FAO : stan*, BenR etc

[stew]

My final year project and dissertation is on the evaluation of high temperature piston ring coatings.

I need to ideally source some rings with different coatings, and some standard-ish liners for my experimental work.

Any ideas?

Out of interest do any of the reanult engines use fancy rings or are they all bog standard steel etc?

Any information would help! Thanks.

[BenR]

There are dozens of ring materials and manufacture process, everything from plain iron, to ductile iron, to centrifugally spun iron, iron moly, chrom plated iron, steels, too many periphery coatings to think of which all claim one thing or another.

Rings in their own right are a science upon itself.

I dont know what you plan to experiment with or test with a liner and some rings.

Its a good thing its a dissertation, but even then you wont have enough words to allow a comprehensive explanation of everything.

[stew]

yeah its just a pathetic investigation really Ben. Im sure i could spend all year looking into this on its own, but i dont have the time or facilities.

Basically we have a test rig, which allows oscillating motion of a test bed, where a small part of the liner is clamped. a section of the piston ring is held above the liner, with a load applied, and the rig similates the stroke of an engine. it is basically to see how different materials perform under different loads, temperatures and with different lubrication.

[rob16v]

wish i got something interesting for my project :( still haven't really done much and presentations in december shite shite shite!!!

[BenR]

did you get to choose your topics?

Anyway, thats going to be a hard test as differing rings are used on differing bore materials, all designed to work with different hone patterns with different ra's. You just cannot test broadly like that.

Unless you do a most basic test of specific rings for that specific liner. But once you have run the first test you'll have to run a new liner as you'll destroy the peaks of the hone and plateu it....making it useless to test the next ring on. Then you have the issue of making sure each time you run a new liner that its exactly the same as the previous one.

Then you'll have interactions between one type of piston material and the rin material or coating you are using.

Will you be measuring the effect of just the top ring, or both comp rings, or including the oil control and scrapers as they add ALOT of friction to the total values.

There are hundreds of things to think of, and most of the time you'll end up explaning why your test wasnt any good, rather than analysing the results. Maybe it would be better to use your disertation to explain the short comings of the test and explain what would of been better and why.

?

[stew]

just the one compression ring ben.

yeah its a bit of a joke, as most uni stuff is, but as long as i can write a good report, discuss some stuff, then i should pass this year. then who gives a ****. lol

cheers for the help. may bug you later about this if you dont mind...

[BenR]

yea no worries.........keep the ol brain rattling.

[stan]

A better (easier and more fruitful) projoect would be to keep the ring/liner combo the same, and only vary hatch pattern for e.g. The test rig could then maybe rigged to check cranking pressure, and so you can analyse how different bore surfaces alter pressure holding ability.

[BenR]

it would be hard to do that without seating the rings and without any cylinder pressure to bed in the rings?

All round sounds like a pretty impossibly flawed dissetation, i would complain and put your reasons forward......unless they give you a grant of several thousants to run a 6 cylinder with each cylinder running differing ring packs.

Or a single cylinder engine that you have to rebuild everytime.

[stan]

it would be hard to do that without seating the rings and without any cylinder pressure to bed in the rings?

yup didnt think of that lol.

does sound like a bit of an arse to be doing