I and another user have some miles on ours he went public with the repair offer. He is getting inundated with requests from owners of the older engines from the 60s and 50s.

Those cases are rare as hen's teeth, if you mess yours up it is a lost cause. A lot of people who have that happen end up putting later engines in, unfortunately.

Now they have a repair option!

(It appears at least one other person does this, but he only does a few each year and charges a lot of money for it)

P.S. the original factory repair was to use an industrial type of JB Weld and then machine back to spec. People have done it, but the repair only lasts a few thousand miles before compression starts to fall off again.

grcamna2 · « **Reply #106 on:** April 23, 2012, 07:39:35 pm »

I'm sorry to hear about you're flywheel..

;that MOD Spec. isn't in the manual..,the part about torquing w/ the impact wrench...I KNOW you'll never forget that again.That rotary valve repair to you're original cases..;what happens to them? something to do w/ the spacing between the casing around the rotary valve disc and the port? or is it around the bearing/seal area ? porous casting ?

Rgconner · « **Reply #107 on:** April 23, 2012, 08:36:03 pm »

You get dust/sand past the filters and they wear to over 3 mil. and they need to be built back up. Sometimes getting an oversized crank will fix that. Lack of oil lets them overheat... etc.

Or, something like a circlip or a failed bearing gets trapped, you run without a filter and ingest a screw or a washer... REALLY gouging them out!

Al prefers using spiral retaining rings over circlips. He feels they are less likely to fail under the harder conditions of a tuned engine. He has yet to have one fail that he has installed himself.

Circlips have a nasty tendency to fail, especially the ones on the piston wrist pin.

grcamna2 · « **Reply #108 on:** April 24, 2012, 06:56:30 am »

I want to be clear then..;are you saying that the flat mating surface of you're case that sits flush w/ the flat sealing surface of the rotary valve disc? or just in different high stress points around it ? What type of repair does Al do to fill the casting back in ?

grcamna2 · « **Reply #109 on:** April 27, 2012, 08:08:34 pm »

I would imagine it'd be best if it had a mirror finish to the casting where it slides smoothly along the rotating rotary disc..if that was possible..;the less friction there the better.A good air filter would be the best insurance.

Rgconner · « **Reply #110 on:** April 27, 2012, 09:24:45 pm »

Sorry, been on travel for a few days.

Yes, the crank valves rotate against the casing.

He fixed it by removing some material, then welding in bar stock bent to the right radius, then milled that down to match the crank to 1 mil, not the stock 3 to 4 mil. The whole assembly was heated to make sure the weld was stress free. So far, so good!

So even little imperfections are not going to hurt it, it can take it a lot of wear before I will see pressure loss. you put a capfull of 2T oil down on the closed valve and if it stays there for 5 min, it is just fine.

Meanwhile, I continue with replacing parts that were not part of the build that are failing under the new strain. Kickstarter, quadrant, some cables, the shifter cable anchors up at the shifter.

Little stuff, but annoying.

grcamna2 · « **Reply #111 on:** April 27, 2012, 09:41:48 pm »

That man AL is REALLY hooking you up w/ all the right technical high performance fixes and mods needed for the best job you could ever have...,I'd like to see other bike mechanics care so much.

Rgconner · « **Reply #112 on:** April 27, 2012, 10:07:06 pm »

The best part... He is trying learn the CBxxx platform to aguement the Vespa side of the house.

So expect some cool things at reasonable prices... Starting with a cb550 gentlemans express type motor.

grcamna2 · « **Reply #113 on:** April 28, 2012, 04:25:12 am »

I would certainly like that Rg.I want to look for a barn find of my own..and would love to find an early CB550K0-k1 in original shape w/ factory parts still in good condition(exhausts,etc.)and make slow improvements to it as I plan on owning it for a long time.
Did you see "another N.Carolina barn find" ? a member here just posted a thread(1 page)on it late last week & that is exactly what I'm looking for

.

You own a CB550 also don't you ? Can you tell me about that motor work that AL is considering for the CB550? or maybe just a hint of it ?

Rgconner · « **Reply #114 on:** April 29, 2012, 07:56:53 pm »

I think we will start here:

http://forums.sohc4.net/index.php?topic=20601.0

with the Gentleman's express. Maybe add slightly larger valves and also the oil galley mod that helps get rid of the leakage.

grcamna2 · « **Reply #115 on:** April 29, 2012, 09:06:11 pm »

Rg,
I completely enjoyed that "Gentleman's Express" thread and I want to first find a Stock CB550 and do many improvements to my suspension & the ergo dept. and the rims.I have to try to save a few $ to do this after I get the bike..but I'm certainly UP for it

. I hope AL will be able to set up for it.
Did you ever try a pair of Cartidge Fork Emulators in you're CB550 forks ?

Rgconner · « **Reply #116 on:** May 03, 2012, 09:17:37 am »

No, I still have stock springs.

I really want to try a set of the Progressive springs first, I think they are the cheapest and most straight forward solution.

Continuing to work on the P200. having reliability issues around the exhaust. The exhaust is an upgraded and tuned version of the stock, but it seems to not be keeping up. Max RPM is 7000, and it has blown off the exhaust a few times. I re-did the connection to the header with some crosshatching and that seems to be giving enough grip. This is a slip on, not bolted like our SOHCs.

