Champagne wishes...

[gstallons]

Yes . IDK if MG has a diagram of indexing piston rings. Your piston pin will be 3 o'clock and 9 o'clock looking down at the piston . You do not want ring gaps in or around this part of the piston pin area.  You will probably want the top 2 compression rings at least 90 degrees from each other .Maybe 10 o'clock & 4 o'clock  I can't tell if the oil wiper ring is a 1 or 3 piece device . If it is 1 piece you want it 120 degrees from the compression rings . 3 piece oil wiper rings , you will want the expander and the wipers 120 degrees .

Do some investigating or some others can give input .

[MartyNZ]

What does "index the piston ring end gap" mean?

 

Is that where I make sure the gaps are not aligned? I noticed that the gaps were at the 6 o'clock, 9 and 3 positions when I removed it. I assume I should keep the rings in the same positions.

Gregory Bender has an excellent presentation here: http://www.thisoldtractor.com/projects_roy_smith_2013-03-19_install_the_left_piston_and_cylinder.html

Yes, it is a roundfin engine, but the principle remains the same.

The V11 workshop manual is less specific, just saying : The end parts of the compression rings must be fitted “out of step” with each other.

[Chuck]

Actually, in service, rings move around. Just give it your best shot, it'll be fine. 

[gstallons]

Hmmmm.

[Scud]

Good link Marty - thanks.

 

Here's the piston after an overnight soak in diesel and a wipe-down. The worst of the carbon is gone.

 

 

Is it worth the effort to get it even cleaner than this? If so, I can try Simple Green tonight.

 

 

[MartyNZ]

Here's the piston after an overnight soak in diesel and a wipe-down. The worst of the carbon is gone.

Is it worth the effort to get it even cleaner than this? If so, I can try Simple Green tonight.

It is worthwhile to remove the loose & flaking carbon. You would only remove the rest if that makes you feel good. In service carbon builds up again quite quickly, then reaches equilibrium. So after a few hours it would look as though you had never been in there at all.

[bbolesaz]

Scud, I'm thinking you are the kind of person who hates to put a dirty part back on a bike.

 

I was shocked by how well the simple green worked when someone told me about it.  I had used Berryman Chem-Tool soak before with less than satisfying results.  I decided afterwards that simple green is neither simple nor green !  No more pouring that down the drain, it goes to the household waste collection now.

[Scud]

Scud, I'm thinking you are the kind of person who hates to put a dirty part back on a bike.

 

True, especially for things I can see. But I also hate to waste time by doing unnecessary things. Conversely, I don't want to miss an important "while I'm there task" and later regret skipping a step. So I have to balance the competing drives... this is Zen and the Art of Motorcycle Maintenance to me.

 

In this case I don't currently have the new circlips and cannot re-assemble the motor, so I might just try some Simple Green in the name of science.    If I had the clips in-hand, I'd be in a hurry to put it together.

[docc]

 

... this is Zen and the Art of Motorcycle Maintenance to me.

 

"And what is good, Phædrus, And what is not good - Need we ask anyone to tell us these things?" Pirsig

[Lucky Phil]

Actually, in service, rings move around. Just give it your best shot, it'll be fine. 

Yep they do Chuck, just start them 120 deg apart and away from the thrust face is the accepted methodology but at the end of the day they are free to and do rotate around the piston.

 

Ciao

[Lucky Phil]

Good link Marty - thanks.

 

Here's the piston after an overnight soak in diesel and a wipe-down. The worst of the carbon is gone.

 

IMG_5987.jpg

 

Is it worth the effort to get it even cleaner than this? If so, I can try Simple Green tonight.

Lets do this the right way, remove the carbon. Then you can set the squish as well if you like. After years of scraping the carbon I bought an ultrasonic cleaner. Much easier and faster but less therapeutic.

 

Ciao 

[MartyNZ]

Simple Green will clean really well, but be careful. It is corrosive to aluminum if not diluted. This is why they make a different product specifically for aluminum alloys. Aircraft alloys do corrode easier than automotive alloys, but the difference is only a matter of degree.

For your pistons, brief exposure at low temp, and washing it off well with hot water & detergent should avoid surface dulling and corrosion pits forming.

Their data sheet http://simplegreen.com/gsa/data-sheets/ says it has alkaline pH 9.

Simple Green's website says this:

Aircraft — Is Simple Green All-Purpose Cleaner safe for cleaning aircraft?

Simple Green manufactures a product specifically designed for use on aircraft - Extreme Simple Green Aircraft & Precision Cleaner. This product was initially developed for use in the aircraft industry and extensive testing shows it to be safe for use on aluminum, plastics, rubber, and high tech alloys, in both normal and extreme temperatures and stress conditions. Extreme Simple Green passed a variety of aircraft industry tests. Testing has been performed by Scientific Materials International, Inc. and is available upon request. http://simplegreen.com/en-nz/household/faqs/

 

You don't need to take my word for it, a web search for "does simple green corrode aluminum" should say something similar.

[swooshdave]

Simple Green will clean really well, but be careful. It is corrosive to aluminum if not diluted. This is why they make a different product specifically for aluminum alloys. Aircraft alloys do corrode easier than automotive alloys, but the difference is only a matter of degree.

For your pistons, brief exposure at low temp, and washing it off well with hot water & detergent should avoid surface dulling and corrosion pits forming.

Their data sheet http://simplegreen.com/gsa/data-sheets/ says it has alkaline pH 9.

Simple Green's website says this:

Aircraft — Is Simple Green All-Purpose Cleaner safe for cleaning aircraft?

Simple Green manufactures a product specifically designed for use on aircraft - Extreme Simple Green Aircraft & Precision Cleaner. This product was initially developed for use in the aircraft industry and extensive testing shows it to be safe for use on aluminum, plastics, rubber, and high tech alloys, in both normal and extreme temperatures and stress conditions. Extreme Simple Green passed a variety of aircraft industry tests. Testing has been performed by Scientific Materials International, Inc. and is available upon request. http://simplegreen.com/en-nz/household/faqs/

 

You don't need to take my word for it, a web search for "does simple green corrode aluminum" should say something similar.

 

If you're going to use Simple Green use the purple stuff. Does't harm aluminum.

[bbolesaz]

I've done a couple of BMW Airheads with the pistons face down overnight in the green Simple Green.  Yes, it does "corrode" the aluminum, there will be a light patina on the piston where bare metal was exposed.  It cleans right up and 60K miles later the piston is no worse for it. No pits, no erosion, no dimension changes etc.   No, I wouldn't use it on a nice shiny bare aluminum skinned airplane. That would be bad.  Very bad. Hugely bad.

[gstallons]

Lucky Phil's ultrasonic cleaner is the only way to go .