Febi rockers? Whats your take??

[DirtyTh3rty]

Just curious I noticed I have Febi rockers so obviously they have been replaced at some point by the PO

I have heard bad & good about them probably more bad but what is everyones take on the Febi's??? Anyone have experience with em?

[M20]

I have Febi wheel bearings. They were more middle of the road between junk and fag/skf branded bearings.

Febi is part of the Bilstein Group and should be OE quality. Don't have any experience with them with rockers, but I would think they're good enough.

[nando]

I have Febi rockers in my M20, but they're more than 10 years old now. I wouldn't worry about it, although apparently the newest batches from them haven't been very good.

[DirtyTh3rty]

I have Febi rockers in my M20, but they're more than 10 years old now. I wouldn't worry about it, although apparently the newest batches from them haven't been very good.

Yeah I mean I'm familiar with the brand itself I have other small Febi parts but just heard things about the rockers. And wouldn't be too concerned if i wasn't planning on boosting down the road. I know things like this should be replaced obviously if i was going to boost so i figured i would just replace em with some HD's but then i saw they had already been replaced.

Even though these are much newer than the old stockers would you stilll replace with some HD's before boosting? I have the head open right now replacing cam and gasktes, arp studs.. thats why i ask.

[digger]

If you can afford better get better. I've used mm peened and inspected rockers but they are like 40 each. These days people use HD, I know they had the odd failures early on but don't know if they still do

[jeffnhiscars]

I bought new Febis and didn't care for how they looked so I sent my OE rockers out to be refaced for 1/3 the cost

[digger]

I bought new Febis and didn't care for how they looked so I sent my OE rockers out to be refaced for 1/3 the cost

the viability of this method would depend on how worn they were, if too much material was removed i could see the valve motion beng affected. ive seen some terribly worn ones and i have some that have next to no wear having only done low mileage

[nando]

Boost shouldn't matter to the rockers.

[jeffnhiscars]

the viability of this method would depend on how worn they were, if too much material was removed i could see the valve motion beng affected. ive seen some terribly worn ones and i have some that have next to no wear having only done low mileage

There are all kinds of worn parts that can effect valve movement...cam, rocker shafts, rocker arms, eccentrics & valve stems. I'm not aware of anyone actually measuring how the cumulative wear of all of the above can impact valve movement but I'm reasonably confident that if they are all new except for refaced rockers valve movement should be well within spec.

[packratbimmer]

I was at Jim Rowe's (Metric Mechanic) shop one day when he was testing rockers and their "point of failure." He was literally pressing them until failure in order to evaluate them. I'm not sure where he was in R/D at the time, but he was measuring the amount of stress a rocker could take before and after peening. I am assuming he had a method of determining the quality of the rockers as he sorted them before peening and testing. Three things I remember are as follows.

1) Out of the box rockers are not consistent in quality
2) The castings are prone to porosity
3) Some porosity/irregularities are visible to the naked eye

[Gregs///M]

Garbage. My rebuilt engine and head had FEBI rockers that the PO installed. One broke and I replaced them all with Ireland Engineering HD rockers which are much better quality.

I drive like a grandma most of the time and rarely give my E30 full throttle. I have an M3 too so my E30 is just a cruiser. Still broke on me.

[digger]

Garbage. My rebuilt engine and head had FEBI rockers that the PO installed. One broke and I replaced them all with Ireland Engineering HD rockers which are much better quality.

I drive like a grandma most of the time and rarely give my E30 full throttle. I have an M3 too so my E30 is just a cruiser. Still broke on me.

It’s not just about rpm as many have reported the same failure at low speed , at low speed the rockers still see high loads over the nose due to spring tension and as rpm rise the nose pressure actually reduces until the rocker loses contact with lobe nose at some point and the valve starts lofting .

The rpm causes higher dynamic impact loads as the cam takes up the lash and has to accelerate the valve, keepers, retainer, and rocker to open the valves. The cast stuff doesn’t have much ductility and is relatively brittle so they don’t like dynamic loads as the material can’t absorb much energy.

If the clearances are too loose the valve is jolted a lot more as the velocity on the lift curve when the lash is fully taken is higher and dynamic loads increase (velocity squared factor) so valve clearances are critical and erring on the tight size is better for the valve train life especially if the engines sees a lot of revs.

Loose clearances and lotsa revs is a good way to kill things.

[digger]

I was at Jim Rowe's (Metric Mechanic) shop one day when he was testing rockers and their "point of failure." He was literally pressing them until failure in order to evaluate them. I'm not sure where he was in R/D at the time, but he was measuring the amount of stress a rocker could take before and after peening. I am assuming he had a method of determining the quality of the rockers as he sorted them before peening and testing. Three things I remember are as follows.

1) Out of the box rockers are not consistent in quality
2) The castings are prone to porosity
3) Some porosity/irregularities are visible to the naked eye

It is kind of weird that they'd do that. Shot peening is about reducing initiation and growth of cracks by the introduction of residual compressive stress on the surface. It only has effects on the surface and a very small depth and the purpose is for better fatigue life. So doing a static test won’t measure the true benefits.

You might argue that a stronger rocker in a static test would equate to a rocker with better fatigue resistance but this is not good engineering or science it isn’t always true so you can draw some wrong conclusions if you aren’t careful.

AFAIK they inspect rockers and peen them. I don’t know if its just a visual inspection or if they get the X-rayed to I seem to recall they did. Reducing flaws and peening perhaps smoothing is about as good as you’ll get with stock type rockers. I don’t know who make the brand the MM use but it’s probably the same people who make the ones you get from the dealer.

[DirtyTh3rty]

So one guy has them for 10yrs and they are fine and the other says there crap and they broke..

Mixed review is all I seem to get on this topic so that just leads me to believe what either some are defects maybe or people that have had the problem possibly have other worn parts of their motor (springs, shaft, etc..) causing more stress on the rockers?

I mean they are an oem supplier they do make decent enough stuff to sell through BMW so they cant be that bad right? or wrong? haha I'm trying to convince myself here help me out

(Seeing as this is my daily and I've already been out a car over a week now I'm still waiting for my new camshaft to get here and i can finally throw everything together hopefully tomorrow or the next day. I really don't want to wait another week or so for some rockers if i don't need them.)

[TobyB]

If they are ok now, they will be ok later.
Febi is equal to OEM, up until recently.

If your valve springs are weak and you regularly bounce it off the limiter,
you may have problems with either.

t
"another guy who says they're ok on the internet"