Topic: CB650 Cam in CB550 , any concern for valve/piston clearance interference ?

[eworth]

Hello,

For those who've done this or know positively,   Is there any concern for valve/piston interference when using the CB650 cam in a CB550?   Stock 550 pistons are being used with stock valve springs if that info is needed.

Appreciate any definitive answers before I drop the dough on headwork.
Thanks!!
Mark

[vincentlefre]

bumping this up as I'd like to know the answer to this too...

[eworth]

I did the install and had no clearance/interference issues.   Also, I upgraded to heavy duty valve springs.  Runs like a raped-ape !!

[vincentlefre]

Where did you get your valve springs from?

[eworth]

KPMI Valve Springs from dynoman.net

[Gman]

Not having done this, don't take it as gospel... (but I've read about it quite a bit, as this is a mod I'd like to do at some point).  My understanding is that there shouldn't be any interference w/valves, but some people have has slight problems with clearance in the head.   You should just search "650 cam swap" and you'll get a bunch of posts about it - check them out and you'll find plenty of info about fixes, etc.

Cheers,
G

[eworth]

Ya, G has a good point.   Set the cam in place and rotate it to make sure it doesn't hit.   Also, set the cam in the upside down rocker cover and rotate it also.   Gets pretty close but mine was ok.

[lone*X]

Just curious, a local has an complete 79 650 engine that turns over and looks decent for sale that I have been toying with the idea of picking up just for the cam and tach drive.  I haven't seen any on EBAY lately so what is the cam and tach drive worth these days?

[eworth]

I paid $200 for an OEM cam, never previously installed.      Much less used on ebay for used but you aren't always sure what your getting quality-wise.   I didn't want to take a chance so I paid more.   

[lone*X]

Odd you quoted 200.00.  That what the neighbor wants for the engine and some assorted extras.  He was going to build a cafe and instead of picking up a whole bike he just started buying parts to put one together from scratch.  Wound up buying a late model Ninja and totally lost interest in the 650.

[Gman]

FWIW - I was watching a 650 cam auction on ebay recently, and I think it went for approx. $40-50.  Something like that; can't remember if there was shipping on top of that. Still seems reasonable for a proven drop-in performance mod.  I asked the guy about the tach drive and he didn't have it, so I didn't pursue the auction.  If you do end up installing one, keep us posted about the procedure, outcome, etc.

G

[Danno]

the 650 cam is a drop in solution other than the cam tunnel modification that has to be done
 the cam has roughly the same lift just longer duration to the 550 the cam
tunnel mods can be done with a dremel and a steady hand but you will also need the tach gear for the cam which will use the stock cb550 mount for it

[Scott S]

 I'm pretty sure that whole 650 engine will bolt right in to your 550 frame. Just sayin'.....

[eworth]

I agree with above but you'd lose the kickstart if that mattered.