WANTED - 1000 SFC/RGS Corsa head

that "CR" stamp looks (a bit) fake to me.
Corsa heads are rarer than rocking horse shit, but strangely, back in the day Slaters ran out of/ could no longer buy, stock 180 or RGS heads, (well that was what he said) several riders at the time had to have head repairs done and only the Corsa speck one was available, so that is what was bought, ex committee member the late Henry Morgan being one of them, for his 180 Jota, that of course meant buying a whole big box of other hardware that was not compatible with the smaller valve head. It always seemed a bit weird to me that the Corsa head had 41.5mm inlet valves, 36mm diameter inlet ports but only 32mm carbs.
CLEM
 
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I discussed this with Piero in 2006 or 2007 at Willy Werndel's meeting when we also discussed my 40 mm carbs conversion. I asked him why they went with the 32mm carbs instead of the 36mm and he said that for street usage, most focus was on torque and throttle reaction rather than excessive power (I think though, it was a question of keeping all the carbs the same and having something to sell as upgrade, just like you could buy the corsa head, too, as an upgrade; and also maybe cost efficiency...). As Uwe Witt had a big influence into the RGS1000SFC development at least, I assume Uwe (who had a professional dyno in his workshop and made TONS of development work there - and still does) agreed to that strategy, as he could have ordered the bikes differently (he pre-paid lots of them...). But that is just me speculating regarding Uwe.

I asked him also, why they did not taper the manifolds at least to get smoother running then and he said that they did not see the need for it as cost compared to efficiancy/torque output did not make sense. I had no diagrams to show him wrong and looking at the improvement my bike went under by changing the exhaust, I must admit that the real problem wasn't the non-tapered manifold (allthough it might not have been ideal...).
 
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Oh - forgot one major thing...: homologation! With the RGS sharing the same frame and engine (basically...), it was easier to homologate the Corsa and the SFC with the same size carbs as "just a variant" of the RGS in Germany (and as Uwe ordered most of the 1000 SFC and re-sold them to the other dealers, it was easier to do that in Germany that way as far as I recall.
 
Laverdalothar said:
Oh - forgot one major thing...: homologation! With the RGS sharing the same frame and engine (basically...), it was easier to homologate the Corsa and the SFC with the same size carbs as "just a variant" of the RGS in Germany (and as Uwe ordered most of the 1000 SFC and re-sold them to the other dealers, it was easier to do that in Germany that way as far as I recall.
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I'm sure you're quite right about the issues both of homologation and inventory management, Lothar.

There's much, much more involved in 'getting something to market' than just 'simple' technical issues. Those are just two examples of the kind of things that owners often have no awareness of/overlook.
 
you went to a lot of trouble to take that picture Adam, shame that the font is incorrect, the R is not stamped deep enough, the broken fins, oil leaking from cam cover, silcone oozing out of the joint, chisel marks on cam cover etc etc, still I would take it off your hands for a bag of sand to save your grief if that works for you.
CLEM
 
CLEMTOG said:
you went to a lot of trouble to take that picture Adam, shame that the font is incorrect, the R is not stamped deep enough, the broken fins, oil leaking from cam cover, silcone oozing out of the joint, chisel marks on cam cover etc etc, still I would take it off your hands for a bag of sand to save your grief if that works for you.
CLEM
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errrr let me just think about that for a nanosecond - noooooooooooooooooooooooooooooooo enjoy it from a distanceCorsa right side (Medium).jpg
 
CLEMTOG said:
you went to a lot of trouble to take that picture Adam, shame that the font is incorrect, the R is not stamped deep enough, the broken fins, oil leaking from cam cover, silcone oozing out of the joint, chisel marks on cam cover etc etc, still I would take it off your hands for a bag of sand to save your grief if that works for you.
CLEM
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I can hear a big end from here.
Paul
 
he said big end, not bell end, and anyway I just couldnt bear it on my property with the non stock grab rail, four piston callipers on Red brackets, and on the wrong side of the forks as well! I cant forgive the perished brake hoses (surely) complete with 1983/6 date stamped collar, when Hamish eventually got round to changing same on his 3C (done here at Knockholt after I pestered the life out of him)) we found that (un-beknown to him) one of them was wearing a flat where under hard braking, the oil cooler was grinding it away!
CLEM

ps stock rubber brake hoses can easilly be bought for jack shit money, as they are rears from a Mercedes car, Hamish will advise which model I hope
 
Take an RGS or late Jota 180/120° head, get the seats re-cut and the inlet ported to 36mm and new inlet valves (Opel Vectra 2,0 Liter I think) and you are good to go. Cost of doing that including the head is cheaper and you have a freshly overhauled head.

just saying.
 
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