Conserv

I believe we’re having this same discussion in the NK forum, and, yes, 9.3:1 appears to be the answer for a 1966-69 2000ti engine’s compression ratio. And that was certainly not a flat-top piston. As to heads, I think we all agree that, prior to the spring of 1972, all 2-liter heads were 121 or 121ti’s. And 121 heads used a variety of bathtub-style pistons to achieve higher compresssion ratios. Regards, Steve

Maybe a 2000 sub-model, as opposed to a 2000ti. One source — not definitive, in my mind — states the 1969 2000ti had a 9.3:1 compression ratio. https://www.automobile-catalog.com/auta_details1.php I’d find it impossible to believe a flat top piston with a 121 head could get anywhere near a 9.0:1 compression ratio. I notice, in the same document, that the 1969 2000 had a compression ratio of 8.5:1. Maybe that had a flat-top piston. Maybe...although I’d expect flat tops to be closer to 8.0:1. Sorry, dp! I failed to read the entire thread, and thus failed to see that you had already discussed and resolved this issue (but for the question of flat-top pistons in a 2000 engine)! Regards, Steve

I would think that a 2000ti originally had the same setup: high-compression bathtub pistons and a 121 head. Regards, Steve

Someone suggested a possible replacement tip a few years back. It was not an actual antenna tip, but a toy or bauble, if I recall. Regards, Steve

If you keep the three drains clear, the bottom of the plenum is not a particularly rust-prone area. The original design, in this particular area, actually works! ? I wish I could say the same for front fenders...? Regards, Steve

@LarsAlpinaprobably knows as much as anyone alive about the Rentrop seats in the turbo. I’ve seen them referred to as Rentrop Sportsitze, but I assumed that “Sportsitze” was a formal model name. That might not be the case, and “Sportsitze” may have been used solely in a general sense. Some believe the turbo’s Rentrops were designed exclusively for the turbo. Rentrop was, not coincidentally, the manufacturer for BMW’s standard seats. PARA, on the labels of most ‘02 seats, is an abbreviation for P.A. Rentrop — no, I don’t know where the final “A” in “PARA” comes from. ? Below are three examples of the common PARA (Rentrop) label found in many ‘02 seats, the first one on a seat dated October 12, 1972 (“12.10 72”), The second one on a seat dated June 20, 1972 (“20. 6. 72”). Best regards, Steve

We’re talking the same thing: they, of course, are not actual seams, but a heat process was originally used to form the faux seams. The upholsterer (the Mad Stitcher of Atlanta, GA) who rebuilt spare front seats for my ‘73 and ‘76 still uses the term “heat seaming” to describe the original process used for the seats’ pleating. And that’s also why I was wondering about “embossing” door cards and whether that is (a.) the same process by a different name, (b.) a different process that achieves a similar appearance, or (c.) something completely un-related. On other matters, let me look around for the Rentrop model name. I have seen it. Best regards, Steve

No. There were several importers that divided the Canadian market among themselves. But, again, although there was not a sole importer, importers independent of the factory — akin to Hoffman Motors Corp — handled the Canadian market. And, yes, someone should track down the names of these Canadian importers — I’ve seen most or all of them mentioned on this forum — and find out if any records survive from the ‘02 era! Regards, Steve

Ryan, These have been identified as the ONLY part on an ‘02 that has never rusted out! ??? Best regards, Steve

I haven’t a clue, Todd! But Hoffman Motors Corp no longer exists. I would guess that the records were simply discarded at some point before, during, or after the dissolution. Unless, of course...the bookkeeper stuffed the records away in his/her attic and those records are sitting there collecting dust....? Best regards, Steve

Service Bulletin #12-25: Installation of Christmas wreath requires installation of 400mm tropical fan....??? And a Happy New Year.... Regards, Steve

This doesn’t alter the challenge of finding matching, heat-seamed vinyl for the original seats, but the turbo seats were manufactured by Rentrop, not Recaro. I’d probably track down Lars of Lars Alpina if I was looking for the best current-day match. I’m guessing there won’t be any genuine heat-seamed replacement and you’ll have to simulate the heat-seaming with actual stitching. Or...is modern “embossing” actually a heat-seaming method? I simply don’t know. Regards, Steve

