Rods
12-03-2015 | 09:06 PM
#62
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Joined: Oct 2013
Posts: 1,953
Likes: 2
From: rock Island wa
Buck, Your average cost to rebuild a set of used rods, is around 150 bucks these days, give or take. . New ARP2000 bolts, are around 150 bucks as well. That's 300 dollars you're spending, to recondition, and upgrade your old rods, Eagles in Dan's case.
A brand new set of Eagles, are 500 bucks, WITH ARP 2000 bolts. Now, this new rod will also have to be checked out for roundness, , pin fitted, etc.
Dan could sell his old rods, on ebay, or whereever, and probably get 150-200 bucks easy. So, its a no brainer to me, to simply buy brand new rods, that havent been fatigued, etc. He does not know the history of them, how old they truly are, etc. If he was going to reuse them in a 500hp deal, maybe it be worth saving a couple bucks keeping them, but in a 900hp blower engine, ehhh,...its one thing to even use that rod in this application according to some, let alone saving a case of bud light worth of money, to rebuild the old stuff. I mean, I think he's fine either way, but sometimes, when its only a few bucks, going new is nice sometimes.
Just to give you an idea what is involved in reconditioning rods, look here
http://www.enginebuildermag.com/2007...nnecting-rods/
A brand new set of Eagles, are 500 bucks, WITH ARP 2000 bolts. Now, this new rod will also have to be checked out for roundness, , pin fitted, etc.
Dan could sell his old rods, on ebay, or whereever, and probably get 150-200 bucks easy. So, its a no brainer to me, to simply buy brand new rods, that havent been fatigued, etc. He does not know the history of them, how old they truly are, etc. If he was going to reuse them in a 500hp deal, maybe it be worth saving a couple bucks keeping them, but in a 900hp blower engine, ehhh,...its one thing to even use that rod in this application according to some, let alone saving a case of bud light worth of money, to rebuild the old stuff. I mean, I think he's fine either way, but sometimes, when its only a few bucks, going new is nice sometimes.
Just to give you an idea what is involved in reconditioning rods, look here
http://www.enginebuildermag.com/2007...nnecting-rods/
12-03-2015 | 09:44 PM
#63
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Joined: Feb 2011
Posts: 769
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From: Brookfield Wi
Personally I never rebuild rods. As a old crank grinder i'm extremely picky when it come to re-sizing. i've yet to see a perfectly square machine / hone job. As for changing rod bolts, as we know caps will shift requiring re-sizing and balancing. Pressed pin style get to go through the heater again. I've used H-beam Eagle with good success. Never been an import fan though. I like to spend time on the complete rotating assemble. if it spins, it goes on the balancer after the crank and harmonic balancer are done first.
Wait, it's winter. We are talking rod bolts without drama so far? Is this OSO or too early yet? AB
Wait, it's winter. We are talking rod bolts without drama so far? Is this OSO or too early yet? AB
12-03-2015 | 10:23 PM
#64
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Joined: Oct 2007
Posts: 8,439
Likes: 93
From: yorkville,il
Personally I never rebuild rods. As a old crank grinder i'm extremely picky when it come to re-sizing. i've yet to see a perfectly square machine / hone job. As for changing rod bolts, as we know caps will shift requiring re-sizing and balancing. Pressed pin style get to go through the heater again. I've used H-beam Eagle with good success. Never been an import fan though. I like to spend time on the complete rotating assemble. if it spins, it goes on the balancer after the crank and harmonic balancer are done first.
Wait, it's winter. We are talking rod bolts without drama so far? Is this OSO or too early yet? AB
Wait, it's winter. We are talking rod bolts without drama so far? Is this OSO or too early yet? AB
12-04-2015 | 07:22 AM
#66
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Joined: Oct 2015
Posts: 277
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Well, we know how many stock 502 shortblocks with GM 7/16" 6.135 rod has been hammerd and all has been well. 800+hp even. Everyone remember, 4.00 stroke. When these are ever torn down, many people will rebuild with a stronger rod bolt, just because.
Now, with the 4.25" stroke motors how many stock rods where kept ? Probably not many, therefore we really won't know. Most step up to a 6.385 rod (or longer in some cases) and thus aftmkt rods and bolts.
Longer strokes = more piston speed.
Now, with the 4.25" stroke motors how many stock rods where kept ? Probably not many, therefore we really won't know. Most step up to a 6.385 rod (or longer in some cases) and thus aftmkt rods and bolts.
Longer strokes = more piston speed.
4" with 6.135 rod = 1.53 ratio
4.25" with 6.135 rod = 1.44
4.25 with 6.385 = 1.50
We build a lot of 532" (4.6 bore x 4.0 stroke) combinations with a 6.535 rod and that seems to be a really nice combination. Puts the rod ratio @ 1.63 and these engines always seem to make great power with exceptional tq curves.
12-04-2015 | 07:29 AM
#67
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Joined: Oct 2015
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Paging thru some catalogs on these price related rods. Fwiw, heres what Im seeing. For 6.385 H Beam, with ARP2000 bolts except compstar, those have L19s.
Molnar 729 grams
Eagle 785 grams
K1 technologies 740 grams
Manley 810 grams
Engine pro 809 grams
Lunati 790 grams
Callies Compstar 816 grams
A visual difference I noticed, out of all of them, is the Callies Compstar rod, has a reinforced area on the cap. Design wise, they all about look the same. The Molnars and K1's, look to maybe have a slightly narrower beam. Thats just looking at various photos though.
Molnar 729 grams
Eagle 785 grams
K1 technologies 740 grams
Manley 810 grams
Engine pro 809 grams
Lunati 790 grams
Callies Compstar 816 grams
A visual difference I noticed, out of all of them, is the Callies Compstar rod, has a reinforced area on the cap. Design wise, they all about look the same. The Molnars and K1's, look to maybe have a slightly narrower beam. Thats just looking at various photos though.
12-04-2015 | 07:33 AM
#68
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Joined: Oct 2015
Posts: 277
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This is a pretty easy to read and easy to follow write up on rods, designs and applications:
http://www.enginebuildermag.com/2008...-many-choices/
Last edited by horsepower1; 12-04-2015 at 07:41 AM.
12-04-2015 | 07:39 AM
#69
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Joined: Oct 2007
Posts: 8,439
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From: yorkville,il
scott,the longer the stroke the faster the piston travels per revalution period.the piston has more distance to travel so it has to go faster,this is why it is harder on the rod on the exhaust stroke.it is my understanding that rod angel is not as important as it was once thought to be.
12-04-2015 | 07:49 AM
#70
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Joined: Oct 2015
Posts: 277
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scott,the longer the stroke the faster the piston travels per revalution period.the piston has more distance to travel so it has to go faster,this is why it is harder on the rod on the exhaust stroke.it is my understanding that rod angel is not as important as it was once thought to be.
