Laverda Jota camshaft differences

I agree with Red - the country was the dictator of specs. In Italy the later (Orange & Silver)Jota was offerred with a "sports kit" - which consisted of the 4/C cams and H/C pistons at extra cost. Of course there are so many now that are no where near the original specs - thousands of Jota cams, pistons and silencers  must have been sold over the years - not to mention 1200cc conversions -good business for myself and many others - Regards - Phil
 
cape said:
Why do some Jota?s (like mine) have standard A11 camshafts instead of 4C? Is this a model for specific market area? If so, what other differences are there? Oh, the year model is 1981.

Regards,
-Sami
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Hi Sami

looks like you are likely in Finland? For cams an 81 Jota could have had from the Laverda factory any of A12, A11, or 4C, and could have had flat top or high compression pistons. Depends on what country it was destined for.

A12's with flat top pistons would be the lowest power combination, and I would replace the A12's with anything else.

A11's with flat top pistons would likely give the best running, most torque, smoothest power of any of the original combinations from Laverda, really nice to live with, and easiest to run these days even on today's octane reduced fuel.

4C's are kind of "lumpy", they feel like they have a huge top end rush, likely exagerated by the hole in the torque curve lower down around say 4,000 - 5,000 rpm, so the top end hit is really pronounced. Add high comp pistons to that, and you get a really hard top end hit.

other options are a cam grind from Axtell, which seems to sort of combine the best of the A11 and the 4C, and Wolfgang and others have been offering a similar cam regrind.

then the later 120 motor cam grind, the F1 profile, has apparently been transferred by Keith Nairn to a cam suitable for a 180. This is the only cam profile I have no experience with in a 180 motor myself, but is one I would like to try. Perhaps someone who has run one of these cams, or Keith, can explain.

anyway, the A11's are decent, just not the fire breathing monster version of a "Jota", but if you want the fire breathing monster, easy enough to build that motor or swap cams or pistons, as so many others have done......

Paul LeClair
 
Hi Paul,

What a great answer. And yes, I'm from Finland (member of Scuderia Laverda Finlandia) and the bike is from German market. You told me practically everything I wanted to know. I'm more than pleased with my Jota and I'm not going to do any changes. I love the way it is. Was just curious about the combination...

Thanks,
-Sami
 
Mmhh - I don't know why people don't like the 4/C, it is running more than great in my 1200...

The drop in Torque and power is existing with ANY cam with the original collector and Dell Crapo carps, it is simply more visible with a higher power output... With the right collector and carbs, there is absolutely nothing to claim about regarding the 4/C.
 
Laverdalothar said:
Mmhh - I don't know why people don't like the 4/C, it is running more than great in my 1200...

The drop in Torque and power is existing with ANY cam with the original collector and Dell Crapo carps, it is simply more visible with a higher power output... With the right collector and carbs, there is absolutely nothing to claim about regarding the 4/C.
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I agree entirely (apart maybe the crude comment about the Dell'Ortos as I still think that they can be efficient, with siome efforts BTW) just like I also disagree about some comments about the lack of top end power with the A11s. With a well tuned engine, there is no real drop in torque with 4C cams (really below 4000 rpm...) while A11s can be really performant. I would sum up by saying that 4C cams are just hotter than A11s, but all in all both works well, which is quite remarkable for such an old design. It is even not rare that fine tuned engines with low comp pistons and A11s work really better than some hot motors equipped with the 4C kit.
 
Efficiency aside, the F1s seem to have a longer duration- A11s are awfully pointy cams.  Gotta give the valve train an easier time of it.
 
Paul and JLO,
Your comments ring very true for me about the A11's.
When everything clicks into place on my 120 (A11's) the bike feels punchy, sharp and very smooth for the vast majority of the rev range. Very pleasurable to ride.

 
My 1200, big valve head, flat top pistons, A11 cams with Toddy's 3/1 and head cleaned up slightly has never been a slow bike. Kicked plenty of real Jotas arses over the years even passing some down the straight at Eastern Creek. Have seen 240 kays on the [vaugelia] clock. Very nice motor and been very reliable for 170,000 kays.
Once it goes back together it'll be even better with Mikunis, Sache, Ross H/comp pistons, Axtel cams and lashings of ceramic coatings.
I should also mention that the bike has a weight advantage with the Motodd frame.
I rode a 120 jota the other day and reckon my 1200 is quicker all through the rev range.

Phil T, out of interest, do you know how much weight a Mk3 frame kitted triple is compared to a standard triple. I've never had mine on scales.
 
      Interesting Thread,    my 76 3CL runs 4C inlet and A11 exhaust cams, has the the 2.5 inch collector but I am unsure if she has high compression pistons.  I believe that the 4C/A11 combination is supposed to be one of the better original setups (disregarding later set ups ie P1, Axtells etc) I think from memory that Tim Parkers Green Book likes/recommends this 4C/A11 combination. Invites comments from our more technically minded members......  I do understand thats its all about where you want your power/engine behaviour to be.

