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Author Topic: 2nd ring on a M21D24 piston  (Read 1904 times)

August 09, 2009, 05:09:40 pm

klang

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2nd ring on a M21D24 piston
« on: August 09, 2009, 05:09:40 pm »
Probably a stupid question, but I want to get this right.

I pulled my BMW M21D24 IDI Engine apart 8months ago, and had everything lined up, balanced etc.

Now, when I'm putting everything together, I'm not sure about the second compression pistonring (the middle one)

I can be mounted in 2 different ways.

The "groove" should be down? Is this correct?  ???


Dont want to have to pull the engine apart again just because of stupidity  :(

// Klang



Reply #1August 09, 2009, 06:37:01 pm

Rabbit on Roids

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Re: 2nd ring on a M21D24 piston
« Reply #1 on: August 09, 2009, 06:37:01 pm »
pretty sure the groove in the scraper ring is supposed to face up.

Reply #2August 09, 2009, 11:00:14 pm

Rabbit TD

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Re: 2nd ring on a M21D24 piston
« Reply #2 on: August 09, 2009, 11:00:14 pm »
Most rings that are designed to face a certain way have a mark on the flat surface right near the gap area.  Does yours have a small mark there, if it does it should be facing the top of the piston.

Reply #3August 10, 2009, 11:14:29 am

Rabbit on Roids

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Re: 2nd ring on a M21D24 piston
« Reply #3 on: August 10, 2009, 11:14:29 am »
oh yea, there are marks on the top of the ring. on the top edge.

Reply #4August 10, 2009, 03:45:05 pm

klang

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Re: 2nd ring on a M21D24 piston
« Reply #4 on: August 10, 2009, 03:45:05 pm »
Thanks for the answers.

I checked the ring, and close to the gap I found "TOPC" written.

So I mounted it that way, and the groove is facing down. (the letters up)

The top ring had "PC" mounted on it, so I mounted that facing upwards as well.

The oil ring had nothing on it, looked to be the same on both sides, so I just put them on  ;D



Hope I have compression later =)


Thanks.

Reply #5August 10, 2009, 06:23:26 pm

Rabbit TD

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Re: 2nd ring on a M21D24 piston
« Reply #5 on: August 10, 2009, 06:23:26 pm »
Thanks for the answers.

I checked the ring, and close to the gap I found "TOPC" written.

So I mounted it that way, and the groove is facing down. (the letters up)

The top ring had "PC" mounted on it, so I mounted that facing upwards as well.

The oil ring had nothing on it, looked to be the same on both sides, so I just put them on  ;D



Hope I have compression later =)


Thanks.
If you have those letters facing up you have them on right.

Reply #6August 11, 2009, 07:22:25 am

klang

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Re: 2nd ring on a M21D24 piston
« Reply #6 on: August 11, 2009, 07:22:25 am »
Thanks for the answers.

I checked the ring, and close to the gap I found "TOPC" written.

So I mounted it that way, and the groove is facing down. (the letters up)

The top ring had "PC" mounted on it, so I mounted that facing upwards as well.

The oil ring had nothing on it, looked to be the same on both sides, so I just put them on  ;D



Hope I have compression later =)


Thanks.
If you have those letters facing up you have them on right.


Great!
Thanks

Reply #7August 11, 2009, 09:35:49 am

arb

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Re: 2nd ring on a M21D24 piston
« Reply #7 on: August 11, 2009, 09:35:49 am »

The oil ring had nothing on it, looked to be the same on both sides, so I just put them on  ;D
 

That's correct, the oil scraper rings have no up or down... (the spacer accordion ring goes between the 2 scrappers)

 

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