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Discussion Starter · #1 ·
ok ive read so many different hp #'s made on the stock rods.ive read over 900hp in magazine tha ive seen some hp #s in the 800's.i just want to know what hp range exactly can the rods be used to reliably without worrying about it bending?
 

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thats a pretty vague question. no one can say what hp range the stock rod can handle and still be reliable. Thats like asking how many exact miles will my engine last. But if I did have to guess i would say 650-750 with a fair amount of reliability, but then again theres alot of factors that go into consideration. also if you interested I have some BNIB eagles for $325 shipped
 

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it all depends on how hard you hit it,

if you do drag racing then Im pretty sure you´ll bent your rods at 800-850rwhp,
Im doning highway races since 2 years with that engine, always hit it after 5000rpm and everything last just fine,
I put 895rwhp DIN on dynojet
 

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Discussion Starter · #7 ·
i kno it depends on my factors but the thing i was trying to get at was under the worse conditions say full drag what would be its max but i pretty much got an idea now.im just going to rebuil this whole engine correctly so i dont have to worry bout much.
 

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+1 for the use and abuse the engine will see being very important for overall longevity...

i'm no authority, but my builder (one of the very well respected engine builders here on SF's), told me he trusts the stock bottom end to around the 800-850whp range for a street/strip car. my setup will be gt4202r, stock bottom end with headwork and cams, supporting fuel and other mods looking to make 750-800 on E-85.

the obvious caveats regarding how hard you beat on it, how well you maintain it over time, and 'no guarantees' apply.
craig
 

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916whp, but I believe it was the 100shot of nitrous at 5800rpm that bent it. My clutch wouldn't hold the nitrous below that, or it probably would have been fine. These were also with ARP bolts. I would be more concerned about the bolts than I would the rods. You will spin a bearing probably before you bend a rod as for as longevity goes.

 

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SuperRunner,

thanks for sharing your experience and some objective evidence... are you saying you think it would have been better for the rods if you had the 100 shot come on earlier, and if so, why?

TIA!
craig
 

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At peak torque the rods are already under a lot of stress, and basically it is like I just hit them with a hammer.

It is much better if the pressure is put on a bit earlier. This could be wrong thinking, as I know it is harder on the drivetrain components, but the engine itself...I can only assume at this point.
 

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ok... makes sense that you wouldn't want the shot to come on right at peak torque.

regarding WHEN though... i remember a thread not too long ago, discussing how torque affected the rods, and whether or not they are more likely to bend if the torque increased rapidly at lower rpms vs higher... is it a 'balancing act' then - you want the shot to hit before peak torque but not TOO early?

thanks again,
craig
 

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ok... makes sense that you wouldn't want the shot to come on right at peak torque.

regarding WHEN though... i remember a thread not too long ago, discussing how torque affected the rods, and whether or not they are more likely to bend if the torque increased rapidly at lower rpms vs higher... is it a 'balancing act' then - you want the shot to hit before peak torque but not TOO early?

thanks again,
craig
I first started it at about 3500, but at 30psi the clutch would let go at 5600rpm. I think 3500 was probably a little too early because I did have a nitrous backfire. I think that is why you don't want it too early, among other reasons I am sure.
 

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I first started it at about 3500, but at 30psi the clutch would let go at 5600rpm. I think 3500 was probably a little too early because I did have a nitrous backfire. I think that is why you don't want it too early, among other reasons I am sure.
alright... cool, thanks for the explanation.
craig
 
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