[Loose cooling fan]

I’ve thought several times about putting this on here, but here goes…

I think the Heat Capacity of water is approx 4.2 kJ per kg per deg C, but ethylene glycol is about 2.4 kJ per kg per deg C.

The engine is the source of heat (the kJ producer), and assuming the pump flow is the same for water as glycol (roughly will be) then water will take away from the engine 4.2 kJ verses glycol taking away 2.4 kJ per one deg Celsius rise in temperature.

Very similarly the radiator is a fixed surface area and the air temperature it cools with is the same with either fluid, so with one deg C reduction,  water will lose 4.2 kJ vs glycol with 2.4 kJ.

So for a given flow rate, less energy will be taken away from the engine with 100% glycol vs pure water.

With regard to operating temperatures at steady state, the radiator will compensate to an extent with higher inlet temperature so will remove more heat with higher inlet temp. But I think likely there will be a difference to temperature but there are other heat losses from the engine other than cooling fluid, so these other heat loss sources will probably have a bigger contribution as well.

I will retire to my bunker  

 

[Early TR6 CP series water pump needed please - now sorted]

Bill, I’ve sent you a PM. Maybe able to help.

[Best way to bend a new clutch pipe to match old one?]

Steve,

I’ve done this couple of years ago now. I did use the old pipe as a guide / template. With the pipe off the car started with the MC end and did what Andy said and taped the pipes together as I bent it to stop them twisting. Did most of it by eye and only used pipe bender for tight or 90 deg bends. It’s very easy to put small bends in what should be straight and then very hard to get back to straight. The new pipe I purchased was slightly longer than the old when I got to the end, but the flexible end to the slave took up the difference. If I had done this a few times I could have got it better, but I was okay with final result. Not perfect but looks good. I had run new brake pipes, so had some practice before hand but it’s not that difficult. Also unlikely you would work harden the pipe. Hope this helps.

[Clutch master]

Steve, I changed out a master clutch cylinder a while back. I found it easier to drain the fluid down thru the slave cylinder. I wasn’t sure how old the fluid was so it made sense to me to replace all the fluid and discard the old. I think even with just draining MC you will still need to bleed thru the whole system.

I also put a lot of cloths / sheeting around the master and the pipe connection to avoid getting fluid on paint. Mostly successful. Other than that I think your steps match what I recall doing. 

With the new master, it is worth wetting the internals before installing, even taking internals out and lubricating the seal and (small smear) reassemble. This helped in my view.

[PI fuel filler cap breather hole?]

Steve, I’m pretty sure there should be. I had very similar experience when I had just got my TR6. When I drove for a while the engine would splutter and even stop. It did sound like a fuel problem, but I was lucky as I opened the filler cap with intent to check level. But there was a whoosh / vapour escaping sound as I opened the cap. I ran a couple of times with same experience and sound but I realised it was a vacuum and not a release. I should have asked this forum before I did this but I made a cut hole in the cap seal. The issue never came back and I’m pretty sure there should be a vent hole in the cap seal. Not sure how or why the car didn’t have it when I purchased it and it must have been a late mod by PO I guess. The Rimmer part shows a vented seal with a hole in middle as well.

[Measurement required please.]

Missed this one.

[Measurement required please.]

Does this help?

[Setting the Fast Idle]

A question partly related to this. When I start my CP car with full choke from cold, it does rev up to 1,500 rpm or possibly higher but around there. The oil light goes out after 1 or 2 seconds which I think is due to the spin on oil filter conversion. Oil pressure is good. The question : Is 1,500 + rpm for cold start coke too much?

I have the twin cable choke fitted as original. A couple of years ago now I did go thru the whole throttle system and set it up. I spoke with Martin at Fredmillturn who was very helpful as was considering to buy / change to his throttle set up. But after speaking with him and following some tests I got the original system to work. Made a big difference to the acceleration, warm idle, and cold starting.

[Grommet part number needed]

Tim, is it part numbers 600399 and ADA803? The diagram is confusing to me but looks like the plug and grommet?

[TR6 servicing]

Does seem high, but looking at it from what Jonny put it would be good idea to ask them what their all in labour rate is per hour excluding parts. Would give you an idea of the hours they are billing. Would be a reasonable question in my view.

[New battery...]

+1 for Halfords. My local one has always been very good.

I fitted a while back a battery isolator (manual one you screw in/out) and it has made a big difference to the battery performance. I don’t use the car much in winter and the isolator seems to have helped the life of the battery a lot. Just started the car after 4 or 5 months (my bad) and it fired up on second crank. Needed choke for a minute or so but warmed up nicely. Even with 4/5 months in garage the battery kept its charge well.

[Replacing the diffential]

I made up a simple wooden saddle for the diff, and used cable ties to hold it onto a jack. I put the front rubber washers onto the support rods and taped them in place before lifting the diff. I recall I had to raise the front of diff a little and then move the trolley jack forward a little to get clear access to support rods at the back end. It was tricky and I had a few goes at it before success. Took a few tea breaks as well along the way! Good luck.

