Royal Enfield Interceptor Owners

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Print some parts of the workshop manual -Edgar (Thu, September 26, 2002)
It's a restoring project for my son and I. -EODMike (Thu, September 26, 2002)
Locate bits f Royal Enfield 250cc Crusader Super 5 -EODMike (Thu, September 26, 2002)
Hello Hitchcock About Mufflers and news -Royal (Thu, September 22, 2002)
I ended up purchasing the 1966 Interceptor that was on eBay -Bob (Sun 22 Sept 2002)
What are the best Vacuum gauges - ..gREgg(Sunday, 22 September 2002)
Whitworth , SAE, UNC, BSP, BA, UNF BSW and BSF fasteners -gREgg/ Bob C/Bob(Sunday, 22 September 2002)
High output Alternators -gREgg /Rick/ Joerg/ Orlan/Ole/Bob C - (14 Sept 2002)
Banjo Bolts   -gREgg /Bob H- (Thu 12 Sept 2002)
Oil pressure concerns - Oil Cavitation and solutions - Ole / Peter/Bill/Royal (20/08/2002)

Help to identify an MK 1 (Sun Jul 28, 2002 ) -Jennifer
Getting my Amals to idle!  Good points  -Gridley Bruce /Rick F / gREgg/ Bob C/Bob St/(Thu Jul 25, 2002)
Primary Transmission Troubles (Thu Jul 25, 2002) -Rick F/ Bob C
Oil pressure relief valve and warning light -Paulus - (Tue Jul 23, 2002 )
King Kong-Royal Enfield Interceptor 1965 Cycle World Road   -Billy Dean (Sun Jul 21, 2002)
Clutch Drag and Hitchcock's belt conversion kit.!  -Karin /Rick F- (Sun Jul 21, 2002)
Shrouded Rear Shockies! - Rod / Bob/ Dave/ Rick L/ gREgg-(Wed Jul 17, 2002
Oil for transmission - Bob St/ Bob C/ Roger/ gREgg / Royal (Sun Jul 14, 2002)
How to install the rubberized Swing arm bushes Great- gREgg - (Thu Jul 11, 2002 )
American Indian Interceptor models . Royal/ Bob/ Robert S/Jennifer(Tue Jul 3, 2002)
Good Enough Mufflers or dissatisfaction? -Rick F/ Royal- (Wed Jul 3, 2002 )

Royal Enfield US made as an Indian (30/06/2002) -Jennifer
Need oil cooler lines -Rick Fisher -(27/06/2002)
Neutral Finder Operation -ksmith1939 / Anders (26/06/2002)
Correct Location of Horn -Anders L /Bob/Don L /Royal Robert S - (24/06/2002)
Carbs and Fuel Mixture Excellent Bob!  - Bob Cram - Sat Jun 15, 2002
Nearly there now, Ben's Interceptor - Ben -Wed Jun 12, 2002
Proof of ownership issue, US Custom!- gREgg / Royal Tue Jun 11, 2002
Bullet - Interceptor for sale at eBay - Anders / gREgg - Mon Jun 10, 2002
Stroehle about their alloy Interceptor cylinders. Good Comment! - .. gREgg -Fri Jun 7, 2002
Original Airfilter confusion -Bob /Rick/ Royal- Thu Jun 6, 2002
Problems registering his Interceptor Royal- Mon Jun 3, 2002
Existence of the '66 Inter Bob H - Sun Jun 2, 2002

Progressive front fork springs the MK II -Bob -Thu, 30 May
How have low bars affected ride -Bob -Tue28 May
Burton Bike Bits info -Anders- Tue28 May
Built at Bradford-on-Avon - Robert S - Sat, 25 May
Compression plates under the cylinder barrels - gREgg - Sat, 25 May
The "TT-7 Interceptor" name - gREgg -Wed 22 May
1965 seems to have been the last year of Redditch production Wed 22 May
My Series 1 was a 1966. - Don - Wed 22 May
The 1966 model year ... it really doesn't exist, - gREgg -Wed 22 May
A owners manual for a 1966 Royal Enfield 750 TT Interceptor - Eddie -Wed 22 May
Your bike is either a Chief or a Trailblazer. -Don-/Howard- Wed 22 May
A 1960 Indian RE Twin Howard- Wed 22 May
Boyer Bransden ignition for Inter? -Anders/Royal/George/Dick- Tue 21 May
1970 SII Interceptor for sale. -Rick F/ Royal Thu 16 May
Interceptor Tyre (Tire) Discussions. -Don-/gREgg/Bob Wed 15 May
Ben's New Interceptor -Ben/gRegg/Rick L/Orlan/Royal- Mon 13 May
How to start the Interceptor! -Ben/gRegg/Rick L/Royal- Mon 13 May
My first was a 350cc single -Billy Dean -Saturday, May 11, 2002
Tank transfer "Royal" in red script -Bob Fri 10 May
Paint info that might be of interest . -Bob Tue 7 May
Rickman production started in 1970 with six prototypes -Bob Mon 6 May
Virus vigilance ! -Royal- Mon May 6

