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TR6 TR6 Piston rings

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TR674

TR674

Jedi Warrior
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Hello all
I'm after a bit of preemptive advice. My motor is starting to show symptoms of blow back, oil is starting to bubble up the dip stick tube.
Reading the Triumph Maintenance Manual, replacing the rings with the motor in place seems straight forward.
Am I assuming right that this is correct? And are there any tricks I need to know before I tackle this job?
Regards
Craig
 
Well, changing the rings is easy enough, but as the rings are chromium steel running on plain cast iron; odds are good that the cylinder walls need freshening too. Which pretty much requires pulling the engine.

Not that there's anything wrong with just stuffing rings in it; bound to make some improvement, only don't expect it to be a new engine afterwards.

Oh yeah, might as well do the rod bearings while you've got them apart. Again, the crank might need turning, but even so, just changing the bearings should help some.
 
Not saying you don't need rings, but when I had oil blowing up the dipstick, I traced down the problem to be a clogged up ventillation line. The one between the valve cover and the carbs or air filter box.
Have you run a compression test? Bone-up on the technique for both dry and "wet" and the interpretation of the results.
But check the vent, there needs to be some suction to vent the rocker cover.
 
Strong recommendation that before you jump in with both feet, check the water depth first.


Do a cylinder leakdown test, or take it to a shop that can perform a cylinder leakdown test.

A cylinder leakdown test pinpoints where and how much it is leaking. That way you can determine, if in fact, it needs rings, or some other internal repair, before just tearing into it.
 
First read my page on head removal.

https://www.74tr6.com/cylinderhead.htm

Next, go have a few beers and think about what you just saw.

And then think of what it will lead to if you are like me, 2Wrench, Bill, Tom and everyone else who has opened up a 30+ year old car with mileage on it.

My car is now sitting without an engine, which is not all bad, but because I took the head off, I saw that it needed a cam, lifters, and ended up doing a complete overhaul, now that it's all apart.

After 54,000 miles, I have no complaints, but you are really opening up a "Pandora's Box" when you do that.

If I were smart and it's obvious that I'm not, I would have pulled the engine and done it all correctly when I saw the wear inside. I never thought that I'd get a spare to rebuild so fast, so I figured that I'd drive mine for the spring and summer and do what I'm doing now in the winter of 2008.
 
Just replacing the rings isn`t something I would do.
IF the rings are that bad you can bet other components are not far behind in the wear/worn categoey.
Do as suggested, the leakdown test. It will Indicate valve condition as well as ring condition. You problem may not be rings at all, as suggested it could be crankcase ventalation system problems. A lot cheaper to fix than a ring job so I would check that first and foremost.
If it turns out to be a ring problem then the BEST {Not the cheapest} way to go is a complete overhaul.
Just replacing the rings may give you some extra life out of your engine but in the long run something else will fail internaly and will more than likely be costly. Basicaly, IF the car is a keeper! Do the right thing.
Just my .02 cents worth.
 
Just to weigh in on the opposite side; stuffing in new rings (and rod/main bearings) was exactly what I did to my 59 TR3A in about 1984. I knew the cylinder walls should have been replaced along with many other things; but I had no money and no place to work on it, and swapping out the broken rings for new ones (in the street in front of the house) let me drive it for quite a few years and many thousands of miles after that.

I unfortunately didn't keep records, but we had already moved to a new house in 1989 before I found time, inclination and space to swap the engine out (and even then it was more because the original OD had quit than because the engine was a problem). And for most of that time I was driving it to work almost every day.

Never did really overhaul an engine for it ... the parts I started accumulating way back then for a "hot rod" rebuild are still in boxes in the garage. But the OD I bought happened to come with what I thought was a better engine, so ...
 
As the old expression goes, there are two sides to every story....

Randall's plan probably worked better and longer than he thought that it would at the time. That was a good thing for him. Under different circumstances, I may have just changed the cam & lifters.

It's really a personal decision based on what you find when you get it apart.
 
Thanks all.
It makes sense to diagnose the source of the blow back first. The rocker cover vent is clear, the first thing I checked.
In the back of my mined is the issue of opening up a 34 year old motor.
Anyway, the motor is running very well at the moment, so I'm not too concerned. The valves are all good, as I only just put the head back on last week after a valve stem started to disintegrate.
Paul, I'll have those beers anyway............
Thanks
Craig
 
Okay, if we're gonna play "shade tree motors". First thing to do is get a can of GM top end cleaner. Divide it up 1/2 way, take the air cleaner off so the carb face is open. With the engine running(warm) siphon the top end cleaner into each carb, while running the engine at fast idle, few quick rpm increases, adding more cleaner to the point where just as it sucks up the last you dump it into the engine where it richen stalls. Let it sit over night. Start it up, with good ventilation, as it will smoke like a three alarm fire for a few minutes. See what that does.


Helps clean the carbon off the rings(and anywhere else in the combustion chamber)..

Drive it for a day, then do a leakdown test.
 
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