GAHH calls their version Saddle. World Upholstery calls their version Gobi Tan. BMW, on their window stickers, called it Nylon Brown, but called it Beige on their paint and upholstery brochures. Simple? ? Merry Christmas! Regards, Steve

That sounds right, Regards, Steve

Although the LSD was standard equipment on the U.S, 320i S-package cars, some non-S cars came over with optional LSD’s, hence there are some early (1977-79) LSD’s here in the States. In my ‘76, I’m currently running a 3.64 e21 LSD, manufactured May 1978 (“5” over “8” on the left front side of the housing, second photo) in a housing cast April 26, 1978 (“26478” on the top rear of the housing, third photo). These early differentials (pre-‘80? pre-‘79?) use four-bolt output shaft retainers like ‘02 differentials. As to ratio, the second photo also shows the number of pinion and ring teeth, as “11” and “40”, respectively (40/11 equals 3.64), with an intervening “S” signifying a limited slip unit. I suspect the stamped “S”, as here, preceded the much larger painted “S” we commonly see on the right front side of the housing, which also signifies a limited slip unit. Regards, Steve

I can’t believe it’s been three years already, Nick! Enjoy the Holidays! Best regards, Steve

There is at least one thread...that provides the heights of the piano tops for various (maybe only two?) compression ratios. Yes, from the photos I might guess they are more likely to be 9.0:1. But we’ve been putting higher compression pistons into these cars since the 1960’s, so don’t let the age of this rebuild lead you to any particular conclusions. If these pistons, possibly with new rings, meet factory specs in terms of clearances, and they are 9.0:1, I’m guessing there would be marginal value to replacing them with new 9.5:1 pistons. But you really need to look at everything, the old components and your goals for this engine build, to decide whether they will get you to your goal. Regards, Steve

This is partly because the nature of importing to the U.S. and Canada, through sole or limited importers, contrasted with a direct consignment or sale arrangement in Europe. The U.S. market had Hoffman Motors Corp as the “sole importer” until approximately the end of 1974/beginning of 1975. But ownership — risk of loss, benefit of gain — was fully transferred from BMW A.G. to Hoffman Motors Corp before the cars went on the ship. And they were no longer BMW’s asset or problem: they were Hoffman Motor Corp’s! The dealerships during this era were Hoffman’s dealerships, not BMW’s. So Hoffman maintained records — now unfortunately lost — of the cars’ Ports of Entry, delivering dealership, etc. Once BMW of North America (“BMW NA”), a BMW subsidiary, assumed the role of sole importer for the U.S. — no longer an independent entity — information was maintained by BMW NA, including interior color, delivering dealer, and initial delivery date (to the retail customer). Sadly, this latter database is not in the possession of BMW Group Archives, and Archives appears to be completely ignorant of its existence: I’ve tried to tell them about it. But the no-longer-active-on-this-forum c.diesel, while working at a BMW dealership, ca. 2012, was able to pull up this data with nothing but my ‘76’s VIN. He performed this magic for me on a number of BMW NA-imported cars, to prove the data was there in the database. Regards, Steve

The original pistons on a U.S. ‘75 were flat-tops. Compression ratio was 8.1:1 (see attached January 1975 version of the U.S. 1975-76 brochure). The original head was an E12. The E12 head can accept higher compression ratio pistons, provided you’re using the correct pistons — or you’re very lucky! So, assuming this is a U.S.-spec ‘75 engine (which would generally have a casting date from August 1974 through July 1975) and still using an E12 head, I’d say that it got upgraded at some point. The mid-‘72 though 1974 U.S. tii’s used the same E12 head and received higher compression pistons: 9.0:1. So I’d assume that those pistons would probably work in a 1975 engine with an E12 head. Regards, Steve

Uh, yeah...that would be me.... ? When I was younger, I could chirp the tires shifting into second, third, and fourth...? Even the guys with hot domestic cars were impressed...I’m guessing! But 100% of my downshifts use a double-clutch! ? Regards, Steve