Jump to content

DYNO GALLERY


dlaing

Recommended Posts

...

There is also this kind of camshaft that is very popular in Germany, alo has inside holes for better lubrication

....

:bier:

 

There is rumour in Germany also, that most of the cams sold here are copies of Scola's ones. Except those of Schrick probably.

I also know Scola as the real Guzzi man here in Europe, would't say god, but something like that indeed.

 

I once bought a used LM3 coming of his shop. This bike now has 80000 km and has seen nothing more but things like worn tach snails, brake pads and such. The gear box was shimmed by his shop, works as good as the one of the V11, if not better!

 

Great shop, great mechanic, probably great man (unfortunately I don't know him personally, buddies of me do).

 

Hubert

Link to comment
Share on other sites

The cams is the real heart of tuning. Valve rising fron 7mm to 10mm. And different timing. With fast extraction exhaust and a correct eeprom map, you easily get up to 15 hp.

Only KS cams gives 15hp. Oss maybe 4-5 less. They are cams with profile tested in 30 year on guzzi Vtwins.

I think I should make clearer some things concernig camshafts.

The V11 cam has a valve lift of 10,5 mm. The OSS cam lifts at a max of approx. 11 mm having shorter duration of 276 deg quoted compared to the 301/305 deg of my V11 cam measured with the same clearence of 0,5 mm. From the lift figures above the valve clearence has to be subtracted.

Shorter duration is good for power in the lower rpms and can help fill up the dip in the torque curve, while the higher lift will help restore the max power at high rpms. To get more power at high rpms from the OSS cam should be difficult, as the stock cam isn't that bad. Compared to the cams of the earlier Tonti framed Guzzis, the gains are much smaller.

More lift and shorter duration means also faster opening of the valves, which ist good for the volumetric efficiency (VE) of the engine, but not so good for the valve acceleration. When you take this into account, the valve springs have to be stronger (for the same max rpm) and thus valve train wear increases.

To get such big gains like quoted above is difficult on a V11 engine and needs extensive work.

I agree, the cam is the heart of every tuning, but only when it is the weak point in the system. To increase the max power, the OSS cam is not the way to go. For that purpose, a cam with more lift and duration is needed, but at the expense of the much liked low rpm torque. This should be the domain of the OSS. :2c:

 

PS: An OSS cam is already in my house awaiting the installation and measuring the valve lift curve. I will look forward next year. :bike:

Link to comment
Share on other sites

 

Great shop, great mechanic, probably great man (unfortunately I don't know him personally, buddies of me do).

 

Hubert

 

I have a chance and met him by Agostini last Sept. I didn't know it was him since it"s first time I hear this name.Easy person, with interest on Guzzis,and friendly as well,we had a short discussion on the fuel maps I was doing for the bike showing him fuel charts and Dyno runs and telling him what and how I did to correct some differences on mine and why, seemed to agree on that.

A latter test ride of the bike from the younger but excellent mechanic Meme, witnessed the well improved mapping (that by that time wasn"t as good as now. as a couple un-smoth spots existed) over other 1100 Sports he has experienced.

Link to comment
Share on other sites

 

 

To add further Power graphs:

 

Here are 3 different V11 Guzzis in original state of tune, measured on the same dyno:

 

Red is my 2000

Green is a 2001 naked

Blue is a 2005 Rosso Corsa with Catalyst

 

Note: the first 2 bikes do have the same engine except the black engine coating of the newer model; Even the software in the 1.5 M box is identic. Bike nmber 3 is much different, improvements by the Guzzi factory are visible.

Link to comment
Share on other sites

PS: An OSS cam is already in my house awaiting the installation and measuring the valve lift curve. I will look forward next year. :bike:

 

could you, or any other enlightened and fine person on this forum, explain the differences between the cams Scola is providing ? I have the RS but i have no clues where it fits in the HP food chain so to speak :)

 

scola.jpg

Link to comment
Share on other sites

could you, or any other enlightened and fine person on this forum, explain the differences between the cams Scola is providing ? I have the RS but i have no clues where it fits in the HP food chain so to speak :)

 

scola.jpg

Jihem

 

There is never a clear point to be made about camshafts, as the quoted figures only allow very rough comparisons from one to another. :homer:

 

The best possible information is the measured lift curve: :luigi:

