16-10-2018, 08:05 PM
(This post was last modified: 16-10-2018, 08:24 PM by Bob Culver.)
If there is no intention of using the revs or close to, extra valve springs contribute nothing but friction, wear and stress.
Cranks which fail have generally been cracked for thousands or tens of thousands of miles prior. What triggers the final failure of the sliver of remaining metal is barely relevant. ( Somewhat over a million cycles just above the fatigue limit stress lead to failure. The typical old crank even if at only 100,000 miles will have clocked possibly 600 million revs. The mystery is just which 1/2 % or so start the cracks. Revs at closed throttle are not good; best to coast down 60 mph gradients!)
I found on various old cars years ago on a surprising numbe the throttle did not open fully.
In the gears the car should accelerate continuously albeit sedately. With seriously retarded spark may accelerate in surges and die off.
I found that with an engine using oil and the earlier head a decoke transformed performance for a while. Some claim that a long run will rejuvenate oil using engines used only for short runs.
Cranks which fail have generally been cracked for thousands or tens of thousands of miles prior. What triggers the final failure of the sliver of remaining metal is barely relevant. ( Somewhat over a million cycles just above the fatigue limit stress lead to failure. The typical old crank even if at only 100,000 miles will have clocked possibly 600 million revs. The mystery is just which 1/2 % or so start the cracks. Revs at closed throttle are not good; best to coast down 60 mph gradients!)
I found on various old cars years ago on a surprising numbe the throttle did not open fully.
In the gears the car should accelerate continuously albeit sedately. With seriously retarded spark may accelerate in surges and die off.
I found that with an engine using oil and the earlier head a decoke transformed performance for a while. Some claim that a long run will rejuvenate oil using engines used only for short runs.