Quote:
Originally Posted by Dave Neptune
Any kind of lead substitute is a waste of money on an A-4 or any low compression engine. The lead was mainly to "cushion the valve seats" and was only necessary on higher compression engines. As performance increased and compression was raised the lead was necessary to handle the additional valve loads of more duration and lift. The setting of the valves back down on the seats is greatly (stronger valve springs) increased as performance is gained.
The lead also helped in ring wear however the newer metallurgy applied made this a moot point and again the Hi-nickel A-4 block made it unnecessary.
The Hi-nickel block of the A-4 is more than stout enough for this valve seating.
Back when the lead was being removed 'Harder valve seats were sold unnecessarily on low compression low HP engines however anything with HP absolutely needed the harder seats and or the lead substitute.
Dave Neptune  |
Are the valve seats cut right into the block or are they added into the block? I was of the impression that the valve seats are replaceable. (not that it is an easy job)