Topic: 500/550/650 pride (pictures added)

[turboguzzi]

a few answers....

First of all, sorry, but these are more or less all the pics in the story

Bill, this story came out only last month in the magazine, I built my bike more than a year ago. I guess that basically the cylider spacing in the 500 block is just too small to really push it out to a full 750 with reliability.

Bwaller, as faded as that old picture is, i can see quite cleraly the rear tank feed pipes, the very flat sump, as well as a pretty stock looking oil pump outer cover and that's strange. if you look at pic 009 you'll clearly see the double width of the oil pump in the racer, as there must be two rotors.

Brad, many sohc racers here are run without adjusters but they do have steering dampers. Without adjusters, if you ever got a strong tank slapper, it can push the pads into the calipers and next time you reach for the lever, you are without brakes... and dont ask me how  I know. CB500's with worn tires can tank slap at times, so better run with adjusters or fit a damper.

Scunny, the term is used among the Guzzisti, the 750-1100 twins are big block, the 350-650 are the small block.... allowed myself to borrow it from there, so it's OK to steal from a thief I guess.....

TG

[Ecosse]

TG,

I really don't remember if I even talked to this guy, too long ago. I did check the bike out in the paddock and recall thinking it was a very cool ride with what I expect was a dry sump. It looks to me to be a stock pump, but who knows.

Like you he had to content with TZ's and the like.

The pic is a little grainy......well it is rather aged!

bwaller, so glad you posted your avatar for a better look. I've been squinting at it for a while now. I'd like to know a bit more; if there's a thread elsewhere please direct me, or can I trouble you to elaborate?

 turboguzzi, thanks a million for this  great post; I love motoring history and the more obscure the better. My 550 will be pleased to know she's descended from greatness too.

[bwaller]

Sorry guys no further info, it's just a race bike I took a picture of in 1974 at Bryar Motosport Park in Loudon, NH. that (as mentioned to TG) ran a dry sump lube system.

[bwaller]

Total loss ignition so no need for charging system.

[kayaker43]

turboguzzi

Any chance you can post a link to that italian magazine article, or scan a copy for the archives? I'm sure someone could translate it for us. If nothing else let us know the month or volume number so I can try to obtain a copy?

Its amazing that this has been a secret for so long.

[paulages]

i'm surprised with the stock brake setup. the rear backing plate is different, and there is a second disk up front of course, but the capilers stock and the rotors undrilled.

such a beautiful bike though.

[mlinder]

i'm surprised with the stock brake setup. the rear backing plate is different, and there is a second disk up front of course, but the capilers stock and the rotors undrilled.

such a beautiful bike though.

You could make your 550 racebike look like that, Paul.. that would be freakin awesome.

[Deltarider]

That external oilfeed would have saved us a lot of trouble.

[bwaller]

Typical old gorgeous Honda racebike stuff, man oh man.

Deltarider the external oil lines is a snap on these things.

[MRieck]

I don't know how I missed this thread originally but I have to say that factory bike is very cool for all the right reasons such as dry clutch, rear shock lay down design, magnesium lower triple tree etc, etc. The clutch is what I really love.

[turboguzzi]

delta, I guess you mean the dry sump?

if yes, then i wouldnt say its so easy to do..... you need to turn the single rotor oil pump into a twin rotor and redo all the oil galleries.

Paul, other than the basic castings of the motor, I'd say there are no stock parts here, brake plate looks off one of their GP racers,

Kayaker, PM'ed you

Mike, there's one pic i didnt posted before becasue it was too small but it was mighty interesting. it was a shot of the little book that accompanied the race bike that was full of hand sketches with all the details. in the one shot that they put on the mag, you could see that there were dimensions showing that honda reduced the included valvle angle in order to fit bigger valves in the head.

it shows that in theory at least, bigger valves AND seats can be mounted on the small blocks, if you are up to it.

TG 

[paulages]

Paul, other than the basic castings of the motor, I'd say there are no stock parts here, brake plate looks off one of their GP racers,

yeah, i was only talking about the brake system.

[turboguzzi]

P, did you manage to sort out the damn cam ear?

TG

[MRieck]

delta, I guess you mean the dry sump?

if yes, then i wouldnt say its so easy to do..... you need to turn the single rotor oil pump into a twin rotor and redo all the oil galleries.

Paul, other than the basic castings of the motor, I'd say there are no stock parts here, brake plate looks off one of their GP racers,

Kayaker, PM'ed you

Mike, there's one pic i didnt posted before becasue it was too small but it was mighty interesting. it was a shot of the little book that accompanied the race bike that was full of hand sketches with all the details. in the one shot that they put on the mag, you could see that there were dimensions showing that honda reduced the included valvle angle in order to fit bigger valves in the head.

it shows that in theory at least, bigger valves AND seats can be mounted on the small blocks, if you are up to it.

