Those Chinese 3.5's are complete junk either way around.... And I don't know if that's just because where they're made lol

 

that guy is totally legit......... really he even said it that it looks like someone poured sand in it. Its a junkyard engine. Hes getting all of these statements from ALLData which is very vague and I think the guy sounds like a total douche. He didn't say it wiped a lobe off just that there was some scoring on it. I just don't buy it. Did you know comp actually bout the machines that manufactures use to grind cams? Read about that the other day. But even if the cams were ground over there, they use certain steel for certain cams. This guy probably doesn't even know that.

 

Not sure how true this is but we have been replacing a lot of cams under warranty at work lately on the 07 and up gm v8's, the newer ones have only been worse so far? Makes me wonder, half if not more than half of the GM parts i install at work are from China or South Korea!!

 

Whats wrong with the cams your replacing. I know for Ford it was the followers that would start losing roller bearings fly off and chew up a cam.

 

just seem to be going flat, looks like it wasn't hardened to me, lots of pitting and damage to the lobes and some of them are very low miles too!

 

how low of mileage are we talking? because i remember a couple times GM made me send in brand new t-cases that were mucked up. Like less than 10K miles so they could tear it apart and find out whats wrong with it.

 

While the issues I have seen have typically resulted in the customers running low on oil. there is no way to Prove any 1 thing as being the culprit.

In regards to the Cams them self's there heat treated in large batches so In my mind it is possible to get a few out of each batch that were not surfaced hardened properly or as deep as the others. They are typically heat treated first and then the main journals are ground to spec. This is done to ensure that if the camshaft had any core shift that the journals are still in the correct spot. Then they are either sent out to a company to be ground to spec or depending on the manufacture of the cam blanks they could be grinding them to spec in house and shipping directly to Manufactures assembly plant.

 

the steel they use for cams is whats breaking down not the grinding of the cam. every couple of camshafts they put in a tester to make sure everything is staying true and what not. So who cares where they are manufactured its the quality of steel thats sucking.

 

It's either cast or forged depending on application case hardened which is a form of heat treating. If not done properly it won't live, that's why it matters how it manufactured.

As you take off material by grinding the exterior of the part the heat treated area becomes thinner. If the heat treated are is not thick enough it will not support the wear. There are usually specifications set forth on minimum depth for heat treating.

If you run it low on oil there is a lack of lubrication increasing the wearing forces.

If it was the metal alone they would all fail. They usually do extensive testing to insure this is not the case. They also make sure its fairly consistent from batch to batch.

The motor was second hand out of a wrecking yard. No one knows how it was treated by the original owner, what happened to send that car to the wrecking yard, Or even how the wrecking yard stored the engine.

With that being said I am not saying there aren't Crappy parts that come out of China but in this case, there is nothing to prove this one did come from China or that Metallurgy was bad on this particular part.

With out testing the failed part No one will ever know.