EAGLE, MANLEY, CAT RODS, DIFFERENT ? YOU DECIDE

John, that was me, LOL. glad to see you recognized me. just wait until you see next weeks episode...you won't believe it...

well obv. those rods are not all alike but.....

The distributor I got my rods from swore up and down that he got shippments of all 3 of those brands with the machining for the tangs for the bearings all machined incorrectly, all exactly the same and incorrect. I assume if he was a web savvy type guy he would have taken digital pictures of all those. It would be very interesting to have that picture to put in this thread as well.

Well,well,well,maybe some of the people on this board should listen up instead of talking about things they have never held in their hands,or compared side by side. I posted,and several others mentioned 2-3 years ago that Manley rods were quite different,and better in the big end in my opinion than Eagles and was told no they are the same,I thought I needed glasses or was seeing things,so I gave up,thanks for posting this Performance Only. I will never buy anything but Manleys for a budget build like I do.

i think someone famous once said, a picture is worth a thousand words. of course, that was before photoshop came out, LOL.
the photo's are not doctored in any way here. i would like to see pictures of all three of those brands with the tangs all machined incorrectly. do you want to reveal your source on that wayne?

the rods, from left to right are, eagle, cat, manley. as i said, when i get my order of scats in, i'll post that pic too. all rods are in out of the box condition. the machining differences in some area's appear subtle, but can make a difference in strength characteristics overall.
the area where machined threads are not present in the big end is because they don't want stress risers there. as you can see, some manufacturers must not think it's an issue. bolts do not protrude in to that area.
this is one of those cases where a connecting rod looks like such a simple thing but there is way more to them than meets the eye. i'm not looking for anyone to agree with my taste in con rods, just to understand why i prefer some over the others. after all, in the end a 100 bucks for a biuldup isn't much, but when things go wrong because of a lesser quality part, and they do sometimes if pushed to the limit, the 100 bucks would have been worth it.

However, we are definately looking at three different length rods there. All three are different without question, but I need to see three of the same before saying for sure theyre not made in the same foundary, unless someone in the foundary says so.

Also, just because the finished product may look different, doesnt mean that the basic forging didnt start out the same.

gary, send me three identical rods and i'll post pics of them, LOL. the differences are more than just what is apparent in the pictures, it is also in the critical mass measurements. don't be so skeptical, open your mind. any engine builder that see's these rods on a daily basis will tell you they're different, unless they're blind.
now, just to prove a point, notice the squared off end on the eagle big end? you can't make the same end on the cat, the forging is different. have i ever steered you wrong before???

Without a failure rate, this post is useless! At least to me, I already have the Cat's and I'm using them.

Ofcourse not Dan. Its just that the rough forging makes almost any finished size possible. Even if they were the same, the end product is much, much different by looking at those rods and that proves a point in and of itself. Theyre different even if the forging came from the same place.

And, I for one see the value in this post. I see 3 pretty beefy rods there.

good answer, but rough rod forgings don't have much extra mass in them. the outer surface you see on the H beam is about the same as what you end up with even after the rest of the machining is done. the final machine process is what really makes the difference in the end anyway.

plum, what do you want? if i posted about failure rates from my own experience, it would be worthless to anyone except me, and ridiculed by some as well. many peoples experiences are based on 1 or 2 engine builds or by the friends they know. my experience has been from over 30 years (whoopty do LOL) building at least 50-70 motors a year. i've said over and over which rods i prefer, and the reasons for my choice. i don't expect anyone to agree with my opinion, or my findings, but if they do, thats great. of course, if they don't, i probably won't change their mind and thats okay too.

all of the rods above are good rods, some are better than the others. if the final machining on those rods was equal, it would make my choice harder on which ones to use by just a tiny bit.

Thanks Dan. And I must agree with one thing.. Considering my next crank is going to be $1300, a couple hundred more for what an experienced builder deems the better rod is chump change!

I see the manley's needing a lot less block clearancing on strokers compared to the eagles and especially the cats (:

The Manleys were my first set of aftermarket rods, and I thought they were pretty darned nice for the money. Of course all the small ends had to be honed, but that was expected. The big ends were dead nuts, and needed no work.
I put them in and was happy...