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Print some parts of the workshop manual (Thursday, September 26, 2002)

Message: I want to print some parts of the workshop manual to give it to my Mechanic, He has a Royal Enfield 750cc of the 50s and need it. I have a 1948 BSA 500cc, and triyng to give this pages, but I can't print the pages You've putted on this site. Could You help him?

Edgar
Rosario, Santa Fe, Argentina

Hi Edgar

This workshop manual is only for the Royal Enfield Interceptor Series II of the late sixties. I can see that there are probably the odd pages applicable for him anyway. Just let me know which ones.

The reason it's non print is that it's supposed to be information only, not piracy.
Some people just make a quick raid to a site like ours, contribute nothing, trying to just grab what might be useful.
Thousands of hours have got into the site.
Many people contribute tips stories and experiences, which only in this way can be shared between owners, helping each other.
Well that's why I spent the thousands of hours putting it together.

If he's a mechanic, maybe he has some experience worth sharing as well. Anyway, a couple of pages would be ok.

Why not have a look in the Buy and Sell section of the web page, there is a great workshop manual which covers all the 50's models. Very comprehensive and an opportunity to buy.
Regards
Royal

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I just picked up a 69 and I'm looking for parts sources, and in general any info I can get on the bike. It's a restoring project for my son and I.
Thanks PS as soon as some one tells me where to find the numbers I'll put them on the site

EODMike. Merritt Island, Florida, USA

(I guess there are several hoping to pick up a 69, "Royal")

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Sunday, 22 September 2002

Michael from Loddon, Norfolk, UK writes:
Message: Hi, I am trying to help my father locate a few bits for his Royal Enfield 250cc Crusader Super 5 (c. 1964/65) including a front engine plate, Alloy centre stand and the appropriate (he's not that fussy) tank badges or decals.

A pointer in the right direction would be appreciated. Thanks, Michael

Any tips?
Regards Royal

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Hello Hitchcock

Thanks for keeping stock to the classic Interceptor

Just a quick e-mail from the Interceptor Owners web site. If you have any news about space parts , specials, new productions or whatever, don't hesitate to send us an e-mail and we'll include it on our web site.

For our knowledge base update in September maybe you could help us clarify something. One of the U.S. Interceptor owners recently bought mufflers from you.
He wasn't satisfied with the fit on an interceptor with the pipes angled up a bit (like the U.S. Model is). The indentation on the inside of the muffler, appeared inadequate to ensure clearance from the wheel axle.

Could you confirm that the fit might be questionable for the U.S. Model?

Also, do you manufacture more than one type of muffler inserts?

Looking forward to your reply (see reply on new Dealer page!)
Royal

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Greetings to all members of the RE_Interceptor group. 22 September

My name is Bob; I just joined the group this morning, and have spent some time now reading the archived posts...very interesting and informative. Here's my situation.

For better or worse, I ended up purchasing the 1966 Interceptor that was on eBay last week. I would like to ask the group members for their input concerning serial numbers.

Here is what the seller reports to be the serial numbers: VIN # 70736 Engine# 16629 My first concern of course is that the numbers don't match. Of even greater concern, however, is that I'm not sure that these numbers even make sense in the factory's scheme of issuing serial numbers.

Can anyone shed some light on this issue? Also, does anyone out there have any specific knowledge of this particular bike (1966, dark green, approx. 5000 to 6000 miles, basically in good, complete condition, located in Jacksonville Florida)? And last,any comments or opinions on the final selling price of $3306?

Any and all comments are welcome, the sooner the better. FYI, I used to own a 1965 Interceptor when I was a teenager. I christened it King Kong(after reading the Road Test in Cycle World way back then), and the bike more than lived up to it's name. It took a whole bunch of time and attention to keep it on the road (including countless road trips to Shillingford's in Philadelphia), but it was an awesome thing...I wish I never let it slip away from me.

