 |
|
Having my head rebuilt over the winter. I’ll be replacing the cam with a new one. My understanding is that a new cam requires new rockers. Now, being the frugal type - ok cheap - I’m looking for opinions on what rockers to purchase.
I’ve been fortunate to have never broken a stock one. With that said, I don’t want to go through the expense and time to have a rocker let go in my refreshed head.
OK, so the options; BMW OEM, Febi, IE heavy duty.
Suggestions, pros, cons?
Thanks
Crap, my post got eaten by an Internet hiccup.
Cliffnotes.
AFAIK a new cam does not “require” new rockers.
Febi is one of the mfrs of OEM rockers so any purchase of OEM rockers might come out of a Febi batch.
If you definitely want to replace rockers and IE HD rockers are still pretty cheap, I’d get those.
Another option, is to take your stock rockers and remove the casting marks from the sides. It is probably debatable if this truly helps, but the theory is that if you remove the cast line, there is less chance of a crack forming there. Plus, it might also eliminate some oil windage on the arm itself.
Though seeing as how we are supposed to be running the stock chip, and shouldn’t need to be shifting at 6000+ like we did in PRO3, breaking arms shouldn’t be a huge issue. That along with not using the motor to slow the car down…
If your rockers have any visible wear, they are in drastic need of replacement. Even with rockers that don’t have visible wear, a dial indicator measuring valve lift normally proves they in fact are worn and I always replace rockers and cam for new engine builds.
Most folks stay away from Febi rockers because their fork design makes them less durable and prone to breaking. Then again, some have run Febi’s for multiple seasons without any breaks. I suspect mechanical over revs to be what causes most Febi failures.
You can’t go wrong with OEM rockers from dealer ($29.96 from thebmwpartstore.com). I actually was talking with Jim at Metric Mechanic today about another project and somehow we got on the subject of rockers. Some time ago, Metric Mechanic started usin the Ireland HD rockers, but has recently had both Metric Mechanic and Shrick cams quickly eaten up when using the HD rockers. They have switched back to the OEM units for their builds, but it’s too early to tell if the IE HD units will be okay in stock/spec builds. Metric Mechanic/Shrick cams are much higher lifting and therefore experience higher nose pressure on the cams. Apparently this is a bad combination with the IE HD units. With our lower lifting cams and good oil, I suspect we’ll be fine in our spec motors. Oil choice is very important! Redline, Brad Penn, and Castrol 10W60 (Metric Mechanic’s favorite) are good oil choices.
I would also add, that of all the things to break on your valve train, the rocker is probably the one least likely to cause catastrophic failure of other engine parts. So if you increase the hardiness of the arm, something else is bound to break or fail when all goes south…
Shoot me an email at Anthony@DriveFasterNow.com and I’ll get you good prices on the rockers.
Thanks very much for your responses… No real surprises. If Antony can get me a deal on the IE rockers I think I’ll go that route.:blink: Hopefully our stock cam matches well with the HD rockers
Thanks again!