Exhaust Smoke

[boggie]

Hello all,

Bit of a strange one I am trying to get my head around. The engine was fully restored by a well-known reputable specialist about 10 years ago and as the car has only covered 700 miles, it is still effectively  running in. 

Most of those 700 miles have been in the last 4 years, as the restoration finished and we started using the car. The engine behaved perfectly during that time, with the exception of a brief overheat recently, due to a stuck thermostat not opening on one short drive.

Yesterday, I took her for a 6 mile run and all was as normal. Then, as I was manoeuvring on the drive to put her back into the garage, I got a short blast of quite thick exhaust smoke and again as I was reversing into the garage. Both times on rev-up on throttle, not run-down on vacuum, which suggests this is not head related. No other symptoms and the engine was running well.

I will check the crankcase breather is not blocked and do a compression test to try and shed some more light but any ideas of what the cause might be please?

Thanks,

Ian

[Motorsport Mickey]

Hi Ian,

Only 700 miles and a 10 year usage obviously not ideal,

Firstly I'd remove all the spark plugs and spin the engine over on the starter checking there isn't any water ejecting from the cylinders, if all is ok replace the plugs and a  compression check is worthwhile, hopefully the results are ok. 

Check the oil levels in the carb dash pots, if the oil get sucked in due to some problem it burns nicely and gives off a white smoke.

Although you think it's not head related it's an easy first step to think the head gasket needs retorquing unless you can remember it being done. Back in the 50s/60s the manufacturer used to say 1000 miles but that would be with the engine in daily use, your high days and pussy cats birthdays use pattern allows a LOT of settling of the head and the gaskets. Without details of what was done in the way of the engine rebuild we have to assume a standard piston and liner mix up to 87mm which will run on the standard copper/asbestos/copper head gasket.  So drop the water from the engine (the anti freeze will need changing anyway assuming you've not done it) if the block tap is blocked pull off the bottom radiator hose. Then retorque the cylinder head by first undoing the nuts by approx 1 flat (this is to avoid the sticking friction of nuts left in position for any length of time...stickion) in rotation going around the head in the approved tightening sequence. Then with the torque wrench set at 105 lb ft retighten those nuts up again in one flowing movement in the approved tightening sequence, you may find the nuts go past their original setting position you undid them from, this is the original gasket recompressing as it should taking up the slack the past 10 years and 700 miles have introduced into it and quite possibly allowed a weep of water to be ingested in the engine. Then refill with fresh anti freeze solution and go try it on the road getting the engine up to normal operating temperature, I'd suggest at least a 20 mile run, hopefully the head gasket will reseal if that was what it was.

Mick Richards

[Rob Salisbury]

Hi Ian,

        What colour was the smoke?, .... as a general rule black is fuel related, blue is oil and white is water, ...  (cold weather? ... just condensation 'till the engine warms up)

Cheers Rob  

[boggie]

Thanks Chaps!

I haven't had a chance to check everything yet, as I am away with my girls for an Easter break.

However, what I can say is that the smoke was definitely white but not condensation as it was thick and hung in the air for a while.

The coolant level looked good, should not need changing (Evans Waterless) and whilst there was no obvious signs of head gasket issues, such as emulsion on the oil filler cap or dipstick, I don't know how Evans would behave in that scenario.

The dash pot oil idea sounds like a potential source but I will carry out the suggested tests whan I can get some time on the car, and come back to you.

Cheers!

[boggie]

Ok. I managed to get some time investigating.

Engine oil and coolant levels look good, with no sign of loss or mixing.

Dash pots were both about 1/2" low, so I topped them up to the bottom of the threads.

I took all four spark plugs out. 1, 2 and 3 looked good. Perhaps a little sooty but the engine only had a short run (10 mins) when I last used her, and she had not really got up to temperature. The tips and earth electrodes were clean and biscuit brown. Plug 4 is wet with what I thought could be oil but I was not sure.

With the spark plugs out, I turned the engine using the starter solenoid. Nothing other than air coming out of all cylinders.

Compression test next. All done cold, with throttles open. First number is with no oil added to the cylinders, the second with a squirt of 20/50:

1: 163 lb/ft and 171 lb/ft

2: 159 lb/ft and 167 lb/ft

3: 157 lb/ft and 169 lb/ft

4: 140 lb/ft and 173 lb/ft

Thinking I must have a dodgy initial reading on No4, I decided to run the engine for a few seconds to burn off the oil and take another reading. LOTS of white smoke and only running on 3 cylinders (removing No4 HT lead changed nothing, so No4 was the issue) and a thin/slippery black fluid out of the exhaust! 

