The Triumph Dolomite Club - Discussion Forum

The Number One Club for owners of Triumph's range of small saloons from the 1960s and 1970s.
It is currently Fri Mar 29, 2024 9:21 am

All times are UTC




Post new topic  Reply to topic  [ 35 posts ]  Go to page 1 2 3 Next
Author Message
PostPosted: Sat May 07, 2022 5:16 pm 
Offline
TDC Member
User avatar

Joined: Sun Sep 08, 2013 3:35 pm
Posts: 1735
Location: St Annes on Sea, Lancs.
I just put the new jets and needles in the Sprint, and while it runs okay and the piston lifters tell me it's mixed right at tickover when 12 flats down, there's still a little problem.

I got a pair of brass olives for the seal between the feed pipe and the float chambers. That was because I was concerned about the ethanol issue and the rubber seals. But they leak like buggery.

Are these a poor idea, and I've wasted nearly three whole English pounds, have I just failed to tighten them up enough, or am I missing something else? I'm a little reluctant to over tighten them into the "s##t metal" (zinc-aluminium) alloy of the float cambers for obvs. reasons.

Graham

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).


Last edited by GrahamFountain on Sun May 29, 2022 2:50 pm, edited 1 time in total.

Top
   
PostPosted: Sat May 07, 2022 9:52 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!
User avatar

Joined: Thu Oct 06, 2011 1:13 am
Posts: 3173
Location: The continent
Just a poor idea that will never work.

Jeroen

_________________
Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com


Top
   
PostPosted: Sun May 08, 2022 2:40 pm 
Offline
TDC Member
User avatar

Joined: Sun Sep 08, 2013 3:35 pm
Posts: 1735
Location: St Annes on Sea, Lancs.
Well, it took some effort to find what was wrong, but I've stopped the leak from the olives.

Most was that the threads on the new gland nuts on the ends of the feed pipes weren't running well in the threads in the float chamber. But by screwing them in and out on their own a few times, the olives clamped up tight, without too much force on the nuts and there're no obvious leaks. It's been for a bit of a run to the shops in Blackpool, and remains dry under the chambers. I'm going to leave it overnight and see if the chambers drain down then, with some kitchen roll under that I expect will stain a bit at least. But it's looking good for the nonce.

I just hope I got the gland nut on the back carb right, cos I can't get at that one on the car for the pipes to the heater. The front one I can get at to nip a bit further if needed - and it's the one that would drip on the alternator, so definitely the more important of the two.

Graham.

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).


Top
   
PostPosted: Sun May 08, 2022 2:50 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!
User avatar

Joined: Thu Oct 06, 2011 1:13 am
Posts: 3173
Location: The continent
It will set the car on fire very soon.

Brass olives are meant to crimp around a steel or brass pipe to have a tight and leakfree fit.

You cannot tighten brass olives in the alloy float chambers. The thread isn't strong enough and will strip long before something happens to the brass olive.

The plastic tube isn't suitable for a brass olive at all as the olive will never clamp around as it's not a solid metal material. A few times choke on and off will have the tube pop out of the chamber.

The original rubber crimp ring is to clamp in the chamber and clamp around the plastic tube as the rubber is easy to deform where the olive doesn't.

What you are doing is trying to use materials and systems that will never work and as it's the fuel system, failure is disaster.

Jeroen

_________________
Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com


Top
   
PostPosted: Sun May 08, 2022 6:52 pm 
Offline
TDC Member
User avatar

Joined: Sun Sep 08, 2013 3:35 pm
Posts: 1735
Location: St Annes on Sea, Lancs.
Quote:
It will set the car on fire very soon.

The plastic tube isn't suitable for a brass olive at all as the olive will never clamp around as it's not a solid metal material. A few times choke on and off will have the tube pop out of the chamber.

Jeroen
Ah yes, but you're forgetting the flanged brass insert in the end of the plastic tube to the jet. That insert is what the rubber seal is normally squashing the tube onto as it's compressed by the gland nut and the flat washer behind the rubber. Otherwise, that rubber seal would equally never hold just the plastic pipe in place. And the thinnest part of that end of the olive is crimping to trap the end of the tube between it and the flange, just as the rubber would. And, as the sharp end of the olive should "dig in" to the tube, it should pull out even less easily than with the rubber.

