Mercury Mark 58, Why The Preferences?
Lately there have been real good preferences expressed about Mercs Mark 58 outboards that were some of Mercs earliest 44s as were the Mark 55A and Mark 55A(E) engines. What makes them so special to some people? I have at least one Mark 58 block sitting as an empty spare. Any enlightenment?:)
Three Screw Port Covers...
When Merc went to the three screw port covers, the in take side was much larger, but you lost crankcase pressure....
Actually, I thought the early blocks had more water in the jacket and thinner sleeves....they have more holes, too, as a restule they didn't idle as well as the hotter running motors, but they ran faster....I', pretty sure the early 58 E's had very high compression head...I KNOW the 55 E's did...The black blocks with the 89 serial number as the first two numbers...
Add: I thought all 44 blocks said "SUPER THUNDERBOLT" on the them.
30's said TURBO FOUR
40's said Thunderbolt
44's said Super Thunderbolt.....Only from memory, so, like often, I could be wrong...