I took the plugs out (No4 was VERY wet) and turned her on the starter. This time No4 shot fluid up the wall of the workshop. Definitely Evans coolant smelling stuff. The black fluid from the exhaust is presumably the same but with added carbon). So, definitely head gasket!

I whipped the rocker cover and rocker assembly off, removed the rocker studs for better access to head boots 3 and 6, slightly backed off the head nuts in the correct order, then torqued them up to 105 lb/ft. Left them 30 minutes (cuppa) and rechecked them. 

I refitted everything, set the valves, cleaned the plugs and fired her up. Same damn issue. So, it looks like the head gasket has gone. Does that sound about right? Or is there something else it could be?

Thanks,

Ian

[Motorsport Mickey]

Afraid it sounds like the head gasket, had it been retorqued since it's initial rebuild and torque 10 years ago ?

Mick Richards

PS: The Evans waterless coolant is a bit contentious but our own cars are our own choices.

Edited April 18, 2022 by Motorsport Mickey

[BlueTR3A-5EKT]

2 hours ago, Motorsport Mickey said:

Afraid it sounds like the head gasket, had it been retorqued since it's initial rebuild and torque 10 years ago ?

Mick Richards

PS: The Evans waterless coolant is a bit contentious but our own cars are our own choices.

Do you know what diameter the piston and liners are?

You will need to know this to get the correct head gasket.   If up to 87 mm and the head still has the shroud over one valve the standard gasket will do.    If thecshoud in the head chamber has been removed you are in for a gasket with the correct ‘cut out’ to seal correctly.   More on this when you know piston and liner size plus head chamber.

[boggie]

I retorqued the head about 2 - 3 months after I fitted it. Whilst I had not had the car out on the road much during the restoration, I ran the engine up to temperature at least once a month.

I am pretty sure the head is standard, so an off the shelf gasket from Moss or Revington should be fine. As it happens, I do need to remove the Head anyway as the rear exhaust manifold stud let go inexplicably last year, probably due to poor quality steel. Annoyingly, what's left is buried in the head so I have to get it out.

The thing that worries me a little is that this happened the first time I drove the car after it overheated. I hope it is a simple head gasket job, not something more sinister....

Thanks.

[Motorsport Mickey]

If you are going to remove the head beware "the rear exhaust manifold stud" which has snapped, if the hole has been drilled deeply (and lots have) and it's had a long stud screwed in there it...ditto, it can snub out against the side of the short corner cylinder head stud locking it in. Not normally a problem in use, but if the head is reluctant to come adrift after the head nuts are off and you try to unscrew the studs by double nutting, to take the rearmost stud off can be possibly a struggle.

Remove the foremost and rearmost manifold studs first (your rear one is sheared off) and the cylinder stud should unscrew ok by double nutting. If not you will probably have to drill the sheared stud and use a fluted extractor to drive in and wrench it out before removing the stud remains.

See more under Manifold Stud Positions another thread that was running a couple of weeks ago complete with pictures, the search facility will spring it for you.

Mick Richards

[boggie]

Thanks Mick.

I am pretty sure I fitted the head with the manifold studs in place, so I assume I don't have the deep hole / long stud issue you mention. All will be revealed tomorrow evening...

To remove the broken rear exhaust stud, I am thinking of turning a shouldered sleeve on the lathe that will slide into the stud hole snugly and be long enough to touch the broken end of the stud. That way, when I get the head onto my pillar drill, the sleeve will guide my left-handed drill bit to the exact centre of the broken stud face, supporting it so that it doesn't wander of centre and potentially damage the head. With a bit of luck, the action of drilling into the stud with a left-hand drill bit will unscrew it from the head. However, knowing me, the stud is likely to be fitted with threadlock (I just hope I used 248, not 270). So, I have a number of extraction tools I could use, but potentially tapping the hole with a LH thread and screwing a LH bolt in to wind it out might be a safe first attempt. That way, if it shears, I will not be left with a hardened steel extraction tool left in the middle of the broken stud. 

What do you think?

