JohnC
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Posts posted by JohnC
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FWIW I fitted "natural" colour, which is a white translucent material. Helped me diagnose a poor starting problem immediately - I could see the air bubbles in the pipes after the car had been sitting even just overnight. Refurbished injectors (just add $) - problem sorted
John
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On 4/22/2022 at 9:22 PM, Mike C said:
heated the nylon tube ends in hot water
Don't do this.
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On 3/24/2022 at 6:15 AM, Andy Moltu said:
I use a dead blow hammer. The surface is rubber and filled with shot. Doesn’t bounce or mark the spinner.
Likewise. Although the surface of mine is nylon or some similar hard plastic.
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Are you sure all indicator lights are working? What you describe could be caused by one or more bulbs being blown.
Oh, I don't know the impact of having a hazard flasher/switch as I don't have one. The odd behaviour there does make it sound like you have something dodgy in the hazard stuff though. Still, def check that all indicators are working.
J
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On 2/26/2022 at 3:49 AM, BlueTR3A-5EKT said:
When used in conjunction with the close ratio gearbox ratios and a J overdrive working on 4 th only, it gives a delightfully spaced 5 speed gearbox…..or so Abingdon said.
Newbie to gearbox stuff, but considering an overhaul. This sounds like a worthwhile change. Is there only one set of close ratios? And do you change the diff ratio to retain the final drive gearing in OD 4th? Or is this really only for racing? I already have a Quaife ATB in the diff BTW.
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As for whether a screw or bolt is required, a bolt is far preferable (i.e., use one!) if it's mild steel. In this case the bolt will be in shear and you want the smooth shank to take the load (and to fill the hole). If the spec is for a high tensile bolt in a High Strength Friction Grip (HSFG) connection, then you *could* use a screw (but it goes against all sense to do so and introduce more potential fracture sites). In this case the load is taken by the friction in the two surfaces bring connected. The bolt/screw simply applies pressure to generate the friction. Better informed folk than I can guide on which connections in our cars are HSFG, but I suspect only those in the engine taking high loads (big ends, con rods, cylinder head, crankshaft). I'd only use a screw if I couldn't find a bolt to fit, or to join thin material.
John
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1 hour ago, Rob Salisbury said:
Simple question, Why doesn't that work for brakes?
Because the volume of air changes as it compresses. Not an issue for the gauge as the pump just keeps pushing more oil in until pressure is equalised. If the same happened in the brake or clutch line you’d get less movement at the business end for the *limited* amount of movement at the pedal.
JC
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5 hours ago, cp25616 said:
Its all about working your way through the problem in a logical manner really.
Totally agree. So an MU diaphragm? No way. That would give you grief from when you first turn the key. What changes after an hour (and in what conditions?)? Electrics heating up seems most likely. But is it always an hour? Or just "quite a while"? I had a piece of plastic (like supermarket bag) in the tank and it blocked the fuel flow every so often. And it clogged up quickly after a brief stop. I guess it got sucked into the tank outlet soon after startup. It was an absolute bugger to diagnose! Is your fuel filter clogged?
How long must the car sit before it will run for another hour? Until cold? Then temperature is a likely problem, so the suggestions re coils etc make sense. Seems random? Then maybe a loose electrical connection, or a fuel blockage. But a PI problem? Not so likely.
Keep posting here with what you find. Plenty of folk here to help.
John
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Replied and realised I hadn't read the whole thread. I'm outa here!
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On 11/2/2021 at 7:56 AM, Nigel A said:
This is what I have just done to remove the gearbox
My mind is boggling just thinking about how you drove the car up opposing sets of ramps!
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Is this a TT1200 type extractor? I had one and replaced it with the standard cast iron manifold. Before and after rolling road sessions, with no other mods, showed how the TT1200 was designed to maximise high-RPM torque/BHP. My car became so much more fun to drive after the "downgrade". Much better torque at lower RPM. Standard cam, btw. I have become very sceptical of claims made for extractor manifolds. In combination with gas-flowing etc, or for racing, I accept the potential benefit. But for a standard road car? Not so much. Full transparency, I haven't had the luxury of putting a Phoenix 6-3-1 onto my car and testing on a rolling road, but that's on the list. Mind you, I now have what I think you guys would call a Stage 2 head, so that may even not be in any way definitive.
I now run a standard exhaust system from manifold to tailpipes. My car sounds, to me at least, like it should. I used to have a 2 1/2" single tailpipe and got self-conscious about the loud pedal. Now I'm happy to play. And the work on the head was worth every cent. BTW, in my experience, mild steel sounds better than stainless (is it thicker gauge?), but I've gone with ss for the longevity.
John
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That calc of over 10:1 assumes the chambers haven't been worked on. Just a thought.
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On 10/23/2021 at 10:04 PM, Motorsport Mickey said:
In contra intuitive leap let me state that a 5/16 UNF helicoil requires a greater hole dia be drilled for the core dia - .328 thou. Whereas a 3/8 UNC tapping size hole is only - .312 which is 5/16” which is the size the studs are tapped at in the trailing arm, which is the remains in the pile of grey dust which comes out of the hole. Often you don’t even have to drill the hole, it’s ready to accept a 3/8 UNC tap.
Some pedants would argue that saving the wall thickness by a small amount of 16 thou overall dia is pointless, however better in the hole than on the floor is how I reason it.Ohh, and the studs don’t need to be stepped, drill out the hub flange to accept 3/8” UNC and replace the studs with 3/8 UNC cap heads through the hub and into the trailing arm parent thread you’ve just tapped. Cheap and freely available, that’s what the racers do.
