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piston ring gap

 
novagearhed
I love my Chevy Chevette!
Posts: 5
Joined: 04/10
Posted: 04/24/10 10:47 PM

this is my first post and i am building my first motor. 350 4 bolt, .060 over, aluminum heads i am trying to find the equation for the ring gap size. is it true that the two compression rings have differnt gaps?  

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gettnlarge01
I mow my lawn and find Chevys
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Posted: 04/25/10 02:40 AM

what type pistons are you using?  
luck is when skill and opportunity meet

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Pontiacman2
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Posted: 04/25/10 05:38 AM

Yep need more info.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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novagearhed
I love my Chevy Chevette!
Posts: 5
Joined: 04/10
Posted: 04/25/10 06:47 AM

i have sealedpower cromoly rings with flattop hypereutectic pistons .060 over  

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tuffnuff
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Posted: 04/25/10 06:49 AM

Icon Quotenovagearhed:
this is my first post and i am building my first motor. 350 4 bolt, .060 over, aluminum heads i am trying to find the equation for the ring gap size. is it true that the two compression rings have differnt gaps?

I'm starting a new thread,,, called "Ring End Gap",,, check it out
Grin  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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gettnlarge01
I mow my lawn and find Chevys
Posts: 3330
Joined: 09/09
Posted: 04/25/10 08:47 AM

+1 tuff,good idea  
luck is when skill and opportunity meet

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Pontiacman2
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Posted: 04/25/10 10:33 AM

You will need a min. of .016 on the top ring and .014 for the second ring.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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novagearhed
I love my Chevy Chevette!
Posts: 5
Joined: 04/10
Posted: 04/29/10 12:28 AM

The rings tell me that if there is a beveled edge which there is on one set, that it should face up. but it does specify whitch ring is the top ring. Is the top ring beveled?  

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tuffnuff
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Posted: 04/29/10 07:56 AM

I thought the thread I started on ring gap, was easy enuff to find,,, "IF" you use the "search" button on this forum,,,
Here it is,,,
Again.

Ring End Gap

Ring End Gap,,, Check,,,

Failure to ensure proper ring end gap may cause the ring tips to butt, and engine damage could occur.

1. A torque plate should be attached to the engine block or cylinder (if applicable),,,  and torqued to specifications.
2. Check the end gap by placing the ring into the cylinder. "The cylinder bore should be free of taper". Use the piston to square up the ring in the bore, and check the end gap by using a feeler gage.
3. See table below for proper ring end gap for your application.
4. The oil rails may be installed, by spiraling them on, without modifying the end gap. The gap should be a minimum of .010”.

Ring Gap Table Instructions,,,

1. This table is in inches. If you are measuring your bore in millimeters, you will need to convert to inches by dividing your bore size,  by 25.4.
2. Multiply your inch bore size by the “Bore x” column for your application to determine the end gap.
Example: For the top ring of an ATV with a 4.0” bore, multiply 4.0" X .004" = .016"

Application,,,

Top Ring/Second Ring

Bore x
Dirt / ATV / Snow / PWC
.0040”
.0050”
High-Performance Street / Strip
.0045”
.0055”
Street-Moderate Turbo / Nitrous
.0050”
.0055”
Late Model Stock
.0050”
.0055”
Circle Track/Drag Race
.0055”
.0060”
Blown Race Only
.0065”
.0070”
Nitrous Race Only
.0070”
.0075”

Notes,,,

1. The chart above is a general guideline. Each ring should be fitted to the particular cylinder in which they are to be installed.

2. The gap on the second ring should "ALWAYS" be larger than the top ring end gap, this will help to reduce top ring flutter or lifting.

Filing Gaps,,,

1. Wiseco recommends filing ring end gaps using the proper ring end gap filing tool, either an electric ring grinding machine or manual hand crank style grinder.
2. Always file from the ring face towards the inside diameter to avoid damaging the face coating.
3. File only one end of the ring. Use the unfiled end as a reference.
4. Be sure to keep end gaps square.
5. File until the desired end gap is achieved.
6. Remove all sharp edges and burrs.

Failure to remove all burrs and sharp edges could cause engine damage, by leaving lateral score marks on the cylinder wall.

Ring Installation,,,

1. Check each ring in its corresponding piston groove to ensure proper axial and radial clearance. This is important on new and used pistons.
2. Oil ring expander (the corrugated ring),,, place the oil ring expander into the oil groove with the butted tips of the expander 90° from either end of the wrist pin. Be sure the tips of the expander are visible and properly butted. If the expander tips are overlapped, the engine will smoke due to excessive oil use, and engine damage could occur.
3. Oil rails: The oil rails can be installed with either side up. I don't recommend using a ring expander (tool) because it has a tendency to buckle the narrow rails, instead, I spiral the rails into the oil groove, placing the first rail below the expander, and the second rail above the expander. The rail end gaps should be located at least 90° from each other. After the oil rails are installed, double check that the tips of the expander are properly butted, and not overlapped.
4. Second ring: Using a piston ring expander , install the second ring with the marked side up. An unmarked 2nd ring with an inner bevel should be installed bevel side down. If the ring is not marked on one side near the end gap, either side can be up.
5. Top ring: Using a piston ring expander, install the top ring with the marked side up. An unmarked top ring with an inner bevel should be installed bevel side up. If the ring is not marked on one side near the end gap, either side can be up.

Once again,,,

Failure to ensure proper ring end gap may cause the ring tips to butt, and engine damage could occur,,,


That pretty much sums it up,,,

Read it,,, until you understand it,,, all the info you will need,,, is here.

Grin  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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Pontiacman2
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Posts: 8956
Joined: 09/08
Posted: 04/29/10 01:24 PM

+1  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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