Pistons For a 347 Turbo Build?
04-02-2014, 01:07 AM
#1
Pistons For a 347 Turbo Build? Hey everybody, I am in the process of building an LS6/LS1 with a power adder. I am on the fence about going with nitrous or boost. I come from a turbocharged tundra and had to sell my kit to purchase and build this engine and now I'm really missing the fun of a turbo lol. Anyways, if I were to go with a turbo build, what pistons should I be looking at? My bore is 3.905 and I'd like to get a piston that'll work with the stock 6.098 rod length for now. Anyways, my main problem looking at all these pistons online is that they all have different -cc reliefs and I have no idea what that will bring my compression ratio to. If I go with a boost build, I'd like to run 93 pump gas with meth injection so I'm not to sure what my CR needs to be to be able to run that. I was thinking 10.0:1-11.0:1? But like I stated earlier, I have no idea what pistons to run that'll put me in the desired CR range. Thanks for y'all's suggestions and inputs in advance, I really appreciate it!
04-02-2014, 03:15 PM
#5
Go wild
use a -.006" deck height if its a standard block
http://www.rbracing-rsr.com/compstaticcalc.html
-11cc pistons and 62cc heads gives me a cr of 9.6. K1 rods/wiseco pistons going in mine
why do you want to stay with the 6.098" rods? There isnt really a benefit.
use a -.006" deck height if its a standard block
http://www.rbracing-rsr.com/compstaticcalc.html
-11cc pistons and 62cc heads gives me a cr of 9.6. K1 rods/wiseco pistons going in mine
why do you want to stay with the 6.098" rods? There isnt really a benefit.
Last edited by Ryans99ls1; 04-02-2014 at 03:23 PM.
04-02-2014, 08:27 PM
#6
Appreciate the feedback guys.
I am keeping the stock 6.098 rods for now just so I can throw the engine back together quicker so I can have some fun with it until they break or snap lol. Boost or nitrous, whichever way I choose to go, will not come until way later in the build. I'm worried about building it NA first, getting results, and then putting on the power adders. But it basically all comes down to MONIES. If I happen to have the coin to shell out for new rods before I end up putting the motor in then I will purchase them but if not, then ill run the stock rods until they blow once I get into the boost or nitrous stage of my build.
What would the Mahle -4cc 3.905 Flat Top pistons bring my CR to? Sorry guys, I'd do the math myself but I don't know what the formula would be to figure out compression ratio. Unless someone cares to share it :0 haha.
I am keeping the stock 6.098 rods for now just so I can throw the engine back together quicker so I can have some fun with it until they break or snap lol. Boost or nitrous, whichever way I choose to go, will not come until way later in the build. I'm worried about building it NA first, getting results, and then putting on the power adders. But it basically all comes down to MONIES. If I happen to have the coin to shell out for new rods before I end up putting the motor in then I will purchase them but if not, then ill run the stock rods until they blow once I get into the boost or nitrous stage of my build.
What would the Mahle -4cc 3.905 Flat Top pistons bring my CR to? Sorry guys, I'd do the math myself but I don't know what the formula would be to figure out compression ratio. Unless someone cares to share it :0 haha.
04-03-2014, 08:17 AM
#7
Appreciate the feedback guys.
I am keeping the stock 6.098 rods for now just so I can throw the engine back together quicker so I can have some fun with it until they break or snap lol. Boost or nitrous, whichever way I choose to go, will not come until way later in the build. I'm worried about building it NA first, getting results, and then putting on the power adders. But it basically all comes down to MONIES. If I happen to have the coin to shell out for new rods before I end up putting the motor in then I will purchase them but if not, then ill run the stock rods until they blow once I get into the boost or nitrous stage of my build.
What would the Mahle -4cc 3.905 Flat Top pistons bring my CR to? Sorry guys, I'd do the math myself but I don't know what the formula would be to figure out compression ratio. Unless someone cares to share it :0 haha.
I am keeping the stock 6.098 rods for now just so I can throw the engine back together quicker so I can have some fun with it until they break or snap lol. Boost or nitrous, whichever way I choose to go, will not come until way later in the build. I'm worried about building it NA first, getting results, and then putting on the power adders. But it basically all comes down to MONIES. If I happen to have the coin to shell out for new rods before I end up putting the motor in then I will purchase them but if not, then ill run the stock rods until they blow once I get into the boost or nitrous stage of my build.
