[Need help with my Spit/GT6 conversion.]

Hello, thought I might be able to help a little. I put together the attached diagram when investigating some slight overheating issues a few years ago.

My advice would be not to jump into upgrades as standard should work ok - better to fix the cause. Also try to be systematic, eliminating causes by investigation rather than jumping into replacing random parts.

Sorry if I'm teaching granny to suck eggs here ... But here are a few thoughts

 

Questions I would ask:

I would think there are three immediate causes of fluid loss via cap:

- cap failure - seems unlikely from symptoms, but try to rule out.

- head gasket failure

- boiling cooling water

Head gasket failure - sounds like you've ruled this out - worth being sure though. I understand you would normally see water in the oil or oil in the water or excessive steam from exhaust when hot.

That then leaves boiling cooling water.

 

So why would that happen:

- high frictional heat load i.e. overtight engine as you mention or lean mixture can cause a hotter engine.

- no or reduced flow through block due to broken water pump or blocked waterways.

- reduced cooling capacity due to stuck thermostat, fouled radiator core, poor air flow through core.

 

So is the bottom hose getting hot? With slow flow temperature differences are higher, i.e. cold water going into engine becomes very high temperature leaving and high temperature entering radiator becomes cold coming out. Whereas a radiator that is just struggling to cope with additional heat load will have a bottom hose temperature that follows the top hose temperature at a reasonable difference. A poorly radiator will give very little temp difference at all.

 

How do you know the pump is fine? I think i read somewhere that impellers can become damaged or spin on the shaft so that the pump no longer works.

How hot is the gauge reading when water starts ejecting? Might be worth checking where 100degC is on your gauge by putting the sender in a pan of boiling water whilst still wired up. You can do this by having a kettle right at hand in the garage (also useful for emergency tea) or a camping stove is better. Note water at 13psi boils at 119degC.

 

Anyway hope that is of some help.

Mike

[Safety of our hydraulic brakes?]

Yes brake fluid has been changed - usually because of other things needed doing. Although must admit, maybe claiming never topped up might be a slight exageration, certainly can't remember having to do it when checking though.

 

But ... Now i'm not too sure about my "safety" mod.

I knew i was getting rid of the little breather hole in the middle of the cap. But thought the need for the brake cylinder to breath would be minimal, with very little actual movement of fluid when you press the brakes. Also, likelyhood of the cap being sealed well enough to allow vacuum to be pulled seams unlikely.

 

But I did a little searching online and found some info where a different type of cap could get its breather blocked and result in erratic brakes. The main requirement for breathing according to this article being expansion of the fluid as it gets hot.

 

Seeing as its brakes, and not wanting to take any risks, i'm now going to reverse the mod and put the old cap back on. At least until I can confirm whether this is an issue or not.

[Safety of our hydraulic brakes?]

Well thanks all for the comments.

I've thought it through and concluded that my clutch hydraulics must have an issue - probably the bore of the old master cylinder deteriorating the seal, so hopefully the new cylinder has sorted that. Whereas my brake master cylinder hasn't needed topping up in the 16 years I've owned the car. So I think the brakes are fairly low risk. Based on that have decided not to go with the complicated circuit originally considered.

I had already ordered the float switch and buzzer as a test so thought i'd take a look and see if its worth instslling something or not.

Turns up, installing a simple buzzer based alarm is very simple. Float switch fits really easily into spare master cylinder cap, power comes from the green cable connected to the windscreenwiper switch straight to the buzzer, through the bulkhead to the new float switch on he brake cylinder and then to earth next to the wiper motor.

So my little safety improvement is now installed. Probably not really needed, but just a little extra protection. I'll still check the fluid levels though.

I'm taking the GT6 to LeMans so gives me more confidence that the brakes will keep me safe!

 

[Safety of our hydraulic brakes?]

I agree wirh everything you say John and I do check my fluids regularly, just not every trip. In this case the check had been something like a week earlier with as normal no issue - and only a short 3 mile journey to work and back in between the check and the longer journey. The difference here was that I had just completed that long journey, I would think whilst only doing short journeys the clutch doesn't get cycled that many times, then go on the long one it does.