[Anyone have experience of these remote battery isolating switches]

I do use the one that KC posted above with the green knob. I got it to save the battery and to date it does seem to make a big difference to the battery holding its charge. It takes less than a minute to pop the bonnet and isolate or reconnect. Over the summer the car gets used when and as much as I can, but in the winter I’m reluctant to take it out unless its dry / no salt. So in winter the battery doesn’t get many charges but this manual isolator has made a difference with keeping the battery charged & car starts fine.

[Fuel Tank woes]

Keith, I would try to flush the tank and see if more particles come out. Not sure if you can do that with tank in-situ but the more rigorous the flush the better and would give you more info on status of the tank

The filter by the looks of it has done its job and quite likely caused fuel restriction.

If more particles do come then as the prior comments its  probably better to cut your losses and replace the tank. But if the flush is clear, maybe you’ve seen the worse of it? Not sure how long you’ve been running car since the original tank cleaning. Just thinking to try another test before paying out for expensive new tank. Just a thought.

[Re-starting from warm]

John, do some of your injector pipes touch rocker or hot surface on way to injectors? Just thinking if it starts okay from cold, are you getting vapour block in one or two of the injector pipes when no flow of fuel and if pipe is picking up heat from touching hot surface. Easy one to check / look for. Not sure if vapour lock is feasible but just a thought.

 

[Inertia switch]

Andy, Tom, Thanks. Useful to know. I still have the original Lucas pump and will install a new inertia switch. Not had any problems with the pump to date.

Derek again good to know. Thank you.

[Inertia switch]

Thanks Jonny but nothing there. Not even fixing or bolt holes. The pump feed cable has no break in engine bay and disappears into wiring loom. Pretty sure I don’t have one which triggers my question.

[Inertia switch]

I have looked high & low on my TR6 (early PI) and cannot find an inertia cut off switch. I also looked on the wiring diagram and can’t see any switch shown in the diagram. What is the history to these switches?

It does seem to be sensible safety item but were these always a dealer addition or an after market addition. I just wanted to check if I’m not looking in right places, or if the car was sold originally without it? I intend to add one - I’m pretty sure (99.9%) it is not fitted so I’m guessing it was sold without one.

Regards Martin.

[Engine cut-outs]

Steve, is there chance that the “relining” of the tank is causing the issue? I’m no expert on how tanks are re-lined but how is the re lining verified / checked? Could it be coming loose in area causing temporary blockage? Just a thought.

[Lights]

Thank you. This is perfect. Just wanted to be able to quote reference if needed and peace of mind. 

[Lights]

There seems to be a lot of info on the internet for LED bulb replacement external / internal on legal or illegal and if it would be MOT failure or not. Does someone have a definitive link for document which is latest position?

It seems to have changed with Brexit, and since Jan 2021. But then it may have changed again with “E” or “CE” marking of LED bulbs. Anyway seems very confusing to me and don’t really want to be running illegal lights. A definitive reference would be good if any has one out there?

[Diff re-fit issues]

I did same/similar to Dave & Peter. The front supports i taped the rubber mounts before trying to lift. I also made a rough wooden saddle so that it would clear either side. I found i had to angle the diff from horizontal with nose up. I had to move it forward at same time raising it on jack. The front supports went in first, and then close behind rear. It was a fiddly but took it slow. I did pre fill with oil. I had several tea beaks as it did p—- me off a lot. Good luck. Very satisfying when done.

[Moss emergency bonnet release]

I installed this few months ago. I measured where the rod dropped down, measuring to the edges of the bulk head in either direction. I then took these measurements to inside and measured same inside to fix a spot to drill. I did couple of double checks as wanted to make sure I came thru at a point that worked okay and no clashes before I drilled. Was not difficult (must have been easy for me to do it). It works perfectly and is now my main bonnet opener. 

[Broken diff]

I have just had my diff overhauled by PeteCox Sports Car. Tom Cox was the person I dealt with. They did a very quick turnaround and the overhauled diff is good. Just for info.

I also have a spare diff that I purchased only a few weeks ago. I was thinking to swap the diffs over but my diff was overhauled in two weeks so kept original. If you want the spare diff I would sell for same price I purchased - it was from someone on the TR Register. It appears to be good but it is hard to judge when the thing is not installed. It is heavy so not sure it can be shipped / posted. I’m in Southampton area. If interested maybe best we PM to chat?

 

[1969 PI Intake Plenum and injector clamps issues.]

Andy, difficult to tell from photo, but is the nozzle on the air bypass valve sufficiently orientated toward the air plenum? On my car the nozzle is about 45 deg toward air plenum and allows the hose to come away in right direction for the air plenum nozzle.