What would the Mahle -4cc 3.905 Flat Top pistons bring my CR to? Sorry guys, I'd do the math myself but I don't know what the formula would be to figure out compression ratio. Unless someone cares to share it :0 haha.
And you dont need to do the math, just click on the link i gave you.. you havent said heads you are using so getting CR is impossible. You have a 3.905" bore, a 3.622" stroke, either .04" or .051" depending on your head gasket, a (-).006" deck height (negative stands for out of hole in this calculator), 4cc piston reliefs (reliefs are entered as positive numbers in that sheet) and then input your head info. If you dont have your head info, google will answer that in .002secs with the right part number.
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04-03-2014, 10:44 AM
#8
Thank you Ryan!
And yes I understand that the stock rods are weak. That's why ill run them until they blow if I happen to put them in just to get the motor up and running. If I happen to have the coin laying around before my preferred swap date to buy new rods then I will. If not then it will not be a problem for me to pull the engine to replace the rods once they break/snap since this build is not my daily driver.
And yes I understand that the stock rods are weak. That's why ill run them until they blow if I happen to put them in just to get the motor up and running. If I happen to have the coin laying around before my preferred swap date to buy new rods then I will. If not then it will not be a problem for me to pull the engine to replace the rods once they break/snap since this build is not my daily driver.
04-03-2014, 12:02 PM
#9
Is there a difference between static compression ratio and regular compression ratio? The online calculator Ryan gave me tells me that my Static CR will be 10.25:1 with the -4cc Mahle pistons and 64cc heads but everywhere online says I should have 10.1:1 CR with 64cc heads and the -4cc Mahle pistons??...
04-03-2014, 01:34 PM
#10
Throw a set of Manley's Pistons in there for now. 592007C-8 - These will fit a 3.905" bore and stock Rod and wrist pin Dia.
that will get you down a bit below 10: 1 with the LS9 Head Gasket. You'll be fine running 93 Fuel alone, but if you're going add Meth as well, you'll be just fine to tighten the screws a bit in the 8-13 lb range. Just remember that you're running around with stock rods and (Rod Bearings?)
that will get you down a bit below 10: 1 with the LS9 Head Gasket. You'll be fine running 93 Fuel alone, but if you're going add Meth as well, you'll be just fine to tighten the screws a bit in the 8-13 lb range. Just remember that you're running around with stock rods and (Rod Bearings?)
04-03-2014, 03:16 PM
#13
Is there a difference between static compression ratio and regular compression ratio? The online calculator Ryan gave me tells me that my Static CR will be 10.25:1 with the -4cc Mahle pistons and 64cc heads but everywhere online says I should have 10.1:1 CR with 64cc heads and the -4cc Mahle pistons??...
Higher CR and boost mix really well.. you just have to get a great tune cover you
04-03-2014, 03:25 PM
#14
I always thought you wanted a lower CR for boost and higher CR for naturally aspirated and/or nitrous? I know you can have a somewhat "higher" CR with boost as long as you have high enough octane fuel, meth injection, or e85 right? I've been doing tons of research and it always throws me off when someone posts something differently then what I've been reading but I'm here to expand knowledge anyways.
04-03-2014, 03:34 PM
#15
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If you aren't going to replace the rods with a 6.125 when you replace the pistons then find another block with stock pistons and rods. If I were in your shoes I'd just wait and save the coin to replace the rods at the same time but don't forget you need to balance the rotating assembly as well. Stock crank, 6.125 eagle or callies rods and wiseco, diamond or malhe forged pistons with good rings will safely handle 800+ horse power. File fit the rings .024/.26 top and .028/.030 second and you can handle a decent size nitrous shot and/or boost.
04-03-2014, 04:41 PM
#16
Yup I think I will just save up for the rods. I was only going with Mahle since the have pistons that fit te stock rods but what other good choices are there? I've read about wiseco as well. For rods, I'm thinking h-beam 6.125 from Callies or Eagle.
04-05-2014, 06:55 PM
#17
Another question for you Guru's. So gaining compression ratio gains your horsepower right?.. So if I pick up these Mahle -4cc pistons and they drop my CR from 10.5:1 to 10:1; will I lose horsepower? Reason why I'm asking is because ill be running naturally aspirated for awhile before I go boost or nitrous..