more clarification
Though having arrived "late to the dance", the "j-58/j-93" issue carries a bunch of additonal questions for me.
For openers, specs, especially physical dimensions, on both(!!) the J58 and the J91 seem to be almost imossible to come by. Bought a copy of "Advanced Engine Developement at P&W", and found only passing refernce to the J58, and nothing about its immediate predecessor, the J91, let alone the sole reason I bought the book, i.e. the JTF-17 duct-burning turbofan that was offered for the L-2000 SST.
Also curious about the "80% scale down" of the J58 from the J91. Was that a direct linear reduction or overall mass? Saw one quote where the J91 diameter was cited as "72(!!!) inches), a figure only reached by the AB nozzle of the GE-4 for the Boeing 2702 SST.
BTW, am less than impressed with the "air bleed" version of the J58, as the J57-p43WB, of which the B-52G I crewed, nearly a half century ago, had eight, featured the same thing, and for the same reason, i.e. to keep the N1 low pressure compressor (think first four stages of the single-spool J-58) from stalling when the engine was throttled back. except instead of dumping into the AB, (the BUFF didn't have any!), it simply vented straight out laterally, and would knock you on your can if you happened to be under it when it opened, as I was a couple of times. In short, any info on the J91 or the J58 would be most appreciated!. Even directions to reference sources would be good.
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