But what was the name of the famed Ether based " kiss of life " used throught history?
And what did over eager hands over use cause to happen to the engine?
And where nine times out of ten was the fracture?
And what was the exact give away noise produced?
And why was it nearly allways in the same place?
And it was never in the exhaust manifolds nor uptakes?

And why despite the major damage when one major component became two did the engine continue to run?

And now, to compound the problem even further the aerosol can of the sixties onwards has expired.
MT in other words.
That clapped out old engine with virtually no rings left on it displaying excess crankcase compression is flying over like its got bent valves so whats the next move to start this fumer?
Whats the next move?
What you gonna do?
Quick easy way out of this problem?
Done it millions of times in the old days?
Flashes up straight away no probs?

And to what extent was the S cam type fracture of this mysterious as yet unknown component a distinct advantage as to versus a 90 degree fracture?
This and this only permited the engine to run on?

OMG we're into some old-timey stuff here

Indeed JK indeed.
And on the subject of smokey I have smoked you out here as you have now disclosed your age to all those out here who understand what I am banging on about.
Actually the noise is a rumble not a knock?

Broken crank.
85% of the breaks were always directly across the rear main.
The S shaped break allowed it to run on and even maintain the oil pressure.
Bit like a dog clutch jobby.
Over enthusiastic young hands doling out the Bradex appeared to be the main cause.
Frank Perkins were the main contenders here.