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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter #1 (Edited)
well, after hearing horror stories of failed eagle rods, and then about people fitting "bigger" bolts to the Eagles... i started asking around and doing a little bit of research. Im sure you all are going to rip me a new butt hole because your friend's grandmother's cousin's aunt uses Eagle rods in their High horsepower (insert Domestic or 4 cylinder import here). the Truth is that the rods themselves are not weak... sure they are made in china, but thats not the problem. The problem lies within the Cap screws. the Cap screws, if you look at a set of current production Eagle Rods, are fitted with "ARP 2000" series rod bolts. these are what come with the Eagle rods if you just order a set Off-the-shelf, no questions asked. As it turns out, these rods have been rumored to fail in high horsepower 2jz's. Eagle rods have gotten the Stigmata that they are WEAKER than the stock 2jz rods. typically, the weakpoint in the stock 2JZ's are their rods. they fail at a lower stress level than the pistons do. so theoretically, you can do 1000rwhp on stock pistons and upgraded rods. however, due to the fact that the Eagles come w/ the ARP 2000's, and the urban legend of rod bolt failure is abound; its general consensus that the Off-the-shelf Eagle rods are a DOWNGRADE for 2jz's. this worries me. if an off-the-shelf Eagle rod has failed in a 2jz before hitting 1000rwhp, how are any one of Us supposed to expect to hit that mark? well, the key is to Do your homework and find out whats available. i looked around and heres waht i found;

65vette396 said:
O.k. I did some reasearch directly from ARP's website:

MATERIALS USED IN THE MANUFACTURE OF CAP SCREW TYPE CONNECTING ROD BOLTS

8740 CHROME MOLY: Until the development of today’s modern
alloys, chrome moly was popularly considered a high strength material.
Now viewed as only moderate strength, 8740 chrome moly is seen as a good
tough steel, with adequate fatigue properties for most racing applications,
but only if the threads are rolled after heat-treatment, as is the standard
ARP® production practice. Typically, chrome moly is classified as a
quench and temper steel, that can be heat-treated to deliver tensile
strengths between 180,000 and 210,000 psi.

AERMET® 100: With a typical tensile strength of 280,000 psi, Aermet
100 is a new martensitic super-alloy that is stronger and less expensive
than the super-alloy austenitic materials that follow. Because it is capable
of achieving incredibly high clamping loads, it is ideal for short but
extreme environments like top fuel, funny car and some short track
applications. Although Aermet 100 is a maraging steel that is far superior
to other high strength steels in its resistance to stress corrosion, it must
be kept well-oiled and not exposed to moisture.

ARP2000: An exclusive, hybrid-alloy developed to deliver superior
strength and better fatigue properties. While 8740 and ARP2000 share
similar characteristics—ARP®2000 is capable of achieving clamp loads
in the 215,000-220,000 psi range. ARP®2000 is used widely in short
track and drag racing as an up-grade from 8740 chrome moly in both
steel and aluminum rods. Stress corrosion and hydrogen embrittlement
are typically not a problem, providing care is taken during installation.

L19: This is a premium steel that is processed to deliver superior
strength and fatigue properties. L19 is a very high strength material
compared to 8740 and ARP®2000 and is capable of delivering clamp
loads in the 230,000-260,000 psi range. It is primarily used in short track
and drag racing applications where inertia loads exceed the clamping
capability of ARP®2000. Like most high strength, quench and temper
steels—L19 requires special care during manufacturing to avoid hydrogen
embrittlement. This material is easily contaminated and subject to stress
corrosion. It must be kept well-oiled and not exposed to moisture.
MATERIALS USED IN THE MANUFACTURE OF CAP SCREW TYPE CONNECTING ROD BOLTS

INCONEL 718: A nickel based material that is in the high temperature,
super-alloy class, it is found to be equally suitable in lower temperature
applications. This material delivers tensile strengths into the 220,000 psi
range and exhibits improved fatigue properties. Best of all, Inconel 718
is completely immune to hydrogen embrittlement and corrosion.

ARP3.5 (AMS5844): While similar to Inconel 718, these super-alloys
are found in many jet engine and aerospace applications where heat and
stress attack the life of critical components. The high cobalt content of
this alloy, while expensive, delivers a material with superior fatigue
characteristics and typically tensile strength in the 270,000 psi range.
The immunity to hydrogen embrittlement and corrosion of these materials
is a significant design consideration. These materials are primarily used in
connecting rods where extremely high loads, high RPM and endurance
are important factors—Formula 1, Winston Cup and CART applications.

