Piston advice and LS Fuddlore
05-28-2024, 08:45 PM
#1
Teching In
Thread Starter
Piston advice and LS Fuddlore I need to order pistons for V2 of my engine for a .05 overbore to tighten up clearances post spun rod bearing. I'm currently sold on 1.2 or 1.5mm ring packs, retain around 10.5 static, and 4032 pistons because this will be a daily driver that will probably see 40k/year. I'd like it to be not only bullet proof but durable/offer the same longevity as an OE longblock. My current pulley with my D1SC starts making boost around 2500-3k and builds to about 12-14psi with my current camshaft and RPM cutoff. Most of my miles are interstate miles and I drive like a grandpa unless I'm feeling like embarrassing somebody because AWD truck and boost.
My understanding (Fuddlore?) from lurking here and the darker corners of the web have led me to believe that a thicker ring will last and hold up to heat longer/transfer heat faster, 4032 pistons won't wear out/wear out the bore as fast as 2618, and strokers with a wrist pin into the oil ring pack will need tore down every 60k +/- of street miles while potentially having blowby issues.
That being said, I'm going with a 3.622 stroke 4340 crank and 6.125 H beam rods, and am trying to find a 4032 piston that will meet my CR and ring pack desires.
Where can I be tightened up on my selection?
My understanding (Fuddlore?) from lurking here and the darker corners of the web have led me to believe that a thicker ring will last and hold up to heat longer/transfer heat faster, 4032 pistons won't wear out/wear out the bore as fast as 2618, and strokers with a wrist pin into the oil ring pack will need tore down every 60k +/- of street miles while potentially having blowby issues.
That being said, I'm going with a 3.622 stroke 4340 crank and 6.125 H beam rods, and am trying to find a 4032 piston that will meet my CR and ring pack desires.
Where can I be tightened up on my selection?
05-28-2024, 09:13 PM
#2
ModSquad
iTrader: (6)
I need to order pistons for V2 of my engine for a .05 overbore to tighten up clearances post spun rod bearing. I'm currently sold on 1.2 or 1.5mm ring packs, retain around 10.5 static, and 4032 pistons because this will be a daily driver that will probably see 40k/year. I'd like it to be not only bullet proof but durable/offer the same longevity as an OE longblock. My current pulley with my D1SC starts making boost around 2500-3k and builds to about 12-14psi with my current camshaft and RPM cutoff. Most of my miles are interstate miles and I drive like a grandpa unless I'm feeling like embarrassing somebody because AWD truck and boost.
My understanding (Fuddlore?) from lurking here and the darker corners of the web have led me to believe that a thicker ring will last and hold up to heat longer/transfer heat faster, 4032 pistons won't wear out/wear out the bore as fast as 2618, and strokers with a wrist pin into the oil ring pack will need tore down every 60k +/- of street miles while potentially having blowby issues.
That being said, I'm going with a 3.622 stroke 4340 crank and 6.125 H beam rods, and am trying to find a 4032 piston that will meet my CR and ring pack desires.
Where can I be tightened up on my selection?
My understanding (Fuddlore?) from lurking here and the darker corners of the web have led me to believe that a thicker ring will last and hold up to heat longer/transfer heat faster, 4032 pistons won't wear out/wear out the bore as fast as 2618, and strokers with a wrist pin into the oil ring pack will need tore down every 60k +/- of street miles while potentially having blowby issues.
That being said, I'm going with a 3.622 stroke 4340 crank and 6.125 H beam rods, and am trying to find a 4032 piston that will meet my CR and ring pack desires.
Where can I be tightened up on my selection?
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G Atsma (05-28-2024)
05-30-2024, 09:23 AM
#3
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Thread Starter
What’s your bore size here? If you want ultimate reliability you should stay with Hypereutectic pistons. Using the LSA piston as an example, it’s a hypereutectic piece that’s got GM’s anti-friction coating on the skirts. Rings are 1.5/1.2/2mm. Those engines take a beating yet hold up very well.
I currently have Mahle coated in there, but I bought the pistons after the hone was done and they are on the loose side of clearance for a DD, or FI application for what Mahle specs. This time I'm sending it all to the machine shop so he knows what to bore/hone for final.
I've found a few 4032's between Summit and CNC so far that retain 10-10.7 static, thicker ring pack, and 4032, but one that I really like has a compression height of 1.315 where I *think" I should be at 1.304 for zero deck. Is .011 out of the bore asking for trouble, and am I overthinking this too much?
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G Atsma (05-30-2024)
05-30-2024, 02:25 PM
#5
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05-30-2024, 02:41 PM
#6
.011 out of the bore is just fine, and actually what I'd prefer as you can now use a factory LS7 head gasket and save some money vs ordering custom or decking the block. The piston is supported much further down in the cylinder. I would not use an .045 gasket if they're .011 out of the hole that is too tight imo. I would lean toward a factory .051" gasket and quench at .040".
Before you order head gaskets I would assemble and measure the four corners of the block I've never had an LS where the pistons are all out of the hole equal, and it usually does not line up perfectly with the assumed deck height, compression height etc.
Before you order head gaskets I would assemble and measure the four corners of the block I've never had an LS where the pistons are all out of the hole equal, and it usually does not line up perfectly with the assumed deck height, compression height etc.
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DualQuadDave (05-30-2024)
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05-31-2024, 12:55 PM
#8
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.011 out of the bore is just fine, and actually what I'd prefer as you can now use a factory LS7 head gasket and save some money vs ordering custom or decking the block. The piston is supported much further down in the cylinder. I would not use an .045 gasket if they're .011 out of the hole that is too tight imo. I would lean toward a factory .051" gasket and quench at .040".
Before you order head gaskets I would assemble and measure the four corners of the block I've never had an LS where the pistons are all out of the hole equal, and it usually does not line up perfectly with the assumed deck height, compression height etc.
Before you order head gaskets I would assemble and measure the four corners of the block I've never had an LS where the pistons are all out of the hole equal, and it usually does not line up perfectly with the assumed deck height, compression height etc.
Gasket is .048 compressed- Felpro 26192PT. I'm not married to it though. I ordered head gaskets a while back when we thought a 'soft' cam from Comp or a bad lifter was creating all the metal in the oil filter, not a silent spun rod bearing which is why I'm abandoning the new Mahle pistons and 120k mile rods/crank.
05-31-2024, 01:15 PM
#9
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Thread Starter
Honestly never heard of Autotec until a few days ago or DSS until a week before ordering the Mahle pistons the first time, but this is more of a hobby and deep crash course dive into finer aspects for me. Prior to this motor 18 months ago, my last build was a 4bbl SBC in 2007.....lot of new to me names with great quality, and familiar names whose product is now trash by comparison or otherwise.