1971 K0 restoration into a sohc RC181 Replica.

[2wheelsarebetterthan4]

Hi Everyone,

I'm a newbie to the group! I bought an American import CB500F K0 frame & swing arm last year & I've been slowly adding to the list of parts needed for it's restoration to rebuild it into a sohc daytime road legal/parade replica version of the RC181. I've been trying to source a reasonable engine for the project & have been struggling to find a complete 500 engine that at least turns over. Have the option to use the 550 motor, but it'll obviously not keep it as original as possible. What are people's opinion on the two engines? Is it worth considering the 550 engine instead to get things moving? I've read that the clutch & gearbox are far better on the 550 & they appear easier to get hold of as complete engines. Anyone know of anyone selling a complete 500 engine that still turns over? I currently have a seized one lined up but would prefer buying an engine that still turns. Even though I'll strip & rebuild it. Maybe however I'm expecting too much? Your suggestions are most welcome....

I live in the Guildford area (Surrey). Thanks!

[Trigger]

Welcome, that is the longest forum name i have ever seen. You will find the answer to your question very soon. The forum members are just a bit slow tonight.

[Bryanj]

Decent 500 gearboxes are few and far between now, so from that point a 550 is better

[mickwinf]

welcome, that sounds like an interesting project! 500 engines do turn up but 550s seem to be more common and cheaper, and not much different in looks.

[Johnwebley]

this may give you some inspiration,

http://www.youtube.com/watch?v=t0wpki0b6Kk

http://www.youtube.com/watch?v=hRiBDLf8UCY


http://www.d-mengineering.co.uk/index.php?option=com_content&view=article&id=77&Itemid=88

I have no connection to this company,but they look like they know what their doing !!

see the video of the bike at the IOM,

[2wheelsarebetterthan4]

Thanks for the information! Dave Beeby at D-M Engineering were my first port of call in fact. Dave's been tremendously helpful & I'm wanting to build something similar but including the front disc instead of a drum making it more similar to the Davies Motorsport Classic racing TT CB500 4 that William Dunlop rode in 2013 to 2nd place (68bhp at the rear wheel). Obviously I won't be lavishing £25k at my project as it's not going to be aimed at racing, but I'd like something with a modified stock frame instead of the Reynolds race frame (for period registering) & some reasonable engine tuning to enjoy classic track days & parades. I chose the Honda 4 cylinder as it's cheaper to build than many other iconic TT bikes such as the Manx Norton & Matchless G50. Bonkers money & they can't match the sound of a Honda 4 cylinder being rung! If only I could afford the little 250 6 cylinder . What a sound! Anyway, back to the real world. Look forward to hearing more from you guys regarding engine suggestions etc. Thanks