Regards Bob

Hi Bob Thanks for your feedback and subsequent long email. I'm looking ofrward to more such input, with contributions to the knowledge base at www.ozemate.com/interceptor

Like a couple of detailed JPG pics on those wall charts that depict the technical specifications for the Whitworth thread system. Also, feel free to scrutinise existing content in knowledgebase for comments as well. There is an attempt there for assisting with becoming a member of that discussion group.

I wouldn't be concerned about the fact that the numbers don't match. And I don't think there is that much specific meaning in the Royal Enfield Interceptor serial numbering scheme.

Congratulations to your buy of that bike on e-bay, price sounds ok to me, it's a demand driven thing. I believe I saved the pics of it when it was up there. I might use the lines you've written plus those pictures in member stories on the web page.

REgards

Royal

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From: sandbergoldchief (Sunday, 22 September 2002)

Vacuum gauges What are the best Vacuum gauges and where to buy, are they anything special?

For any of you who are still synching their carbs the old time- honored way, all I can say is stop now, and get with the times.

The vacuum gauges make it easy to get the carbs synched all the way from idle to WOT, and what a difference that makes in throttle response.

Of course, once synching is done, you re-install the balance tube.

................................

My vacuum gauges are a bank of 4 dial-type instruments I bought at a motorcycle shop years ago, and are made specifically for synching carbs.

I built a set for a friend with some small vacuum gauges I bought from a surplus automotive shop b... they worked well too. You can differentiate them from pressure gauges because they read backward from right to left.

The only thing you have to include (no matter what you do) is a needle valve in series with teh gauge, otherwise you the instrument's reading will oscillate wildly. You can get suitable needle valves from an aquarium supply store (they're used in aquarium aeration systems).

.. gREgg

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Whitworth , SAE, UNC, and BSF fasteners.

(Sunday, 22 September 2002)

Bob, re your Whitworth questions, this site gives a pretty good and
brief overview.

http://www.flyingcircuscars.com/whitworth.htm

I'm pretty sure Walridge in Ontario sells Whitworth fasteners, which avoids the hassle of importing. If not, they can probably refer you to Canadian suppliers.

http://www.walridge.com/default.htm

Finally, there's a relatively new Brit bike parts supplier right in your neck of the Canadian woods, Edmonton. I've dealt with them a bit now, and they seem pretty good. They might have Whitworth stuff too.

http://www.motopartsinc.com/

Bob Cram

Regarding thread forms, I note that Bob Cram sent a URL with some info. The short answer is that as England became industrialized, each industry developed what it thought would be the thread forms to best suit its needs. And of course, these threads were not adopted by North American industry.

You are right that Whitworth is analogous to our UNC, and BSF is like our UNF. There is also a BA thread, which is mainly found in smaller electrical fasteners, and CEI, which was defined by the Cycle Engineers Institute. CEI is unusual, because it specifies a 60 degree Vee thread, but with a constant 26 tpi thread for all sizes from 3/16 to 9/16" .

To be 100% accurate, I should add that there are a couple of the smaller sizes with a finer thread, but I have not committed those to memory. Our bikes are built with a mish mash of all these threads, and I've noticed that the thread pitch used say, for the rear axle nut changed from year to year. (bet no one can guess how I found that one out ...)

There are a few instances in which our SAE fasteners can be forced to mate with the British ones, because teh threads per inch are the same ... 1/4 x 20 is one that comes to mind. However, even then the fit is not great, because SAE threads are Vee shaped* with a 60 degree angle, while BSF and Whitworth are cut with 55 degree threads having rounded roots and crests. All else being equal, this makes for a fastener with superior accuracy and strength, at the cost of a higher manufacturing cost. (*Most SAE threads are now flat top and bottom to improve fatigue strength and reduce manufacturing cost).

You'll notice that many of your bike's original fasteners were cut on automatic screw machines, while most modern fasteners are rolled. While accuracy is OK, this allows low-cost mass production, and the use of very strong steel alloys, which could not be economically screw-cut the old fashioned way.

All this of course became moot as England exported more and more machines to North America. First, the automobile industry converted to SAE fasteners by about 1950, and the motorcycle industry converted about 1970.

