HD rocker arms ....lesson learned

[zaq123]

Long story short, I'm replacing cyl. head on my freshly rebuilt M20 after 1000 km. (very slow coolant leak under the valve cover around cyl 5&6). Shop that machined the head never pressure tested the head because they had no proper setup. I never used the head before the rebuild so I don't know if it was pre existing condition or something happened during my engine break in???

But my post is not about that. My new Schrick 288 cam's IN lobe on cyl 1 is all messed up with just 1k km. Clean room assembly with all clean parts, assembly lube, primed engine etc etc. Everything looks very good but cyl 1 IN lobe....the cam is garbage. Also stiffer springs were used.

It appears all this pressure was rocking the pad in one HD rocker just enough to kill the cam.

Here is link Metric Mechanic updated article when they tested these HD rockers in 2021. I don't believe there were any changes to current HD arm design since pre Covid era but let me know if anyone aware of any. But it summarizes my issue pretty well. Enjoy the read. One bad rocker and it's an expensive lesson.

https://www.dropbox.com/scl/fi/dk5iijfcinlt2qxxy803d/E9-MM-3200-Rally-M20-Engine-copy.pdf?rlkey=05uplm86qkia0r52h32u0nbsg&e=1&dl=0

[82eye]

i've read something about this before but never encountered the issue with mine. i run the hd's since i have a lightweight flywheel and can occasionally hit 7k rpm. the stockies are known to fail much more often up there even when only seeing it briefly.

i'm running a mild regrind cam which it probably easier than a billet grind cam on them.

[2mAn]

I've been contemplating which rockers to get for the new camshaft install... Cam is a Billet 272 from Ireland Engineering that I will pair with a MarkD chip so it will see 7000rpms since the car also has a lightweight flywheel. The dyno will tell us that revving it that high is probably pointless, except that it would sound great haha

I'm still on the fence on whether I should get the HD rockers or not. I know MR 325 sells some steel rockers also, but not sure if thats overkill for my cam profile...

[zaq123]

I've been contemplating which rockers to get for the new camshaft install... Cam is a Billet 272 from Ireland Engineering that I will pair with a MarkD chip so it will see 7000rpms since the car also has a lightweight flywheel. The dyno will tell us that revving it that high is probably pointless, except that it would sound great haha

I'm still on the fence on whether I should get the HD rockers or not. I know MR 325 sells some steel rockers also, but not sure if thats overkill for my cam profile...

read that bulletin from MM in the first post. I'm done with HD, like it's an expensive gamble to get one bad rocker out of 12. My options right now are OEM or something crazy expensive like RHD roller ones with their cam/spring package. I'm thinking about OEM /shot pinned OEM since I have another brand new Shrick cam sitting around.

[digger]

if you can check that the lobe didnt run off the end of the pad and the edge of the pad didnt dig into the cam? that was one issue since they were designed for reduced base circle cam that you get with a regrind. i thought was solved so may not be the root cause.

The surface finish of the pads always appeared to be sub standard to the OE rockers.

i use peened and inspected rockers from MM. i dont know if they still sell those. i see with their article they are marketing hard trying to sell expensive unwarranted stuff and trying to fix problems that dont exist

[zaq123]

if you can check that the lobe didnt run off the end of the pad and the edge of the pad didnt dig into the cam? that was one issue since they were designed for reduced base circle cam that you get with a regrind. i thought was solved so may not be the root cause.

The surface finish of the pads always appeared to be sub standard to the OE rockers.

i use peened and inspected rockers from MM. i dont know if they still sell those. i see with their article they are marketing hard trying to sell expensive unwarranted stuff to

Pad was long enough and no run off...there are visible zones on each side of the pad where cam didn't make any contact. I'm not sure if I want another set of HD for my new cam. Go OEM which are Febi? Go Febi ? RHD is an option but the price of the set with springs and the cam is kind of pushing it. What's your thoughts?

[digger]

Pad was long enough and no run off...there are visible zones on each side of the pad where cam didn't make any contact. I'm not sure if I want another set of HD for my new cam. Go OEM which are Febi? Go Febi ? RHD is an option but the price of the set with springs and the cam is kind of pushing it. What's your thoughts?

i would use the peened and inspected rockers from MM if they are available

[digger]

to add to this i use a Catcams cam with 11.95 mm lift with 7000 rpm rev limit and stiffer springs (stiffer than even schricks) and for 10 years daily driving the cam looked like new with the rockers from MM. It wasn't until i mistaken followed a recommendation and tried a different oil that the cam started to scuff (the oil may be a coincidence)

Also there have been issues with schricks and hardness on other engines so its the world we live in

[varg]

Pad was long enough and no run off...there are visible zones on each side of the pad where cam didn't make any contact. I'm not sure if I want another set of HD for my new cam. Go OEM which are Febi? Go Febi ? RHD is an option but the price of the set with springs and the cam is kind of pushing it. What's your thoughts?

Any pics of the of the pad and cam? Areas of no contact on the pad as in a concavity or raised surface profile that's causing isolated areas of wear instead of a clean, even contact patch?

Also there have been issues with schricks and hardness on other engines so its the world we live in

Really? Pretty inexcusable for such a big name with fairly premium priced cams to have a pattern of obvious quality escapes. I wonder if Schrick does their manufacturing in house or if they have a supplier who is slacking on hardness testing parallel with production.

Does anyone offer inspected rockers? I don't see it on MM's website so I'm assuming they no longer do. It would be nice to be able to buy a set of rockers that have been checked for pad profile and dimensions.

[It's Soda Not Pop]

I've had the HD rockers from Bimmerheads snce 2017 and I have kissed (bounced off) 7k rpms a few times. I've never had any issues. I also have a regrind cam (274/280).

[82eye]

I'm still on the fence on whether I should get the HD rockers or not. I know MR 325 sells some steel rockers also, but not sure if thats overkill for my cam profile...

the febi hd rockers being discussed are now nla. the choices are down to the bimmerheads steel rockers, the IE peened rockers, or the rhd sprung rocker. bimmerheads and IE used to carry the febi hds but can no longer source.

if you order febis you sometimes get an hd. they just deleted the internal part number and rolled what was left back into their regular stock. they don't make a distinction, and they don't worry about it creating cam issues on a stock engine.