1034cc SF Engine build (Slowly)

julian said:
One thing that bothers me about the RCs is Lothar's comment about giving full throttle and having to feather it!  That in my book for my use would be un-tolerable. Is this a feature of CRs etc or just on occasion?
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Hi Julian,

good to have you back healthy :-)

Not sure what you refer to, can you explain a bit, please?

I only have experience with FCR, not so much with the CR. What the FCR do definitely deliver over the PHF/PHM is lighter and shorter actuation (the PHF you have to turn throttle almost 1,5 times to give full open, on the FCR it is roughly 0,75 times), the "desmodromic actuation" (one cable closes the sliders), way better response to throttle action and more torque. Especially when fitted with power-blades, the response in low-end is significant. I assume this to be the same on RS36 from what I've heard, never tried them though.

The max power wouldn't bother me to much, too, but low end and midrange being their strengths, this makes them my desired carbs.

HTH
 
I think the throttle is turned one and a half handfuls for Dellortos, but not 1.5 times, that would be 540?.
Maybe something like 180? vs 90? for Mickeys or FCRs (or a little bit more).
 
More turn yes but as Grant says not that much,no cronic hand cramp since I ditched the Tomasselli Quick Action though :D
 
Laverdalothar said:
as usual on flatslides - you need to only gently pull the cable; if you open it at once, the vaccum goes down to fast and the bike stalls or accelerates badly. Surely different, if you take smaller carbs, 39mm might be a bit on the big side for a 1000ccm engine.  ;)

However, yes, you can make them work but the difference to the flatsliders in throttle response, actuation forces needed etc. is significant. Maybe not so much to the CR's, have no experience with them.
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Hi Lothar,
It was the above comment that phased me!  maybe I misunderstood you.

Regards,
Julian
 
Hi Julian,

well - it is all a question of how you typically ride a bike. Are you normally pulling to WOT from idle? Normally not, at least not me. The actuation of the FCR is way shorter than the Dell'Orto (even if not 1,5 turns but 1,5 TIMES as much as on the FCR...) and with that, you can make them fully open by just a twist of your wrist. If you would be able to do that on the Dell'O's, you would maybe experience the same effect. As you can't (you have to change the grip on the handlebar once to get them to full open throttle...), you will have smoother opening, which leads to a less significant effect. Also, if you put 40mm Dell'Orto on the bike and compare them to FCR39 or 41, the effect will be - I think - almost the same. Simply to less under pressure for proper vaporization at idle with WOT.

You get used to how to handle the FCR quite quick and there are several things to smoothen out the effect, but you will never fully remove it unless you go down to FCR 33 or so.

HTH

BTW: FCR's are very common on GSX-R's. In a German Forum a guy once complained about this symptom and another one said: "To ride with FCR's properly, you first have to learn to ride with them properly!" Says it all for me...  :D
 
The off idle response to small throttle openings on flatslides is IMO usually solved by tuning the accelerator pump circuits.
If Julian goes the FCR way I don't think he'll have those problems with the big twin...the problem is usually most noticeable on small cylinders with big choke sizes - like the GSXR's quoted.
The ease of throttle opening mentioned is typical of reel type cable mechanisims - the CR's are the same.
The CR's are very responsive off idle without pumps - sometimes too much so - our GS racebike caught out the owners brother coming off a slow corner recently...
I've used Mikuni RS flatslides a lot and they seem to take less setting up than any of the other options.
I came across a Dellorto set a couple of years back which were off a Japanese market small Pantah. Two 32's paired up with a cross shaft and reel type cable drum. Don't know how common these were but I reckoned the mechanism would have transferred to bigger Dellortos quite easily.
 
lemonjelly said:
More turn yes but as Grant says not that much,no cronic hand cramp since I ditched the Tomasselli Quick Action though :D
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i was just going to ask. For me, i'd like some shorter 'stroke' on the gas than the stock trottle grips. but i take it they're too much of a good thing?
 
and is a linking word for joining compatable/additional ideas together in a single sentence.
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and your point is  :P :P :P

BTW, when quoting something, it is customary to enclose the subject in quotation marks - thus:

""and" is a linking word for joining compatable/additional ideas together in a single sentence."

