Flow bench measurements

[raz]

This reminds me Greg mentioned building a flow bench. Any news, Greg?

[Greg Field]

Yes, I've been playing with it a bit. I'm "learning" the ins and outs of small-valve roundfin heads. Then, I'll move on to medium-valve heads and then to large-valve heads, as on V11. THere's a lot to learn.

[raz]

Are all flow benches just sort of a vacuum cleaner and a flow meter? I wonder if you'd get different results with something that pulses the flow like a real engine.

[Hoodrewoodre]

Are all flow benches just sort of a vacuum cleaner and a flow meter? I wonder if you'd get different results with something that pulses the flow like a real engine.

 

Yes sort of... (besides there is more to it than a flowmeter and using the flownumbers)there are in fact some sort of real state flowbenches (like avl and the kryptic ones by the czech prof.) but also they take preassumptions(nevertheless a idiot on the wheels styas a idiot on the wheels if you dont mind me saying ihihi), and as a matter of fact there have been tests undertaken by curtiss allready b4 the war in order to check on that and there are sorts of correction factors but if one is wild on mathematics one could pull out the depression numbers of P-I-diagramms and go havoc..(not that would change too much though ehehe ;-) ), as a matter of fact there is allways the unknown variable of the infinite amplitude waves which are hard to take into acccount (especially for mixture ditribution etc.)

 

@ the swedish guys: why not gettin into contact with erland cox who is a master of the art and a world reknown tuner and besides that a mighty nice guy!!! :-)

 

wishing you folks a mity dolce ;-)

 

buona notte e sogni d' oro

 

ciao a tutti

 

christian

[raz]

@ the swedish guys: why not gettin into contact with erland cox who is a master of the art and a world reknown tuner and besides that a mighty nice guy!!! :-)

That was a great tip, thanks! For some reason I had never heard of him

 

Seems to be lots of good info on his site, unfortunately in Swedish only. I have some reading to do!

[motoguzznix]

Hello Christian

 

thanks for your reply

 

During the last two years I had to build a house for my family and my bikes, so the effort for the Guzzi stuff was very limited. But now I'm going to get my V11 back on the road.

Concernig the heads I started by slightly reworking the port in the area indicated by the arrow. As you would expect the effort was almost zero. The next step will be to enlarge the port around the valve guide. I have one spare head to play with and I intend to enlarge the port in little steps and check the effect on flow.

As soon I get results I will share the information here.

 

Some information about the rebuild of my V11 you can find here - for german speakers: http://www.world-of-guzzi.de/forum/index.php?topic=27638.0

[raz]

Some information about the rebuild of my V11 you can find here - for german speakers.

Ernst, that link is broken

[motoguzznix]

Ernst, that link is broken

Sorry - should work now

[Skeeve]

Sorry - should work now

 

Well, it works now, but requires a login... Not that I speak Deutsch, but I'm not afraid of trying machine translation & puzzling my way thru!

[raz]

Well, it works now, but requires a login... Not that I speak Deutsch, but I'm not afraid of trying machine translation & puzzling my way thru!

I made it through now. I do read German... sloooowly. Threads like that one is a good reason for excercising. Excersising. Dang I need to ex-er-size ingles too.

[luhbo]

This flowbench stuff reminds me quite fataly to those great oil temp sensor threads: First class, high speed wanking, nothing else. Get rid of these 120° bends in the inlet ducts, put in 2 extra valves and you have a basis for such semi scientific procedures.

 

Or, as one once had said: real life sex will never hold what masturbation did promisse you!

 

Hubert

[Hoodrewoodre]

This flowbench stuff reminds me quite fataly to those great oil temp sensor threads: First class, high speed wanking, nothing else. Get rid of these 120° bends in the inlet ducts, put in 2 extra valves and you have a basis for such semi scientific procedures.

 

Or, as one once had said: real life sex will never hold what masturbation did promisse you!

 

Hubert

 

Well hubert than i would recommend that you keep doing your stuff like a lot of the other old "know it all fellas" in austria (or anywher else for that matter) are doin.

I myself am still gratefull to have that tool since i would not be able to imagine how else i would have gotten about 55-57 ps out of an XT/Sr-500 engine at somewhat reliable rpms.

Besides its also a valuable tool for making your learning curve quite a lot steeper, if one doesnt like learning thats fine too at least for me "less" competition. besides with the aid of such a tool one can even leave 120 degr. turns and achieve almost the same flow and quality but pscchhhhhht "DONT TELL"

 

kind regards

[luhbo]

Maybe. Anyway, RL happens somewhere else.

 

BTW, what figures had the Manx or those old GP Guzzis?

 

Hubert

[Hoodrewoodre]

hmmm RL ??? no me understand?

anyways,.. an old G50 (dont have numbers of Manx's since they are practically not there in the classic race circus compared to the matchless) is in the range of about around 50 horses where the newer repro ones with more modern head architecture (thanks to flowbench work that gets published by the SAE) and more modern state of the art Camshafts (more lift less overlap) are in the range to about 60 horses and are often even more rideable because of the lesser overlap in comparison.

I reworked a while ago some Goldstar heads and made them in some sections even smaller with modern camshafts, seemed to have worked out quite fine :-)

 

ciao a tutti

 

Christian

 

PS: bout the old GP guzzis i have no figures besides some cam timing figures but i guess the gambalunghino should be also to modern comparison quite hot with the stroke+bore dimensions besides that most old bikes have somewhat low compression and to lil valve lift compared to moderns designs.

But i know for sure that the quoted figures for the dynotec guzzi in the last edition of MO cant be for real especially after considering that nobody would know where to get 119 horses from, maybe some german wondersalt and a bit of magic???

[Skeeve]

But i know for sure that the quoted figures for the dynotec guzzi in the last edition of MO cant be for real especially after considering that nobody would know where to get 119 horses from, maybe some german wondersalt and a bit of magic???

 

I thought that much of that figure came from the 1225cc displacement, plus pulling the numbers from the crank rather than the rear wheel? Figuring a 10% driveline loss ( I know, very favorable!), that still only works out to 107hp; about 12hp up from the stock 95 w/ 1000cc. 12hp from a 200cc bump seems reasonable... but not at their prices!