Eagle rods

[JohnStanden]

I have read a few bad comments regarding current Eagle con rods, apparently they are forged and machined in China and their accuracy is not very good , whereas Scat rods are forged in China and finished in the States.
However as in all these discussions some people swear by Eagle and swear at Scat ,is this just a question of personal choice or maybe even fashion?
Do any of you engine guys out there know about these issues?
If neither of them are any good, which rods to buy on a budget?

[scott]

If you have some time and are not searching for an unusually dimensioned rod, you can do very well by searching eBay. New-in-box rods are auctioned every day. Carrillo, Crower, Oliver, Pankl, Scat, Eagle, billet, forged, titanium... I've seen and purchased rods this way and saved a fair bit of money. For example, I'm currently seeing an auction for 32 new in boxes Carrillo rods for starting at $1500...these rods have some odd dimensions but it's a reasonable example of someone (perhaps not this seller) taking a fair $$ hit to sell them.

[Ron Earp]

Originally Posted by JohnStanden

I have read a few bad comments regarding current Eagle con rods, apparently they are forged and machined in China and their accuracy is not very good

I know people that have used them with no issues. I don't think that "machined in China so no good" phrase holds much water these days. Some of the world's most advanced factories are located in China (as well as some poor ones). Naturally, that doesn't mean Eagle is "off the hook", but I wouldn't let location hang me up.

R

[Bill D]

I used Scat forged H-beam rods in a 645 BBF that I installed in a Factory Five Cobra. I never had a problem.

I'm using Scat forged I-beam rods in my 331 SBF destined for my GT40.

They're great for a street/strip car - affordable and very good quality. For an all out race car, I would probably go with one of the high end makers listed above.

Bill D

[JohnStanden]

Thanks for that guys, looks like its Scat for me then!!

[John W]

So, to follow on from this, are Eagle considered a budget conrod ?

I was under the impression the key to keeping an engine together was more to do with the quality of the rod bolts than the rods themselves as long as they are all closely balanced, and that all H beam were generally the same regardless of manufacturer.

I assume that all are okay for a street/strip engine with a sensible rev limit (e.g. 6k5 rpm) ?

How do Scat, Carillo, crower, etc compare to each other?
or put another way:
- if money no object which is best for an all out race engine ?
- if money no object which is best for street / strip weekend toy ?
or is it like most other things, and simply a case of engine builders preference

Cheers,
John (who's just brought a set of Eagle Rods & ARP Rod bolts...)

[Jac Mac]

I have also heard these rumours, but have yet to see any problems in regard to tunnel size etc. Since in most case's the customer has supplied the 'kit' of crank/rods/pistons I often dont have much say in the matter. There is a difference in finish quality and detail machining when you lay several different brands out on the bench. Regardless of brand It would pay to measure the bores for size and width & check the total end float on the rod journal along with side clearance @ the pin end. Also trial fit the brg shells, measure/check the 'crush'/and that both shells are fitted away from the fillet radius side of the rod/journal.( this is an area of concern with many of the brands).Some brands carry a bit much weight which means any $$$ saved on the rods may be spent/plus more on the balance job especially if you have to pay for some 'mallory' to get the job done.

John W, I dont think you should have any concerns with your 6500 rpm limit. The standard rods with ARP bolts & shotpeen are good for 7000 rpm +.

Jac Mac

[John W]

Thanks Jac, I won't cancel my order then

I'd still like an idea on the pecking order for which is best though if posible if anyone knows, or has an opinion

[scott]

I'd still like an idea on the pecking order for which is best though if posible if anyone knows, or has an opinion [/quote]

I'd say that everyone has a favorite version of their manufacturer's rod but I'm not sure that anyone has a definitive answer as to who's is "best." The top of the main-line here in the States is usually held by a few names like Carrillo, Oliver, or Crower. After that things get a bit fuzzy...Pankl makes rods that are very popular in some racing circles, Pauter makes rods popular w/ some european builders. Scat and Eagle make very popular rods that offer good value. I suspect there are other brands I've omitted that work very well too.

[Lynn]

The only ones, IMHO, to stay away from are CAT. I really believe that Scat and Eagle are very close, but when SCAT told me that there was no such thing as a 0 balance crankshaft for any engine and that someone would have to know magic to produce one, it kind-of turned me off. I bought Eagle crank and H-Beams. Comment on bolt strenght is valid- bolts are often what lets go- to a point: to be confident in your build, you can't buy complete junk and put ARP bolts in them.

If money had been no issue, I would have bought some of the high end (read Carrillo, Oliver, etc) I-Beams. This would have given me equal or better strength with a significant savings in rotating mass. It's always a balancing act between strength, weight and cost. Most vendors will give you a rating on the strength of their various offerings and this should help you and your machinist decide on the compromise that fits your situation best.