Then a couple months later I saw my first set of Eagle rods in person, and I thought "well they're kind of the same basic shape, but they sure are alot uglier."

Not very technical, and I doubt I'm making enough power to break any of them...but it's comforting to know I got the right ones to begin with. One less thing to mess around with later! Thanks for the pics, Dan.

Rich

Glad to know I got the right rods! Guy I got them from showed me the eagle VS. the Manleys.....I took the Manleys!

He was the one to point out the difference & the Manleys were only 50.00 more, from him anyway. Nice to know my eyes were'nt lying.

Great stuff! Also makes the guy I got my stuff from seem all the better!

good decision on your part IMO.

Thanks for taking the time to do this post Dan. I have had Eagle, Scat and CAT H beams in my hot little hands before. The Eagle's were a little rough for my liking, but I bought a set anyway, it was what was available to me at the time. I have since sold them anyway. I liked the look of the Cat rods, the cutout along the beam is much cleaner than the Eagle's. I cannot honestly say anything regarding the Scat's , my engine builder had problem's with their sizing a few years ago, and has since steered away from them. I think he has started to order them in again. From the pics, if I was to buy any of the three, the Manley's look the best. When the Scat's arrive, I would be keen to see what they look like. Thanks again Dan,
AL...

Very good post. I am a numbers guy, so could you give nomimal measurements of the dimensions in my attachement? ie. E1, E2, C1, C2, M1, M2? Also, is the beam the same size in the other direction?

It appears that the Manley rod (right) has the outer part of the bolt area machined straight, while the CAT (center) is tapered toward the total width, is that right?

Do all these use the same bolt length? It appears that the part the bolt threads into are different lengths. Is that right?

E2= .098"
C2= .089
M2= .080

I'll have to remeasure the other area's. i won't trust my memory on those, LOL. i'll post back when i get them.

Thanks.
The meaning of the dimensional differences is debateable, sometimes extra thickness is mostly weight and isn't needed. But just for comparison.

I've heard several of you mention the differences in surface quality between the rod manufacturers. Since cracks and failures often initiate from a surface flaw, like a nick, divit, or pit, then the surface quality should be a seriously considered as well, shouldn't it?

i agree that sometimes extra weight is just that and nothing more. a perfect example would be to take a look at an oliver rod. they keep the weight down but those rods can handle 1400 hp without even breaking a sweat.

surface finish is more important in the critical area's IMO. area's around the bolt holes, threads etc. i think all of the pictured rods have sufficiant strength for the normal combos in the 7-800 hp range. after that things do get critical. lighter mass if done properly is alway's your friend on those motors. i guess the fact of the matter from what we typically see listed on this board is that very few actually put any connecting rods to the limit. on the other hand, i do a number of "serious" motors every year and rod choice becomes even more critical.

I too, would like to see some comparison shots of the SCAT rods when you get 'em. Thanks for the info!

guys i keep reading posts about H beams doesnt anyone use I beam any more, arnt you guys concerned about the extra 70 odd grams. im starting to get paranoid about my sir eagles,(that measure up perfectly) rod rating is 550hp. joe sherman used them in s/b shootout, or maybe 4" rod/stroke ratio too hard on them, wots your thoughts? assie dollar, not to mention supply, is a killer when it comes to buying a good rod here!

Any high dollar rod steel rod is an I beam, their weight to strength ratio is believed to be higher than the H beams. With most of the Nascar teams etc running them, I would be inclined to agree. Here's a pic of what can happen to a Eagle SIR rod when over stressed

If I was running an engine with a light piston and not revving it past 6500, I wouldn't be too stressed about running them. If you're swinging a heavy ol TRW slug, or you're turning it hard, that would be a different story.
AL...

Me not being n engine builder I wonder about the bolt holes on the import rods. Look like they would collect oil and sling it on the cylinder walls like the old Chevy "dip and splash" oiling system. Maybe creating windage? What do you guys think?

what surprises me is that all the guy's that jumped on the bandwagon to say all of these rods are the same have disappeared. i wonder where they went? maybe all of a sudden they no longer feel the need to bring attention to themselves, LOL.

I sent you the promised info

Yesterday, I had a look at a set of Scat rods, they look very similar to the CAT rods, it would be interesting to see them side by side.
AL...