Cheap conrods

[rockmonkey69]

An engine I helped assemble (parts were sourced and supplied by them) had failed recently running a very mild 460bhp, ultra low boost and super smooth mapping, below are the pictures:



The conrod were un branded but sold as forged according to the buyer.



There have been claims that many lesser known manufacturers manufactured their conrods to the same ISO standards as that of the premium manufacturers, this has nothing to do with the overall strength of the product, it is merely an operating standard to show that processes are inline with documentation and that working processes on site are recorded to a standard.

There had also been claims that these lesser conrods looked remarkably similar to integrated engineering rods, again - this might be the case, but as we all know, imitations are designed to look similar and little can be said of the overall strength of a product from it's physical appearance.

So, thinking of doing an engine rebuild are we? Tempted to save a bit of money on engine internals?

[Wazzzer]

wow, definitely something to chew on there...

I know exactly how ISO standard operate as we need them for my line of work and you're right; they give no guarantee to the final product

[rockmonkey69]

Yea they was lucky that it didn't do any real damage, could have trashed his engine had it gone horrifically worse. Fortunately the only thing that needs doing is the conrods - which are getting changed for some scat rods

[Wazzzer]

that was gong to be my next question: any damage

very very lucky to get away with that

[brianpologti]

Wow very lucky , buy cheap buy twice comes to mind

[shaft69]

That's Deffo not good some cheaper ones aren't that back lad by mine runs s3 with maxspeeding rods with standard pistons his well over 500bhp and rods were only £220. Tracks it and hammers it everywhere.  His mate runs them in subaru and that runs close 500bhp too.

[rockmonkey69]

I think everyone has a different approach. I see an engine build as something that you only want to do once, if it's to be done then it should be done properly. My mate however has been running over 400bhp on a completely standard 1.8t, 100% stock engine. But he expects it to go anytime, so he has a couple of 1.8t engines ready and he picked them all up for next to nothing. Then I suppose you have everything in between...

This guy was lucky when the rod went, that it did not take out his titanium valvetrain or his forged pistons, if that had been the case it would be a real bummer just for the sake of £100 saving. You also have to factor in all trivial bits he had spent first time around building the engine, circa £600 in ARP bolts alone, hundreds in fluids and all the time spent building the thing and running it in.

For me it's simply not enough assurance that someone running - let's be honest - mild/healthy power (circa 500bhp) is using these rods. The price isn't the only difference, have a look at the physical dimensions of said imitation next to a scat rod:


It may not be very apparent but measured, the imitation conrod was 5mm thinner...

[james2]

I think everyone has a different approach. I see an engine build as something that you only want to do once, if it's to be done then it should be done properly. My mate however has been running over 400bhp on a completely standard 1.8t, 100% stock engine. But he expects it to go anytime, so he has a couple of 1.8t engines ready and he picked them all up for next to nothing. Then I suppose you have everything in between...

This guy was lucky when the rod went, that it did not take out his titanium valvetrain or his forged pistons, if that had been the case it would be a real bummer just for the sake of £100 saving. You also have to factor in all trivial bits he had spent first time around building the engine, circa £600 in ARP bolts alone, hundreds in fluids and all the time spent building the thing and running it in.

For me it's simply not enough assurance that someone running - let's be honest - mild/healthy power (circa 500bhp) is using these rods. The price isn't the only difference, have a look at the physical dimensions of said imitation next to a scat rod:


It may not be very apparent but measured, the imitation conrod was 5mm thinner...

Maybe he was trying to save weight, but on the wrong parts . 

[rockmonkey69]

I think everyone has a different approach. I see an engine build as something that you only want to do once, if it's to be done then it should be done properly. My mate however has been running over 400bhp on a completely standard 1.8t, 100% stock engine. But he expects it to go anytime, so he has a couple of 1.8t engines ready and he picked them all up for next to nothing. Then I suppose you have everything in between...

This guy was lucky when the rod went, that it did not take out his titanium valvetrain or his forged pistons, if that had been the case it would be a real bummer just for the sake of £100 saving. You also have to factor in all trivial bits he had spent first time around building the engine, circa £600 in ARP bolts alone, hundreds in fluids and all the time spent building the thing and running it in.

For me it's simply not enough assurance that someone running - let's be honest - mild/healthy power (circa 500bhp) is using these rods. The price isn't the only difference, have a look at the physical dimensions of said imitation next to a scat rod:


It may not be very apparent but measured, the imitation conrod was 5mm thinner...

Maybe he was trying to save weight, but on the wrong parts . 

No No No, if that's the case he's doing it wrong, you're supposed to file down your bearings! That's where the real gains are to be found 
Initially I suggested sourcing a set of titanium conrods, so it came as quite a shock when these imitations arrived to be fitted. I've only ever seen titanium conrods used once among my close circle of friends, was on a blown NSX and it begs belief how light they were! Felt as though I was holding plastic.

[LR5V]

I assume these are those rods you see on ebay for less than £200 claiming to have ARP bolts and being the some sort of engineering wet dream.

There are few interesting threads out there talking about how poor these are.

One post I found was from an engine builder who had been approached to use them, they asked the builder what brand he wanted putting on them...