A new type engine test plant is described, and service experience and cost information collected during six years of actual operation is given.
The new design seems to give several advantages compared to conventional test plants, such as:
Better sound proofing
More compact size
Higher capacity - up to 1200 engines per year per test bed may be run due to the sound proofing permitting round the clock operation and because very little time is lost on engine changes
More convenient working conditions due to engine being installed at suitable working height above the floor and all work being carried out in regular shop standard localities
Better engine cooling through ram pressure simulating airplane operation, and easily adjustable, sufficient air flow for the entire power range
Better measuring facilities
Constant induction air temperature and carburetor altitude chamber
No requirements for auxiliary power (the amount absorbed by servo and lighting circuits is negligible). Power for cooling air and brake fluid circulation is delivered by the engine being tested
Optional sense of rotation. - Right and left hand engines can be tested subsequently if called for
Provisions for power recovery
Takes complete power eggs if desired
The system is suitable for any size power plant and can be adapted for small automotive engines as well as for 10,000 HP turbo props. The type of brake used is well adapted to handle even larger powers, for example for development work on turbines. The same plant can be designed to cover a fairly wide range of engine powers. Thus engines ranging from the R-1830 to the R-4360 can be handled in the same plant and tested alternately without any mechanical re-arrangements.
The lay-out permits fairly simple installations for routine testing, while it also lends itself to more advanced designs, for example for research or educational purposes. The degree of simplification will influence the cost, such that a routine test plant may be $50,000 less expensive than a completely equipped one.
Based on experience from the existing plant in Stockholm, Sweden the cost today of an intermediate size plant for 2500 HP engines is in the order of $125,000 and the direct operating cost of such a plant is roughly $190 per engine tested assuming regular airline run-in and check procedures.