Teminology: four corner scoring on piston

[guen84]

Wow you guys are funny. This sounds like a conversation you have while sitting around he bong smoking the devils lettuce

seems to me this is how its gets every time someone says something bear doesnt understand. he starts calling people stupid to make himself feel better..

[guen84]

FOUR-CORNER SEIZURE
This piston has vertical seizure marks at four equally spaced points around the circumference. A four-corner seizure is caused when the piston expands faster than the cylinder and the clearance between the piston and cylinder is reduced. Another common problem of this type is a single point seizure on the center of the exhaust side of the piston. However this occurs only on cylinders with bridged exhaust ports. The main causes for this problem are too quick warm-up, too lean carb jetting (main jet), or too hot of a spark plug range.
[/url] http://www.smellofdeath.com/lloydy/pist ... de.htm[url] theres even some pretty pictures for you...


i can prove you wrong all day bear next ill start posting movies for you maybe you cant read thats the problem..

[guen84]

heres some pics: note the scouring is by the corners of the cut out for the wrist pin. which is the thickest part of the cylinder

[guen84]

and since we are on the topic, all shapes can be made out of a circles, just by swinging arcs. and a fun fact a circle is the only shape that wont fall thru its self. thats why man whole covers and valve cover on the road are round.. so they dont fall thru the whole when placed back on.. i just love geometry, if you want bear i can start with chords of a circle, never mind you couldnt pass algebra let alone learn some trigonometry...

[noiseguy]

[swimmingfree]

man i just look at this ..lol lol
i have had some of those thing happen to me ...
swimmingfree

i think this shod be in the Wikispreedia

http://www.smellofdeath.com/lloydy/pist ... _guide.htm

[guen84]

ya me neither i was tring to see if my plug was to hot and now im giving geometry lessons...

[guen84]

man i just look at this ..lol lol
i have had some of those thing happen to me ...
swimmingfree

i think this shod be in the Wikispreedia

http://www.smellofdeath.com/lloydy/pist ... _guide.htm

ya i picked that one cause it has a great url...

[mousewheels]

Thanks for the pics guen84

At the first post of this thread are some ideas for discussion. Here's some digging into another controversial name .

Has this failure gone by other names in the past?
Cold seizure: "Initial inspection of the engine by the main UK agents for Rotax showed classic signs of cold seizure at four different places around the circumference of the cylinder. A cold seizure can occur if an engine is run at full power before it is fully warm, the piston then expands faster than the cylinder leading to the seizure."


Couple more links:

http://www.ultralightnews.ca/advisories ... eizure.htm

http://www.groupk.com/tec-seizures.htm

http://www.thumpertalk.com/topic/512796 ... with-pics/

https://www.slipstreamperformance.com.a ... Path=4_567

i think this shod be in the Wikispreedia

http://www.smellofdeath.com/lloydy/pist ... _guide.htm

Opinion: Links are good. Copying into the wiki verbatim from other sources, I'm not hot on. Copying part is simple. My issue is once info is at 2,3...100 sites, there becomes an info synchronization issue. When one site updates, there's a whole lot of folks behind the curve - serving up old info to their sites.

Personally, I like direct info/pics from members, and add links as support in the 'wiki.

[wiguy05]

How long does this s*** have to go on? It's just a commonly used term to describe the condition of a round piston .
What happened to the days when someone asked a question they actually got help? WOW!

Common my butt. No one with half a brain uses the term corner to describe anything to do with a round object. If they taught you otherwise in school, the education system failed again.

What happened to the days when people asked questions without sounding like a total moron?

Well then there are several hundred thousand snowmobilers worldwide that are "morons" as well too. A four corner seizure is very common with 2-stroke snowmobile engines and it is referred to on forums and in performance shops almost daily.


Honestly, I can't even believe you are arguing about this Bear. You must have run out of OBAMA topics to b**** about?


I vote lock this up and give Bear a short vacation. The personal attacks in here are worth some time off.

[ottoman]

Wow how did I miss this thread!!
Four corner scoring terminology has been around as least as long as I have.. and Im old.
A piston isnt round when its cold or when its hot... measure one if you dont believe me.
The more material there is in a section of the piston the more that section expands with heat.. no mystery here.
4 corner seize = piston running too hot... motor not warmed up properly or not enough wall clearance.

[b18Eric]

a round object with four corners. here ya go

Yes I know its a square and a circle but its the only way its going to happen! /Conversation

[Red Eft Performance]

Yes this terminology is used quite often. I have even seen it used in a factory service manual before. Usually its caused by putting a cold engine under heavy load causing the piston expand faster than the cylinder.