those of you running c.a.t. rods

scxr7

Registered User
I got my 93 sc motor back from mosler today, they basically did all the machine work and I'm going to assemble the motor myself. the machinist said he's never seen rods so cheap and flimsy in his 30 year career. I was under the impression that they were stronger than stock, correct? I got the 5.915 cat rods with arp bolts and wiseco pistons. he also said that the rods were out of round on the big end and little end. I already paid for the machine work etc. but this is just an after thought. were c.a.t. rods a good decision? the way the engine builder was talking about them, I should've stayed with 94 rods. I'm just looking for a little re-assurance from those of you running these rods.
 
CAT Power Products. I assume they were H-Beam rods.
CAT, Eagle, and SCAT H-Beam rods are all basically the same rod. They are made at a foundry in China into a near finished state and the individual companies do finish machine work themselves.

I'm not familiar with the shop you are talking, but lots of machine shops are used to working with different motors. If they've only been working with big block stuff, then a small v6 might seem flimsy. Out of round though would be an issue. I'd be a bit disappointed if he tells you this after he's done all the work, especially if he did any balancing, as I might be tempted to contact cat and get a replacement rod for any out of round. Did the shop grind the rod bearing to bring it back into spec?
 
I've got scat h-beam rods and they do not look anywhere near flimsy compared to stock. If I remember right, there are a bit heavier
 
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I had CAT rods in the motor Chris Wise built for me back in 2001 and at that time the quality was on par with Scat and Eagle and the rods held up well during the 8 year hard life of the motor. Several other high powered SC motors were using the same rods.

When dismantled and closley inspected, by Dave Dalke in 2009 the only issue reported with the rods were worn/elongated wrist pin bushings.

Don't have a clue as to the current level of quality, but they were fine back in 2001.

David
 
I recently got my engine running with Dave's CAT rod and Wiseco Forged Pistons and my machinest is very prestigious on the west coast and he said the only difference (and why they are cheaper than SCAT and Eagle) is because they need a little work before you install. Such as the no quite roundness. But all in all its a H-beam rod that is way stronger than stock so your all good. Just sounds like your machinest isn't aware and yeah probably just works on bigger engines.
 
The main reason I chose SCAT over Eagle or CAT was that SCAT had them in the longer length, the others did not. Scat also puts extra work into the rods, including creating balanced sets thus the rods I had were all within 1 gram of each other and the machine shop that did the balancing and clearance checking had no issues with the quality of them.

The stock rods are no doubt strong. But I can't imagine that they were stronger than an H-beam rod. In addition, most after-market H-beam rods are fairly light especially compared to production. When I had my parts weighed, the stock connecting rod came in at 662 grams, the Scat H-beam rod, 630grams (and the scat rod was .204" longer than stock)
 
hey thanks for the replies, the machinist re-rounded(if that makes sense) the big and little ends so the rods are good to go. the only reason he said they seemed flimsy was because when he torqued the rod bolts down to measure the clearances the ends of the cap kept sucking in even tho he kept machining big end. supposedly he got them all round again tho. as long as they do their job its no big deal I guess. I was just curious what your experiences were with the cat h-beam rods.
 
hey thanks for the replies, the machinist re-rounded(if that makes sense) the big and little ends so the rods are good to go. the only reason he said they seemed flimsy was because when he torqued the rod bolts down to measure the clearances the ends of the cap kept sucking in even tho he kept machining big end. supposedly he got them all round again tho. as long as they do their job its no big deal I guess. I was just curious what your experiences were with the cat h-beam rods.

Again, he should have called you when that happened and then you call your supplier. It isn't impossible that some problem in metallurgy occurs with a production run and I know I would have wanted to address that with CAT.
 
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