 

What worries me is that it seams weekly check is not enough. I guess a small weep might have been noticeable under the gaiter if I had checked there. But I wouldn't normally check there. If I had checked whilst parked up at the inlaws I might have spotted something. But this was for me a sudden failure, repeated checks of a full cylinder, then empty less than 400miles and 1 week after the last full check.

 

So I'm treating it as a bit of a near miss, how can I reduce the risk without impacting my enjoyment of the car!

Hence the idea of fitting a switch to the brake master cylinder - at least would be able to bring the car to a halt before a complete failure then. Not worried about the clutch as worst thing then is that it leaves me stranded.

[Safety of our hydraulic brakes?]

Dual circuit master cylinder is definitely a good solution. I'd personally rather leave as original as possible. I know I'll have an odd switch sticking ouut the top of the master cylinder, but that's easy to reverse if needed.

I like the idea of ultra bright LED - that might be a simpler way of ensuring its noticed rather thgan my rather complicated design. I'll think about that one.

On the cap, I've bought a switch designed to be retrofitted to an existing cap - see picture in original post. So bought a spare cap to modify and fit it to. Reverting to original is then just a case of swapping caps.

[Safety of our hydraulic brakes?]

Thanks for the replies.

I checked the bore and it seamed fine. But i will now see if i can hone it. I've replaced.with a new cylinder for now, but i'd like to replace the original girling unit eventually.

 

The complexity of the electronics was for 2 reasons.

 

Firstly i wanted to reuse the demister light rather than have something adhoc - but still use it for its intended purpose.

Secondly, i'm not sure I would notice a little light coming on quietly in the middle of a journey. Whereas something that flashes gets the attention.

But then i suppose simple often works best!

The one thing that worries me is sealing the floatswitch into the cylinder cap, it would be ironic to cause the cylinder to lose itse fluid by making this mod.

[Safety of our hydraulic brakes?]

This has come up actually on my clutch, but the same could happen on the brake system which worries me a little.

I check the fluid levels regularly, and both clutch and brake levels were fine a couple of weeks ago.

I did a 300 mile round trip without problem.

I then came to use my car for work on my regular "fun car Friday" (I usually cycle) and no clutch.

On investigation there was no fluid in the clutch master cylinder.

 

I found fluid under the master cylinder gaiter and on dissassembly found the remaining fluid to be a mucky grey as if the seal had decomposed into the fluid. Yet the seal looked fine. This is a seal i fitted a year or so ago, so could be poor quality part?

Does anyone have experience of failed seal in this way?

 

What worries me is if same failure occurs on the brakes when on the motorway the consequence could be shall we say not good.

 

So to reduce this risk I was thinking of fitting a low level warning to the brake master cylinder.

By careful use of relays think i can use the demister warning light, so that it flashes on low level, and yet still use it for its intended use.

 

Also by powering the level switch off the IND terminal of the alternator to energise a relay, the system will self test when ignition is on without the engine running. When the ignition is turned before start, power comes onto the flash circuit causing the bulb to flash. It is only when the engine is started that power comes from the IND terminal and pulls the relay in and turns the flashing light off. If the float goes low the relay de-energises and we get flashing again.

 

Any thoughts or experience on doing this sort of thing?

 

[GT6 tailgate aperture drain]

That was me Colin and have to admit John's is better :-(

But then mine works and is still in place. Looks a bit tidyer now I've repaired and painted the area.

[Headlights and voltage drop]

Much appreciated - yes bigger cables plus relays and fuses is the way forward for me ... But of course the same current goes through the earth wire, hence the question where does the earth terminate?

 

Anyone know?

[Headlights and voltage drop]

Dear all,

I've always thought my headlights were a little dim, but always thought it was just a Triumph thing!

I've considered for sometime whether to go for the halogen upgrade you can get and finally bit the bullet and purchased a pair of headlamp units with standard wattage halogen bulbs.

 

Whilst doing this job thought I'd rewire through fused relays to reduce the fire risk - and yes I did once have a dash fire where the wiring shorted - not a good experience.

 

Thought i'd measure what voltage drop I currently had and was stunned at the result.

 

The wire goes ...

Battery to solenoid to dash switch to column switch to headlight.

 

I dropped the headlight out of its position to get to the connector on the back, switched it on and measured the voltage going in.

The result was 0.9V with 12.3V at the battery.

I.e. around 11v drop over the wiring and switches.