CUSTOM AGE 625 PLUS®: This newly formulated super-alloy
demonstrates superior fatigue cycle life, tensile strength and toughness—
with complete resistance to atmospheric corrosion and oxidation. ARP®
is the first to develop manufacturing and testing processes for fasteners
with Custom Age 625+. Best of all it is less expensive and expected to
soon replace MP-35 as the material of choice in the high strength, super-alloy
field. Typical tensile strength is 260,000 psi.

BTW, ARP will custom make rod bolts for you in any material they have available, however you will pay for it. Drew
Turns out, if you want High horsepower-capable rods, you need to specify that you do NOT want the ARP 2000 series bolts. the SAY that the bolts can handle 1000hp in our applications and that Domestic guys are making those power figures... but just tell them you want at least the L19 series bolts. i personally think that for any one of us shooting for the 1000rwhp mark (i know a couple of us are), then you should order up the ARP3.5 (AMS5844) or Custom Age 625+ series rod bolts for your Eagle Rods. with these optional rod bolts, the price may jump up, but the added insurance is worth it for anyone trying to Rev past 6500 and make over 700rwhp.

hope this sheds some light on the subject.
 

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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter #4
thanks brad

Yup, its the bolts... the rods and caps are fine.
 

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For Sale
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453 Posts
so where do i get some LM19 or ARP3.5 bolts that will fit these rods? i dont see them listed on a few of the sites ive visited. they list ARP rod bolts, but im assuming they are the same ARP2000 bolts. Are these ARP2000 series bolts bad with stock rods?
 

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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter #6
i think your best bet is to call the vendor/retailer and ASK them about custom ordering the EAgle rods w/ the bolts you want. i dont think its something that you can just look up and order. ive never seen an available optoin to the public.

the ARP bolts/cap screws in the Eagle rods are a different design than the stock 7M rods. the stock 7M rods have a "stud" that presses into the rod beam, the cap goes on and is held on w/ a Nut. the Eagle rods are threaded on the beam side and the ARP is a real bolt that screws thru the cap into the rod... so they arent really interchangable from the Stock rods to the ARP's.

you might call and ask if they have L19-grade rod bolts for the STOCK 7mgte rods, if thats what youre interested in.
 

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Universal Torturer
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219 Posts
great info

Great info but i have to ask-why not just get crower rods that come with the bolts you need?
 

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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter #9
well, Crowers are a butt load of money... ringing in at a hefty ~$1089. im sure i could get them for under $1000... plus, i really want Pauters w/ CP pistons hung on them. i was quoted a combined price of something like $1600 shipped. Considering that Pauters weigh in at a hefty $1199 would make just about EVERYONE reconsider Eagle rods... which are going for Mid-$500's these days. which means i might be able to put together a CP/Eagle setup with the Custom Age 625+ bolts for around the $1000 mark. if i can order the Eagles w/ the better bolts and end up supporting the same power as the Crowers or Pauters and spend less money... theres no reason to buy the Crowers at that point.
 

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Banned
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I am sorry but flux on the last comment I don't agree. The Crowers are much better in my opinion. But yes they are pricey.
But nice write up. I think those rods with upgraded hardware should suffice.
 

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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter #11
Mike, im not disputing that Crowers are lesser in quality than the Eagles. i see eye-to-eye with you on that area. Crowers have a nicer beam design and reduce the windage as compared to Eagle rods. i like the Pauters even more because of their beam design and itll reduce the windage even more.

i think that the Eagle rods will actually have a fighting chance w/ the optional rod bolts in regards to peak HP figures. Crowers and Pauters are almost guaranteed to withstand 4-digit HP figures... Eagles are questionable, but they will have better luck if they are upgraded ;)

Regards
chris
 

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This Is Why I'm Hot.....
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1,984 Posts
flubyux2 said:
.....the ARP bolts/cap screws in the Eagle rods are a different design than the stock 7M rods. the stock 7M rods have a "stud" that presses into the rod beam, the cap goes on and is held on w/ a Nut. the Eagle rods are threaded on the beam side and the ARP is a real bolt that screws thru the cap into the rod... so they arent really interchangable from the Stock rods to the ARP's.....
I'm no expert on fasteners, but I have read that studs are normally considered superior to bolts. Do the 2JZ-GTE rods have the stud set-up too? Have you considered using studs on the Eagles? Just curious, since I will start building up my spare engine before EOY.

