ok my son has got this question and its a bit beyond me so any help would be great. what is the magic formula to calculate the ovality of a crank???

this is the actual question...........

"list the measurements you made from the crankshaft of your engineand work out the ovality of the big end and main bearing journals."

now obviously i don't want the answer , just how to work it out. many thanks mick

 

Give us 5 and I'll dig my old text book out, what is it your sons doing may be worth getting him a couple of textbooks if he's in college

 

1st year at motor vehicle studies............ he's got a couple of work books but i can't find my hilliers text book........ebay or amazon when i get paid then..

 

you measure the crank jounal at 4 points, each separated by 45 degrees so you have 4 thinkness measurments, then after finding the smallest and largest measurments, the difference is the ovality of the particular journal.

this is how it was tought when i was studiying for my NVQ "motorsport vehicle maitanence and repair" course

 

Yeah was thinking of hilliers although it doesn't seem to be helping now as I cant find any reference to ovality of any component!

 

thanks guys, the way it was descibed is that there is a mathmatical formula to work it out............. when it fact the common sense way is the way to do it..

 

Damn it was going to say that earlier but didn't want to look a twat! Isbn for my copy of hilliers (5th edition) is0-7487-8082-3 and book 2 is 0-7487-8099-8
Dont know if the isbn no's change with editions though!