LT1-LT4 Modifications 1993-97 Gen II Small Block V8
View Poll Results: What length rods should I use?
5.7"
4
20.00%
6"
15
75.00%
Other
1
5.00%
Voters: 20. You may not vote on this poll

5.7" or 6" rods??

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Old 01-30-2010, 11:11 PM
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Default 5.7" or 6" rods??

Which should I go with? Here is what the complete build will be when complete.

LT1 SB 350 bored .060 (362)
Mahle PowerPak Pistons
Stock Crankshaft turned to .010 rod/.040 main journals
AFR Heads modded by TPiS, Manley 2.02/1.65, 187cc, 54cc chamber
.600 lift Springs
Comp Cams 1.6 Self-Aligning RR's
Trick Flow 7.200" Chromemoly Pushrods
LS7 Lifters
TPiS ZZ409 Hyd Roller Cam, Adv. Dur. 287/287, Dur. @.050 226/226, Gross Lift .520/.520, Lobe Sep. 112

Stock Repl. Opti w/ MSD Cap and Rotor Kit
MSD 8.5mm Wires routed OTVC
MSD Heavy Duty Coil
MSD 6AL Ignition Control
30# SVO Fuel Injectors
Walbro 255 Fuel Pump
Ported Stock Intake Manifold
58mm Throttle Body
Moroso Cold Air Intake
LPP Long Tube Headers and Y-Pipe
3" Exhaust w/SLP Loudmouth I Resonator, No Cats
Resurfaced Stock Flywheel
Stage 3 Clutch
LS1 Aluminum Driveshaft
4.10 Gears
MAC Rear End Girdle
Custom Dyno Tune

Other Upgrades:
BMR STB
BMR SFC's
Eidbach LCA's
BMR LCA Relocation Brackets
BMR Panhard Rod
BMR Driveshaft Loop

Long list but I just wanted to cover everything. The only other things I plan on doing to the car is upgrade to some 205cc heads and maybe play with the cam. Thats it.
Old 01-30-2010, 11:12 PM
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Oh, didnt know you had a BMR panhard bar, go ahead with the 6" rod then.

-Dustin-
Old 01-30-2010, 11:13 PM
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I have been getting alot of mixed signals, just wanna get some more opinions.
Old 01-30-2010, 11:14 PM
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haha, thanks smartass lol. I was just putting it all out there lol. I know those mods wont matter
Old 01-30-2010, 11:17 PM
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There are around 30-40 threads just on two LT! forums discussing this. The responses in those threads come from folks with alot more experience than 98% of the people here. I suggest you start searching.

I'm kinda making a point here with the last few posts. LS1tech [LT1 secton] looks busy, but whenever I come hear it's "Best CAI" or "Will a LS1 catback fit my LT1". Just try searching guys, lots of people have already walked this path and asked those questions.

CamaroZ28.com has a ton of good info. Used to be THE LT1 spot.

-Dustin-
Old 01-30-2010, 11:18 PM
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Are you planning on any kind of Forced Induction like a blower or spray ?
Old 01-30-2010, 11:23 PM
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No FI and no spray.

And yes your right, but EVERY engine combo is different. Some people will get a different answer than me and I am not going to take a chance of messing up my car because I overlooked something somewhere.
Old 01-30-2010, 11:26 PM
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Voted.
Old 01-30-2010, 11:27 PM
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Pretty simple. More rod = less piston, less rod = more piston. You want more piston for power adders, less piston for N/A [at least mild compression levels]. Pretty much a generalization, but it works.

And the rod length isnt going to hurt you motor.

-Dustin-
Old 01-30-2010, 11:28 PM
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By the way Calvin, I read that writeup you sent me. Explained alot and I appreciate it.
Old 01-30-2010, 11:29 PM
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Cool.
Old 01-30-2010, 11:40 PM
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Bersaglieri has it
Old 01-31-2010, 12:54 AM
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Keep in mind detonation is the biggest killer of pistons not cylinder pressure. I highly doubt the OP will be running anything high enough to see a difference either way. Flip a coin here. 6.0 rods have survived well in quite a few LT1s running a **** ton of boost. Pic a good piston, very strong rod and have it tuned properly. An improper tune is the culprit in many LT1's that come apart with boost. Its nice to have more material but if the knock is substantial it wont matter one bit.
Old 01-31-2010, 01:09 AM
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Well I am not going to boost or nitro it...Just an N/A street car with 400rwhp hopefully. I think I may just stick with the 5.7"rods and call it good like gregrob said. He gave me good advice I just wanted a few more opinions. Someone posted a recipe for 400rwhp that mentioned I need 6" rods which is why I was so hesitant on 5.7's...but after the research and talking to people now, it looks like I can use 5.7's and still hit 400rwhp.
Old 01-31-2010, 01:12 AM
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I vote 6" rod. I think you'll find that most (the majority) N/A builds use a 6" rod.
Old 01-31-2010, 06:51 AM
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For an N/A build I'd go with the longest rod you can safely use. You'll have no issues with either choice.
Old 01-31-2010, 08:40 AM
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For equal pricing for the same quality of components, I'd choose the 6" rod for a 350/355. B U T .........any advantages in your application are SO negligible, it really won't ever matter for you. Anybody that tells you that you'll have trouble reaching a certain power level with the 5.7 rods is full of crap; seek your advice elsewhere.
Now having said that........because you're running that ZZ409 cam with less than optimum valve events, especially overlap, I see a tiny advantage to the added TDC dwell you'd get with the 6" rods.

btw, I'm curious why you're thinking of changing from the AFR heads. Did TPIS do any porting on them? If not, you have a good set of castings already in your hands to make great power in the hands of a good porter.
Old 01-31-2010, 09:07 AM
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I really doubt that you will see any gains with either rod length. For N/A horse power you need to be focusing on rotating weight. The further away from the crank that you make the savings the better. Spending your money on good light weight pistons will reap big gains.

Why do you guys never talk about ring package? Lot's of N/A HP available.
Old 01-31-2010, 10:01 AM
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Originally Posted by GIZMO
I really doubt that you will see any gains with either rod length. For N/A horse power you need to be focusing on rotating weight. The further away from the crank that you make the savings the better. Spending your money on good light weight pistons will reap big gains.

Why do you guys never talk about ring package? Lot's of N/A HP available.
X2.. You will find much more power in a smaller ring package than rod length. SRP professional series pistons now have the 1.2,1.5,3.0mm ring package on their lightweight forged pistons. the ring package alone is about 14 grams lighter than a 1/16 1/16 3/16 ring package. I will have to pull both sets to see how many lbs less the small package is. Maybe i will get time at work to do that next week and post some numbers on here.
Old 01-31-2010, 10:11 AM
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Originally Posted by wht97ws6ta
X2.. You will find much more power in a smaller ring package than rod length. SRP professional series pistons now have the 1.2,1.5,3.0mm ring package on their lightweight forged pistons. the ring package alone is about 14 grams lighter than a 1/16 1/16 3/16 ring package. I will have to pull both sets to see how many lbs less the small package is. Maybe i will get time at work to do that next week and post some numbers on here.
There's a lot more to rings than weight.


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