I fitted one of the old jets to a spare chamber using an olive, and I couldn't pull it out with a fair bit of tension on the tube. I can't say the tube would have torn first, but it felt pretty solid in the hole. So I ain't overly worried.

And I don't see that there's a lot of tensional stress on the tube as the jet is moved up and down by the choke anyway - the outer spring on the tube will always be trying to keep the tube straight and should ensure it's always pushing into the chamber orifice whether the jet is up or down, and also when it's neither up nor down.

But, given your obvious and touching concern for my safety, I will look at putting something between the front carb and the alternator to deflect any drips. I admit, at this stage, I'm thinking about bacofoil and tiewraps, though.

As a matter of interest, the AUD 545's don't have an overflow pipe on the float chamber tops - at least mine didn't. So, if the float needle wore or jammed, like they do, the front carb would have overflowed straight onto the alternator. I have swapped them for lids from some 663s off a later Sprint and fitted the green plastic tubes. But did that many of the first batch Sprints spontaneously combust?

Graham

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).


Top
   
PostPosted: Mon May 09, 2022 7:37 am 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Thu May 17, 2012 9:34 pm
Posts: 867
I agree with Jeroen.
Fire waiting to happen.
It's not a suitable place to fit a metal olive, the original rubber seal is the only thing to use here. Burlens supply ethanol safe versions for a couple of quid.


Top
   
PostPosted: Mon May 09, 2022 4:22 pm 
Offline
TDC Member
User avatar

Joined: Sun Sep 08, 2013 3:35 pm
Posts: 1735
Location: St Annes on Sea, Lancs.
Quote:
I agree with Jeroen.
Fire waiting to happen.
It's not a suitable place to fit a metal olive, the original rubber seal is the only thing to use here. Burlens supply ethanol safe versions for a couple of quid.
On what basis do you judge it's not a suitable place to fit a metal olive?

I dealt with Jeroen's argument that the olive couldn't grip a plastic pipe on its own: The rubber ring couldn't either, which is why there's a flange ended brass insert in the end of the plastic tube.

And even if the olive didn't grip the pipe, which I checked it does, the tube wouldn't pull out because it is longer than the longest gap between jet and chamber and the spring around the tube is trying to hold it straight. So there's a force always pushing the tube into of the chamber orifice, even as the choke mechanism moves the jet up and down.

So, there's absolutely no risk at all that "A few times choke on and off will have the tube pop out of the chamber."

And Jeroen's argument that the brass olive won't deform enough to make a seal before the threads strip is also shown to be pessimistic by the fact that it does seal.

It may be a moot point whether the olive is deforming more than it's shaping the curved face around the inner hole in the zinc-aluminium alloy of the orifice. Zinc-aluminium alloy isn't very mailable or elastic, and it's harder than most annealed brasses at 80-20 to 70-30 mix. So, because the olive does seal at a reasonable tightness on the gland nut, I suspect the thin edge of the probably softer and more mailable brass olive is indeed being deformed by the curved face in the orifice to clamp the plastic tube against the brass insert.

Graham

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).


Top
   
PostPosted: Tue May 10, 2022 10:17 am 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Thu May 17, 2012 9:34 pm
Posts: 867
A brass olive is not going to seal against an aluminium casting, not properly. You will get corrosion and a leak.
It's up to you - your car.
You've asked for opinions, I've given mine, Jeroen has given his.
It was designed with a rubber seal as standard. If a brass olive as better, that's what SU would have done.
Run it like that - if it does not spring a leak then we are wrong and you are right. Keep us updated please.


Top
   
PostPosted: Tue May 10, 2022 9:08 pm 
Offline
TDC Shropshire Area Organiser

Joined: Sun Aug 21, 2011 5:12 pm
Posts: 7014
Location: Highley, Shropshire
Quote:
A brass olive is not going to seal against an aluminium casting, not properly. You will get corrosion and a leak.
I've stayed out of this so far as I haven't experimented enough to form an opinion.

