how much power will stock rods survive?

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duster340

street racer
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just starded thinking of this after doing another post about building a stroker engine..
my stockrods has survived 4years with heavy TRW pistons in i stock stroke 340 and this motor has seen 7500rpm many times
so whats the aproximat limit for these rods?
mine are ARP bolted btw
 
I'd call 7500 rpm the limit in most every case. Well preped rods that are shot peened, debured, polished and rebalanced with the mentioned superior bolts could probably hand some more with a lighter piston.
8500 absoulute seiling is my guess. But I would have replaced them when my finish line RPM hit 7,000 rpm.
 
With stronger, lighter aftermarket rods available so cheaply nowadays, there's no reason to use factory pieces except for a cruiser. With the money invested in a motor today, to scrimp on rods is crazy. Ask anybody who has grenaded a motor and they'll tell you that a rod let go. Buy yourself a nice set of lightweight pistons, too. For the extra $200-$300 you will have a longer lasting piece. When you think about it, most people run a motor for probably 4-5 years. if you divide that extra cash by 5 years, its peanuts per year for the better parts.

don
 
My moto has heavily worker stock rods in it, 500hp at 7000rpms. I have very light pistons and pins however. H beams are cheap now and much stronger.
 
will go for H-beams for sure, its scary to think of the fact that these rods have survived over 450horsepower and over 7500rpm screaming so many times and even a few late night runs on 150hp nitrous and that they havent failed even with these stupidly heavy pistons but i wont take that risk again fore sure no mater if i build the 340 into a stockstroke high rpm machine again or stroke it out for more cubes(depends on money, but iam real close to be able order up everything for a stroker build) there will be some nice new rods in it!
thanks alot your knowledge helps alot :)
 
dusterdon said:
With stronger, lighter aftermarket rods available so cheaply nowadays, there's no reason to use factory pieces except for a cruiser. With the money invested in a motor today, to scrimp on rods is crazy. Ask anybody who has grenaded a motor and they'll tell you that a rod let go. Buy yourself a nice set of lightweight pistons, too. For the extra $200-$300 you will have a longer lasting piece. When you think about it, most people run a motor for probably 4-5 years. if you divide that extra cash by 5 years, its peanuts per year for the better parts.

don
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I would have to agree with Don when you are spending that kind of money whats another 300.00 bucks
 
duster340 said:
will go for H-beams for sure, its scary to think of the fact that these rods have survived over 450horsepower and over 7500rpm screaming so many times and even a few late night runs on 150hp nitrous and that they havent failed even with these stupidly heavy pistons but i wont take that risk again fore sure no mater if i build the 340 into a stockstroke high rpm machine again or stroke it out for more cubes(depends on money, but iam real close to be able order up everything for a stroker build) there will be some nice new rods in it!
thanks alot your knowledge helps alot :)
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Go for it I wish I had the xtra cash :headbang:
 
when i was circle track racing my 360 with slivolite pistons I had the lighter "273" rods in it to save weight, I also had the crank lightned and internaly balanced. this combo would see 6500 and back to around 2000 around 100 times a night and I was never worried about the rods. when i did blow it up it was beacuase a valve broke at around 6500. every engine failure i ever had in 10 years of circle track racing was caused by valve train falure. I blew up a 340 once beacuase a rocker broke and the lifter jumped out of its bore. THIS CAN BE A REALLY BAD THING!!! lol you cant just shut it off in traffic when something sounds wrong and it took me about 1/2 a lap to get off the track.
 
duster340 said:
will go for H-beams for sure, its scary to think of the fact that these rods have survived over 450horsepower and over 7500rpm screaming so many times and even a few late night runs on 150hp nitrous and that they havent failed even with these stupidly heavy pistons but i wont take that risk again fore sure no mater if i build the 340 into a stockstroke high rpm machine again or stroke it out for more cubes(depends on money, but iam real close to be able order up everything for a stroker build) there will be some nice new rods in it!
thanks alot your knowledge helps alot :)
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Not advertised very well - but 440Source.com sells SB rods also - and are what I bought for my 388 stroker. They are a premium grade I beam rod with ARP 3/8" capscrews. They steered me away from the H-beams -said these were a better rod. I had a little rework issue - pin dia. was too tight, but other than that they are a very good rod - very similiar to their Platinum series BB rod.
 
just found a set of eagle H beam rods for sale over here in sweden for a real nice price and they are brand new and they will be sent to me tomorow gues its a pretty good christmas gift for my self:)
388dart i would have taken a good look at those if i had not found a new set of eagles for a nice price today :)
 
duster340 said:
just found a set of eagle H beam rods for sale over here in sweden for a real nice price and they are brand new and they will be sent to me tomorow gues its a pretty good christmas gift for my self:)
388dart i would have taken a good look at those if i had not found a new set of eagles for a nice price today :)
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So YOU are the one who bought them right before me :angry4: :angry4:
I have to be quicker next time. :thumbup:
 
valiant65 said:
So YOU are the one who bought them right before me :angry4: :angry4:
I have to be quicker next time. :thumbup:
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its a real small world we live in, i was looking at that for sale ad for a few hours before i decided that the price was as good as it could bee, and just a few hours later you see it over here that i bougt the rods ;)
where in sweden do you live?
have you noticed how many swedish members there is on this bord yet? most havent listed where they are from but there is a lot ;)
 
I've got a set of Eagle sir's in my 416 stroker,just had the motor disassembled after a season of racing and the rods checked out fine,they should be fine for your engine also theres upwards of 500 h.p. in my stroker,i'm using nice light weight Diamond pistons,well worth the money spent..Of coarse there are guys that will tell you the Eagles are garbage,but there are quite a few running the I-beams with no problems me included,and for what it cost to redo a stock set,your better off with the Eagles......
 
