Exploring the Early 1958 430 MEL Engine
Posted: Fri 3. Jun 2011, 08:04
Decided to start a new topic for exploring and tracking changes on the early 430 engine. I happen to be restoring a vehicle with just such an engine and am learning that the design underwent many changes between the summer of 1957 and early 1958.
I will attempt to discuss and document these changes as best possible, but it dawned on me recently that these changes resulted in 3 engine variants:
1-big valve, high compression engine (from around 9/1957 to 1/8/1958)
2-small valve, high compression engine (from 1/9/1958 to 2/16/1958)
3-small valve, lower compression engine (from 2/17/1958 onward)
The changes primarily came about from issues regarding fuel detonation and rough idle. The factory service bulletins discuss the issues and stressed the importance of using a high octane fuel and keeping the timing and idle adjusted correctly. There was also an early issue with defective gas tanks causing clogged fuel lines or filters. Some older restorers have also told me their belief that Lincolns were only affordable to the older, wealthier crowd who typically did not drive them hard enough to clean out the engine deposits and other buildup. Bad gas tanks, bad gas, elderly drivers...
Prior to the above releases, the distributor had been re-worked to correct for light spark knock that was noticed under light load drive-away conditions:
I will attempt to discuss and document these changes as best possible, but it dawned on me recently that these changes resulted in 3 engine variants:
1-big valve, high compression engine (from around 9/1957 to 1/8/1958)
2-small valve, high compression engine (from 1/9/1958 to 2/16/1958)
3-small valve, lower compression engine (from 2/17/1958 onward)
The changes primarily came about from issues regarding fuel detonation and rough idle. The factory service bulletins discuss the issues and stressed the importance of using a high octane fuel and keeping the timing and idle adjusted correctly. There was also an early issue with defective gas tanks causing clogged fuel lines or filters. Some older restorers have also told me their belief that Lincolns were only affordable to the older, wealthier crowd who typically did not drive them hard enough to clean out the engine deposits and other buildup. Bad gas tanks, bad gas, elderly drivers...
Prior to the above releases, the distributor had been re-worked to correct for light spark knock that was noticed under light load drive-away conditions: