Pistons for a turbo build
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Pistons for a turbo build I知 going to turbo my 5.3, I知 using 706 with 61cc chambers, I知 going to use summits own forged pistons, do I use flat tops or dished? And using eagle forged I beam connecting rods. Anything I need to consider guys ?
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From: Shlumpt, TX
I say dished to keep the compression low but at the same time maybe bump it. Flat tops are gonna put it at like 10.4? That's not so bad
Don't forget new bolts! I say ARP Head Studs just to be fancy
Don't forget new bolts! I say ARP Head Studs just to be fancy
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Compression with 61cc and the 7cc dish is 9.7:1 and compression with the 2cc domes would be 10.9:1. The lower compression would be the one we recommend for pump gas. If the car was ALWAYS on E-85 (meaning no oopsies - I can't get fuel today so I will just lower the boost), the higher compression pistons would work. But the nice thing with lower compression is you can always up boost higher for any given octane of fuel. The tuning window is much bigger and this saves a lot of heartache.
We have the Gen. 3 pistons with a .945 pin gen. 3 rods and the Gen. 4 rod pistons with the .943 pins. Your Eagles are likely a .945 pin rod and that's fine because we include clips and circlip grooves in all versions.
Compression with 61cc and the 7cc dish is 9.7:1 and compression with the 2cc domes would be 10.9:1. The lower compression would be the one we recommend for pump gas. If the car was ALWAYS on E-85 (meaning no oopsies - I can't get fuel today so I will just lower the boost), the higher compression pistons would work. But the nice thing with lower compression is you can always up boost higher for any given octane of fuel. The tuning window is much bigger and this saves a lot of heartache.
We have the Gen. 3 pistons with a .945 pin gen. 3 rods and the Gen. 4 rod pistons with the .943 pins. Your Eagles are likely a .945 pin rod and that's fine because we include clips and circlip grooves in all versions.
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Actually your guess is pretty good for flat tops but our "mid-compression" 4.8-5.7L pistons all have small domes. These are intended for pump gas guys with some spray, but also work equally well with E-85 and boost. The reason for this is 4.8, L33 5.3 and LS1s came with true flat tops (no valve reliefs) to begin with. To accomodate bigger cams, the added valve reliefs knock compression down too much and power/toruqe along with it. Especially when camshafts are added on these smaller displacement engines. We tune compression ratio around the common chamber volumes to be about 1/2 point higher than stock. The torque/power gains are "free" and pretty much a no-brainer.
Summit's Pro LS line was the first to apply these very finely tuned volumes to eak out power at no added expense to the customer. Other's just throw a flat-top at it and called it a day. That being said, our 6.0 pistons have enough swept volume that a flat top makes sense with the common chamber sizes.
Summit's Pro LS line was the first to apply these very finely tuned volumes to eak out power at no added expense to the customer. Other's just throw a flat-top at it and called it a day. That being said, our 6.0 pistons have enough swept volume that a flat top makes sense with the common chamber sizes.
