Topic: Norris RX3 cam in a ported 1000cc engine

[gschuld]

I'd like to know more about the Norris RX3 cam.   I have read that the cam has roughly a .380 lift intake and exhaust with about 300 degrees of duration.  Is this correct?  Big Jay, if you read this, I understand that you have the full specs on this cam.  I'd like a look if you wouldn't mind.

Any history on RC Engineering's use of this cam in their motor builds would be helpful.  I have heard that RC used this cam (and other Norris cams) on occasion for Cobra 1000 builds(rather than the RC #327 cam)

A few specific questions:

1- Does anyone have any experience to know what the rpm range(power band) this cam would give a 1000cc motor with RC fully ported heads, lightened and polished rockers, HD springs, aluminum retainers, RC 4 into 1 exhaust? 

2- At roughly what rpm level would I expect the power band to top out?

3- How does this cam compare the RC range of cams? (#295,#315, #327)  The photo below is from the 1971/2 RC Engineering catalog

3- Would the carb airflow requirement be too great for a set of properly jetted/tuned factory K0 carbs at the upper rpm ranges?

4- Keeping to pre 1972 vintage style, other carb options would really be limited to RC weber conversions, modern accelerator pump versions of vintage CR carbs, or having a custom "maxibore" modification done to a set of early factory carbs.  (the bike does need to be functionally streetable, so early race only CR carbs are obviously out)

5- What would be limit(cam wise) for the above 1000cc, RC ported head motor without choking out(cfm wise) a set of factory unmodified K0/K1 carbs on the big end?



Reference to Maxibore carbs:  http://www.x-pipe.com/motorcycle.html

From website below: (quite the sales pitch anyway )

PRECISION MAXI-BOREtm carb boring service allows you to have the best top end air flow - and - even more low end power than you now have. Impossible? MAXI-BOREtm Carb profiles are designed on a flow bench for maximum air flow and are tested on the strip for maximum response and acceleration. Precision cuts allow air to pass over critical jet orifices creating the maximum jet signals possible. Tests have shown that even though a stock 29mm Smoothbore carb outflows stock 28mm mikuni carbs, the stock 28mm carbs actually outperform the Smoothbores at the drag strip, because the Smoothbores have very poor low speed response due to poor jet signals. From these tests it is easy to see why a MAXI-BOREtm 26 or 28mm carb (the "sleeper" carb) easily outperforms the stock Smoothbore; both in terms of throttle response and top end power. It is also easy to see why a MAXI-BOREtm Smoothbore is the best carb money can buy.


Thanks in advance for helping to make me smarter (I can use all the help I can get )

George

[BLUE71TURBO]

  How many times do ya gotta ask ?          JUST KIDDING !   

 I just noticed that the pic of the R.C. cam spec's is out of my catalog.      That's my hand writing on the page.   

[gschuld]

Computer snafu....  why do you think I like 40+ year old machines!

George

[MRieck]

Computer snafu....  why do you think I like 40+ year old machines!

George

I was just gonna type that. Still waiting to hear from my buddy about those parts. He was away but I'll call again tomorrow. THANKS for the old RC catalogs.......you are right about the #'s.

[gschuld]

Glad that you got them!  Should keep you entertained for a while......    As you can see, I'm still actively learning, scheming, and planning regarding the 1000 motor.  My goal is to some day be smart enough to at least sound like I know what I'm talking about!

George

[Bill/BentON Racing]

Just nod and grunt....and as Joe Walsh  ;Dsaid.....just ACT like you do! Oh and smile! Bill
Mike, how old, I have 1980 and 84, would like to see earlier! Don't have 1880 though!!

[gschuld]

Bill,

PMs sent

George