<html><body>Thanks to Curt for this accurate and informative article. I totally agree that the early part numbers ie: 1B--- would designate British fasteners, and the later three letter, three number designation aligned the UNF hardware. That is our best clue to what was used back then. <div><br></div><div>This early engine has stumped me on a number of occasions and I really feel that for that first year anything goes to get the product to the market...a real scramble. I have a notion that this engine was sitting in stock as surplus A-90 leftovers. The block was factory painted dk. blue. The head on this car was "Gold Seal" rebuilt. The threads I discussed, are most definitely British Standard Cycle (CEI) 26 TPI.. Many of the studs are BSF on one end and BSC on the other. Luckily, these parts are available from British Tool & Fasteners, including a full line of BSC hardware. Unfortunately they were out of 3/8 BSC helicoils, so I had to get some from, you guessed it... Amazon. Big $$ rather than Pence. </div><div><br></div><div>Yes, all this is another great unsolved mystery in Austin/BMC history. But, what else would we have to discuss...covid? Regards, Hank<br><br><div class="reply-new-signature"></div><p>-----------------------------------------</p>From: "Curtis Arndt" <cnaarndt@gmail.com><br>To: "Hank Leach"<br>Cc: "Michael Salter", "Healeys", "Bob Haskell", "Curtis Arndt"<br>Sent: Thursday February 10 2022 6:22:39PM<br>Subject: Re: [Healeys] 100 fasteners<br><br>
<div dir="ltr">
<div dir="ltr">Regarding the steel and strength ratings of British
and other fasteners, they were either <u>"Mild"</u> Steel (British
grades unmarked or A, B, C or K for nuts with "B" being the most
common after unmarked) or <u>"High Tensile"</u> steel (all other
letter grades D-G [pre 1950] and R-Y [post 1950]). The
confusion appears in calling "<u>High Tensile Steel</u>" - "High
Speed Steel" as Michael has pointed out.
<div><br></div>
<div>See my attached article...</div>
<div><br></div>
<div>Also with regard to fastener listings in the various parts
manuals and other BMC publications, if a fastener is noted with a
"part number", it is typically a Whitworth type thread form. When
the changeover to "Unified " fasteners occurred in the
mid 1950s, all Unified fasteners were noted with a new designation,
describing in code the size of the fastener. I would
assume that all Unified fasteners fell under this new coding
system... But we know what happens when we assume.</div>
<div><br></div>
<div>BTW, this Unified fastener coding is published in a chart that
most of you should be familiar with by now.</div>
<div><br></div>
<div>For those unfamiliar, the "British Standards" define
"Whitworth" as all thread forms with a pitch angle of the threads
measuring 55<font face="arial, sans-serif">°, e.g., BSW, BSF, BSPP,
BSPT, BSB, etc... This is in contrast to Unified (UNF/UNC), SAE and
BSCy thread forms which have 60</font><font face="arial, sans-serif">° </font>pitch angle of the
threads.<span style="font-family:arial, sans-serif;"> </span><span style="font-family:arial, sans-serif;"> </span><span style="font-family:arial, sans-serif;"> This is why British Standard
Cycle are NOT a Whitworth thread form </span><span style="font-family:arial, sans-serif;">despite </span><span style="font-family:arial, sans-serif;">the bolt heads using BSW/BSF
spanners, and what is erroneously published in Wikipedia... But I
digress.</span></div>
<div><br></div>
<div>That being said, I would assume that part numbers (11B122 and
11B 298) are both Whitworth fasteners since they are listed as
part numbers. Again, we all know what happens when we
assume! Since these are specialty fasteners, and not your run of
the mill bolts, who knows how BMC designated them? One may be BSF
and the other UNF. Measure twice or have a Helicoil kit on
hand!</div>
<div><br></div>
<div>Cheers, </div>
<div><br></div>
<div>Curt</div>
</div>
<br><div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Thu, Feb 10, 2022 at 4:23 PM
Henry G Leach via Healeys <<a>healeys@autox.team.net</a>>
wrote:<br></div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px .8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex;">
<div>I don't want to be a smart ass, here like Ralph found in
"Christmas Story", and stick my tongue to a light pole, but the
treads found on my rocker oil feed pipe are <b>HSS, 26TPI</b>. Here
are two measurements with a gauge showing the pattern. If it was
3/8 x24 UNF the job would be done. However, I had to order a
special $65 kit for the HSS Helicoils to repair this block.
<div><br></div>
<div>Now, here are our 55 degree choices: <b>UNF 3/8 x 24</b>, BSW
3/8 x 16, <b>BSF 3/8 x 20</b>, HSS 3/8 x26, BSC (old CEI) 3/8 x 26
as well, or BSPF 3/8 x 19. Unless someone re-lathed this part it is
factory 26TPI for sure-ran a tap and die in both parts.</div>
<div><br></div>
<div>A note in the Sept. 1956 parts book refers to a service change
shown here. (Vol 25, p.13 engine) The BMC group is trying to
standardize this item. Accordingly, it appears to have been
UNF (11B122) on the 2.2 Diesel engine and then changed to BSF (11B
298) at engine #225030. This engine I'm doing is from 1953 so who
knows what the correct part is?</div>
<div><br></div>
<div>In my March 1954 parts book the number for the "valve rocker
bracket with tapped hole" is 1B2110 and locating pin is
1B2111. (no mention of TPI) That changed to 11B298 and
99.(BSF) in 1956. Of course the later 6-cyl. engines used
AEC162-probably unified, but maybe still BSF.</div>
<div><br></div>
<div>If someone has the right answer, I will stick my tongue to a
light pole. Hank</div>
<div><br><p>-----------------------------------------</p>
From: "Michael Salter"<br>
To: "Bob Haskell"<br>
Cc: "Bob Spidell", "Hank Leach", "Healeys"<br>
Sent: Wednesday February 9 2022 10:52:51AM<br>
Subject: Re: [Healeys] 100 Road draft (vent) pipe fasteners<br><br><div dir="ltr">
<div style="font-family:arial, sans-serif;font-size:small;">The
fasteners wouldn't be HSS ...that is used for machine tools like
drill bits and lathe tools.</div>
<div style="font-family:arial, sans-serif;font-size:small;">
<br></div>
<div style="font-family:arial, sans-serif;font-size:small;">
M<br></div>
</div>
<br><div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Wed, Feb 9, 2022 at 1:47 PM
Bob Haskell via Healeys <<a>healeys@autox.team.net</a>>
wrote:<br></div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px .8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex;">
Bob,<br><br>
HSS - high speed steel.<br>
I think the threads are 3/8"-26 BSF (British Standard Fine).<br><br>
Cheers,<br><br>
Bob Haskell<br>
Austin Healey 3000 BN7/BT7 registrar</blockquote>
</div>
</div>
</div>
</blockquote>
</div>
</div>
</cnaarndt@gmail.com></div></body></html>