I'm from Karlstad and we are building a a Valiant -65 for street & strip use.
The price for the rods was absolutely right :thumbup:
 
valiant65 said:
I'm from Karlstad and we are building a a Valiant -65 for street & strip use.
The price for the rods was absolutely right :thumbup:
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ok, im from stockholm those early abodies are nice looking and lightweight making them good for racing ;)
yeah figured that they where cheaper than buying them from any speedshop nomather if i had imported them from summit or bought them from a swedish speedshop, think there will come up more ads for nice rods on nitroz during the winter just have to be quick there is alot of stuf being sold there :thumbup:
 
340s it's not the Eagles..Its only the SIR Eagles. I wasnt aware that Brandon had small block ones too...I'll have to look into that...
 
I'll leave it as a difference of opinion. I'm glad they work for those that run them.
 
This is where a Dyno pull would help. You may not even halve to turn your motors that hard to make the same power. I just Dynoed a 377 ci and my max hp was 469 @5800, and max torque was 493 @ 4350. In my case anything over 6200 would just be RPM's and not Horse Power or Torque.
 
moper said:
I'll leave it as a difference of opinion. I'm glad they work for those that run them.
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I'm curious are you saying they're no good from personal experience or going by what you hear??......
 
2fine69s said:
This is where a Dyno pull would help. You may not even halve to turn your motors that hard to make the same power. I just Dynoed a 377 ci and my max hp was 469 @5800, and max torque was 493 @ 4350. In my case anything over 6200 would just be RPM's and not Horse Power or Torque.
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that was with a nice solidrollercam with about 270degres of duration at .050"lift with just 345cui and that thing realy loved those rpm but i think it was just about the limit for those rods.. well atleast i have a stronger set ordered now and i will feel alot safer using them, when im going stroker since i will probably end up with about 550horses at 6000rpm, this thing will probably see a dyno before i hit the streets with it;)
 
I personally think it would be well worth your time and money to dyno it. Why guess about the power and waste motor, these toys are high dollar. Rear wheel dyno's are also a great idea, shift points are critical even in street cars. Most think that if you don't have 700 hp that it's not strong, well let me tell you a 550hp motor will be scarry! in a street car.
 
2fine69s said:
I personally think it would be well worth your time and money to dyno it. Why guess about the power and waste motor, these toys are high dollar. Rear wheel dyno's are also a great idea, shift points are critical even in street cars. Most think that if you don't have 700 hp that it's not strong, well let me tell you a 550hp motor will be scarry! in a street car.
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i know just how bad a 450+horse 340 is on the street but you know how easy it is to get used to the power and i just need more ;) horsepower is a drug and i am addictet to it;)
will dyno this thing when its all done and make sure it runs right there is a guy with camaro where i work that would be nice to show my taillights at the strip ;)
 
340srule said:
I'm curious are you saying they're no good from personal experience or going by what you hear??......
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Both.
I read about them after the shop had used 2 sets. What we did notice was there was a .003-.005" variance in center to center length between 10 of the 16, and 9 had issues with being out of round on the big ends after being cycled. The pin end always needs honing, so I dont consider that a problem. They were installed, and as of this point (2 years later IIRC) they have served well. After reading of other failures and agreeing with the failure analysis of people much better than I, I decided not to bother with them. I use basic specs as a good indicator of quality control in all areas of manufacture. In this case for me, they arent "good enough".
The cost if I were to buy the SIRs today is $240 to us. Add $100 for the labor to fix them. We can get a set of Eagle H beams for $430. The H beams I've done (3 sets) have all been within .002" (in terms of center to center length) of each other, and after cycling have no issues with the big ends. They are also stronger than an SIR. Interestingly, the new Mancini site says "use under 500hp and 7K rpm" for the SIRs. My mild 408/416 combos are making over 450. So even if the SIRs are good after cycling, I'll pay the $190 more for the stronger piece. It's cheap insurance for me when spending someone else's money.
You are not alone in having these rods work for you. It's no reason to get defensive. I just choose to use what I consider a better rod. In milder std stroke engines, I use factory rods with good bolts all the time. The 340 rod is a stout part to begin with, and I've had heavy piston 340s I personally bounced off the rev limiter at 7200 once or twice...(not on purpose, but they did it...lol)
 
2fine69s said:
This is where a Dyno pull would help. You may not even halve to turn your motors that hard to make the same power. I just Dynoed a 377 ci and my max hp was 469 @5800, and max torque was 493 @ 4350. In my case anything over 6200 would just be RPM's and not Horse Power or Torque.
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can you tell us MORE about your combo??
 
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