In terms of ordering new fasteners, I've found that many of the replacement ones are of pretty poor quality. Therefore, I spend a lot of time re-claiming original fasteners where possible. I build up worn or hacked areas with weld, machining back to size. It pays to have a screw cutting lathe to rough out the thread, and size them with the proper British die. Some applications, such as with through studs, it is possible to replace with an entire new SAE part.

In other cases, you may be able to cut down a longer stud, and re-thread the new end with an SAE thread. As with so many things in restoration, ingenuity is the call of the day.

I've only scratched the surface, but I hope this has been of interest

gREgg

Thanks for that "Royal"

Hi Bob...back from the mines again, time to catch up again, thanks for your reply to the (for me)Whitworth mystery Yes I know John Oland in Edmonton, have dealt with him previously for BSA stuff, I believe he's the guy who bought out most of Bernie Nicholson's stock when he retired, never thought to go to him for fasteners tho, thanks for the idea. The URL I gave should take you directly to a page with the title History of Whitworth. However, the Whitworth explanation Gregg gave a few days back was an even better one.
Bob

just tried the site again and got it to work this time...have just read the whole thing and I find that I have retained practically nil...other than the fact that there were good reasons for the way the systems evolved...well I'll keep the site for reference along with the other good sites you and Gregg have posted here..will be useful when reassembly of the bike commences...sometime this winter..I hope..
Bob

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High output Alternators?

(14 September 2002)

Does anyone offer a higher output Alternator to replace the original weak Lucas kit?

I know that the Ducati Bevel guys fit modern Duc alternators and also re-wind the stators of the singles to get more current. I've been meaning to find out if there is a bolt in replacement I can fit to my Series 1a.

Thanks
RickL

HI Rick,

I've never had problems with my battery going dead, but many people do, especially Nortons. Usually results from one or both of the following:

1. The magnetic rotor having gone weak over the years
- usually because of incorrect storage
2. Incorrect alignment of the rotor with the stator
- shim the rotor to ensure the magnets are in perfect alignment with
the stator

The alternative (pardon the pun) is to install a 3 phase Lucas alternator, along with the correct rectifier and matched zeners. Many people report
good success with this.

.. gREgg

Hi, I own a ?64 series 1 Interceptor and changed the electrical system to 12
Volts. I installed a Lucas Powerbase 3-phase alternator in 1984.

This kit came with stator, rotor,three phase redtifier and Zener diodes. This
alternator gives about 85% of its full output (180Watts) at 2400rpm.

Fits without problems.
regards joerg

Hi Rick
Do you know the number of your stator? what sort of regulator are you
useing? what voltage? How many amps @3000 RPM. are all six coils connected
permanently for full output? My 1965 is useing a stator # 47162, a full wave
Selinium Rectifier and a Zener Diode for regulation.

I converted to an electronic regulator and was dissatisfied with the results.
so I changed back. I use Halogen Bulbs both head and tail. My bike has a magneto ign. and does not seem to have any trouble keeping up with the amp. draw at about
2400 rpm.

I have Lucas Motorcycle Alternators service manual printed May 1966 and if I
can help with any information feel free to ask.

Orlan

My '67 uses coil ignition and it stock. I am using the Lucas rectifier and the zener. I will have to go take another look at the bits tonight and see what is there. I think my Inter spends a lot of time below 2400 rpm, as I ride it in the city and at night. If I don't trickle charge the battery once a month the battery goes flat after a few months.

Orlan, is your alternator 2 phase or 3 phase? per gREgg's message I will look at installing a 3 phase unit and tympianium.

-RickL

Not long ago, I asked on the Triumph Twins list if it was possible for a Triumph to handle an electric vest, and got this answer from Frank Snively, which relates directly back to your question about alternators.

I've since checked this out a bit further and the Widder electric vest draws only 33 W, and one of the Triumph list guys uses one with his Norton. One other guy suggested, with tongue firmly in cheek, that I try towing a trailer with a tractor battery.

Bob Cram

Excuse the Triumph question folks, but I figure that the question is as relevant to RE's, and I know that Gregg is the guy to answer it. The rotor on my Triumph is a bit low on magnetism, not drastically, but enough that I thought I'd replace it this winter. For the conversion you describe I'm assuming I can just use the rotor off the later Triumphs with the 180W 3 phase alternator, and whatever matching stator, rectifier and zener they used on those models.

Is that correct? Did they have solid state rectifiers by then? If not, is there one of those Radio Shack replacements for this rectifier too? Anything else I need to worry about? Thanks.

