How can we get SBC pistons to fit LS1?
12-08-2001, 10:06 AM
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How can we get SBC pistons to fit LS1? Mainly thinking of a 6.0L block (4.030" bore). As much as custom pistons are cool, theyre expensive. Can we get forged or hypereutectic SBC piston to fit? I recall 2Quick saying something in HERE about modifying the skirts and rebalancing. I know SBC 6.125" rods work.
Any thoughts?
Ryan
Any thoughts?
Ryan
12-08-2001, 10:51 AM
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LSxGuy widda 9sec Mustang
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Re: How can we get SBC pistons to fit LS1? One word "hacksaw" <img src="images/icons/grin.gif" border="0">
I've found some forged SBC pistons that would work with a stock stroke 6.0L, the only problem is they were almost the same price as custom pistons.
Once the stroke and connecting rod length is desired everything is just math. Since you stated you want to use a 3.9" stroke with 6.125" rods you need to figure what compression height piston you will need. This is where deck height becomes useful also.
First you want to divide the stroke in half, so that you can measure from the centerline of the crankshaft bore.
3.9" stroke /2 = 1.95"
Use the actual rod length 6.125"
Now add these 2 numbers together = 8.075"
Take the results of adding these together and now you subtract the block deck height 9.24" - 8.075" = 1.165"
1.165" of compression height on a piston would give you close to zero deck, meaning the piston would be flat with the cylinder head surface at top dead center, assuming a true block.
Stock LS1 engines have the piston out of the cylinder .006-.007" out of each cylinder, so to duplicate that with compression height just add the .006" to the 1.165" that we came up with earlier.
Now here is the fun part, you need to look through a couple of piston manufacturers books to match bore size and compression height and piston pin diameter to your specs. It take some time, but you may be able to find what you need. Try some other combinations of stroke and connecting rod length also. If there is a off the shelf flattop piston available, it would be a low-buck engine buildup. <img src="images/icons/smile.gif" border="0">
I've found some forged SBC pistons that would work with a stock stroke 6.0L, the only problem is they were almost the same price as custom pistons.
Once the stroke and connecting rod length is desired everything is just math. Since you stated you want to use a 3.9" stroke with 6.125" rods you need to figure what compression height piston you will need. This is where deck height becomes useful also.
First you want to divide the stroke in half, so that you can measure from the centerline of the crankshaft bore.
3.9" stroke /2 = 1.95"
Use the actual rod length 6.125"
Now add these 2 numbers together = 8.075"
Take the results of adding these together and now you subtract the block deck height 9.24" - 8.075" = 1.165"
1.165" of compression height on a piston would give you close to zero deck, meaning the piston would be flat with the cylinder head surface at top dead center, assuming a true block.
Stock LS1 engines have the piston out of the cylinder .006-.007" out of each cylinder, so to duplicate that with compression height just add the .006" to the 1.165" that we came up with earlier.
Now here is the fun part, you need to look through a couple of piston manufacturers books to match bore size and compression height and piston pin diameter to your specs. It take some time, but you may be able to find what you need. Try some other combinations of stroke and connecting rod length also. If there is a off the shelf flattop piston available, it would be a low-buck engine buildup. <img src="images/icons/smile.gif" border="0">
