Piston Rings

[sven]

Ive come to the conclusion that I need to pull the head off my SIII petrol. Ever since driving back from MAR, truck runs hotter than normal, lost significant amounts of power. Plus its hard to start (used to start very easily) and puffs blue/white smoke at startup. All tune-up parts are in good shape. The worst part: I went through 4 quarts of oil on the entire MAR trip (under 800 miles!!!)

I plan on rebuilding the head as unleaded.

So my question is: How do you visually check the piston rings? Would I see scoring on the cylinder walls and go by that? Or should I just replace the rings (with the block still installed) for good measure? I wanna avoid a full on rebuild if possible.

[Rusty and Tad]

Or should I just replace the rings (with the block still installed) for good measure? I wanna avoid a full on rebuild if possible.
Sven,

Many years ago, when my truck was still a gasser, the very first time I ever got into an engine (besides lawn mowers) was to do what you are thinking about.

I had thought I was smoking because I had rings fail but it turned out that I had a cracked head. Anyway, I took out the pistons from above (head removed) put in new rings, and after a new head from Wise Owl, I had a very peppy, non-oil burning 2,25.

And now I have a very slow 2.5 diesel :confused: but when it was running (that is another story) I was getting 25 MPG :)

Look for deep scoring on the cylinder walls and inspect the rings, I think you will find one broken, or that they have lost their "spring." Hone the cylinders, buy new rings, have your head shaved to 8:1 and put in the valves and guides for un-leaded and I think you will be very pleased! You might as well do new big ends (bearings) since you have the pistons out.

Then you might as well put on parabolic springs and new shocks. But as long as you are doing that then you might want to get it repainted. And a new wiring harness. And...

Good luck!
Tad

BTW If you need a piston ring compressor let me know. I know that they are inexpensive, but I have one that is just sitting in my tool box.

[sven]

In-situ rebuild is exactly what Im thinking about. I may do a leakdown test (I think advanceauto loans them out for free) first before I dive in. If I find that the lower end is OK, then I'll just do the head. My coolant has been brownish too so its possible oil is getting mixed. The weird thing is that the dipstick doesnt show any signs of coolant... I thought coolant would also show up in the oil. It amazes me how tough these little motors can be!

[kirkt]

I think Sven should definitely shave his head.

[sven]

I think Sven should definitely shave his head.

Ya :D

[Rusty and Tad]

My coolant has been brownish too I don't think that oil would turn the coolant brown since oil and water don't mix... I maybe wrong, but to me it sounds like rust. Does the top of your oil filler cap show any signs of condensation?

[sven]

I don't think that oil would turn the coolant brown since oil and water don't mix... I maybe wrong, but to me it sounds like rust. Does the top of your oil filler cap show any signs of condensation?

Yeah it could be rust. I replaced the rad a few months ago. I noticed the coolant passage in the head looked really nasty..scaley rust. I probably flushed the system 10 times or so.

Under the oil cap looks fine, no milky condensation or anything like that.

[Evan]

Sven... I'd bet its the top of the motor .. check compression twice,first normally, second with oil added big differences usually mean issue is in the block... Careful skiming the head as it may have been allready deck milled. Pushrod lenght will change and the lumps bottom end wasn't intended for "higher compresion"

[sven]

Thats what Im hoping. Top end only.

The last time I did a compression test, one out of 4 was 20 PSI lower than the rest. I added oil to all cylinders a second time and they all went up about 10-20 psi or so. Sound "normal"?

[Evan]

Sounds as though its the head gasket...Which cyl was low?

[sven]

It was one of the ones in the middle - I guess 2 or 3..

[Rusty and Tad]

If I remember correctly there is a weak spot on a 2.25 series gasket. Since I am new here and I don't know the history please forgive if this has been covered before:

Is the engine original? Do you know if it has been cracked (separated) before? Is it 7:1 or 8:1?

If it would be a head gasket that really wouldn't account for the use of so much oil. Plus the "smoke" would be all the time and not just on start up.

BTW it is not unusual for Rover engines to have a puff of blueish smoke on start up.

Since you used so much oil it had to go someplace. Either you burned it up (leave that to us diesel drivers) or it is leaking out (more than usual). Has the EPA been around asking about the high oil content in the water table near you?

This may seem like an odd question, but any clutch slipping since you started using so much oil?

Just another thought, did you say that you were losing power, too? I am wondering if you have valve problems... Do the easy things first: Check valve clearance, then a compression check - dry then leak down.

Tad

[sven]

Yeah the motor appears to be original (I dont know for sure), it also appears to never been separated...This truck is very original everything appears to be intact. Being a 73 S3 I think its a 8:1. No oil leaks either. During the trip, I didnt have any oil residue on my rear tailgate (like most rovers do). It always smoked a little on startup but now it smokes more and is harder to start. I used to be able to pull the choke out and start it without touching the gas pedal. Now I have to play around with the gas pedal to start it. Hot or cold.

[Rusty and Tad]

I bet your plugs are fouled from the oil. Have you pulled them out? I guess you will have to when you do the compression get, huh?:o

That is good news that there is no build up of oil on the tailgate. I was thinking that maybe your main seal went, and that is why I was wondering about the clutch.

[sven]

Yeah I'll report back with some more recent compression #'s when I get the chance. If I pull the head, I'll be sure to post up pics and stuff.

[sven]

Ok finally did another round of compression #s tonight. Did these on a cold motor...should have been warmed up, right?

1 - 140
2 - 135
3 - 142
4 - 140

The green book says a 8:1 motor should be 170 on a warmed up test. Plugs looked perfect, no oil fouling or carbon.

[Rusty and Tad]

That's low, but not rock bottom and they are fairly even.

I don't think you need to do an overhaul but if you are looking for a winter project... why not.

Have you checked the valve adjustments?

[sven]

Valve adjustment was done when I first did the tune up, not too long ago. The disappearing coolant and oil leads me to believe its head gasket related. Plus the coolant is green when sitting, but turns brown/grey when its running. Radiator is new.

Gotta pull the head off! I'll try to do it during TG break.

[Rusty and Tad]

Sven,

If it makes you feel any better I have pulled my head off so many times I no longer need the book for the torquing sequence! OK, I still do, but even with a diesel (you have to pull the injectors - an added step) I can have the head off in less than an hour.

Besides, this will be a good way to get the family involved. Instead of the Traditional after Thanksgiving festivities you gather everyone around the Landy!

Good luck! Let us know what you find.

Tad