Robert...your idea regarding a matrix/spreadsheet of parts issues is great! That is what I'm attempting to do now with distributors, flywheels (I just completed a preliminary analysis), carbs, etc. But it's a massive undertaking!
I do have a near complete set of ihc mts and cts manuals scanned in on one of my machines. But using 'em is a bitch compared to simply flippin' pages and putting stickee notes on pages of paper! And since the info is not inna database format of any kind (only a .pdf), there is no way to sort or find info.
For example...the big service manual file is the cts 2000 which covers nearly all light/medium duty apps other than Scout. It's over 4000 pages!
The last generation of IH parts lists was the same paper simply scanned to microfiche for distribution. That was hi-tek up until about 1994 or so, then microfiche began to disappear from the scene and cdrom took over as the method of technical publications distribution for all oem appps. Don't know if IH/navistar ever included all the old stuff in that dbase or not. But currently parts lookups are made electronically in dealerships, including "old stuff" to a degree. Then the counter dude whips out the tons of old IH paper to really find what ya want. Then he/she enters the numbers into the system for an inventory check and availability in the various navistar pdc locations.
When ya look up all actual replacement part cylinder heads for IH stuff (the sv motor was used in ag products, industrial products, Scout line, light line, medium duty, bus, and motorhome apps), there are actually very few variations as compared to many parts!
But...the majority of stuff like cylinder variations was covered in part bulletins mailed to the dealer base, and May have never been actually included in successive "updates" of the paper parts list (the loose leaf version). And bulletins were constantly being issued! That information is invaluable to those of us in the special interest vehicle arena, but is not available except to those who collect that type of literature and luck out in finding a complete dealer set of info that was kept up to date back in the day!
The folks that repop this literature simply don't see a market for reproducing "sets" of bulletins issued by all the various groups within IH that delt in that stuff. Personally, I see otherwise...but then it's not "my" business (and this is not something ihon can force out of the suppliers). To me, the bulletin sets are actually more valuable to enthusiast than the service/parts lists themselves! But then...I used to be in the business of writing/publishing "tsb" stuff (technical service bulletin" for several oem manufacturers...so I'm prejudiced!
That 1/8"npt "plug" you describe threads into the oil drainback passage on any I-4/sv cylinder head. See this thread for a description:
http://www.forums.IHPartsAmerica.co...I-4-sv-engine-non-oiling-rocker-assembly.html
On medium duty apps of the sv engine equipped with some variation of an air brake system, the air compressor is pressure lubricated from the engine with a tap from the oil gallery (pressure side). However, the compressor does not have a "sump" as we know it. Lubrication oil from the compressor is returned to the engine through that port in the cylinder head with a simple oil line/fitting. In the case of the light duty rigs, that port is simply plugged off. That allows use of the same heads (and all their variations) on any I-4/sv engine app. So that is not a "pressure" tap.
That would make a handy oil return for a turbo install! I don't remember how the corvair spider turbos returned the lube oil???
As for the "ovality" of the hole ya see in the pic, that is a perspective thing! But many times I see various heads where machined or threaded holes used for various accessory mounts on different applications have been scruud over with broken bolts, plugged with jb weld, had stuff welded on!, etc. Again typical "po virus" stuff!
The core supplier I mentioned grades each and every part they make available to the rebuilder industry including a mag-check for cracks. And any broken stuff, welded up stuff, stripped thread stuff, etc. Goes to china, they won't ship stuff like that to a rebuilder as their reputation for "quality" doesn't allow that!
And...there is data available within that industry that actually covers the kinda "interchange" and "identification" of various engine components for all oem manufacturers, not just IH. This is stuff similar to what has already been mentioned in this thread and will never be found in the "retail" auto parts bizz! One of the main reasons dave is gonna intro me to these folks is so that we can have a line into a major resource for this kinda info, it won't happen overnight but no doubt it will pay off in enhancing our ability around here to take care of our customers!
Again...the "casting" number (IH part number) is for the head raw casting only, as a way of identifying tens of thousands of parts as they came out of the molds at the foundry. Then a bom (bill of materials) was used to machine/assemble these castings into an actual part number application for installation onna designated engine build. So the casting number could be used on many cylinder head variations...the u.s. Domestic stuff got one combustion chamber volume/shape, the "export" stuff got a different machining process, then the lpg stuff got another variation, the tractor/combine stuff gotta another variation, etc., etc.