But ( ;) ) the English language is constantly changing, so who knows what will be correct in a few years time  8)

Julian - loving the project - what about a few pics?.....pleeease?

Pete
 
bob said:
henry said:
if my students start a sentence with 'and' I encourage them to self flagelllate with a Sjambok! and is a linking word for joining compatable/additional ideas together in a single sentence.
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Each to his own Henry but it seems a bit harsh to me. But what do I know? I'm one of the semi literate morons you refer to :D :D :D
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no!!!!!!!!!!!!! never meant it that way :-[ :-[. the 'morons' are the ones who write professionally and stuff it up anyway!
then there are the higorani - the arseholes who prove that a little learning is a dangerous thing.

pete, by the way, english is not constantly changing, it is steadily changing! :P
 
Just picked this thread up - "And , and , feckin' and ? What kind of a name for a band is that ?"

Name the movie..

Ally

Henry - not a dig at you - your grasp of English has me in awe.  Just don't get me started on the difference between less and fewer ...
 
Dellortoman said:
"Less" is analog
"Fewer" is digital
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and both have nothing to do with Julians highly technical thread.  :P May I suggest that if this is of so much interest to discuss the nuances of the english language, you please start a new thread to sort that out? Not that I am not known to get off topic, too, but it would help to keep this interesting thread on topic, please.
;)

thanks a lot
 
Laverdalothar said:
Dellortoman said:
"Less" is analog
"Fewer" is digital
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and both have nothing to do with Julians highly technical thread.  :P May I suggest that if this is of so much interest to discuss the nuances of the english language, you please start a new thread to sort that out? Not that I am not known to get off topic, too, but it would help to keep this interesting thread on topic, please.
;)

thanks a lot
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    Here here.


      Keith ( mostly interested in old motorcycles, less so in the English language )
 
julian said:
Laverdalothar said:
as usual on flatslides - you need to only gently pull the cable; if you open it at once, the vaccum goes down to fast and the bike stalls or accelerates badly. Surely different, if you take smaller carbs, 39mm might be a bit on the big side for a 1000ccm engine.  ;)

However, yes, you can make them work but the difference to the flatsliders in throttle response, actuation forces needed etc. is significant. Maybe not so much to the CR's, have no experience with them.
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Hi Lothar,
It was the above comment that phased me!  maybe I misunderstood you.

Regards,
Julian
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Maybe I did misunderstand you Lothar,
I just tested my "CR" 500  :D    CR Honda that is  ;)  But it has a nice big Keihin Flat side on it.
Yep, pickup is instant I can tell you!  Slam the throttle open at any time and HANG ON!!!!!!!!  No hesitation! Just WooooooooooooooooooAhhhhhhhhhhhhhhhhhh!  But the carb still looks to modern  :P

Julian
 
There are no ugly parts on an FCR, Lothar. They are works of art, especially in operation.
Julian, stick a pair of Dello's on it to start with and see how you go. You might not be riding it enough to have to deal with the frustrations of worn carbs anyway. You probably have access to FCRs to try out anyway if you aren't happy.
A mate with a racing Guzzi stayed traditional and fitted huge new Dello's to it. He has a major problem with them sticking open in the wet.
 
Tippie said:
There are no ugly parts on an FCR, Lothar. They are works of art, especially in operation.
Julian, stick a pair of Dello's on it to start with and see how you go. You might not be riding it enough to have to deal with the frustrations of worn carbs anyway. You probably have access to FCRs to try out anyway if you aren't happy.
A mate with a racing Guzzi stayed traditional and fitted huge new Dello's to it. He has a major problem with them sticking open in the wet.
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Tiny bit of oil in the fuel may cure that one Tippie!
We used to have a similar problem when using Methanol, an egg cup full of "R" per 50 litres cured it!
And made it smell nice :D

Julian
 
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