  Cheers Shorty,  Oxford NZ
 
76 3CL with flat top pistons, A11 cams. None of the Jap bikes of the day got close, even those with big bore Yoshimura kits. Would run the speedo needle off the dial and get there with ease. Not unreasonable to use around town, certainly not as tractable as the Jap bikes in traffic but more than made up for it on the open road. Pity about the piss poor alternator.
 
on my 79 1200 after trying all sorts of engine combinations, what I settled on for the long term is standard compression pistons with 4C cams, IIS ignition, IIS alternator conversion (from a Kawasaki ZZR 250) together with uprated regulator/rectifier, and I went back to Dellortto carbs, although a later and fully rebuilt low mileage set on rubber RGS intake manifolds. The result is a really really nice rider, runs well on modern premium fuel, starts instantly at a push of the button, and has enough electrical power to run a heated vest and high beam and still keep the battery charged. I did have Mikuni RS 36's on the 79 1200 for a while, but them moved that set onto the RGS when I was building up that motor. I don't miss the RS 36's that were on the 180 and are now on the RGS,the Dellortto's work very well on my 79 1200 when combined with a decent modern ignition.

my 84 RGS Executive has high comp 80.4 mm J & E pistons in 1200 cylinder liners, with the 120 F1 cams, Mikuni RS 36 flat slides on Red's 36 mm angled intake manifolds, and a whole bunch of other mods including Carillo H beam rods, ported head, larger diameter exhaust, ceramic coated piston crowns/ combustion chambers/valve faces/exhaust tracts and a bunch of low friction coatings. The end result is a wicked fast RGS, but the 79 1200 is actually a bit "friendlier" to live with :o

if I had A11's in a 180 and was using it for general street riding, I don't think I would go out of my way to swap the A11's for 4C's or anything else for that matter......

Paul LeClair
 
Really Paul,you would leave it alone would you,not a chance mate.First snow and it would be in pieces quick smart.I have A11 in mine and have an order in with Keith for a set of F1.There is a que so I hear but better cams are the final peice in the jigsaw for me.That is till Red starts selling billet 4 valve heads
 
Mine's a 79 jota with 4c cams, not sure if they were fitted off the factory. Previous owner put flat pistons and jota replica collector on. The engine gives a pretty explicit power burst from 5000rpm onwards, which -to me- is heaps of fun, but not very useful in street riding, where i spend most time between 2500 and 5000 rpm, exactly in the zone that some people experience as a flat spot. Considering a set of F1's and long bellmouths for more torque and a power burst that kicks in at lower revs.
 
Axtells seem to offer heaps of midrange, I found I was going through the gears quicker compared with the A11s they replaced.
I might add that midrange was at the expence of top end, I'm getting too old for top end so wasn't concerned :D
 
76 3CL with flat top pistons, A11 cams. None of the Jap bikes of the day got close, even those with big bore Yoshimura kits. Would run the speedo needle off the dial and get there with ease.
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Really???  Get away with ya.  Maybe if you flung it out of a plane!  The dial goes to 140mph or more, and most standard Jotas (ie with the cams/pistons etc) make about 75 to 80bhp or so at the back wheel- mine was (IIRC) 79.9 Dyno-ed, although somewhat strangled by the airbox.  That just isn't enough.  I think even Keith's RGS (probably a good one :D) makes about 88 or 89. 
 
Reggie3cl said:
76 3CL with flat top pistons, A11 cams. None of the Jap bikes of the day got close, even those with big bore Yoshimura kits. Would run the speedo needle off the dial and get there with ease.
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Really???  Get away with ya.  Maybe if you flung it out of a plane!  The dial goes to 140mph or more, and most standard Jotas (ie with the cams/pistons etc) make about 75 to 80bhp or so at the back wheel- mine was (IIRC) 79.9 Dyno-ed, although somewhat strangled by the airbox.  That just isn't enough.  I think even Keith's RGS (probably a good one :D) makes about 88 or 89. 
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Well in the 70's I never met any bike on the road apart from the Jota that could live with my 3C (A11 cams and HC pistons) and that was Z1's, Kwacker 750 triples, GS1000's and all other Italian bikes. The 80's was a different matter though, the GPZ1100 could only be beaten by desperate means ha ha!
 
Reggie3cl said:
76 3CL with flat top pistons, A11 cams. None of the Jap bikes of the day got close, even those with big bore Yoshimura kits. Would run the speedo needle off the dial and get there with ease.
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Really???  Get away with ya.  Maybe if you flung it out of a plane!  The dial goes to 140mph or more, and most standard Jotas (ie with the cams/pistons etc) make about 75 to 80bhp or so at the back wheel- mine was (IIRC) 79.9 Dyno-ed, although somewhat strangled by the airbox.  That just isn't enough.  I think even Keith's RGS (probably a good one :D) makes about 88 or 89.  
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Your dial might go to 140 mph but here in the real world the dial goes to 220 real thingies. And yes it would run the needle off the dial. Whether that was real speed or slippage in the speedo I have no Idea as I really didn't want the police involved with the speed check, however the speedo proved to be accurate when I was travelling more sedately. Never got a ticket on the bike but spent a lot of time on the side of the road going through "inspections" and chats - usually along the line of "What is it? Who makes it? How fast does it go? On your way then." - nothing has changed really. Only problem I ever had with the cops was one prat in the '90s who pulled me over with no real excuse, but basically wanted to gawk, had wanted to buy one when they came out but couldn't afford it, and promptly put a yellow unroadworthy sticker on the bike because it had Japanese instruments and they needed calibration. Didn't take kindly to being informed they were original - he knew better as he had been going to buy one etc etc.

And as to Jap bikes in the 70's - pffft. I had a heavily worked 900 Kwaka immediately prior to the 3CL, chalk and cheese. And the 750 Hondas, bleah.
 
I did always think that my old bike was a little lacking in extremis; there was no way it was going to go off the clock at 140 plus, although a 1200 Mirage I rode in direct comparison felt similar.  Anyway, I put that down mostly to the air box which was due to be binned as the next step in the development of the bike.  Certainly it wasn't lacking in the midrange and anything over 120-130 on the roads up here (fast but often bumpy) made for an interesting ride...

Must admit, my Jap bike reference points are a little bit later- GSX1100, big GPZs and the like, but I never did ride them in direct comparison with any sort of Laverda unfortunately.
 
Ithose jears i was joung driving Tomos 90 Electronic and later CZ350 twin , older ones have big jap bike and on coast road from Zadar to Rijeka fastest bike was Laverda 500 .
 
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