But I have to call you on this one, there are plenty of examples on cars just a little older than ours of brass olives and unions tightened into alloy housings on fuel systems, I was working on one last week, a MkI Herald circa 1961 which had a steel stub pipe secured into the tank side of the aluminium fuel pump body with a steel union nut and a brass olive, the pressure side of the pump was secured in a similar manner, both at the pump and the (aluminium) carburettor body. All perfectly original and standard. The Herald is just one example, I could find dozens if I could be bothered, nothing dangerous about it at all.

I'm less sanguine about using an olive on the plastic jet pipe, but that's more natural caution than certain knowledge. I too am watching this experiment carefully.

Steve

_________________
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.


Top
   
PostPosted: Tue May 10, 2022 9:21 pm 
Offline
TDC Member

Joined: Mon Dec 12, 2016 9:53 pm
Posts: 1699
Location: Harrow Middlesex
Apologies if I've got hold of the wrong end of the stick, but AN fittings use a brass olive over teflon pipe, in ally casings to seal fuel

Dave


Top
   
PostPosted: Tue May 10, 2022 10:31 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Mon Dec 03, 2012 6:04 pm
Posts: 1549
I have no idea who right here but I do have to ask the question. Why bother when there is an ethanol safe seal available?

You're solving a problem that doesn't exist because you can use an updated version of the original style seal perfectly safely.


Top
   
PostPosted: Thu May 12, 2022 8:17 pm 
Offline
TDC Member
User avatar

Joined: Sun Sep 08, 2013 3:35 pm
Posts: 1735
Location: St Annes on Sea, Lancs.
I'm also sure there's no intrinsic problem with brass olives into zinc aluminium alloy, which is what the SUs are cast from; especially, given the shape of the face surrounding the inner hole.

And, while it's only been a few days so far, the bacofoil alternator protector (patent not applied for), and a dry finger under the float chamber unions, shows no leakage so far. They are still only tightened with a short hold on an open-ended spanner, not with much force.

From the look of that face round the inner hole that the olive fits into, I might even believe it had been designed with an olive in mind, and that's why the rubber washer needs a plane steel one behind it - I've checked that all four of the float chambers I have, which I'm reasonably sure were in original condition, had the steel washer in first and the rubber one second. Though when I went online, the Moss video on YouTube shows the guy putting the rubber one in first, and the steel washer between it and the gland nut. I suppose it will work that way around too, as long as the space behind the front edge of the tapered face round the inner hole is not larger than the volume of the rubber washer once it's perished a bit. But then it should work with no steel washer at all, if the threads run deep enough.

As to the olive being on a plastic pipe, I think that pipe being supported by a brass insert that can't go anywhere, solves any problems there might be. Moreover, I did test it grips well, and there's no force I can see trying to pull the pipe out - quite the reverse.

As to why use a brass olive not a rubber one that should not rot with E10 fuel, etc. First: Is E10 the end of it? I think that a brass olive has a much better chance of remaining good whatever the fuel composition is going to be, short of red fuming nitric acid. Even salt water in the fuel (as if) shouldn't be that much of a problem with any significant level of zinc and or copper as alloyants in the carb body. Second, I didn't see them on the Burlen fuels site (still don't - tho not looked hard); whereas these olives are all over eBay, and (given the price mentioned above) a shed load cheaper once you factor in p&p. Well, you can pay a little or lots for these olives on eBay, but that's not odd there. Third: Well that's my problem.

But I do admit I am wondering if one of them does leak, whether Sod's Law will make it the front carb or the back one:

The front carb is worse because it's over the alternator. But then, when it first didn't work because the threads needed cleaning a bit, and in the past when the carb float chamber has overflowed without the tube for the green overflow pipes being fitted, there was floods of fuel falling on the alternator, and that did not cause a fire. I wouldn't want to start another argument here (LOL), but free flowing liquid petrol is harder to ignite than most folks think. Older hydraulic fluids, on the other hand...

And the back carb is worse because it really has to come off for the gland nut to be tightened - I can get some effect on it using the 7/16th crows-foot spanner I have for the back bolt on the distributor. But it's not easy.

Graham

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).


Top
   
PostPosted: Fri May 13, 2022 9:01 am 
Offline
Future Club member hopefully!
Future Club member hopefully!
User avatar

Joined: Thu Oct 06, 2011 1:13 am
Posts: 3173
Location: The continent
The correct way IS the rubber first, then the metal ring and then the nut. The rubber is being crimped by the shape of the floatchamber. The metal ring protects the rubber against the turning of the nut making the rubber only be pushed and not rotated/damaged while tightening the nut.

