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TR6 TR6 With the very occasional blue smoke puff.

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Aussie_Dave

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Guys,

Your thoughts please.

I purchased my car 10 years ago. Ex USA with SU Carbies. Ripped the motor out after the first month and did a rebuild. New rings to the honed original bore size and hardened head valves and guides in preparation of the phase out of lead replacement fuel. I can only get unleaded now. The car sat idle for a couple of years and in February I got it on the road again. I have new front rotors, hoses and stainless sleaved cylinders on the brakes. Just recently it started to puff the occasional blue smoke and since being on the road again it has been using about 0.5 litres (1/2 quart) of oil per full tank of fuel if I use the engine for slowing down. (shifting down to a corner). It occasionally “Diesels on” after turning the key off but again only if I shift down before parking and switching off.

I remember 10 years ago the oil control rings had broken into a couple of pieces.
The bores were good.

Do you know if unleaded fuel affects the Triumph rings?
Can anyone recommend a good brand of rings for the next rebuild?

JP Engineering in Australia have a good name. To get a price from them I need the standard bore size, width, depth of the ring grooves. Does anyone know this? I think the oil control ring setup is and upper and lower ring with a wave shaped centre ring. Is my memory correct?

Thanks in advance for your input.
/ubbthreads/images/graemlins/confused.gif
 
Hi,

That's quite a bit of oil usage.

Another guess might be that the unleaded might be effecting original valve guides and you are getting some oil seepage there. Perhaps a leakdown compression test would shed some light on the problem. Or is a "leakup test" when you are "Down Under"? (Sorry, I *really* couldn't resist that!)

I still recommend the test to help sort out the problem.

I don't have enough personal experience with the 6-cylinder TRs to help with your other questions. I'm sure some others will jump in with answers and suggestions.

Alan Myers
San Jose, Calif.
'62 TR4 CT17602L
 
Yes, you should really eliminate the valve guide oil leakage as a possible culprit before considering the oil control ring job.
Do a plain old compression test on each cylinder. Remove the plugs and with a wedged wide open throttle, give each cylinder about 6 compression puffs on the starter motor with a tester attached recording the readings as you go.
Then one cylinder at a time inject a teaspoon of motor oil through the plug hole and recheck/record.
If the readings improve a bunch then you know the rings are shot in that cylinder /ubbthreads/images/graemlins/mad.gif if they don't change much on any of the cylinders then you've got valve guide wear which is easier/cheaper to fix. /ubbthreads/images/graemlins/laugh.gif
Good luck
 
Aussie Dave, AltaKnight is correct in everything he said, so follow his instructions, but if you do come to the conclusion that it might be the oil control rings, try some engine cleaner, before you dive into reringing the engine. I had a similiar problem with a TR6 I owned years ago and after it wasn't driven for several years the oil control rings gummed up with old oil. I ran several cans of engine and gas cleaner through the engine while driving it and the oil rings must have cleaned up and sealed the engine again. I drove the car for several years after that without any oil burning. It took several tank fulls of gas with the additives, but it worked. Remember, the additive may only help if the problemn is gummed up oil rings. Try all of AltaKnights suggestions first. Good luck
 
I agree with above. Do the compression test and leak down test. Valve guide leakage is a possibility as mentioned, if so the end threads on your plugs will have an oil coating. At least that was what I was told by a retired military mechanic.
I had a flat head Ford that did a similar thing. This was in a boat restoration project that I acquired after the guy decided to get into bi-wing airplanes (Stearman). The engine had been freshly rebuilt and used one season, sat for a couple of years and then, when I got her going again, she started to use a bit of oil and smoke some. That old military mechanic told me to use automatic transmission fluid (Marvel Mystery oil was around then) to break any stuck rings loose. Fortunately it worked and after about two tanks of gas and another set of plugs, she didn't blow blue smoke. So, I agree with Blue-man too, try some non-destructive approach first - it certainly can't hurt anything especially if it turns out you need to re-build anyway.
 
I knew you guy's could give me great ideas. I get on it today.

On the oil front I think in retrosect it only used about 0.25 a tank max. Last tank used only a tiny bit but I have changed driving habbits too. On the way to work I got into a fantastic power slide. (Drifting) How I love this car.
 
[ QUOTE ]
On the way to work I got into a fantastic power slide. (Drifting) How I love this car.

[/ QUOTE ]

Power slides in a TR6, /ubbthreads/images/graemlins/tongue.gif were you dodging dingos? They're a lot of fun to drive but keep an eye on that differential mount to the frame if you like putting lots of torque to the rear wheels, it's a weakness and difficult to fix.
Have fun.
 
I need the standard bore size, width, depth of the ring grooves. Does anyone know this so I can price the rings.

Is there a better solution to standard ring style? It's an old design.
 
I put a dose of cleaner through the oil and then changed it. The oil was only a few weeks old and after the dose it went black. I was scheptical but I think it has worked. The oil level has been stationary ( small drop) and I ask a few folk to follow me and no one has seen the smoke. I'll do it again each oil change from now on. The engine stops when the key is turned off now too. I cannot be sure but I'm now using 98 oct instead of 91 oct fuel. When I had the valves and seats done a few years ago I took a bit off the head as well and I think I have a higher than standard compression ratio. The higher fuel octane could be helping stop the run on.
 
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