Nigel Clark

Push the knob fully in to open the heater valve. When you look at the top of the heater valve, the cable should be fully extended when the valve is open. Nigel

On the TR6, the original breather is merely a pipe from the rocker cover to the air plenum, there's no crankcase breather that I'm aware of. There's a flame arrestor fitted in the breather pipe, probably because of fears that malfunctioning over-rich PI could cause petrol to find it's way down the bores and into the sump, thence out through the breather. That could make for an almighty bang in the plenum if the engine were to spit back through the throttles! Nigel

Thank you Marcus. Nigel

Either a blockage as above, or an airlock. It always helps to raise the front of the car when filling the cooling system (and have heater valve open of course). Nigel

Thank you again gents, really insightful input here. I will be using the Victor Reinz silicone when it goes back together, regardless of any theory that may say it's unnecessary. I don't wish to repeat the cylinder head removal exercise for a good long time! As mentioned in an earlier post, this TR6 engine breathes more heavily than other Triumph sixes I've known, including a 100k mile 2 litre and the freshly rebuilt 2.5 litre in my GT6. I base this comment mainly on the fact that the TR engine regularly puts oil in its air plenum, whereas as the other two have never visibly oiled their air boxes. A bigger breather should help, as Marcus says. Nigel

Marcus, Thank you for your detailed response, good to hear from you. Looking closely at the face of the block I can see a pattern broad arcs, apparently from a cutting head when it was resurfaced long ago. Of course they run across the block, so could provide pathways for oil to come out of the side. Sandpapering the top of the block sounds a bit extreme, what grade do you use? I will use the Victor Reinz silicone recommended by Nick along the pushrod side of the gasket and leave it a few days to cure - I can't really take the car far in lockdown anyway! John, Pete, Thank you for your comments again. I normally fit the studs finger tight, after cleaning the holes and blowing out with compressed air, so hopefully no risk if hydraulic pressure developing. I've owned this car for about 15 years and it's always leaked oil here, so who knows what a PO may have done?! I never spotted the bulging around the stud holes when I've had the head off before, and only spotted it by chance this time. I had noticed a small nick in the face of the block near the gasket fire ring recess next to cylinder No.5. I couldn't tell with my finger if this was raised and could possibly disturb the gasket, so I ran the oil stone lightly across it. The mark next to 5 wasn't raised but the stone revealed the raised areas around the studs. Pure fluke that I found this! I'm learning all the time. Nigel

Take your time. The leather will almost certainly recover after a while (no pun intended). Who would have thought there was such a detail difference between now and Mk2? Nigel

Thank you Pete. No gorilla tightening here, just a calibrated torque wrench! Nigel

Here are a couple of photos from my cars. With the screen in, it's difficult to get a good angle to see the shape of the vents but both are as in your second picture, following the curve of the screen. Here's my GT6 Mk3 first, followed by Spitfire Mk3. I've recovered the crash pads in both cars and can't recall particular difficulty getting the vents back into place. I figured the vent through the top of the crash pad first, then offered up the metal fan shaped heater outlet from below. Nigel

Whichever brand of plug you choose, make sure it's genuine. On another forum, its alleged that cheap branded plugs sold online can turn it to be substandard fakes. Best to buy a reputable brand from a local motor factor, or order online from one of the major motor factors' websites. Nigel

Thank you to everyone for your thoughts and comments. I've measured the cylinder head this morning to see if it's been skimmed off-square as Hugh suggested. Taking six measurements with a digital caliper at three positions along each side (front, centre and rear), I get figures all in the range 3.377 - 3.379", so within 2 thou. The repeatability of each measurement is about 1 thou, so I would say within my measurement capability, the cylinder head is square. It's been skimmed by just over 20 thou from its nominal height of 3.400". With a 20 thou over-bore, this must equate to a compression ratio of 10.0:1 or maybe a fraction higher. This could explain why it runs so well and prefers 99 octane fuel! Thank you Nick and Clive for the suggestion of Victor Reinz silicone, I've ordered a tube. I'm familiar with Reinz quality, they are OEM suppliers to much of the German car industry and I've used their gaskets on a couple of BMWs. I've had another look at the top surface of the block. Though it appeared flat when I first checked, there are in fact very slightly raised areas around each of the stud holes on the pushrod side. I've run a nearly new, perfectly flat fine oil stone over this area and round patches soon polish up around each stud hole. The manifold side of the block is perfectly flat. Could this be a Eureka moment? This slight distortion of the block face around these particular studs would certainly be expected to reduce clamping on the pushrod side. The question now is what to do... The correct answer would be to pull out the engine and strip it down to get the block refaced. That's not happening, it's a strong engine and it's a long way from needing a rebuild. I'm considering lightly relieving the raised areas around the studs with the oil stone. It will need care, and probably best to err on the side of removing too little metal. Please can you offer opinions? Nigel PS: I wanted to post a photo of the raised areas around the studs but it's not possible to see them in a phone photo. I will try again with a DSLR and ring flash.