 

One more question please: I have a Phoenix 4-branch manifold and system that I will fit at the same time. I was waiting whilst I decided on whether to have the head ported/gasflowed and fitted with big valves before fitting the exhaust, but I have not found anyone who can do the work at a price I can justify. One thing I have noticed, is that the Phoenix Exhaust Flange is thinner than the original Triumph manifold. As the inlet and exhaust manifolds share the same clamps, it it simply a matter of grinding down one side of the clamp to sit on the thicker inlet manifold, so the clamp is level and keeps the clamping force even?

[Ian Vincent]

24 minutes ago, boggie said:

One more question please: I have a Phoenix 4-branch manifold and system that I will fit at the same time. I was waiting whilst I decided on whether to have the head ported/gasflowed and fitted with big valves before fitting the exhaust, but I have not found anyone who can do the work at a price I can justify. One thing I have noticed, is that the Phoenix Exhaust Flange is thinner than the original Triumph manifold. As the inlet and exhaust manifolds share the same clamps, it it simply a matter of grinding down one side of the clamp to sit on the thicker inlet manifold, so the clamp is level and keeps the clamping force even?

I welded some 3mm packers to my Phoenix manifold to bring the thickness up to the same as the inlet manifold.

Rgds Ian

[Motorsport Mickey]

1 hour ago, boggie said:

Thanks Mick.

I am pretty sure I fitted the head with the manifold studs in place, so I assume I don't have the deep hole / long stud issue you mention. All will be revealed tomorrow evening...

To remove the broken rear exhaust stud, I am thinking of turning a shouldered sleeve on the lathe that will slide into the stud hole snugly and be long enough to touch the broken end of the stud. That way, when I get the head onto my pillar drill, the sleeve will guide my left-handed drill bit to the exact centre of the broken stud face, supporting it so that it doesn't wander of centre and potentially damage the head. With a bit of luck, the action of drilling into the stud with a left-hand drill bit will unscrew it from the head. However, knowing me, the stud is likely to be fitted with threadlock (I just hope I used 248, not 270). So, I have a number of extraction tools I could use, but potentially tapping the hole with a LH thread and screwing a LH bolt in to wind it out might be a safe first attempt. That way, if it shears, I will not be left with a hardened steel extraction tool left in the middle of the broken stud. 

What do you think?

 

One more question please: I have a Phoenix 4-branch manifold and system that I will fit at the same time. I was waiting whilst I decided on whether to have the head ported/gasflowed and fitted with big valves before fitting the exhaust, but I have not found anyone who can do the work at a price I can justify. One thing I have noticed, is that the Phoenix Exhaust Flange is thinner than the original Triumph manifold. As the inlet and exhaust manifolds share the same clamps, it it simply a matter of grinding down one side of the clamp to sit on the thicker inlet manifold, so the clamp is level and keeps the clamping force even?

As you say keep well away from using anything which is of the hardened variety in the way of an extractor. The misnamed "easy outs" are harder than the hobs of hell and with their acute left hand thread have an stress raiser where the thread transforms from screw function to parallel drive surface. As you apply torque they almost explode leaving you with hardened nub stuck in the centre of the broken stud. Then you need a flat faced diamond drill (JCB offer some from memory) to wear your way through it to stand a chance of removing the stud.

The fluted removers as shown in the photos in the Manifold Stud Positions thread mentioned above are parallel from one end to the other with no transitions so no stress raiser, also they are tough rather than hard and so resist fracturing as lots of torque is applied, I've had good success with them. They come in a kit with various sizes centralising bush for the stud (similar to your suggested lathed sleeve you are going to turn) and also the correct drill to compliment the fluted drive to drive into the hole along with a fluted hex nut to slip over the drive to use your wrench or spanners to undo the stud with. As you say the left hand drill bit may have enough torque to shift the stud anyway.

The difference in the manifold thicknesses needs adjusting and as Ian suggests above welding a packing piece onto the manifold in the "pinch" position is a good permanent fix.

Mick Richards   

[John McCormack]

On 4/19/2022 at 4:21 AM, Motorsport Mickey said:

Afraid it sounds like the head gasket, had it been retorqued since it's initial rebuild and torque 10 years ago ?

Mick Richards

PS: The Evans waterless coolant is a bit contentious but our own cars are our own choices.

We have had a few cars with the Evans coolant suffer major engine damage. Most recently in the past month requiring, I understand, a full rebuild.