So, to test I ran a wire direct from battery to headlamp. The brightness increased markedly and the voltage was over 11V proving the voltage drop issue.

 

So, the questions ....

 

Is such a drop "normal" for triumph (GT6 mk3)?

Also, i followed the earth back into the loom, but difficult to tell where it goes from the point where the 2 headlamps wiring joins. Does anyone know where the earth runs? I noticed there are 4 earths connected to an earthing point on the right of the battery tray - I guess this may be it, but wondered if anyone knew?

[GT6 Fan Shroud]

I thought about this issue too and measured the air speed around the edge of the fan on the engine side of the fan. It showed that the fan was definitely drawing air in from around the edges of the radiator when stationary and so bypassing the radiator. (Cheap annenometer purchased from ebay)

I guess the engine valences help to prevent this for those that have them, but i had some aluminium pieces which made a neat box around the radiator and was successful in preventing this side draw.

.

Not sure how much it improves heat transfer and in traffic temperature control, but it cant do any harm!

[Show us you car]

At last managed it - wouldn't work on the ipad, but managed to upload on laptop ...

 

This is at Prescott hill climb a couple of yeas ago giving my young nephew a ride in the GT6 up the hill.

[What's the expert opinion on no lights/radio when engine turned off?]

Hello ... As the power can get from alternator to the various bits but not from battery I would suspect the connections around the starter solenoid where the myriad of these wires join.

Looking at the wiring diagram power from battery, power from alternator and feed to light switch and fuse all join at the starter solenoid. I'm guessing something isn't making good connection. If the alternator wire is connected through to the light switch and fuse but not the battery it would give the symptoms described.

If it was the fuse box itself I would expect it not to work when the car is running either.

Having said that no idea why the interior light would just flash, so I could be wrong.

[engine side valances-yes or no ?]

Yep - can't remember the precise numbers now, but was something like 15 deg c cooler (I think) at similar speeds - although not sure if the ambient temp was the same. I remember being surprised at how much difference it makes, at least in temperature terms. I bought an intake scoop from demon tweeks that I attached to the radiator side of the front grill, that means the flexi sucks the air from outside the car even when stationary.

[engine side valances-yes or no ?]

I thought long and hard about K&N vs cold air feed. So I bought a temp probe from Maplins so that I could measure the air temp in the K&N whilst driving. Surprisingly it was around 40 deg C on a day where ambient was 18 ish when driving at 50 mph. The difference in density at those temperatures equates to around 2%. Not huge but worth having.

 

So I've now modded my filter air box by welding a strip in to make wide enough to fit the K&N's. Whilst doing it I also changed the 2 stubs by welding in 2 pieces of old stainless exhaust - 50mm dia vs the original 35ish.

The result is shown in the photo - if I can get the upload to work ...

[Insurance - commuting]

When I renewed my insurance with Footman James recently I was shocked to discover that Social Domestic and pleasure does not cover commuting to and from my normal place of work. I only realised this because they were trying to sell me this as an add on. It only cost £10 so it's now there.

 

A search of the Internet showed that this was now standard and had changed some time in the past. You have to have commuting specified otherwise it's not covered. Anyone else surprised or caught out by this?

 

Seems like the insurance industry have found another way of getting a few more quid out of us ...

 

So, don't get caught out - make sure you have the right cover and use your triumph to get you to work.

[Stainless shiny bits ?]

Yes, that's exactly what I mean .... Original chrome bits look tired, but if you change for new, after a year or two are worse than the original bits. I've found that on many different chrome bits from different suppliers. Hence the question.

[Stainless shiny bits ?]

I am constantly disappointed with the quality of chrome parts from whatever supplier. This includes bullet mirrors, bumpers, door handles, windscreen wiper boss. All of these have pitted in very short time. My latest was the headlight trims bought from one of the usual suppliers which is pitting to the point of needing replacement at around a year with only limited wet weather exposure.

 

On the positive side I have now a set of shiny stainless steel bumpers and a set of shiny stainless bullet mirrors. Both of these remain shiny with no attention over a few years and I am pleased.

 

So my suggestion is to ask whether the shop could consider sourcing stainless alternatives to a lot of the chrome trim bits ...

Tailgate chrome trims, headlight surrounds, door handles, petrol cap etc etc.

 

Anyone else support such a move ... And willing to spend hard earned pennies on such things?