Author Topic: P38 Racer- 1974 CB550 (Read 29898 times)

Hannibal Smith · « **on:** June 12, 2011, 09:14:24 AM »

After deciding that I need another project, I sourced a 1974 CB550 for $500.00 with title. I scored this machine on October 9, 2009. I have been working on it ever since.
The carbs were leaking profusely, so I rebuilt them "quickie" style, and within 2 hours had my bike on the road. The intention was just see that everything was in working order before I tore it down for the build. Based on past experience, I need to drive/ride the project before I go crazy, as this builds the desire to plug away for the next year or two and finish the project.
As you will see in this build thread, I went nuts and am building damn near everything myself, and this includes a ton of nuts and bolts (no kidding).

Greggo · « **Reply #1 on:** June 12, 2011, 09:19:02 AM »

Subscribed! That looks like a nice score for the dough. Can't wait to see where you take it!

Hannibal Smith · « **Reply #2 on:** June 12, 2011, 09:30:32 AM »

How she got named-

My buddy and I pick the bike up, and take her back to the workshop. We pull the carbs in record time, and get a brand new battery charging.
After I get the carbs done, I realize that I don't have a key!
My buddy Ian says, "Too bad we couldn't just start it with a P-38." (A P-38 is the military designation of those little can openers, it's an Army inside joke).
I call the seller, and he says he forgot to give it to me, and he will leave it out front and we can pick it up when he is at lunch...................
I find the key hidden at the designated spot, and imprinted on the key was "P38", what an incredible coincidence. I decided then and there that would be the project designation.

Hannibal Smith · « **Reply #3 on:** June 12, 2011, 09:42:21 AM »

These modifications and fabrications will be in no particular order. One of the first things I did was start polishing stuff, as I want to get the brutal labor out of the way first............there is no easy way, easier, but never easy.
This is the rear brake drum cover and the torque link I made. I had this stuff done within a day.
I machined the "vents" on the mill with an internal shoulder (inside the cover) and used stainless steel screen to give it that racer look.
The torque link was made from a chunk of 6061-T6 aluminum.

hyde7278 · « **Reply #4 on:** June 12, 2011, 09:49:28 AM »

very nice work cant wait to see more

Hannibal Smith · « **Reply #5 on:** June 12, 2011, 09:50:51 AM »

I also made my triple clamps, and also made the steerer from stainless steel. I used tapered roller bearings.
I kept the geometry stock, I really liked the way she handled before the teardown, great weight distribution, and it felt very stable.

This is the top clamp getting first ops done in the CNC.

Ultra precision bore!

Not polished yet, but you get the idea.

Another shot. I had this stuff done within a weekend.

Hannibal Smith · « **Reply #6 on:** June 12, 2011, 09:58:34 AM »

This is the starter block off plug. I made it out of magnesium. I had chunks in the shop, plus I just couldn't resist.
It uses the factory 0-ring, and I also made an integral castlenut, so once I installed it, I could forget about it. I ties in with another secret setup...................

Hannibal Smith · « **Reply #7 on:** June 12, 2011, 10:07:54 AM »

This is a "dry build" with the top clamp assembly. You will note that the frame is not powder-coated yet, I mock everything up first before painting.
And yes, I also made the flanged top clamp nut.

Hannibal Smith · « **Reply #8 on:** June 12, 2011, 10:24:36 AM »

I polished the hubs, and had Buchanans lace me up a set of Excel "Shouldered" rims with stainless spokes. The rims were polished before assembly, and the wheelset is incredible. Buchanans were ultra professional, turnaround was less than a week, and it was flawless.
Since I am doing serious brake modifications, I wanted to make a "nut plate" on the speedo side and get rid of the stamped steel retainer that comes stock.
I machined the plate, then installed steel thread inserts. It is mega strong and clean.

Outside view.

Inside view with recesses for speedo drive retention.

Installed, but I am going to bead blast it a gray, it looks like it is part of the wheel, and I want people to realize it is a custom part.

Hannibal Smith · « **Reply #9 on:** June 12, 2011, 10:32:40 AM »

I purchased YSS shocks for the build, and they are very nice.
I machined my own acorn nuts from 2024 aluminum, and then used a copolymer to make precision spacers for the shock bushing.

Steve_K · « **Reply #10 on:** June 12, 2011, 10:48:03 AM »

Always like to see inventive design and machining done to a bike. Nice looking project, I like the direction you are going. Good job, show us more as your build goes on!
Steve

Hannibal Smith · « **Reply #11 on:** June 12, 2011, 10:48:30 AM »

This is my points cover. I am going run an electronic ignition.
I made this from a chunk of 6061-T6 aluminum. I wanted to keep it looking "Old School", so I just kept everything simple. It utilizes a neoprene gasket, and not the factory cork.

