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Using bit too much oil


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Hi all

I don't want to overdo the task and start stripping the engine so ask advice.

I use too much oil, I cant give accurate measurements but I seem to be constantly adding.  Now my plugs are a bit dark but I am unsure if the mix is a bit rich, and there is not clouds of blue coming out of the back.  Also its not leaking oil, just the usual TR territory marking!

Now my plan of attack was first to do a compression test, do other more knowledgeable persons agree with this as a first start in the root cause?

Thanks

Rich

 

Edited by AarhusTr6
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Rich

You say that you top up the oil constantly, do you fill it to the top mark on the dip stick? Have you checked that you have the correct dip stick? And finally some of the replacement dip stick felt seals are very thick which moves the stick up by 5 or 10 mm which of course moves the oil level up.

I found that if I left the oil level a bit above the low mark I used a lot less oil. (The joys of owning old cars)

George

 

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1 hour ago, harlequin said:

Rich

You say that you top up the oil constantly, do you fill it to the top mark on the dip stick? Have you checked that you have the correct dip stick? And finally some of the replacement dip stick felt seals are very thick which moves the stick up by 5 or 10 mm which of course moves the oil level up.

I found that if I left the oil level a bit above the low mark I used a lot less oil. (The joys of owning old cars)

George

 

Plus one with George.

Engines "self regulate" even new engines on todays vehicles will push out or dispose of what they think is excess oil in the sump, and that doesn't mean more than the top mark on the stick. Why do you think there is a top and bottom mark on the dipstick ? the engines will run quite happily and without harm if the level is kept on the bottom mark, it just needs checking every day. Instead try filling the sump up to the centre of the top to bottom range of marks and then see if the usage becomes a lot more acceptable. 

Mick Richards

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Once you start on the engine your wallet needs to be bottomless and possibly you will be several months off the road. Why for a few krone worth of oil?

If you still have good oil pressure and do not emit clouds of smoke then just relax and hope you are in such good shape when you are as far past your own use-by date.

 

Alan

 

Edited by barkerwilliams
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Hi Rich,

My friend has just completed an 8 day trip, some 1000 mls in total.

Day 1: 1/2 ltr Added

Day 2: idem

Day 3-8: nothing added!

We think the oil rings became cleaned during the longer drives where the engine and oil thoroughly warmed up.

Could off course be evaporation of volatile components, including water.

So a long run is worth a try, and a good opportunity to measure the actual oil consumption.

Waldi

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25 minutes ago, StuartG said:

I run my TR6 with oil half way between bottom and top mark on dipstick

Or a little lower, mine seems most stable with about 1/3 above minimum.

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Hi all

I am using Millers Oils, happy with it so far.

So the general consensus is keep it going as to address it, is a big cost with a lot of off-road time.  Must admit not the answer I expected and appreciate the help as I know what I am like, before I know it, its in a specialist workshop costing £££/€€€€ and then mission creep comes in when I add this, add that :-)

Rich

 

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Hi all

Went for a blast today . . and a symptom was seen.

I was pushing it a bit hard, but nothing crazy and when decelerating fast I got quite a bit of blue coming out of the exhaust.  I did not see this on going up gears.  Does this give any clues?  Still need to do compression test.

Rich

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Hi Rich,

you are burning oil at that time, since the inlet system (PI or carburettors), the pressure in the cylinders gets very low (“vacuum”) during the inlet stroke and oil is sucked in either via the piston rings or via the valve guides.

Time for a compression test as Jochem suggests. When you read lowish numbers, then do the wet test additionally, to distinguish between piston rings and valve guides.

Waldi

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41 minutes ago, Waldi said:

Hi Rich,

you are burning oil at that time, since the inlet system (PI or carburettors), the pressure in the cylinders gets very low (“vacuum”) during the inlet stroke and oil is sucked in either via the piston rings or via the valve guides.

Time for a compression test as Jochem suggests. When you read lowish numbers, then do the wet test additionally, to distinguish between piston rings and valve guides.

Waldi

Hi Waldi

So compression tell will tell me if its rings or valve guides?

Rich

 

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If you have good compression on all 6, it may be the guides, which have a smaller impact on CR when worn.

If you find one or more low readings (engine warm, TB’s wide open during testing), then squirt some oil on each piston to seal the piston with an temporary oil film, and test all 6 again. If the CR goes up, your rings are worn. If not, they are most likely not the issue and the  valve guides are more likely the cause.

Hope this clarifies things.

