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"Norris SS" cam. I'm interested - any opinions & advic


ScuRoo

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So, the identity question remains, is the "Italian SS (also known as the P3) Raceco are referring to - actually the Norris SS, or has this "SS" designation been coincidently used twice, the Italian SS (or P3) and the US company Norris independently developed their own "SS" version…?

Looks like "SS" could mean four different cams: the original Guzzi P3 (what Raceco calls the "Italian SS"), the Norris SS aka Megacycle 620-11, and the two Raceco cams (SS2 and SS3).

 

Now the trouble doubles. The Raceco duration is specified at closer valve openings (0.5mm instead of the typical 1.0mm opening) which extends the stated duration.

 

EDIT:

Best I can figure, with all the vagueries, is (someone should check my work on this):

 

1064 Sport cam -> 620-10 -> P3 -> SS2 -> 620-11 -> SS3

 

With lift of 0.446"(!), the SS3 would surely make a rousing difference over the Sport's 0.298 lift cam.

 

Interesting statement by Ed Milch I saw on guzziriders.org posted there by dan_s:

 

                                                   "Ed Milich who races guzzis wrote me that no straight drop in cam is worth the hassle."

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 I cleaned up and recombined several of my posts on this thread, so that's all I could pull together for specifications and comparisons.

 

Now, the question remains: Why not cam a V11?

 

My take is that the V11 (1064 Sport) cam is very well optimized for the bike, but surely there are those here who have changed the cam.

 

If so, to what?

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  • 1 year later...

 I cleaned up and recombined several of my posts on this thread, so that's all I could pull together for specifications and comparisons.

 

Now, the question remains: Why not cam a V11?

 

My take is that the V11 (1064 Sport) cam is very well optimized for the bike, but surely there are those here who have changed the cam.

 

If so, to what?

I was looking at this cam upgrade business and came across HMB cams in Germany mentioned on Wild Guzzi.  I googled HMB and their upgraded cam was worth like 3 HP.  On some of the other older Guzzi models gained up to 10 HP.  

 

http://hmb-guzzi.de/Engine-Tuning-Repair

 

My guess is that the cam has to be matched with porting and titanium pushrods + ECU map to get a little bit more.  In all honesty my V11 seems to have pretty solid performance in the sweet spot 4-6k range for a Guzzi. I wasn't knocked out with Norge/Griso 1200 8v except for a little more top end.  The1400 seemed to run good for a 750 lb motorcycle.  Sometimes there is no replacement for displacement? 

 

But if we're saying cam+porting is good for 5 or 6 HP, then I wonder if it's worth the effort.  The V11 is rated at 90 (optimistic) HP?  With maybe 75 at the rear wheels but with a good torque curve.  

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My newest V11 came with FBF Pistons, Carrillo rods, Megacycle Camshaft, FBF xover, and Gianelli silencers.  Oh and a PC3

 

The post Dyno tuning was 77 whp up from 70whp.

 

Not sure if this help but thought I would contribute the data that I have.  

 

Let me know if you want me to post the dyno charts and I will load them up as an image.

 

-Nick

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Does anyone know what a safe redline would be on my bike with the upgraded internals?

 

Aren't the valve springs one of the main limiting factors for redline? You didn't mention any work to the heads in your post.

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Hi Scud,

 

I don't see where any valve work was done on it based on the documentation.

 

Not sure if the PC3 overrides the rev limiter, seems like I have been past 8k and I don't want to do any damage.  Some mention of the Veglia gauges being off by 300 rpm or so though.

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I have said that about the Veglia being off. Some of them even more.

 

Check yours with guzzidiag, at idle and at *some* RPM.

 

Seems to me, it is the valve train that is the limiting factor for "red line." Since your valve train doesn't appear changed, I would not feel confident exceeding the factory redline.

 

Which Megacycle cam do your have (there are several)?

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I am not sure why you need to go past 8k, the power levels off at 7k.

 

Now sure, a new cam might rev it a little more but it appears that you can go to 8k if you can make power up there.  I'd be surprised that any street cam would exceed 8k in power range.

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The new bike has the Megacycle X9 cam and on the dyno result it pulls all the way to 8k without more than a 2 whp dropoff.  Thought it might run out of breath sooner, so was pretty impressed.  Maybe the higher compression pistons help here.

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  • 2 months later...

"

Raceco Moto Guzzi SS2 and SS3 camshafts will be produced during the month of October. Some will be available for outright purchase or you can send your cam to be re-ground. As there still a demand for these cams I intend to have a yearly batch done each autumn ready for winter rebuilds. Pictured is an SS3 cam that is currently available for outright purchase. 

Please get in touch with me by email at a.castellani1@btinternet.com if you are interested in purchasing a camshaft outright or would like your camshaft re-ground. 

The cams will be £175.00 GBP Sterling if reground on your original cam or on an exchange basis if available. Outright purchase, if available, will be £255.00. Carriage extra. As I'm having them done in bulk this is actually £20.00 cheaper than it was four years ago when I was running Raceco UK full time.

For the big two valve Guzzis I would recommend the SS2. We have fitted many since the 80s to everything from T3, Californias, Converts to Le Mans 1,2,3, and 1000. A very flexible cam. Our best seller for many years. This can be used with standard springs that have been shimmed to 36mm. Pulls from 1,500 rpm with extra kick from 4,500 rpm.

Information regarding the SS3 camshaft: Although the SS2 profile is different the cam fitted to the Sport 1100 and V11 as standard, it is very similar to the SS2 in terms of lift and duration. For this reason I developed the SS3 which does give a pretty big improvement. It is based on the RR3 cam that was used by Doctor John Wittner for racing at one point before he started using the "F" full race cam. The RR3 is suitable for high rpm road and race use and is more flexible than the "F" cam. It is a performance cam. It is a difficult cam to fit, will require different valve springs and top collars and in some cases machining of the valve seats so the valves do not touch on the overlap. A cam for the technically minded home mechanic or professional engine builder.   "

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I've installed the WebCam 86b in my '85 LMIV. 
 

.447/.447

298°/298°

260°/260°

86b

 

Though this cam has numbers very similar to the Megacycle 620x7, it has very, very good street manners and low rpm tractability. I haven't dialed in the top end yet, but it's already considerably faster above 5k rpm than my stock Sport i. The difference that doesn't show in the numbers is that the Web cam requires larger diameter lifters, because the lift rate is faster sooner than the Meg cam; that means the valve opens more 'curtain area' (exposed area between valve and seat) sooner in the cycle, and flowing more air off-peak. That translates into not only equal or better performance at peak rpm, but better characteristics off peak and smoother power curve throughout the range. I can't leave well enough alone, and the work and expense of installing the Web probably wasn't worth it simply for the improvement difference (never rode the Megacycle so I'm speculating) but it was as much an academic exercise as anything. 
The roller rockers need a bunch more valve spring to get to peak power, with R&D springs it's limited to 7k rpm before losing valve control. 

 

Here's a pic album showing the restoration with pics of what I had to do to install it. 

 

https://photos.google.com/share/AF1QipP6lOTNerG1sbqs9QkvBwZIQSc6AvZKZD28FDiehtuVaPt8g8hU3yUGBNH2MFwddQ?key=MTgwQ05SWlZyeW9scDZIdHNHdUw4Z2NIaXptWnZR

 

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