TG 

Just about anything is possible TG especially if you have the resources of Honda on your side. That new valve angle would also change the chamber shape allowing for a shallow, smaller and more efficent chamber. Nice stuff dude.

[cb650]

On the 650 site a member bought a 650 with some serious internal (not sprockets) gear changes.  He suspected a race bike at one time in its life.  Havent heard of anything on it lately.

[HB-1fan]

TG,
 Is that a special tank, or borrowed from some other racer? Other than custom head tube angle and chromoly is the frame a stock? Did it say in the article who made it? The pipes would not be to difficult to make considering there is little, if any, taper and no flowing curves like the classic italian(beautiful) pipes. Like the MV Agusta and HB1 pipes. A few years back a crew of retired MV tuners showed up at Daytona with a pair of 500cc factory race bikes with open 4into4 pipes. It was the most beautiful thing I ever heard. It might have been the same day that Agostini was there riding the RC166 up and down pit road. Probably the two best things I ever heard.

HB

[Quorthon]

Anyone have any ideas about cutting up the stock pipes to get this look?   Some kind of ultra slim aftermarket baffle?

[Beans]

Anyone have any ideas about cutting up the stock pipes to get this look?   Some kind of ultra slim aftermarket baffle?

You could make those pics easy. I talked to my pops who ownes a muffler shop and he said it could be done. thought about getting some made for my bike when I have the time to tailer it their.


Also TG thanks for posting this. Ive always wondered if they ever made a race bike since all I see since I got my 550 was 750 this and 750 that.   I can't wait to get cash together to put a big bore kit on one of my spare motors.

[turboguzzi]

TG,
 Is that a special tank, or borrowed from some other racer? Other than custom head tube angle and chromoly is the frame a stock? Did it say in the article who made it? The pipes would not be to difficult to make considering there is little, if any, taper and no flowing curves like the classic italian(beautiful) pipes. Like the MV Agusta and HB1 pipes. A few years back a crew of retired MV tuners showed up at Daytona with a pair of 500cc factory race bikes with open 4into4 pipes. It was the most beautiful thing I ever heard. It might have been the same day that Agostini was there riding the RC166 up and down pit road. Probably the two best things I ever heard.

HB

Hei H

the bike was made as an internal honda effort and built by the "R&D department in Saitama", at least according to the article. It was run in the All-Japan championship as "semi-works" but the tail still sports an RSC sticker. Hard to know the exact story as the bike was never raced outside of Japan (other than one race in 1982 in Italy when it was becoming already vintage).  
Everything on this bike is non stock, the frame has really nothing to do with the production item.
Maybe of even more interest is the second CB500 based racer (bellow) that sits in Honda's museum in motegi. Taken out to 750 with 66 X 54,76 dimensions and a special three valve head it developed 87 hp! if someone happens to visit the Honda museum, it could be really nice to have more pics and info on this one.

At the end of the day, I think that honda lost interest in developing the 500 based racers (which were way lighter ) due to the pressure put on by the z900 and the fact that big superbikes stole the limelight. There was more money to be made from the big ones.

Even if this second CB500R was more powerful, on looks alone I dig the first one I post much much more, that one was really raw.

TG

 

[mlinder]

Pretty sure Pauls makes very close to what that factory 500 makes, if that 87 claimed HP is crank.
3 valve head, though, sexy....

[turboguzzi]

pretty sure paul made 69 hp last time he counted..... :-)

now turns out that someone else had the idea of making a CB500R replica of sorts....

Zoomed into the full size picture and turns out this guy built a dry clutch setup, damn nice!

Anybody's got an idea about these double cradle modification? very nice job!

Cheers

TG

 

[mlinder]

pretty sure paul made 69 hp last time he counted..... :-)

now turns out that someone else had the idea of making a CB500R replica of sorts....

Zoomed into the full size picture and turns out this guy built a dry clutch setup, damn nice!

Anybody's got an idea about these double cradle modification? very nice job!

Cheers

TG

 

That was rear wheel...

I'm interested in the dry clutch stuff myself. Need to figure out how to go about that.

[turboguzzi]

yeah, right, while on the other hand, the bike posted was an endurance racer for the 24 LeMans gig, so actually in a "soft" state of tune (by honda standards) to survive the distance

Mike the bike's GP 500-4 of 68' reputedly made 85hp, from 500 cc's that is,

in any case, we all know Paul is an ace tuner, 

TG

[paulages]

i'll try to get to the honda museum next time i'm over there for sure. i'd love to see this and all of the other beauties they must have (RC166 etc). don't we have a few japanese members here?

[mlinder]

Well, we know with the full support of HRC, just about anything is possible. Still dunno if the 85ish hp listed is RW or crank.

Now, about that dry clutch... how the hell do I convert to dry clutch, where can I find out? Inquiring mind want to know.