Originally posted by Magoo
Tikky, I read an article by a russian pilot where they trashed quite a few engines by running the Allisons at just full power as rated by the manufacturrer so I don't know about that one...Allisons were famous for the metal in the oil pan.
I'll see if I can find the article.
Magoo
The Allison V-1710 is actually one of the most reliable liquid cooled inline V aircraft engines built.
The bad reputation came from poor fuel and poor maintenance. With good fuel and proper maintenance, they are as reliable as any engine of the type. They are tougher than the Merlin ever dreamed of being. A Merlin never won an unlimited title at Reno until a guy figured out how to put an Allison connecting rod in it.
In all fairness, the Allison V-1710 was not easy to build, nor was it easy to maintain. It was very complex, it was cutting edge for its time, much of the basic design is still used today. Further, it wasn't perfect, even in the final versions.
Also, the installation designs were often troubled, at best, the Lockheed installation in the P-38 being among the most difficult to deal with. An Allison in a lightning can be a nightmare to work on. I know how to work on an Allison, and having been up close and personal with "Glacier Girl" and a couple of others, I can say that PITA is not an adequate term for the maintenance routine.
But honestly, the vast majority of Allison failures in the field were due to horrific maintenance and a lack of training of the pilots for proper operation.
On the other hand, I know several P-38 pilots who pushed the Allison -30 engines in a P-38L to over 70" of MAP and over 3200 RPM, which is more than even Lockheed and Allison rated it for, nevermind the lowered ratings the USAAF specified (they were commonly ignored).
Having built a few Allisons I can say the lower end is tough and well designed. About 95% of all failures are human error induced. Half of the rest were caused by the design of the installation. The overhead cam rollerized valvetrain with 4 valves per cylinder is excellent. We often pushed stock Allison valvetrain to over 4000 RPM, fully 1/3 higher than it was rated for.