Bret,
I have seen referencing to blueprinting the steering box on several occasions. I tried to look up what that term means in relation to refurbishing mechanical parts and came up empty. Could you explain, in layman's terms, what actually happens during blueprinting?
Thanks
Basically rebuilding the box to closer specs than what it was originally built with. Any mass produced mechanical product is built within a range of "acceptable" tolerances. Those tolerances are seldom as tight as what the original "blueprint" for that part called for.
Len
X2 what Len said. I think this is a kinda slang usage of the word "blueprint", because the normal online dictionary sources don't seem to cover it. I found this example of the term used in a post on a Corvette forum, where they were discussing rebuilding the steering box:
"Here is the IMPORTANT part: He blueprints the box by assemblying the gears and other components so that there is virtually zero play in the box, including shaft end play. When the box was new from GM these steps were not done and are certainly not done with rebuilt standard boxes."
Years ago I read a book about how Rolls Royces were built "back when". There were a lot of things they did, and one was building the transmission, filling it with oil containing a dye, spinning it up to speed, then disassembling it to reshim the gear lash.
When they were finished, the transmission (and other mechanicals) would run so smoothly it was amazing.
Their ads read that the car was so quiet, "the loudest thing is the clock".
Len
That comment is fact and continued till the big ownership change a few years ago. I have been in a few and even outside one the engine is barely noticable (noise). I worked man years ago actually cutting gears of all kinds for aircraft and helicopter engines as well as the Napier Deltic and we allways "blued the mesh" to make sure the contact point was correct and size of it too. You need clearance between them or no oil will sit on the face and you get noise and wear.
JohnH
Interesting,
I always thought blueprinting meant machining the parts to closer tolerances, matching the original blueprint.
But the RR description also makes sense, using blue dye to let touching parts leave blue footprints.
You were right about closer tolerances. When you blueprint an engine, all combustion chambers have matching cc's and all pistons reach the same height in the cylinder by line boring. Too many other things to list them all.
I still use white lead on rear end gears.
Blueprinting means different things to different people. There is no engineering standard called blueprinting. Closer tolerances also is not always a better thing. Engineering tolerances take in consideration of the operating environment. Items expected to operate in extreme cold as well as extreme heat can fail if you reduce the clearances. I always flinch when someone claims they have blueprinted an overhaul. Seldom can they show you the engineering behind their decision to change tolerances from factory publish standards other than they reduced clearances. They don't test to failure to determine if what they did actually was better.
Tolerances and clearances are two different things. On a stock engine the crank journals are not perfectly parallel to the head surface and combustion chambers are not the same on all cylinders. A "blueprinted" engine actually has more clearance on rods and mains than a stock one. Nothing to do with the steering box but just a different explanation of blueprinting.