Topic: Guys dropping 650 cams in 550's w original 550 rockers? Found many 650 cams!

[Trad]

Are people doing this without issue? chime in if you are running a 560 cam in a 550 without issue and chime in if you think this is a terrible idea. I know that original cams and rockers are mated and wear together but will it burn rockers or wipe lobes when doing this swap? I've read all the threads about this swap but no one has really brought if it this is an acceptable practice.

Long story short an indoor salvage yard opened locally and I found 5 sohc 650's. I was able to pull 2 cams, one for myself and one that is in the for sale area. I have the potential to get the other 3 if interest arises.

[Greggo]

My 500 runs great with the 650 cam and tach gear swapped in..I had to change the gauges to have a functioning tach, but that's the only problem I ran into...dropped the cam right in, no other mods.

[Trad]

My 500 runs great with the 650 cam and tach gear swapped in..I had to change the gauges to have a functioning tach, but that's the only problem I ran into...dropped the cam right in, no other mods.

That's awesome! I guess it's not an issue running the original rockers then. I've heard many people say never to run a used cam with different used lifers/rockers in other applications. I'm curious what makes it that much different on the SOHC4 Honda's.

[bjbuchanan]

My 500 runs great with the 650 cam and tach gear swapped in..I had to change the gauges to have a functioning tach, but that's the only problem I ran into...dropped the cam right in, no other mods.

That's awesome! I guess it's not an issue running the original rockers then. I've heard many people say never to run a used cam with different used lifers/rockers in other applications. I'm curious what makes it that much different on the SOHC4 Honda's.

It is good practice to not mix or match and increase wear but is not a death sentence, a lot of stuff is over exaggerated. Some people also apply high mileage situations and comparable wear when most of these bikes never see 20k miles realistically. Most motorcycles sit around barely used

[Trad]

My 500 runs great with the 650 cam and tach gear swapped in..I had to change the gauges to have a functioning tach, but that's the only problem I ran into...dropped the cam right in, no other mods.

That's awesome! I guess it's not an issue running the original rockers then. I've heard many people say never to run a used cam with different used lifers/rockers in other applications. I'm curious what makes it that much different on the SOHC4 Honda's.

It is good practice to not mix or match and increase wear but is not a death sentence, a lot of stuff is over exaggerated. Some people also apply high mileage situations and comparable wear when most of these bikes never see 20k miles realistically. Most motorcycles sit around barely used

Thanks for the input. The "over exaggerated" aspect is something I was thinking as well.

[Bailgang]

My guess is that unless the rockers or the lobes of thew cam are damaged then the 2 will simply mate and wear as normal. I dropped a 650 cam in my 550 using the 550 rockers along with new valve springs and never had a problem. I would agree that not mixing and matching would have been preferred but it's not a death sentence either so long as none of the components are damaged to start with.

[Trad]

My guess is that unless the rockers or the lobes of thew cam are damaged then the 2 will simply mate and wear as normal. I dropped a 650 cam in my 550 using the 550 rockers along with new valve springs and never had a problem. I would agree that not mixing and matching would have been preferred but it's not a death sentence either so long as none of the components are damaged to start with.

SO what you're saying is that to you, the added performance of the 650 cam was worth whatever risk their may have been mix and matching. It seems like many are just swapping over as without problem.

I had spent the last few moths preparing for this engine build and accumulated 8 NOS rocker arms. I feel like I may have wasted my money as my OG rockers still looked nice and clean. Ah well.

[Bailgang]

What I'm saying is that I'm a tight wad on an even tighter budget.    If budget wasn't an issue I wouldn't have wasted my time with a used cam or rockers in the first place because some of the aftermarket cams have very similar profiles to the 650 cam and I wouldn't have had to mess with using a 650 tach drive and tach. Problem is the cams cost around $300 last time I checked so my budget limited me to a used 650 cam along with my original rockers.

I don't think you wasted your $ at all getting NOS rockers in fact I wish I could've done the same with mine.

[Trad]

What I'm saying is that I'm a tight wad on an even tighter budget.    If budget wasn't an issue I wouldn't have wasted my time with a used cam or rockers in the first place because some of the aftermarket cams have very similar profiles to the 650 cam and I wouldn't have had to mess with using a 650 tach drive and tach. Problem is the cams cost around $300 last time I checked so my budget limited me to a used 650 cam along with my original rockers.

I don't think you wasted your $ at all getting NOS rockers in fact I wish I could've done the same with mine.

Haha, fair enough man. Appreciate the input.

[Duanob]

My 500 runs great with the 650 cam and tach gear swapped in..I had to change the gauges to have a functioning tach, but that's the only problem I ran into...dropped the cam right in, no other mods.

hey greggo, any noticeable difference in performance?

[Greggo]

My 500 runs great with the 650 cam and tach gear swapped in..I had to change the gauges to have a functioning tach, but that's the only problem I ran into...dropped the cam right in, no other mods.

hey greggo, any noticeable difference in performance?

Hell yeah!

[Don R]

Drop in the entire 650 dude.

[bender01]

Id Like to own one of those 650 cams! Let me know if that can happen! Lowest mileage preferred! All the info to get in touch should be in my profile or sig! And yes Im a cheap ass!  If the tach gear is available id like it also! I have no plans to do this mod yet nor do I see my 550k1 leaving me in the next 20-30 years of my life! Ill get  to it eventually!
   Ben

[754]

Look at it this way..
Give the rockers a quick polish with fine emery.. Take off any high spots should be OK....

[Duanob]

"Many 650 cams"

the only cams I can find are for 650 nighthawk DOHC motors. I wouldn't think they will work. In fact isn't that what's in the pic above?

[Trad]

"Many 650 cams"

the only cams I can find are for 650 nighthawk DOHC motors. I wouldn't think they will work. In fact isn't that what's in the pic above?

Nope, That is from an 81 SOHC 4. There are 5 cb650's there from 79-81. All SOHC.

I have pulled two of the cams so far. One for my bike and sold one here in the classifieds.