Cool video

 

The ebay seller got back to me saying this:

"Our Supplier, CAT Power Engine, supplied to Eagle, Lunati, Scat, Summit, and Tomie before. They have the best quality and reasonable price. Don't be fooled by these name brands."



Sincerely
CrankShaft Depot eStore

For $206 shipped we'll see how they are when I get them...

 

I got my rods:

https://www.miataturbo.net/showthrea...=46718&page=34

 

Ive seen cheap rods in lots of SBCs. As long as you have your machining and balancing done properly ive never heard of an issue.

I know of one guy spraying a 200 hit on a 383 lt1 using 5.7" ebay I beams. No problems.
Same story, come to find out they are from CAT which do scat, ohio crankshaft, and a bunch of others.

You should be fine if you actually have them checked and installed properly.

Seems like the majority of built engine failures I see, cheap parts or not, aren't from an overstressed part but are from installer error or a tuning issue.

 

i orderded mine last week they should be at my house today, are the bolts good? or it it worth upgradiong the the 2000's? im looking for 350hp

 

Can anyone confirm this? The M-Tuned rod small end is 0.788". These china rods are 0.791". What is the size of the stock piston hole and small end on the stock rod? I have also read that stock piston hole diameter is 20.0mm

 

Anybody? ^^^

 

Btw, out of the maybe half dozen rod manufacturers, I feel cat power systems is the worst quality wise. Did a lot of research into these companies and traced the source of the materials, foundries for the ingots, etc, and cat is the bottom.

This doesn't mean they wont work, but id go belfab long before CAT. Carrillo does all their own **** with US forged ingots from timken steel, and pauter is also great. Belfab has good controls in place for their product as well.

Just sayin, if you want to save a buck, get aluminized exhaust, not cheap roatating assembly parts.

 

To give you an idea, a piece of paper is usually .005". A press fit rod is usually .001 bigger than the id of the item being pressed in. At work i usually make the rod .002 bigger than the id of the item press fitted and its VERY TIGHT. A .004 difference is enough for knock. If you had a non concentric gear on a rod and that gear was .004 off to one side, when that gear is spinning you'd easily be able to see it wobbling with the naked eye.

 

This sounds bad, I guess we'll have to wait for Leatherface to get his engine finished.

 

Even the big end diameter of this rod is off

China - 1.889"
MTuned - 1.891"

 

The rods I got from belfab a few years ago on their first run came in a CAT box. Just sayin....

 

I asked the seller about the specs and why they're different. This is the response. I'm not experienced enough to know if it's correct or not.

 

the small end can be bushed down if the clearances are too big, but there goes the $ saved from cheap rods to regular ones.

also you can probably oversize the bearing on the big end... big end wasnt a worry when i said that above so i didnt state it.

But i think in this thread we have determined that 0.004" is too loose for the wrist pin.

 

A local shop charges $12 each to put a new bushing in the small end. Still cheaper, but I'd rather have an M-Tuned if this is required.

 

HThey did at one time colaborate but disolved that partnership over 2 years ago.

 

Just noticed the CAT website lists the pin as 20.0 mm. All these mismatched specs are retarded, why didn't I pull out the dial bore gauge 2 weeks ago.

Length 132.0, Rod 48.0, Pin 20.0, Rew 21.84, 323/Miata/Protege, Weight 530g, '85-00

 

so i bought a set of the crankshaft depot rods, got them for 195 shipped? i plan on using them with my b6t build, the spec sheet said 3 of them where exactly the same and 1 rods was off by 1 gram ( pretty good tolerances per the sheet) who knows if there scale is accurate. Well i know theres allot of speculation that these rods (CAT) are the same ones at eagle, bellfab, etd, ect. so i also bought a set of ka1's for my bpt build, got them for a good prices and i figured that ka1 would have better tolerances, from the pics they looked just like the CAT rods, from what ive read is KA1 is owned by carillo but they get everything made in China and they are sent to the US to be finished. well when i compared the 2 there are some pretty significant differences, for one weight Ka1's are much smaller, ka1 have arp2000 hardware and Cat has the standard ARP hardware, the other difference seems CAT has a oil hole on the top of rod im guessing to help cool the piston maybe? the ka1's dont have that hole. they both have brass small ends, seems as thought there is bigger sleeve on the CAT rods. I dont have a scale so i cant give you the exact difference but just some food for thought i guess.

 

looks like a good set of rods for 200 bucks

 

Are you able to measure the size of the big and small ends accurately?