Reverse Engineering for manuals?

[wiking85]

If one nation managed to get their hands on another maintenance manuals detailing an engine, but not an engineering blue print for production, what was the threat of reverse engineering a copy of that engine from just those manuals?

 

[bobbysocks]

not much I think. I have worked on engines using manuals for years. you will get clearances, tolerances, torque settings, and an idea of the components via the exploded view...but you really cannot more than a rudimentary understanding of the engine itself. it would be A LOT of trial and error. you would be better off with a captured piece of equipment.

 

[wiking85]

not much I think. I have worked on engines using manuals for years. you will get clearances, tolerances, torque settings, and an idea of the components via the exploded view...but you really cannot more than a rudimentary understanding of the engine itself. it would be A LOT of trial and error. you would be better off with a captured piece of equipment.

What is missing, other than the measurements of parts and guesstimation of what that would be?

 

[fastmongrel]

It would be like trying to build a replica city just using a 2 dimensional A to Z street map. But it could give an experienced engineer ideas if he was designing an engine.

 

[GregP]

Everything is missing.

Specifications for materials, specifications for coatings / platings, manufacturing dimensions and tolerances, test procedures for acceptance of parts, and otehr small but vital items required to actually fabricate an engine.

 

[Shortround6]

As Greg said "Specifications for materials" is just one. There may be dozens of steel alloys it is possible to make a crankshaft out of. Each has slightly different characteristics and not all respond to heat treatments or surface treatments in the exact same way. Even if you have a "blueprint" of a finished crankshaft with ALL dimensions you may or may not know the exact alloy it is made out of (and some countries used different standards before/during WW II German DIN XXX vs American SAE YYYY vs British Hatfield 75)) let alone the heat treat procedure. Crankshaft "A" made out of alloy XA and using heat treatment X2 and a certain combination of vibration dampers might work just fine even if alloy XA is one that the coping country would never think to use for a crankshaft.
You would need a tremendous amount of information just to build an engine that would run. Getting one to run for dozens or hundreds of hours (at high power) without knowing the manufacturing processes used to the build the originals is much more difficult.

 

[pbehn]

You would need a tremendous amount of information just to build an engine that would run. Getting one to run for dozens or hundreds of hours (at high power) without knowing the manufacturing processes used to the build the originals is much more difficult.

That is the key issue SR. I know nowt about Aero engines or aircraft part metallurgy but spent a lifetime testing metals. A specification gives a range of acceptable values. If you get one part of a plane and test it you get one value. That does not give you a minimum or maximum. The piece you have may be at the maximum or the minimum allowed. A sheet of metal for skinning a wing can be destructively tested to represent that sheet, a con rod cannot be tested because you destroy the con rod. You can test one con rod in 10 or 50 or 100 to represent production with a safety margin for variance, that is what quality control/assurance is all about. Testing 1 con rod only gives only a limited amount of information unless of course you know so much about con rods that you dont need to reverse engineer you are just inquisitive about another, possibly rival product.

Also some values are linked there may be a minimum for Yield strength, a minimum for Ultimate Tensile Strength and also a maximum for the ratio of the Yield to UTS. On top of that a maximum range of yield values (for example min to max of 100MPa).