Bob Cram

Dear Greg and Rick

Here in Copenhagen we have a guy who makes a living of fixing electrical systems for old brits and for all japs. ( Most of his income comes from rewinding new (!) and old jap stators !) He has a test rig that accepts our old Brother Lucas alternator. Last year he tested my original stator with first the old rotor and then with a new rotor.

Output with the new rotor was approx 20% higher than with the old (in average over the interval 1000 - 6000 rpm). I don't recall the output-figures in watts, but I do recall him claiming that the output with the new rotor was fully sufficient if the rectifier and regulator were decent quality.

And when he says sufficient - it means always driving with the main lights on - which is mandatory in this part of Europe ! He incidentally builds his own rectifier/regulator unit from modern components - one which I of course bought pronto - but haven't tried yet because I'm still rebuilding !

Well all this wasn't really what I wanted to tell you. The real story is that this guy claims the following :

Output from the 3 phase Lucas stator is only higher than the output from the original 2 phase stator at above 3500 - 4000 revs !!!
At revs from 1000 to 3500 output from the 2 - phase system is higher !!!
This means ( if he's right - and he normally is ) that for most of us - who pretty much cruise at below 3000 revs - changing to a 3 phase stator is not only a waste of money, but downright stupid.

Best regards
Ole

Re: Output from the 3 phase Lucas stator is only higher than the output from the original 2 phase stator at above 3500 - 4000 revs !!!

I find this very difficult to believe.

Reason being, because of the way the 3 phase alternator works: by virtue of
the stator's windings coming out in 3 phases, these units produce more AC
output pulses per revolution of the rotor than a standard unit. This
translates to more DC output after rectification, hence more power. In
fact, it should produce max power at lower revs because of this.

... gREgg

Gregg,

Your reaction is ok ! I felt and reasoned exactly the same way, when I heard this statement. This issue wasn't high priority for me at the time, so I just thought, well let's try the 2 phase with a fresh rotor and a good control-system and I'll save the money for a 3 phase stator for the time being .

I only recalled this guys statement because of the discussion here. I will get back to him now, his name is Erik Snabel, and see if he will repeat and elaborate on this statement.

....

Gregg,

Talked to my electromechanical wizzard today. Here's what he says :

He has come across (at least ?) 2 types of Lucas 3 phase stators :

One type - which he regards as the common one, and has had in his bench numerous times - is charecterized by having a resistance between the phases of approx. 0.8 Ohms. It is this type that he referred to last time I visited him. He repeats that output from these stators at below 3000 revs ( small correction here ) is inferior to that of an average 2 phase stator when both are tested with the same, new Lucas rotor. ( He warns against new India-produced rotors for the 500 Bullit - their magnetizing is week !)

On two recent occasions he has come across 3-phase stators that were better - all the way - than the 2 phase !!! ( So here things make sense ! ) These stators had a resistans between the phases of approx. 0.5 Ohms.

When asked about Type-designations for the various stators, he was blank. His revised advice is - bring your multimeter when you go to buy a 3 phase, and feel lucky if you find a 0.5 Ohm type.

On my own account, I can add, that the rectifier/regulator unit that he builds and sells ( for old brits ) is designed for the 3 phase stator. When using it with a 2 phase, you simply connect it up differently. ( Just to point out that the guy can't have a hidden agenda here !)

Ole

This may give some insight. There is an early alternator which has 3 leads, and which is commonly mistaken as a 3 phase unit. It is not. It is a 2 winding unit, intended to be used with a special (read 'crude') lighting switch that switched the windings to 'regulate' output voltage (such as it did), instead of using a Zener diode regulator.

These stators were later used for many years with Zener systems, with one common wire, and the other two of the wires connected together. Later, the design was changed to have the "two wires" connected together inside the stator. There you have it: just because a stator has 3 wires, does not mean that it is a 3 phase unit.

Proper three phase stators are by no means common at all. The vast majority have been sold as aftermarket replacements, and I'm not aware of any bikes having been fitted with them at the factory.

.. gREgg

Just a little (final ?) extra from Ole :

With input from knowledgable friends who have followed the discussion I now believe as follows (always willing to stand corrected though ) :

The "bad", 0.8 Ohm stators are most probably the Lucas type, RM 23, part no 47239 or maybe a copy-product of this 1st generation 3 phase. Claimed output: 100 W at 3500 rpm. 2 phase stator RM 21 has better output !

