See Jota are 1000cc or 1200cc and Mirage 1200 cc only i hope this will help

Did you grind them in the RMIT workshop as well as designing them there??

So your 1978 1200 is not really a stock 1978 1200 - but a bit of a hot rod. Nice!!
 
CLEMTOG said:
the 1200TS had A11 cams and flat top 7.8:1 pistons, but the first ones had the "middle head" that is the one with big valves, between the stock head and the RGS head, not a very successfull design was that head, mine now sports and RGS head.
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more info. if you have it Clem ... my 1200 (US) is a series I with A11 and flat-tops but the term 'middle-head' is new to me. I might be able to guess the valve sizes from a recent photo (but the head is back on).
 
first triples had 38.1/35.1 valve sizes
then, 39.5/35.9

big valve head (middle head) 39.5/36.4 or 35.1 (could be either exhaust size)

plus RGS and 120 Jota had 39.5/35.1
lastly Corsa and SFC 1000 had 40.6/34.0

so the best head ever had the smallest exhaust valves

someone correct this if you believe it to be wrong.
CLEM
 
If I'm not mistaken, the short-lived intermediate "Jota" head had 39.5mm in. and 36.5mm ex. valves, which turned out to be a waste of time/effort.

Depending on the OEM batch, the valves could be 0.10mm, or more, under- or oversize. So, generally, it would be 38, 39.5 and 40.5 for the inlets, 35, 36.5 and 34 for the exhausts. A 41.5mm inlet valve was available for racing purposes. Special care was needed to set these up, a missed gearchange could have them tangle with the exhaust quickly.

Never seen OE 36mm ex. valves. Got a part number? ;)

piet
 
"Never seen OE 36mm ex. valves. Got a part number?"

I got this from the Falloon book, but on going back I cant find it, and may have got confused with exhaust pipe size, and was not able to referamnce that in multiple parts books, but..

I did find on page 98 of a 35.9mm ex valve, that I didn't spot first time around!

CLEM
 
Cerianis with laid down shocks do/did exist-no big deal really but the original 1200TI was so equiped,and when Bike magazine tested a Green Mirage and 1200 side by side the Mirage had Marzos up front and laid down Corte+Cossos at the back whilst the 1200 had Cerianis at the front with laid down Cerianis holding up the back.Dave Calderwood rode the 1200 to Corfu and back as part of the test.
 
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