Waldi

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Rich

Before you start removing the cylinder head a couple of things you may wish to look at 

1. If you have an auxiliary oil feed to the rocker gear remove it.

2. If you have an after market alloy rocker box check that it has a suitable baffle over the vent outlet

3. Is your crankcase vent system setup as as Triumph intended

George

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Hi Rich

The auxiliary rocker oil feed is a small braided hose that is up the back of the cylinder head which supplies extra oil to the rocker gear, unfortunately it often supplies to much oil which has a tendency to run down the valve guides and get burnt

The standard rocker box has a baffle plate over the inside of the of the vent pipe ( there is also some wire wool type stuff behind the plate), the baffle is designed to reduce the amount of oil vapour drawn through the vent. Some after market rocker boxes have very minimal baffles which allows oil vapour  into the vent system then via the carburettor into the combustion chamber.

The vent system should be a pipe from the rocker box into a tee then a pipe to the vent port on the carburettors. There are one or two variations to this depending on the year of the car but that is the basics. If the system is blocked or not connected correctly you will get a build up of pressure in the engine which will force oil vapour past the rings or down the valve guides.

The above points are easy to check and cost nothing so worth doing before spending out on stripping the engine 

George

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Hi George

I do not have a auxiliary rocker oil feed - its seems this is an extra add-on?

I have a T pipe coming off the ricker and to the carbs, the carbon cannister is gone.  I will check the airflow from the rocker cover to the T pipe/s.

Thanks

Rich

 

 

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  • 2 years later...

Hi everybody

returning after a couple of years of parking this job due to lots of other personal stuff

so I went for a long drive and on quite hard deceleration I get what looks like smoke …maybe white coming from the back?   So similar to what I posted awhile back.  Also I must’ve used almost half a litre oil  for a 400 km drive

since then I have had the cylinder head completely rebuilt by Steve Burgess and I am sure he did valve guides  and I have now done a compression test of which I attach for results so I’m now a bit stuck on where to head to now

The top row is dry and compression the bottom row is wet compression

Thanks for all of your help and future suggestions

Richard 

 

 

534A709C-1D76-4C4C-9061-30D016B2B4B5.jpeg

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If the smoke is now white ? (instead of the original report of blue) then because you've not used the car for a while it could be condensation in the oil in the engine. The compressions are pretty even apart from No 5 where the addition of oil on the compression test has increased it by about 15% some % more than the others, did you check the tappet settings across the valves before the run ?

Did you just take the head off and send it to Peter Burgess (I think you mean, not Steve) and bolt it back on without changing the oil or doing any other work ?

I take it you didn't pull the pistons whilst the head was off ? ...pity, you could have checked the condition of the piston rings and if they are sticking and measured them and the bores for comparison and wear. There is a method to try and help the piston ring seating's which only requires driving...in a disciplined manner, for maybe 3-4 weeks 

After rechecking the tappet settings and ensuring they are equal take the car out and find a nice long gradual uphill gradient ( I use motorways). Starting on the flat approaching the hill make sure you are top gear 4th, and with maybe 500-1000 revs on the tacho below maximum torque, without knowing your camshaft I'd suggest your maximum torque will be about 3500 revs. So about 2500 revs on the tacho, then checking traffic behind is clear fully depress the throttle fully down to the floor and hold it there whilst the car accelerates up to about 4500 revs, then brake down to the 2500 revs and if you have enough gradient left do it again...and again...and again. I would carry out such a process over 3-4 weeks at least a couple of times a week, it's better than getting oily and more fun, BUT remain disciplined and don't use the upper rev range.

The full throttle on an uphill gradient in 4th gear fully loads the engine, this takes the engine into BMEP* (Brake Mean Effective Pressure) area, (Google it) where the power downward stroke of the piston achieves maximum cylinder pressure, and presses the piston rings out against the cylinder bores. This helps correct polished upper bores (too many revs doesn't push the rings out and polishes the bores) by the rings being pushed into the liner walls and gouging (we are talking microscopic amounts) of complimentary grooves into the bore face. This will maximise your compressions and reduce oil burning by allowing the rings to scrape the correct amount of oil off the bores into the sump.

This is the process I use when breaking a new engine build in prior to racing, or spend a little money and take the car onto a rolling road and ask them to bed the engine in. They can load the engine by applying resistance on the rollers, and watching the engine temperature apply full throttle for about 20 mins and bed the rings in. 

This BMEP running is always worth a try before excavating back into the engine.

Mick Richards

Edited by Motorsport Mickey
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White smoke in exhaust is probably antifreeze burning. "On deceleration" and carb manifold.......maybe  the manifold heater tube has perforated ?

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