The "good", 0.5 Ohm stator is most probably the later type RM 25 that claims 150 W at 2400 rpm !

So, if you buy new - you will most probably get a "good" RM 25 ; and if you buy 2.nd hand - watch out, it may well be a RM 23 type !

Ole

Ole,

Not to question the integrity of your information source, but the RM23 stator (Lucas p/n 47239) is most certainly *not* a 3 phase unit.

The RM23 is a standard 2-wire stator with a claimed output of 15 amps at 6,000 RPM (I couldn't find a power rating). It was the standard factory fitment to the Norton Commando MKIII, and replaced the RM21 (Lucas p/n 47205 / 47205a) stator of the earlier Commando. The RM23 was used in the MKIII Commando because it had a large battery to suit an electric starter, and in most markets it was required to run with its headlights on. I owned one of these machines for over 8 years, and I can state these facts positively.

There may be some confusion about the RM23 unit because it was wired in a slightly unconventional manner. It is connected to a half-bridge rectifier, and two Zener diodes. These Zeners do double-duty as the lower legs of a full wave bridge rectifier, as well as splitting the regulating function between them. Lucas made this change because the output of the RM23 was too high for a single Zener to handle the task, and it was likely the cheapest option open to them.

There are two 3 phase stators listed in another source I consulted. These were both identified as type RM24, but with Lucas p/n 47252, (130 W) for one, and p/n 47244 for the other which is listed as a 180 watt unit. Interestingly, an earlier p/n, 47194 claims to be a 2-wire, 180W unit.No idea why two Lucas part numbers had the same model number and yet different power outputs, but if time permits, I will check into it further.

.. gREgg

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Banjo Bolts

(Thursday 12 September 2002)
Hoping that someone has an Interceptor head handy, or at least one of the banjo bolts for the inlet balance tube.

My Inter is stored across town, and I need to check the correct diameter and thread for the balance tube banjo bolt ... what I thought were the correct ones may actually be fuel inlet banjo bolts from concentric carbs
(The ones I have here are 3/8" x 26 tpi CEI). Since I don't have a head handy, I can't check to see if by some coincidence they also happen to work on the Inter head. (In my mind's eye, I recall the balance tube banjo bolt to be 3/8" x 20 tpi Whit)

Anyone happen to have an Intern head to check for me, or maybe can verify the thread on a banjo bolt they know for sure is from teh Inter balance tube?

Many thanks,
.. gREgg

--Hi Gregg..was cleaning the shop anyway today, so remembering your request here I dug out the box where my Interceptor head jewelry was stored (along with most of the other small parts and pieces from the top end and various new parts)and got out said crossover tube and checked the still attatched banjo bolts out for size

...my thread gauge says 20 tpi and the vernier says the unthreaded shank is right
on 3/8", so looks like your educated guess was exactly right.. You know so far as being Whitworth goes..ya got me, I dont really understand the whole Whitworth

- BS deal, I think Whit is coarse and BS is fine?..maybe you could enlighten me, like for instance can I replace any of my fasteners with anything SAE? I'm thinking I'll have to import all of the ones I need, and not just for faith in restoration, but because the SAE wont fit thread wise, am I right?
Bob

Bob, Thank you for the quick uptake on my query regarding the banjo bolts. Sorry that I've been super busy the last couple of days and unable to respond. I have some time now, so here goes:

1. I needed to know the thread pitch because I wanted to machine up a pair threaded inserts to adapt the hose from my vacuum gauges to the inlet tracts, in place of the balance tube. I have now done this on my current Inter, and this morning I re-synched my carbs (I've been doing this for years with my other twins and fours, but had never gotten around to my Series 1a because it ran so well from day-one .

Hi Gregg, thanks for going to the trouuble to explain the Whitworth mystery so well, will mean much more to me when I actually start to reassemble my bike. One of the things I'm still not sure of is are the banjo bolts we spoke of Whitworth or not?

Yes I intend to reuse the fasteners on the bike I have invested in a home plating kit and will be trying that one out when the weather gets worse. Fortunately for me almost all of my fasteners had been very undertorqued, some of them just finger tight in fact, so were in excellent shape when dismantling was complete, I only had to replace a few so far....reassembly might bring different adventures..
Thanks again for your knowledge Gregg
Bob H

Hello Bob,

Thanks for the thanks: glad I could help.

Yes, the banjos are in fact 3/8 x 20 tpi, which is a Whitworth thread. I made up the adapters and synched my carbs as planned. Counting on going for a long ride on Sunday ... really looking forward to it.

