Hank,
I wonder, since it is an "oil line", could the threads be BSB - British
Standard Brass? I realize that the screw is steel threading into
aluminum, not brass. BSB is a 55 degree thread form. CEI/BSC is 60
degree.
Various threads are described on British Tools and Fastener's web site:
https://britishfasteners.com/threads-bsb
Cheers,
Bob Haskell
Austin Healey 3000 BN7/BT7 registrar
On 2/11/22 4:26 PM, gradea1@charter.net wrote:
> 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.
>
> 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..Â
> 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.
>
> Yes, all this is another great unsolved mystery in Austin/BMC history.
> But, what else would we have to discuss...covid? Regards, Hank
>
> -----------------------------------------
>
> From: "Curtis Arndt"
> To: "Hank Leach"
> Cc: "Michael Salter", "Healeys", "Bob Haskell", "Curtis Arndt"
> Sent: Thursday February 10 2022 6:22:39PM
> Subject: Re: [Healeys] 100 fasteners
>
> Regarding the steel and strength ratings of British and other
> fasteners, they were either _"Mild"_ Steel (British grades unmarked or
> A, B, C or K for nuts with "B" being the most common after unmarked)
> or _"High Tensile"_ steel (all other letter grades D-G [pre 1950] and
> R-Y [post 1950]). The confusion appears in calling "_High Tensile
> Steel_" - "High Speed Steel" as Michael has pointed out.
>
> See my attached article...
>
> 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.
>
> BTW, this Unified fastener coding is published in a chart that most of
> you should be familiar with by now.
>
> For those unfamiliar, the "British Standards" define "Whitworth" as
> all thread forms with a pitch angle of the threads measuring 55°,
> e.g., BSW, BSF, BSPP, BSPT, BSB, etc... This is in contrast to Unified
> (UNF/UNC), SAE and BSCy thread forms which have 60° pitch angle of the
> threads. This is why British Standard Cycle are NOT a Whitworth thread
> form despite the bolt heads using BSW/BSF spanners, and what is
> erroneously published in Wikipedia... But I digress.
>
> That being said, I would assume that part numbers (11B122 and 11B 298)
> are both Whitworth fasteners since they are listed as part numbers.Â
> 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!
>
> Cheers,
>
> Curt
>
> On Thu, Feb 10, 2022 at 4:23 PM Henry G Leach via Healeys
> <healeys@autox.team.net> wrote:
>
> 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 *HSS, 26TPI*. 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.
>
> Now, here are our 55 degree choices: *UNF 3/8 x 24*, BSW 3/8 x 16,
> *BSF 3/8 x 20*, 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.
>
> 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?
>
> 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)Â That changed to 11B298 and 99.(BSF) in 1956.
> Of course the later 6-cyl. engines used AEC162-probably unified,
> but maybe still BSF.
>
> If someone has the right answer, I will stick my tongue to a light
> pole. Hank
>
> -----------------------------------------
>
> From: "Michael Salter"
> To: "Bob Haskell"
> Cc: "Bob Spidell", "Hank Leach", "Healeys"
> Sent: Wednesday February 9 2022 10:52:51AM
> Subject: Re: [Healeys] 100 Road draft (vent) pipe fasteners
>
> The fasteners wouldn't be HSS ...that is used for machine tools
> like drill bits and lathe tools.
>
> M
>
> On Wed, Feb 9, 2022 at 1:47 PM Bob Haskell via Healeys
> <healeys@autox.team.net> wrote:
>
> Bob,
>
> HSS - high speed steel.
> I think the threads are 3/8"-26 BSF (British Standard Fine).
>
> Cheers,
>
> Bob Haskell
> Austin Healey 3000 BN7/BT7 registrar
>
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