Regards,
Lynn

[Jim S.]

Lynn,

Technically SCAT is right. If you were to leave the bob weights off that simulate the piston/rod weight the crank would not be zero balanced.
Once these weights are on the crank it is then zero balanced.

But now that I think about it. An inline 6 is perfectly balanced without pistons and rods. I used to do engine valve train testing for Eaton Corp. and we used electric motors to spin the engine assembly. These didn't have pistons and rods we were only testing valve train. The one motor that we could do this on without haveing a dummy crank (No rod journals) made was an I-6.

Didn't mean to get this thread off on a tangent. Sorry.

To get back to the thread, unless your planning on spinning the motor above 7500 - 8000 RPM for extended periods, I believe your worries are none.
I know several people that have used stock rods in 289, BUT with good rod bolts that have spun the day lights out of them and had no trouble.
Generally speaking RPM kills not HP and Torque output.
I have another friend that runs a superchraged 351W with stock truck rods and Good bolts. This motor is making over 800HP, but he doesn't spin it hard, about 6700 RPM.

These 351 truck rods are nicer rods then what the 289-302 came with. Since rods have become very cheap it doesn't make since not to upgrade, but I'm with most of you, Eagle or Scat I think will work well.

[Brett James-McCall]

Lynn,
Welcome back old buddy - missed you.

Brett

[Lynn]

Thanks, Brett!!

Jim S., of course, you are right about having to use bob weights to simulate pistons, pins and rods. The difference that I am speaking of is between balancing for 0 oz (NO weight) on the flywheel and having a 28 or 50oz counterweight on the flywheel. But I have a feeling you knew that :-)

Regards,
Lynn

[Jim S.]

Lynn,

I was just jerking your chain :-) I figured you knew that, but seriously the I-6 do really have a zero balance with out weights. <--- I know use less information.

Getting back on track, it kinda makes you wonder about some of these aftermarket companies sometimes. Maybe you just had a Dingbat on the phone from SCAT?

[Lynn]

Jim S.

Don't know if you've done a search on this or not, but there have been some discussions of using flat cranks in a V8 on this forum. Some pretty interesting stuff if you've got some time to kill and the will to find it.

Regards,
Lynn

[Keith Hardy]

180 degree cranks Lynn, yes...now you're talking!

Would love to hear what Jac Mac has to say about them....

Yeah, I know, balancing...

[Doug Sainlar]

Re: What block preparation is required for dry sumping a SBF

--------------------------------------------------------------------------------

Doug, Unless you want to spend your retirement working on your motor continually checking bolt torque's etc as well as on every other component that is bolted solidly to the motor, Do Not use a flat plane crank. If you ever get the chance, speak to some of the older Formula A/5000 Engine builders that tried them, bear in mind that they used a 3.00" stroke ( The problems increase with longer stroke ). It was a major problem then with cast blocks & heads, I dont think it would get better when using alloy blocks etc.....

Cheers Jack.

[Jac Mac]

Doug,
Good to see you are concerned about the RSI I get from the keyboard.

I wondered if the comment from the guy @ Scat was a bit of a 'throwaway' myself.

Balancing a V8 will always be compromise.
1 .You cannot balance the crank until you know the weights of Rods,Pistons,Pins,Rings,Bearings,Circlips,etc. If the motor has external balance( std 289/302/351/ etc) these must also be purchased & fitted prior to balancing.
2. With the"O" balance cranks as we call them the same applys, but you could use a neutral balance F/wheel&Damper that had been previously balanced, AFTER having balanced the internal components. Some folk do this on the basis that they wont have to rebalance when changing Flywheels etc.
3. The "Compromise" factor really kick.s in when you start to visualise what is happening during one rotation. At TDC the Big end of the rod has the balance pad facing in to the center of the crank, its companion rod on the same journal has its pad slightly outside the rod journals circle path, now as the crank rotates both pads will move outside that circle & 180 deg later both will move inside ( I realise that most higher quality rods dont have the pads but the heads/nuts of the cap bolts have the same effect). so at no point in actual operation does the crankshaft have a constant effective weight like it has on the balancer, and we have not even considered the rest of the rod,piston monkey motion yet!
When you start to think of the V8 as two 90deg V twins, seperated by a 90deg V4 with a flat plane crank you should start to come to terms with it.( See Keith your halfway there already).

Jac Mac

[Keith Hardy]

Sorry Jac, didn't realise that you had already given forth on this subject. Well, there must be a way otherwise they wouldn't be running V8's in F1 right now would they?

They are all 180 degree jobs are they not?

[Doug Sainlar]

Originally Posted by jac mac

Doug,
Good to see you are concerned about the RSI I get from the keyboard.

Jac Mac

Not trying to do your talking for you, Jac, just smart enough to recognize and remember good advice.

Thanks!

Cheers!

Doug