.. Gregg

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Oil pressure concerns - Oil Cavitation and solutions

Over the last twelve months, now and then there has been debate on the topic of oilpressure on the Interceptor, and that there is sometimes a problem.
Is it the same concern between the Mk I and Mk II and the various years of these?

Bill re-opened this topic below for comments. Some of our Interceptor experts have not commented at all. Some have put forward solutions but have then not followed up, once others have joint the debate. Have we estabilshed some facts?

It looks like some e-mail exchanges might have bypassed the forum. Could anyone who has any exchanges on this topic, Please send them to me and I'll consolidate them for a separate discussion. I think most Interceptor owners have become a bit confused.

I think some of the solutions would do well of having some statement of road test and result as well as a detailed scetch of solutions. Comments?
For the time being, I have collected the latest emails in the september letters / emails on the web site.

Ole and Bill, I have tried to contact some who have contributed in the past. I take it that you question some of the solutions? Others might do the same, and maybe I should remove some "solutions" which are not appropriately supported by their originator.

If you dont want to broadcast some information, feel free to email me direct on
(NOTE email address modified to fool junk mail robots, use an @ instead of the * in the following email address)
interceptor*ozemate.com

REgards
Royal

From Bill:
September 05, 2002 3:04 PM

I am still working on the low oil pressure problem on my 1969 Series II. I drilled into the timeing cover and installed a pulsation dampener as desciribed by Peter in Message 77.

The results were not good. Although the oil pressure was about 70 psi at startup, it
gradually dropped off to about 10 psi at 70 mph. This is the same pressure as without the dampener. It only took about 10 miles at highway speed to get the oil pressure to this point.

I would like to know if anyone else has tried fix or if anyone knows how to get in
touch with Peter in the Netherlands.

Bill

Hi Royal

Yes, I agree that Peters input is in the expert category. My gut feeling is that his approach is the best fix for the cavitation problem.

It would be nice, however, to see this solution confirmed or proven by somebody else ! Hence my immediate interest when Madmax (Bill) wrote that he tried Peters solution - and found that it didn't work !? The question is now : Is it a matter of getting the details right ? ( I was just getting ready to begin the modifications in my own Timing Chest when I saw Madmax's mail !)

Peter wrote (indirectly) that he drilled the hole to the "windkettle" approx. 1/2" from the pump. That makes sense - so lets not question that parameter.
Next question is : How big is this "connection drilling" ?? I guess using the same diameter as the existing drilling - 3,3 mm - would be appropriate ?

3.rd parameter : How long is the "connection drilling" ( through a welded "lump" / tubing insert / threaded fitting ) ?? We must assume that its direction is vertical, upwards - and thus a column of oil will be moving up and down here in order to
compensate for the pulsation in feed pressure ( or in other words - to prevent the emergence of vacuum = cavitation in the feed line as the pump starts its suction stroke.) ! The length or height of this column is equal to (or shorter than?) the length of the "connection drilling" !

4.th parameter : The size ( volume ) of the "windkettle" or vacuum chamber, ie - the air volume above the pulsating oil column. ( I don't personally have a clear feeling about this parameter. If it is "too" big, I guess that it needs to fill itself partially with oil before a suitable vacuum level can be established ? This again meens that a lot of oil will go this way during start-up ? - and that's not very desirable ! If it's too small, on the other hand, the system will be too "stiff" and won't be able to prevent the dreaded cavitation.)

Finally, one could also question the geometry of the "windkettle" or rather the geometry of the transition between the "connection drilling" and the "windkettle". The two extremes would be - a huge "square" volume established by "boxing in" the
whole region above the "connection drilling" with plates welded in place (as Peter seems to have done ?) - or a pipe ( hydraulic tubing/hose ) in upwards continuation of the "connection drilling", curled or wound for length (volume) - and, of course,
plugged at the end.

I hope now - after reading my thoughts above - that you appreciate my attempt to have "Madmax" tell us exactly what he did, and also my interest in getting in contact with Peter again. At the back of my mind I'm kind of hoping that Madmax has made
some obvious mistake, but I have also learnt in life - not to underestimate other people.