Putting the metal ring first in the chamber and then the rubber it won't crimp the rubber and does not make it seal and clamp.

Jeroen.

_________________
Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com


Top
   
PostPosted: Fri May 13, 2022 12:04 pm 
Offline
TDC Member
User avatar

Joined: Sun Sep 08, 2013 3:35 pm
Posts: 1735
Location: St Annes on Sea, Lancs.
Well I can say that the four I looked at, which I think were all as they left the factory, had the steel washer in first. I accept that the replacement jets come with the steel washer up against the gland nut. But steel washer in first looks like the way SU assembled them at the works. It didn't leak like that round, by the way.

Here's a picture of the only one of the four chambers I have to hand that I haven't taken the washers out of. You can see the indent from the back face of the gland nut in the outer face of the rubber, and you can just make out the steel washer behind it.

I wonder if Alun has taken any apart that were original, recently, and can comment whether they are constant in the order of the washers, there's some change over time, or if my four are some sort of statistical anomaly.

With the steel washer in first, the rubber will then seal to the inside of the larger part of the hole in the chamber and the outside of the plastic tube, as supported by the brass insert, as it's squashed between the gland nut and the washer. The seal between the washer and the face around the smaller hole in the chamber orifice is then not an issue.

If the rubber went in first, what would be the point of the steel washer? The back face of the gland nut does all that's needed in compressing the rubber, so the washer would be redundant and SU could have saved 0.1d (on the assumption that washers were 10 a penny) on every carb they made - so they would've wouldn't they.

Graham


Attachments:
DSCF6041.JPG
DSCF6041.JPG [ 383.59 KiB | Viewed 249 times ]

_________________
The 16v Slant 4 engine is more fun than the 3.5 V8, because you mostly drive it on the upslope of the torque curve.

Factory 1977 TR7 Sprint FHC VVC 697S (Now all of, but still needs putting together)
B&Y 73 Dolomite Sprint UVB 274M (kids!)
1970 Maroon 13/60 Herald Convertable (wife's fun car).
Top
   
PostPosted: Fri May 13, 2022 3:55 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!
User avatar

Joined: Thu Oct 06, 2011 1:13 am
Posts: 3173
Location: The continent
Quote:
Well I can say that the four I looked at, which I think were all as they left the factory, had the steel washer in first. I accept that the replacement jets come with the steel washer up against the gland nut. But steel washer in first looks like the way SU assembled them at the works. It didn't leak like that round, by the way.

Here's a picture of the only one of the four chambers I have to hand that I haven't taken the washers out of. You can see the indent from the back face of the gland nut in the outer face of the rubber, and you can just make out the steel washer behind it.

I wonder if Alun has taken any apart that were original, recently, and can comment whether they are constant in the order of the washers, there's some change over time, or if my four are some sort of statistical anomaly.

With the steel washer in first, the rubber will then seal to the inside of the larger part of the hole in the chamber and the outside of the plastic tube, as supported by the brass insert, as it's squashed between the gland nut and the washer. The seal between the washer and the face around the smaller hole in the chamber orifice is then not an issue.

If the rubber went in first, what would be the point of the steel washer? The back face of the gland nut does all that's needed in compressing the rubber, so the washer would be redundant and SU could have saved 0.1d (on the assumption that washers were 10 a penny) on every carb they made - so they would've wouldn't they.

Graham
Quote:
The correct way IS the rubber first, then the metal ring and then the nut. The rubber is being crimped by the shape of the floatchamber. The metal ring protects the rubber against the turning of the nut making the rubber only be pushed and not rotated/damaged while tightening the nut.

Putting the metal ring first in the chamber and then the rubber it won't crimp the rubber and does not make it seal and clamp.

Jeroen.
I really hope you are joking in your last comment but on the otherhand fitting a brass olive as a replacement does make me think you are serious about this one also.

Fit the olive please but don't park it next to my cars.

Jeroen


Image



Image

_________________
Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 35 posts ]  Go to page 1 2 3 Next

All times are UTC


Who is online

Users browsing this forum: AhrefsBot [Bot], Amazon [Bot], Google, Trendiction and 24 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited