by Richard Miller » Tue Mar 22, 2016 2:34 pm
okay I know how that goes ...I looked thru my stuff to find a couple of old reference pieces on clutch etc, first was an old popular hot rodding article ,, November of 1978 article by tom Senter called clutch linkage basics ,, I read thru it and you seem like you should be in the ball park on pedal ratio ,,, he says "it takes between .035 and .090 TOTAL clearance between disc and flywheel and pressure plate to disengage the clutch" he says there is about a 5 to 1 ratio in the pressure plate and if you take worst case about .100 to release then the TOB needs to move about .5 inch ... skipping ahead a little he suggests end of clutch fork where pushrod hits it needs to move about 1.125 inch (about 2.25 ratio in the fork ) anyway I don't know if you can find this old article online anywhere ,, I also have an HP BOOKS CLUTCH & FLYWHEEL HANDBOOK from 1991 I bought when doing my car don't know if that is still available ,,, sounds like the quarter inch might not be enough travel at TOB.might be area to focus on as you thought , pivot ball and throw out arm ,, I am using a corvette clutch and it is the high cone diaphragm type ,,
Richard Miller
West Covina, Ca
'65 V8 Vair