Best regards
Ole

Ole also says:

It's so good to see that someone else has done something to fix that oil-problem !!
Thanks for the inputs Bill and Peter !
Great idea, Peter - with the Damping (vacuum) Chamber. I'd love to see a sketch of the mod. you did in the S II Timing Cover !?
And also to hear you elaborate a bit on the solution.
- How big do you think the (vacuum)chamber should be ?
- How small should the connecting hole be ?
- Any tricks to make sure it stays air-filled ?
- Have you seen this solution used elsewhere ? etc. etc.
- Another question alltogether
- after getting the pump working (!?!)
- is how to use the oil ?!
After recent discussions with succesfull engine tuners,
I'm convinced that the 45psi ( - or Peters 65 !?) is much too high an oil pressure for the big-end.
25 - to 30 psi should be more than adequate.
A higher pressure only means more friction in the Crank oil-feed seal as well as in the big-end.

The big end is a "hydrodynamic" lube-system that works more or less independantly of the feed pressure. Much better to lower the primary relief valve setting (I've got a simple recepy if anyone is interested) and get a lot of oil flowing to the heads and down through the Cam- pockets where it can assist in cooling !
Best regards

Ole, Denmark

Ole, (Bill/Madmax reply)

To begin with, I have not found a solution to the oil pressure problem yet. I tried drilling the suction oil passage in the timing cover through to the outside, tapping it to 1/4-28, brazing a grease fitting to a hydraulic fitting and connecting it to a hole tapped in the oil drain plug to increase the suction flow.

This did not help. Then I saw the message from Peter about the pulsation dampener so I disconnected the hose to the drain plug and capped the hydraulic fitting to make an air chamber. This did not make any improvement either.

So then I thought the chamber was too far from the pump so I drilled another hole in the outside of the timing cover, about 1/4" from the pump and installed the hydraulic fitting air chamber, plugged the first hole, and started it up. Same result, no improvement.

I am to the point of giving up on the air chamber and I am now trying to find the right size ball to make check valve in the suction line. I will keep you posted on the results

Bill

Thanks a lot for the thorough account of your actions and findings !!
As I see it, you have tried to reproduce both Bills- and Peters solution, with no luck in either case!

My immediate comment would be that there are a lot of variables in Peters pulsation damper solution, and you might just have got the combination of them a bit wrong ?
Your vicinity to the pump (1/4") is better than Peters (1/2"). We can't compare drilling sizes, however, nor damper volume - and I think that Peters drilling is vertical (upwards) while yours is horizontal.

It sure would be nice to get in touch with Peter again and get him to reveal all his details - and also get confirmation that his solution still works !?

Your idea with a non-return valve might work ? May I suggest that you try to get hold of a ceramic ball (1/4" or 3/16" for instance). It only weighs about one third of a steel ball and is thus much more responsive !

Best regards

Ole

(Tuesday 1 October 2002)

I wish I did have some better results but all I have managed to do lately is break some parts. I got the idea that the spring that holds the oil pump disk down might be weak after only 30 years hard service.

So I tried to put
a washer behind the spring to tighten it up and guess what...I cracked the oil pump cover because there was not enough free clearance for the washer and the spring. So now I just received a new spring and cover and I hope to try them out this weekend.

This weekend I hope to go to the North Texas Norton Owners Association rally that is being held about 200 miles North of Houston. If the pulsation dampener is ever going to show any results, this will be the time.

The weather will be in the 80s instead of 95 to 100 like it has been here all summer. Anyway, after this next test I will post on the web site.

REgards,
Bill

Previous e-mails from Bill and Peter,,,,

(Bill, Mechanical Engineer, Houston)For years I have noticed the problem of low oil pressure when the bike is above 65 mph. I have
finally isolated the cause of this problem. The 3/16" diameter oil passages in the engine block and timing cover are too small for the
volume of the oil pump. (shortened; sorry Bill)

(Then Peter Netherlands:) Though my relation with the Interceptor is a love/hate one I have a simple cure for the cavitation problem with the quick two start driven oil pumps. I've tried it on my series II,. It worked. 65 Lbs from 2000 to 7000rpm , hot engine, 30+ Celcius.

It needs a pulsation damper in the feed to the pump. That gives a steady flow all the way up to about 1/2 " away from the pump. The last bit will still pulsate with the plunger but this amount of oil is so small that it will easily follow the motion of the plunger.

It does in practice amount to drilling a little hole in the oilway to the pump close to the pump and next welding a little chamber into the timing cover next to the pump. The hole should be a connection between the oil way and the chamber. the chamber must have no leak to the outside.I could go into more theoretical and practical detail if anyone is interested.

Peter