Take care.
 

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Madd Tyte JDM yo ®
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7,014 Posts
Discussion Starter #14 (Edited)
Larry... studs are better in the sense of Head or main studs. you have far more thread engagement in the block. and when torquing a nut onto the thread, youre only overcoming the friction on say 10 threads at once rather than all the threads n the block when torquing a bolt. also, with the thread engagement, i seem to think that the stud may as well be integral in terms of block structure. and then the weak point would end up being the nut itself. but as the nuts are rolled thread and all that good stuff, i think it could "hold" onto the stud better than if it was a bolt head that was forged from the same piece. its really hard to say because i can speak to intelligently on studs vs. bolts in regards to the rods. wish i could help more.

i think it would be pretty interesting to see head/main style studs for rods like the Eagles. thread a stud into the big end, install the cap and then a nut on top. its quite possible that the Nut engagment on a Rod stud could make use of more surface area (total length of the threads) than if it was a bolt head and usable grain structure as the shank transitions from the stock style rod bolt to the flanged head.

here is what an ARP factory Tech Rep has to say about Studs vs. bolts.
For most applications, however, studs are recommended. And for good reason. Using studs will make it much easier to assemble an engine (especially a racing powerplant which must be serviced frequently and quickly!) with the cylinder head and gasket assured of proper alignment.

Studs also provide more accurate and consistent torque loading. Here’s why. When you use bolts to secure the head, the fastener is actually being “twisted” while it’s being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a “relaxed” mode—never crank it in tightly using a jammed nut. If everything is right, the stud should be installed finger tight. Then, when applying torque to the nut, the stud will stretch only on the vertical axis. Remember, an undercut shorter stud will have a rate similar to a longer, standard shank stud. This provides a more even clamping force on the head. Because the head gasket will compress upon initial torquing, make sure studs and bolts are re-torqued after the engine has been run.
Rod bolts/cap screws are a bit hard to compare and contrast. even if you have a press-in rod stud, it essentially has the same clamping characteristics of a cap screw. the flanged head of a press-in rod stud is equivalent to the head of a bolt on a cap screw. so if we quantify the press-in stud in relation to the cap screw, they are one-for-one at this point; both have flanged "heads" so to speak. now on the other end... where you tighten stuff down, its different. The cap screws have more thread engagment than the press-in studs. this means that on its vertical axis, running the length of the fastener, there is more material engagment on a cap screw than what a Nut on a press-in stud can provide. in this area, i think the Cap screw is 2-for-2 whereas the press-in stud (Stock 7MG style) is only 1-for-2.

Also, ive noticed that there are alot of people who arent very clear on the difference between standard shank and Undercut studs. I have seen undercut studs/bolts and standard shank studs/bolts. the Undercut means that the non-threaded shank of the fastener is a smaller diameter than the threaded area. the Nominal diameter of the threads (peaks of the threads) is larger than the diameter of the shank. so, the diameter of a 12mm x 1.25 bolt is 12mm. however, this 12mm bolt/stud is smaller diameter at the Root of the thread, maybe 11mm or less than 11mm diameter, measured root-to-root. so, an Undercut bolt/stud tapers down as you move up from the threads, possibly down to the same diameter as the Root-to-root diameter.

what other rods are readily available for the 7MG aside mainstream Pauter, Crower and Eagle? does Carillo make 7MG rods?
 

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Madd Tyte JDM yo ®
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Discussion Starter #16
Oooooh yeah... thats right!!! i forgot about those. what kind of prices are we talking about for Cunningham rods?
 

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512RWHP... 503RWTQ... 7M
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flubyux2 said:
i personally think that for any one of us shooting for the 1000rwhp mark (i know a couple of us are).
So does that mean yur going for 1000hp? :drool:

Thanks to this post, I'll be going with different rods... :) *pauters*
 

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Beats and Rhythm
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2,732 Posts
Wow, I did not know the rods CAME with the low grade ARP bolts ( basically FACTORY strength). I would of swapped them out reguardless.

Either way Eagle rods are GREAT quality. Held a Crower H beam 7m rod in my hands and an Eagle 7m rod in the other (my local shop is building two MONSTER 7m's right now) and I will say they are very identicle in construction quality outside of the magnifying glass. I would put my money in the Eagles any day!

-Jonathan
 
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