Power ratings of 250 vs. 305 and 360 vs 180 cranks?

65ShelbyClone · Post by **65ShelbyClone** » Tue Apr 17, 2007 12:46 am

I apologise if thise classifies as an ultra-newbie question, but I searched both here and the www with little success.

My question is what were the factory power raitings for the 250 and 305(if any)? If they weren't advertised, are there any private dyno sheets floating around out there?

Also regarding the 360 and 180 degree cranks; was there any performance difference or was it merely a difference in design with no change in function?

305 · Post by **305** » Tue Apr 17, 2007 12:36 pm

according to the owner's manual fo my 1966 CA77 , maximum horsepower and torque:

20 ps/8000 rpm....torque 1.87 kg-m/5700 rpm for 250cc

23 ps/7500 rpm....torque 2.35 kg-m/6000 rpm for 305cc

i have no idea what ps or kg-m stands for

65ShelbyClone · Post by **65ShelbyClone** » Tue Apr 17, 2007 7:15 pm

Thanks!

For the most part, PS numbers can be regarded as horsepower without conversion. They're not exactly the same, but close enough for decent estimation. Just multiply the kilogram-meters(kg-m) by 7.233 to get pound feet. 23hp and 17lb-ft isn't too bad for a 305. I wonder how much that can be improved upon....

I spent half of today getting the rusted up top end off of my CL77 engine. Even smashed my thumb and index fingers pretty good with a bleeder on one trying to knock a piston out of the jug.

305 · Post by **305** » Tue Apr 17, 2007 7:59 pm

we have something in common besides a love of old honda...we both have smashed thumbs!

the hp figures are for a dream motor..single carb..i believe the hp is more on your scrambler motor

65ShelbyClone · Post by **65ShelbyClone** » Tue Apr 17, 2007 8:40 pm

Yeah, I did some digging around and found a past thread where someone posted some old Yoshimura broshure pages and they had the stock CL77 rated at 28hp. Of course, the Yoshi prepped CL made a claimed 37hp @ 11,500.....