My last built engine was a LS/VTEC with shotpeened LS rods, ITR pistons, balanced and had a stock B16 head with Skunk2 stage 2 tuner cams. I drove it hard and attended drag events often. The engine ran great! After about 30,000 hard miles I started to hear a loud clacking noise and I assumed that my poor engine had developed a rod knock. I proceeded to dissemble the engine and to I discovered this nasty little surprise! The pistons, rods and ACL bearings were still in excellent condition. What do you think caused this? I'm fugured it had to be a bad / old style/ LMA so I replaced them all.

In the picture you can see that the VTEC lobe has eroded into the VTEC rocker.

 

Strange right? No one has ever seen this before?

All of my other rockers were fine so its even weirder.

 

Honestly I'd post this in the all motor forum for best responses

 

can be from last set of cams?
stuck/bent valve
damaged spring

 

I second this.

 

i would say a bad LMA.(lost motion assy) vtec free spins on the tappet when not in use..only resistance would be the lma which keeps a slight tension so the rockers dont go crazy.unless that cylinder is stuck in vtec lol

 

wow

 

Thanks for the input. I dont know how to move this to the all motor section. The springs, valves, and vtec engagement parts for the rockre were all good. I think it has to be LMA related. They were old. No matter I got the new type now

 

Just make a new post in the all motor section. The mods can clean it up if they feel the need.

Or you could pm a mod and ask them to lock and/or move this thread.

This section is perfectly appropriate for this question it's just that there are more people circulating in the all motor forum who might have a quick answer.

 

It has much to do with the aggressiveness of the cam lobes. From what I know, its usually just the Pro cams that are an issue. If you have the old LMA style and it wasn't working right, it would have contributed to digging that trench. The "beehive" spring-style LMA's are what should be used in built & rebuilt heads.

I know for the bigger cams the engine builders I know will use some sort of ZDDP additive. Usually it's half a bottle of what guys with old style motors with flat-tappet lifters. Honda lifters are similar in movement, so it helps reduce wear.

 

what valvetrain were you running?

 

What valve springs did you use?

 

Skunk2 pro series springs and retainers with OEM valves.

 

Skunk2 parts are made in china

 

Are they!? How do you know this?


EDIT: Not totally true. http://cms.skunk2.com/id/275/JDM-Made-in-Taiwan/

 

there is a lot of things that could occured to what you live

to much spring rates, bad cams, bad break in, etc

 

search

 

lol here we go again with skunk2.
its funny how quick they are to jump in if someone wants to buy their product but nowhere to be found when theres a technical question about their product origin...( not talking about skunk2 here but in general)


why is it so hard for manufacturers to post real info about where your product is made.

i mean if everyone is askign and theres no responce from manufacturer it confirms the worst rumors.
a picture is worth a thousand words. but a picture of a shipping label from their parts is worth even more.

 

What does it matter if it's made here or china or anywhere else for that matter the quality control is what matters. I'm sure everyone has something made in china and they probably don't even know it.

 

iirc skunk2 said their pro series stuff is made in the US. not that it matters to me.

i would say it was a bad lma on that rocker.

 

^^ This. You can get any quality of product made in china. Stuff just as good as anywhere else. You just can't get it for the price of all the ********* that are knocking everything off. They want if for as cheap as they can get it. thats why the quality is so poor. Just because something is made in china doesn't always mean it such poor quality. I am in no way condoning outsourcing stuff. But it's kinda like selling a tubular ramhorn overseas. Describing it as a full-race style ss ramhorn, made in america. How many shitty homemade ramhorms have you seen come through the threads vs. quality ones, and at what price differences. Just cause it was made in america doesnt guarantee the quality or craftsmanship. Sorry for rant OP. but I have't seen any rockers or cam lobe look like that before. Was the car stored for a long period of time?

 

There's a big thread that discuss the quality of skunk2 parts.

This "looks" like not only accelerated wear, but maybe too tight of a valvelash, improper oiling, possible just a bad batch of cams(it does happen).

There's alot of reasons this could cause that..also to be honest, very high mileage LMAs will sometimes give alittle, when a hard metal meets a softer metal this can occur.

 

Ranting is ok. You have some good points. Except for wanting to support U.S. companies, I really do not care where my parts are made as long as they are quality and perform as expected. There are many reasons why this may have happened as evident on this thread. I really just wanted to find out if anyone had ever actually SEEN this before. Sounds like not. I read what you all had to say. Things such as bad oiling, long term storage, valve lash and bad springs I think I can rule out. Every other cam lobe and all of the other rockers were in good condition. This was an isolated problem. I really think it was a failed LMA. They were all old but that one saw catastrophic failure first. I think that rocker was basically jackhammering that cam lobe when not in VTEC. As far as skunk2 goes I am running many of their parts with no problems and I have been real happy with their products and their service. Thanks for the input.

 

This is a oil issue. Very common on tapped style rockers. Buy oil with high levels of zinc and phosphorous. Brad penn green oil for example. The invention of roller rockers allowed the oil industry to lower the levels of these additives for emission purposes because there is less friction seeing as it is a roller surface but on a flat tapped u need that friction reducing additive which is no longer in regular oil.

 

I use regular ol Castrol 1030. Been using it forever. So if it was an oiling issue why did it only effect one rocker?