162 replies to this topic

[dklawson]

I have stayed out of this thread but have watched as it has advanced to 4+ pages and hundreds of views. We obviously have conflicting information.

Dan, in your posts about which taps would remove material (and I believe Ethel commented about this also) you rightly said that a 60 degree UNS tap would remove material from a 55 degree tapped hole. The Whitworth female thread would in effect be converted by using a UNS tap. I do not remember anyone who has used a UNS tap to chase the threads ever reporting that a lot of material was removed.

I decided to go off this board and contact a couple of people about this. I was directed to K. Calver who offered the following reply:
"The taps I have used to clean/tap the threads for decades is 5/8-in UNS. I have never tried a Whitworth thread tap as I have the thread type from original BL crankshaft drawings."

So the manual says "Whitworth form" (it's in my Red 1967 manual also) but according to KC, the mechanical drawings for the crankshaft say UNS. As an engineer working on products that require manuals for the public, I know it is not unusual for documentation to be incorrect and/or never be updated when engineering changes occur.

A link was posted above for 5/8-16 UNS taps for roughly 67 GBP. In the U.S. they are available from McMaster-Carr. See this page and pick the thread type/size from the first column:
http://www.mcmaster.com/#taps/=17u6rz
Plug, taper, and bottoming taps are all available for $37 each. (roughly 26 GBP). I have no idea what shipping to the U.K. would be but you may want to contact them.

[Nightrain]

Ok I will respond even no actual documented facts have been provided, it's all just talk. There's been too much rubbish talked on this subject already. Instead of hearsay and gossip why don't we stick to some simple facts. Lets see some answers provided by all the doubters.

The thread at the damper end of the crank has not changed since the A series was conceived. Does anyone disagree with this ? If as suggested the thread had been changed how come you can use a verto flywheel bolt in the crank damper of a early A series crank ?

Edited by Nightrain, 29 March 2009 - 11:52 PM.

[Dan]

At least two of us have said we are in the process of trying to gather more substantial evidence, this evidence is going to have to come from companies and as it's Sunday it's not going to happen today. Several people using a tap without producing swarf is neither hearsay nor gossip, it's evidence.

[Nightrain]

Unless your there it is in fact just hearsay.

DK hit on another reason some engineer's use the wrong tap as well, if you paid for it it would be a little more expensive than 67 quid.

Edited by Nightrain, 30 March 2009 - 12:10 AM.

[Dan]

No, someone telling you they have personally done or seen something is direct first person testimony which means evidence. Someone telling you that someone else told them they have done or seen something is hearsay, please don't turn this into another thread about semantics. From my own point of view you telling me that your tap fits the thread perfectly carries the same validity as GuessWorks saying the same. A 40 year old document is also first person testimony although the age and the fact that it is in a form that tends to contain errors (I have to agree with DK on that) puts a certain amount of doubt on it. An original design drawing carries more validity than a consumer manual in my eyes but I haven't seen that directly and so the existance of that is hearsay. I think that sums up the arguments so far and there isn't really a clear favourite from the two options so I am happy to wait until more evidence arrives. Ok?

Edited by Dan, 30 March 2009 - 12:19 AM.

[Nightrain]

No, someone telling you they have personally done or seen something is direct first person testimony which means evidence. Someone telling you that someone else told them they have done or seen something is hearsay

But asking a company, them telling you and then you telling us isn't hearsay, surely then you'd be telling us something somebody else told you ? Hearsay in my book.

Personally (this means in my opinion and does not reflect on this board in anyway) anything a certain person says, needs to be taken with a bucket full of salt. I remember not that long ago reading that same person saying oil got thicker as it warmed up........

[Dan]

You know full well and it's quite obvious from the above that when I say witness testimony I'm talking about the evidence that you keep choosing to ignore. The evidence that several people on this board have used a UNS tap without any issues. The fact that we are even having this discussion is due to us all accepting your statement that your Whit tap fits, kindly give everyone else the same courtesy. I wouldn't be talking about any information I might get back from companies until I have got it because I don't know what they might send. When I get information back from them I won't report on it, I'll post it directly so it won't be hearsay. Either I'm not making myself very clear or you keep trying to twist what I'm saying, personally I think I'm writing pretty succinctly.

To keep everyone up to date, I have now started talking with several compaines about this and I'm trying to track down the maker of all those billet cranks out there and somebody from what's left of Rover Powertrain.

[Nightrain]

Well not wanting to appear to terse in my statements. As your trying so hard to find this company, have you tried goggling Farndon Engineering ?

[Dan]

No, I didn't know what they were called never having bought a billet crank. So far I've asked the A series engineering companies that I have sent messages to who they get their billet cranks from. Thanks for the name, I'll look them up.

[Nightrain]

No worries dan, like most thing's you only need to ask

[Dan]

I have some answers back and so far...

Well it's 50/50. Which is to say the least annoying and confusing.

When everyone has replied I'll post them up.

Edited by Dan, 30 March 2009 - 11:54 AM.

[DaveRob]

Is it just me.........or is the prospect of 50/50 a bit worring.......lol

Rob

[dklawson]

I just received a follow up and corrected email from K. Calver. If this thread continues perhaps I should ask him if he can scan the information on the drawings he has and post it.

KC updated his earlier reply to me as follows:
"Sorry Douglas - I just re-read my roiginal reply to you... what I should have said is i have a 5/8" UNS tap I have used for cleaneing the threads for decades... but the drawings I have show it is a Whitworth formed thread... sincerest apologies for the misleading original reply... must ahve been half asleep... KC"

So the book says Whitworth form, and the drawings say Whitworth form. The only remaining question is what does "Whitworth form" mean... the angle, the root and peak profile, all of these?

[Guess-Works.com]

The whole topic is a bit worrying....

Right, the world is round not flat...

[Nightrain]

I just received a follow up and corrected email from K. Calver. If this thread continues perhaps I should ask him if he can scan the information on the drawings he has and post it.

KC updated his earlier reply to me as follows:
"Sorry Douglas - I just re-read my roiginal reply to you... what I should have said is i have a 5/8" UNS tap I have used for cleaneing the threads for decades... but the drawings I have show it is a Whitworth formed thread... sincerest apologies for the misleading original reply... must ahve been half asleep... KC"

So the book says Whitworth form, and the drawings say Whitworth form. The only remaining question is what does "Whitworth form" mean... the angle, the root and peak profile, all of these?

It means as I've been pointing out for the last few days Witworth Fine ! As for the other, more likely got the drawning (if i excists) out and thought crap NT's right again. Sorry to gloat but after the last few days ...............