Thanks - that makes sense. BTW, is the same 16 ft-lb torque correct for the cap heads?
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On 10/21/2021 at 8:38 PM, RogerH said:
The diameter of the new pins is apprx 8.1mm - you need to measure precisely to get a good fit as they are not the same size as each other.
Just curious - any reason you didn't consider roll pins? More tolerant of hole size, and you can make the diameters of the top & bottom holes a teeny bit smaller than the centre one.
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15 hours ago, Mike Herlihy said:
A better solution is to enlarge the threads to 3/8. A stepped stud is then needed that is 3/8 dia to screw into the suspension arm and 5/16 at the other end to pass through the hub carrier
Why is that a better solution? The helicoils are effectively a 3/8 UNC thread in the alloy. The original 5/16 UNF stud is plenty strong enough, and screws into the internal (5/16 UNF) thread of the helicoil. Also, less chance of damaging an alloy thread in the unlikely event you need to remove the stud in future.
I see no advantage or disadvantage with either approach. And helicoils are easy to source. Are stepped studs? The last I used were custom made by my father in 1980...
John
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19 hours ago, RogerH said:
did you use heat to get the frozen pins to move.
No. Belted them out. TBH I can't remember exactly how, but no heat. I think one came out easily with a centre punch, and I used that one to drive out the next.
Having read this thread, I wouldn't be surprised if the refusals were because I was trying to drive the pin out the wrong way!
John
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FWIW I refurbished a couple using roll pins after drilling out the hinges to suit. Drilled the centre very slightly larger than the outers. Easy, quick and cheap. Only issue was that a couple of hinges I tried to fix refused to cooperate - I couldn't get the pins out. Both the pins and hinges were worn btw. Six years later and all is still fine.
Thanks to Richard Crawley for the idea. I think I have a note somewhere of all the relevant drill & roll pin sizes that I used if you need more info.
Cheers,
John -
10 hours ago, RogerH said:
PS - I have tried to use semiconductor but they tend to be rather iffy in the car electric system - very noisy.
Mine is based on relays and cocks a snoot at rough electric.
I couldn't work out how to get the toggle on/off working with a momentary switch using relays. Please would you post your circuit? BTW a friend of mine has pointed out I could achieve the same using a tiny Arduino compatible processor. That might be my next project, although it wasn't available when the car was built. I wonder if it would better withstand the car environment?
John
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10 hours ago, RobH said:
Yes - so really Q1 isn't needed because the power to the lamp is switched the same way. As I see it, when Q3 is off there is no power to the lamp anyway.
The voltage spike generated by a relay turning off can be quite big - up to hundreds of volts sometimes - and semiconductors can be damaged by it. A diode wired in parallel with the coil, oriented so it is reverse-biassed and does not conduct with the applied current, will short-circuit the spike and protect circuitry.
Aha! The penny drops. Thanks Rob - you're absolutely correct. I designed the circuit in bits and changed my approach a couple of times. Q1 was leftover from one of those changes. Didn't do any harm but completely unnecessary!
And I'll add a diode as you suggest. Updated schematic and Spice file attached.
Exactly the input I was looking for in posting this, even if I was a little slow on the uptake
John
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Hi Rob,
Q1 only allows a current (through D1) if its base is energised by an emitter current from Q3, which in turn is only turned on when there's a high signal from the Q pin of the IC. The overdrive relay is represented in the circuit diagram by R10, and is also energised by the transistor Q3. The Vss pin is simply not earthed when the o/d interlock switches are open, and so the whole circuit is inert. Does that clarify things? I confess I'm not sure what back-emf spike will be generated.
Cheers,
John -
We're still in lockdown here in Sydney, and idle hands the Devils work do (as my old religion teacher told me many times). So I decided to design my own overdrive logic controller. I've always liked the intent of the logic controllers out there, but I prefer to brew my own. I also like to try to do so using components which were available when my car was manufactured. So here's my effort. I really would appreciate any suggestions for improvements (@Lebro - looking at you!).
My intent was this:
- Overdrive only available when inhibitor switches allow it (obviously)
- Overdrive is selected/deselected by a momentary switch.
- Overdrive is deselected whenever there's a gear change, and needs to be manually selected again afterwards if so desired.
- A warning light is illuminated when overdrive is selected.
- The overdrive warning light is dimmed when sidelights are on.
Here's the circuit I came up with. The CD4013 flip-flop IC was first available in 1968, and may well have cost as much as the TR6, but I think I've satisfied my intent to be "period". The circuit works in the LTSpice simulator, and on a breadboard in the car (including the warning light) but I haven't done the work to smallify it onto a soldered board. My next step is to get out the soldering iron, but I thought I'd seek critical input first. Attached is the schematic and the Spice file in case anyone wants to play with it.
Cheers,
John -
On 9/20/2021 at 6:28 PM, stuart said:
Thats from ill informed people who dont read the specs of the links I put up.
...and for ill-informed people who think 105psi is "high pressure". It ain't, in the world of hose manufacturers. Several thousand psi is more like it. But as you say, read the specs!
John
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5 hours ago, Lebro said:
This dimmer circuit works for me
Me too (thanks Bob). Maybe obvious (wasn't to me) but you need to change all the bulbs to LED. If they're a mixture the dimmer will be less effective.
MAX BORE OUT TR6 BLOCK ?
in TR6 Forum
Posted
I had it fitted by my local classic car specialist. It was not a straightforward swap - the Quaife unit needed some machining to fit (slightly too large a diameter).
John