FA45 to 45S conversion update
Warning: Technical stuff
My 45 to 45S conversion is not going well. As you all may remember when I tried to put a 62 cam (wrong cam) in the 45 to convert it to a 45S and had problems with bottoming out the valve springs at full lift. So Crunchy sent me a 45S/50/56 cam and it does exactly the same thing. Turns out the only difference between the cams is the thickness of the gear. Lift, lobe separation, base circle and profile are identical as far as I can measure without using a degree wheel.
So why does the 45S/50/56 cam produce too much lift in my 45? I'm not positive but I suspect the geometry of the tappets in conjuction with the pushrods is effecting overall lift.
The 45 has short tappets and long pushrods whereas the 45S and up engines have long tappets and shorter pushrods. There must be enough difference in the angularity of the two configurations to cause excessive lift when using a 45S/50/56 cam in combination with the 45 tappets and pushrods. There could also be a difference in the tappet bore angles between a 45 cam gear housing and the 45S/50/56 housing.
What to do, what to do? The easiest way to see if my theories are correct is to swap parts over from my perfect running 56, but do I really want to go there?
Now all this brings up an interesting question. Does the RCU guy who said he did the "S" cam swap on his 45 MKII without changing ANY other parts still have a running engine? I doubt it, he probably has broken valve springs, bent pushrods or a gouged camshaft; maybe all of the above.