I’ve finally had an opportunity to run a couple of tanks of fuel through Marlene since installing her 4º offset woodruff key and bringing her valve events back to spec. The jury is in, and the verdict is that she has much better performance and significantly better fuel economy.

After 200+ miles in-town and 400+highway miles her new highway average is 25.1 mpg (city is about 21.3) . Prior to this, overall highway average was barely 22 mpg and city was somewhere between 20 and 21.5.

Off-idle performance has improved to the point that I no longer have a burning desire to install a manual transmission…my desire is merely smoldering now.

While doing this maintenance, I also took the opportunity to compare the accuracy of both the ‘mark alignment’ and ‘dial indicator’ methods of determining timing chain elongation. I set up my dial indicator and then pulled the engine through and aligned the marks 5 different times comparing the results to the dial indicator. Depending on the angle at which you view the marks and which part of the notch in the cam washer you align with the tower mark there is anywhere from 2º to 6º error in the reading you take from the crank.

IMHO, the mark alignment method is only marginally reliable for determining if you have chain elongation greater than 6 degrees of crank rotation and then it is not an accurate method of determing elongation when considering which offset key to use.

__________________
Never a dull moment at Berry Hill Farm.