I don't know the cause but my gut feel is that the Evans coolant allows the engine to run too hot causing a breakdown in the oil properties.

Any knowledgeable advice would be welcomed.

[Motorsport Mickey]

3 hours ago, John McCormack said:

We have had a few cars with the Evans coolant suffer major engine damage. Most recently in the past month requiring, I understand, a full rebuild.

I don't know the cause but my gut feel is that the Evans coolant allows the engine to run too hot causing a breakdown in the oil properties.

Any knowledgeable advice would be welcomed.

Well I guess the most knowledgeable advice on engine possible problems running Evans is from Peter Burgess at Alfreton ....Automotive Power Engineering well known for cylinder head tuning on both TRs and MGs, from his website...

"Waterless Coolant . In our opinion using coolants other than water with antifreeze/corrosion inhibitor addition as recommended in the original workshop manual can allow the engine to run too hot and cause problems such as sticking valves and piston damage. We offer no warranty on our engines and heads if waterless coolants are used. Water is the best liquid for transferring heat. "

In addition Peter used to refuse to rolling road engines with Evans coolant (not sure if this is still the case, years since I've talked to him about Evans). As always opinions vary about additives, so what owners add to their systems is their own choices, but if the man I trust to develop my heads and then rolling road my engines doesn't want to be involved with Evans fitments...I'll go along with him. 

Mick Richards

[RobH]

4 hours ago, John McCormack said:

Evans coolant allows the engine to run too hot

Yes that is exactly right.

As has been explained several times, the  pure glycol coolant has a much lower specific heat than water meaning that for a given volume flow through the engine, it just can't move as much  heat from the engine to the radiator.  It is also more viscous than water so the flow is actually lower too which compounds the effect. The cooling system operates to keep the coolant at the desired temperature as shown by the gauge, which seems to show that all is well,  but since the glycol can't 'pick up' the heat as well as water, less heat is being taken away and the engine itself runs hotter than it was designed to do.  That extra heat must mean hotter oil and more stress on gaskets and seals. 

Pure glycol can work in engines but you would need to redesign the cooling system with more flow to account for the lower thermal efficiency. 

 

 

Edited April 21, 2022 by RobH

[John McCormack]

Thanks Rob and Mick. I've posted your comments, without names, in a post on the TR Register Australia website to provide your views to our members,

Edited April 21, 2022 by John McCormack

[stuart]

I dont use or recommend the Evans stuff and a direct quote from someone who shall remain nameless but is involved with marketing it was "Snake oil"

Glycol was used in aircraft engines that operate in altitude and cold and their cooling systems were designed for it.

Stuart.

[boggie]

Thanks all, great info!

I will NOT be replacing the Evans Waterless Coolant! I had a dodgy temperature sensor at the time, so did not realise the thermostat had jammed shut. Drove 6 miles to Dad's funeral but the Evans coolant did not boil, so there were no signs of overheating! I just hope it is only the head gasket that has been affected...

On the fluted extractors; any recommendation on the best make to buy please? I have a basic set of Sealey fluted extractors, but I want to get the best I can on this job. 

Thanks

 

Edited April 21, 2022 by boggie
Added info

[boggie]

Quick update:

The head is off. The gasket has suffered an impressively catestrophic failure between the rearmost waterway and cylinder No4. The head and block / liner seem to have escaped unhurt.

The broken stud would not move, no matter what tools or heat I hit it with. So, I have drilled it out with the correct size drill for a 3/8 UNC tap and have ordered a bottoming tap (I only have a taper). 

A quick question on the head studs. Some years ago, I had one let go on the TR. It had torqued up fine and the car had done a few hundred miles, than whilst cleaning the engine, I noticed that the nut was loose and I lfted it out, complete with broken stud!. Luckily, when I took the head off, there was enough stud protruding to remove it. On close inspection (Dad, being a former aircraft designer and crash investigator, looked at the shear face under a microscope) it was poor quality steel and there was corrosion within the steel itself. So, I replaced the lot with a brand new set from Revington. Since then, they have been torqued up twice (once back then and once last week). Are they OK to reuse, or should I get another new set?

Thanks, Ian

[boggie]

Ended up treating the TR to a set of ARP studs. Very nice quality indeed. All torqued back up now and refitting all the anciliaries. I hope to have her back on the road this weekend!