Thank you Nick. Good to know I'm not the only one who finds this side of the head is difficult to seal! Which silicone do you use? And would you expect it to work better than Wellseal? Nigel

Thank you Hugh. I haven't come across that before! I had the head skimmed by a machine shop that I trust about 10 years ago. It is still flat when checked on the lower face. I will try to measure the thickness of the head in different positions tomorrow, which may give a clue if it's been skimmed at an angle rather than square. Nigel

Here's a link to the thread where I mention the cowl around the fan on the back of the radiator: If you want to read more about GT6 cooling, try this link too: I hope this helps. Nigel

Hi Alberto, Welcome, and congratulations on saving a GT6, the Mk1 is a special car, and I say this as a Mk3 owner! There's lots of good advice here. I've found over 20 years of GT6 ownership that if the cooling system is in good condition, airflow through the radiator is critical to keeping the engine temperature under control at low speeds (at high speed, there is usually plenty of air passing through the radiator core). So to make sure your cooling system is in top condition, follow the advice here, flush the cooling system well and Pete's suggestion of a low temperature thermostat sounds good - I hadn't heard of that before. Back to the airflow at low speeds. The cowl in front of the radiator is essential; some owners also advise putting a metal plate between the chassis rails just below the radiator grille, so air entering through the grille must pass through the radiation not under the car. Don't be tempted to fit an electric fan, they cover too much of the surface area of the radiator and make cooling worse. The original factory fan bolted to the front of the crank pulley is best. Finally, if you need to improve cooling further, consider fabricating a cowl that fits on the back of the radiator, around the fan. I've written about this in another thread on this forum and will try to post a link. Good luck, Nigel

One other thought about what could cause poor clamping and oil leaking from the pushrod side. It's a recessed bore block. If the block face has been skimmed in the past and the recesses weren't machined to match, the fire rings may not be able to compress enough and hold the cylinder head away from the block. I've measured the depths of the recesses around the bores at 29 thou. The compressed fire rings on the old gasket are 30 thou thick. That seems fine to me, the old gasket has simply relaxed by 1 thou after removal. Can anyone here advise how deep the recesses should be? Nigel

I've just fitted the head studs and measured their angles in the block face, side to side and front to back. None deviate from right angles but more than 2 thou in the length of the stud's shank. I hope that has little impact on how the cylinder head is clamped but stand to be corrected. Nigel

Thank you John, that's something I will consider. I'll fit he head studs and check with a set square to see if they are perpendicular to the block. However, I have heard of a number of Triumph sixes that leak oil from this joint. I do agree that applying sealants really shouldn't be necessary. Nigel

Triumph sixes - and probably the four pots too - are prone to leaking oil along the pushrod side of the head gasket. The reason seems obvious, as the head studs are clustered around the bores, providing insufficient clamping around the pushrod tunnels.The result is a messy oil leak down the distributor side of the block. I've always understood the answer is to use Wellseal along the edge of the head gasket and around the rocker oil feed hole to seal this leak, and this has worked well on two six cylinder motors I've built in the last few years, both remaining oil-tight. When I discussed this problem with a well know trade engine builder, he advised using Wellseal over the entire head gasket. My TR6 is the worst example I've found for this problem and it's always leaked oil from this this of the head gasket. Last time I removed the head, it was perfectly flat, as is the top face of the block. I refitted the head with a Payen recessed bore gasket (correct for this engine) and Wellseal on both sides of the gasket around the offending area. The engine has ARP head studs, washers and nuts, which I torqued down according to ARP's advice, using light oil to lubricate. I believe I've done everything correctly but it still leaks. The TR6 does breathe quite heavily, as there's always a bit of oil in the air plenum from the breather but even so, I can't accept it's impossible to make the head gasket oil tight. With time on my hands in lockdown, I've removed the head again for another attempt. Before I put it back together, I'm looking for some more opinions from the wise ones here... - How do you ensure the head gasket is oil tight along the pushrod side? - Uncle Pete's favourite Loctite 574 is recommended for sealing flanges where this isn't a gasket. Would it work better than Wellseal on the problem side of the head gasket? Any other advice before I reassemble with lots of Wellseal and crossed fingers? Thanks in advance. Nigel

No... Is the short answer. Our engines were designed to run on 20W50 mineral oil and that's what's best for them. Lower viscosity modern synthetic oils will cost more and increase oil consumption. Just choose a good quality classic 20W50 oil. Castrol, Miller's, Morris are all good. Other good brands are also available! Change the oil and filter at least once each year and your Triumph engine should be happy Nigel

That's a very neat job! Nigel

Castrol LM in the steering rack, hub bearings, UJs, handbrake cables and pretty well anything else that needs grease on any Triumph I've owned over the years. Nigel

I insure with Peter James and the policy includes breakdown cover. This is a multi-vehicle policy with modern and classics. Fortunately I've onlyneeded to use it once, about 18 months ago. The service, bringing my broken GT6 home was excellent. Nigel

These adaptors can be tricky. You appear to have the later version with the spring-loaded clip on the central mounting bolt. It's very important this is fitted correctly, with the clip floating on the plain section of the bolt above the thread. These clips can ride up the thread, which will cause leakage, sometimes inside the adaptor so the oil can bypass the filter. Service kits are available for the adaptor: https://rimmerbros.com/Item--i-RR1238SKIT Nigel

Only just seen this thread. On my Rotoflex GT6 I had to release the spring from the diff to get the new CV shafts in, so I'm sure you're on the right track now. It will be worth it, no more knackered rubber doughnuts to replace, even the genuine Metalastic ones don't seem to last more than a few years now. Don't forget to check the hub end float and re-shim if necessary. Nigel