Adjust the valve clearence to zero

put a dial gauge on the valve spring retainer

fix a disc with a 0 - 360 degrees scale on the crankshaft, adjust it exactly on TDC

measure the valve lift every 2 or 3 degrees of crank angle

Measure the intake and exhaust valve without touching the disk on the crankshaft to get the correct overlap

Send the measured figures to me via email, I will provide you an analysis of the cam with excel

 

Concerning the RS cam: The 8,7 mm cam lobe gives a valve lift of approx 11,7 mm, 1,2 mm more lift than the stock cam. This should be good for some more HP at the top end. But only when the ports in the head allow better flow at the higher lift, which is not a must. If this is not the case, the higher valve lift only contributes to increased valve train wear. Bruno Scola himself quotes this cam works best above 3000 rpm as it is a sports cam.

Very important for a cam is the amount of overlap (area, degrees, lift), the acceleration off the seat (here is the biggest drawback a pushrod engine has compared to a DOHC design), the area under the lift curve, the timing with the adjusted valve clearence while running. All these figures are not quoted by the manufacturer and can be calculated when the lift curve is measured.

 

Put your bike on a Dyno. Why doing that much work on the engine and not checking if it is worth the effort? :doh:

Link to comment
Share on other sites

Here's my dyno run. We talk about rearwheel horsepower. Stucchi crossover and Gianelli's exhaust.

We have to do something about the on/off effect around the 3.000 / 3.500 tpm.

post-3016-1163159796_thumb.jpg

Link to comment
Share on other sites

Put your bike on a Dyno. Why doing that much work on the engine and not checking if it is worth the effort? :doh:

 

merci for the analysis btw !

 

i'm just awaiting for the PC III to be tuned as good as possible before lashing out the mad HPs on a bench ;)

It's nearly good now, just a far too soft spot round 2000 to 3000.

for infos, the heads were flowed and yes, i can feel a real and very strong difference above 3000. my pb now is actually to find places where i can test the bike without running in too many cars or radars. The bike just rushes to insane speeds (for me) now. I'm not very confortable riding above 220 kmh on the sole purpose of testing a newly acquired Scola camshaft, officer.

Link to comment
Share on other sites

Here's my dyno run. We talk about rearwheel horsepower. Stucchi crossover and Gianelli's exhaust.

We have to do something about the on/off effect around the 3.000 / 3.500 tpm.

 

It just seems you are too lean for HP at the lower rpm till at least 4000,Improve that AFR first nd you'll see results.

Link to comment
Share on other sites

My efforts on remapping my 2000 KR:

 

The bike was equipped with Stucchi X-over and my modified stock mufflers on all 3 runs.

 

green is with the stock mapping in the Weber Marelli computer

red is with first modifications doing Lambda-measurements on the road and modifying the map accordingly - a little scary driving approx.180 km/h in 4th gear at max rpm on public roads

blue is the result of further measurements and modifications on the dyno

 

By some reason (don/t know why) max power is down by 6 HP compared to the run one year ago. First I suggested the slightly different mufflers may contribute to that, but a back test with the older mufflers showed no difference. This years measurements are in proper relation to each other.

 

I lowered the rev limiter to 8300 rpm in my custom mappings. I also did part throttle measurments at every throttle opening point of the map to get better allround performance. These results are not visible on these WOT power graphs.

Link to comment
Share on other sites

The following graph shows the influence of the spark map on power:

 

The bike runs in the same hardware configuration than in the previous post.

 

blue is the best result in my post above

red is with the ignition at full throttle 3° retarded

 

In a post of dlaing some time ago the stock spark map was included. According to this, the max advance at full throttle was 44 deg at 8500, whereas a former LM never had more advance than 34 ° from 5000 rpm onwards. This convinced us to try a reduced spark advance. I wanted to go further that route, but my mapping system finished to work and so my efforts were stopped. Next year....

My suggestion is that the very lean stock mapping needs that much advance, whereas my enrichened map can make use of the better timing now.

Link to comment
Share on other sites

The reason for 44° spark advance is that it can be favourably done on modern engines with modern engine management. Such high advances would be advantageous also for older, points equipped engines, of course. The only problem was, you couldn't go back when and where in the map it was required. So some safety distance had to be kept. That's all.

 

One question BTW: why do some of you that are able to do so lower the max. RPM limiter value? Why don't you go up to 9000 instead, just for safety reasons for instance?

 

Hubert

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...