Not polished yet, but you get the idea.

Hannibal Smith · « **Reply #12 on:** June 12, 2011, 11:01:00 AM »

I made my own front and rear axles from stainless steel, and I even made my own castlenut on a CNC mill. I made the hex surfaces 26mm, so one wrench size is used for the wheels and the steerer stem nut.

Hannibal Smith · « **Reply #13 on:** June 12, 2011, 11:34:10 AM »

I got new tubes for the forks, and machined my own dustseals. I am not going to run the factory bellows, and the forks needed that "finished" look.
I sourced some hydraulic seals, then machined a retainer so that it looks really clean.

Hannibal Smith · « **Reply #14 on:** June 12, 2011, 12:03:02 PM »

This is just a teaser of the modifications..........you can see the starter plug in action.

I am running a remote oil filter, so I made a filter bracket that puts the filter where the starter was. I sourced a common 68mm filter, and designed the bracket to fit it. I am using a K+N HP-1003 race filter.

I plumbed the apaptor with -8 and ran -6 fittings...............you will see why later! I don't want to show too much just yet. Needless to say the motor adaptor where the old filter went is insane.

Starter opening.

bwaller · « **Reply #15 on:** June 12, 2011, 12:23:07 PM »

Beautiful work Hannibal.

mrrch · « **Reply #16 on:** June 12, 2011, 01:11:45 PM »

NICE STUFF!
I would be building one off parts daily as well with some equipment.

FunJimmy · « **Reply #17 on:** June 12, 2011, 01:18:12 PM »

Mr. Hannibal

That's some outstanding workmanship.
Koodos

FJ

immortal · « **Reply #18 on:** June 12, 2011, 01:30:56 PM »

Great workmanship and great photos too!

brandEn · « **Reply #19 on:** June 12, 2011, 02:17:26 PM »

WOW, just amazing. I really wish I knew how to do machine work. That remote filter is just amazing and a great idea.

haill · « **Reply #20 on:** June 13, 2011, 01:27:19 PM »

Dude, those anodized blue things stick out like a sore thumb. You better make those too. it's a slippery slope once started. It all looks very tasty and reserved.
maybe one day soon you'll get the camera off of macro til then keep up the good work...

Hannibal Smith · « **Reply #21 on:** June 13, 2011, 02:40:49 PM »

Quote from: haill on June 13, 2011, 01:27:19 PM

Dude, those anodized blue things stick out like a sore thumb. You better make those too. it's a slippery slope once started. It all looks very tasty and reserved.
maybe one day soon you'll get the camera off of macro til then keep up the good work...

Thanks, guys.....................I am keeping it on macro to hide the overall look for now!
And yes, it will be a classic reserved style Cafe bike, that will look very 1970's with nothing obviously modern, even the new front brake was available in the mid 70's (Brembo P08)- I am hoplessly addicted to making stuff!

Bankerdanny · « **Reply #22 on:** June 13, 2011, 03:37:40 PM »

Amazing fabrication look. I can't wait to see the finished bike.

It looks like you have to remove the whole remote filter assembly to get the filter out. How easy will that be one the carbs are in?

Hannibal Smith · « **Reply #23 on:** June 13, 2011, 05:25:59 PM »

Quote from: Bankerdanny on June 13, 2011, 03:37:40 PM

Amazing fabrication look. I can't wait to see the finished bike.

It looks like you have to remove the whole remote filter assembly to get the filter out. How easy will that be one the carbs are in?

I will just unscrew the 2 6mmX45mm fasteners and pull it out/off as it is attached to flexible hose- that is why the 2 fasteners start halfway up the adaptor, I can easily get a hex wrench in there without having to remove carbs or the side cover. It only took maybe 2 hours to make, but I thought about it off an on for many days beforehand.
It also had to be "cross-drilled" so to speak, as the inlet/outlet fittings are not direct feed, you only have so much room with a 68mm filter- Anyway, it comes off easy for oil changes-

My stainless Yoshimura headers also are not made to have oil filter access if I used the stock system, and pulling headers vs. 2 fasteners....................no debate.

hapakev · « **Reply #24 on:** June 13, 2011, 10:23:02 PM »

This is a SICK BUILD!! I will be watching with bated breath.

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Author Topic: P38 Racer- 1974 CB550 (Read 29898 times)