Topic: CB750 RC 315 Cam Question

[750]

Hey All,
Does anyone have experience with the RC315 cam in a 750 motor?  How does the bike respond after instillation (what rpms do what)?  I really don't want to build an unridable, unreliable bike and I know this is a lot of cam so I'm hesitant to install.  I bought it from a motorcycle dealer that had some old 750 parts laying around.  It's in great shape with virtually no wear (Looks as if it's never been run).  I'm building an 836 out of a 78CB 750K motor.  The only mods to this motor will be the 836 kit, (maybe cam), porting, polishing, (Honda Man Hemi), slight Intake floor build up .125", slight decking .008", K&N in stock air box, and a Honda Man ignition with stock coils.  O, almost forgot, APE cylinder head studs, and an oil cooler.  The carbs will stay stock but will obviously be jetted to the plugs or Dino depending on when I actually run out of money on this project and the verdict is still out on the exhaust (might keep it stock, trying to build a sleeper). I'm not new to motorcycles or riding them so if it's just a matter of making use of a little different RPM range it's no big deal, but if the thing will only run at 5 grand and won't be fun as a daily rider to shoot around town or ride on the interstate then I won't be using it.
Thanks For any help you guys can give me.

[City Boy]

Hi 750.I used the 315 in my 1000 Cobra.The machine was quite streetable in my opinion.RC had this to say about the 315;"Strong torque curve from the ground up---comes on low and never quits.This one makes lots of horsepower.Very good for heavy street and altered bikes.Our favourite in street class.Has twisted us to many national records.Very streetable.Fair idle---quiet."Good luck and Rock On

[750]

Hi 750.I used the 315 in my 1000 Cobra.The machine was quite streetable in my opinion.RC had this to say about the 315;"Strong torque curve from the ground up---comes on low and never quits.This one makes lots of horsepower.Very good for heavy street and altered bikes.Our favourite in street class.Has twisted us to many national records.Very streetable.Fair idle---quiet."Good luck and Rock On

Wow!!!!!!!!   Thank You vary much for your reply! This makes me so much happier about spending the money. Can't wait to finish this thing.  Does the rest of it sound like I'm on the right track??
Thanks Again 

[754]

It will have good midrange.

 I went from a cam  that really had nothing under 4K  (also had pretty hi compression).. to a 315 with 10.5 : ! compression, and it was very nice..  I run Weber carbs , that may be boosting the midrange a bit more..  but I am running stock ports. If you get carried away on the porting, it may change things down low..

 And as far as the huge valve clearances go, they do run well set like that, I would not second guess them, and its not as noisy as you may think..

 if you end up not liking it, I want first dibs on it..
 754

[750]

It will have good midrange.

 I went from a cam  that really had nothing under 4K  (also had pretty hi compression).. to a 315 with 10.5 : ! compression, and it was very nice..  I run Weber carbs , that may be boosting the midrange a bit more..  but I am running stock ports. If you get carried away on the porting, it may change things down low..

 And as far as the huge valve clearances go, they do run well set like that, I would not second guess them, and its not as noisy as you may think..

 if you end up not liking it, I want first dibs on it..
 754

Thanks 754 you have first dibs if it doesn't work.

[newday777]

Hey 750 are you still around? Did you end up doing anything with the 315 cam?(yes I saw the date of this thread was 2009 and 750 was last active this past spring) Just wondering how it worked out for you. I haven't searched through your posts yet to see what you did with it. I have a 76 K motor I'm going to build and haven't fully planned out what I'll be doing to it yet, still in the planning stages.
I picked up a RC315 that looks in good condition yesterday at Rice-o-rama from an old guy(he was a dealer back a while ago) that didn't know much about it.