I might have to pop for a more serious exhaust, but that means louder and it is plenty loud now.

grcamna2 · « **Reply #117 on:** May 03, 2012, 12:48:19 pm »

Can you find a way to install some strong springs onto it like a Motocross Bike ?
I wonder if the muffler is up to the job of "exhausting" all the extra flow from you're excellent porting work.

Rgconner · « **Reply #118 on:** May 11, 2012, 11:39:00 am »

It is not able to move the air. But I don't have the $500 for a proper exhaust just yet.

Had it running good for a week, then the clutch started dragging. Shifting into first from neutral killed the engine unless you revved it just right and took off immediately. Could not stop in gear, had to shift to neutral. Took it apart and found that the spring carrier had hammered itself against the clutch basket.

Not supposed to happen with the HP generated by the Alpha Torque specification. It should be able to run a stock clutch basket. We suspect the 1mil tolerance he machined into the valve seat is sealing so much better we are getting less loss of pressure. Spec is 3 to 6mil.

Here is what it did to the clutch. Note the bending and warping of the corks, the steels were all teacupped too.

Hammering on the spring carrier:

And here is one from one of those crazy bastards that did Savannah GA to San Diego CA on a P200 tuned by Al, same valve pad repair. His is much worse in the hammering but his plates did not warp as fast as mine because he was doing WOT on the freeways.

Solution?

Hardened and banded clutch basket and carrier from SIP motorsports to prevent spreading the fingers and/or torsional movement of the fingers. Heavier springs, to replace some of the ones I have. Carbon based friction plates that generate less heat on the steel plates.

grcamna2 · « **Reply #119 on:** May 11, 2012, 11:45:21 am »

lol

It's good they have a set of clutch parts able to handle the increased torque & HP that little mill is turning out...,you'll certainly need it when you install the tuned expansion chamber exhaust system you're planning on !

I imagine AL knew you'd be calling him again

.

Rgconner · « **Reply #120 on:** May 11, 2012, 12:04:23 pm »

Nope!

He was totally shocked. Hundreds of Alpha Torques out there on the road, never see this before... not until the pad repair ones hit the road.

3 on the road, 2 show damage from too much HP for the stock basket.

Rgconner · « **Reply #121 on:** May 14, 2012, 06:43:07 pm »

So... rally this weekend.

Parts stuck at customs, no chance of me getting them in time.

Solution?

Bodge it!

If put 3 plates in the stack it would idle properly, with no drag. But... not enough spring pressure to hold the friction.

So, thinking about it, I took the top clutch plate, shown in the picture, and put the old top clutch plate on top of it.

It is corked on the other side, and added 1.5mm to the stack. That gave me enough pressure to not slip, but enough gap to not drag the engine in gear when fully depressed.

It is running really well, clutch engages nice and smooth with no "insta-grab" like 4 plates.

Engine zooms 2K past the stock redline and just pulls, pulls, pulls!

I will fix it all when the parts come in, but I am on the road for the short 3 mile run to the rally on Saturday!

grcamna2 · « **Reply #122 on:** May 18, 2012, 12:05:44 pm »

That's excellent Rg

& it's good to know you can get by w/ what you have for now;I hope you really enjoy the Rally and the engine gets a chance to braek in even more...,Nice to hear the top end RPM's are a Blast also

The only way to handle that torque will be a Heavily modified cluth assembly.

Rgconner · « **Reply #123 on:** May 30, 2012, 05:17:10 am »

Well, it has taken me a bit to get up to writing this, but the long and short of it is I got hit.

The Friday before the rally I was running errands to finish up the brisket I was making for the ralley and an arsehole in the center turn lane signaling left suddenly turned right into a driveway.

I was a car length behind him doing about 20 in a 35 zone and could not turn behind him like you are supposed to do, I would have ended up in oncoming traffic.

Hit and run, he left me unconscious on the Tarmac. Good Samaritan got his plate, another blocked traffic until it was safe to get me off to one side.

Here a pics of the damage and where it happened:
http://s1211.photobucket.com/albums/cc431/rgconner-gmail/P200%20damage/

Not sure what I am going to, retained a lawyer. About 2k to fix the bike.

Friend of mine wants the engine, will trade his stock P200 and 1k cash. That more or less gets me out of the hole if they total it.

Trying to avoid that, and maybe get it fixed and make it a show/rally bike, wait for a good offer on it.
Hard to get a good offer with a salvage title.

Wife wants me to not ride it around town, she feels it is too small and too grey to be seen. She is ok with me riding with others in a group.

She who must be obeyed must be obeyed... I don't want the contagion to spread to the other bikes...

grcamna2 · « **Reply #124 on:** May 31, 2012, 02:15:02 pm »

Rg,
I'm sorry to hear that mishap on your ride to the rally..,and I would have liked to be a witness for you

in court. I hope they don't total it;if the frame isn't bent...,you can possibly repair that bike,but either way, SAVE THE ENGINE FOR A FUTURE SCOOTER OF YOUR'S !

Rg, how badly were you injured?...if at all ?

News:

Author Topic: "barn find" (Read 15024 times)