Rocker pad damage due to aftermarket valve springs?
I haven't been on the board much lately but wanted to share something- an NTPOG member recently came to me for a valve adjustment. We found out his rocker pads were BADLY scored with a "dip" where contact from the cam lobe occurs. He has Skunk2 springs (and retainers) with STOCK cams (base). No other mods, other than valves (Endyn, supposedly).
All the headwork was done after an overrev where he cooked the top end. He went with the valvetrain upgrades to improve resistance to overrev disasters but left the stock cams due to financial constraints.
After the head was done he complained of valve tap. I checked the clearance and all the valves were a little loose. Buttoned it up and the noise was better. Fast forward 6 months (to present), valvetrain is noisy again. Valve lash was off by at least .050" or more (yes, .050"). I checked the rockers and found the damage.
This is the second such time I have seen stiff valve springs do damage like this, or at least I ASSUME the springs cause the damage (the other time was 71dsp's failed Webcam/Type S cam install). I can't for the life of me come up with an explanation as to why there would be a problem, other than too stiff of a spring.
The rocker pads had a "divot" in them (in the middle at the normal contact area) and the cams were "ground" down at the point of initial and peak lift.
Any other reports of this, or any ideas? This could be VERY problematic for people buying Skunk2 springs and I'm worried about Crower stuff (hopefully not as stiff?).
I had that problem with my rockers at 80k..... I was running Type S cams with the stock valve train. It leaves a very faint line on wiper where the lobes ramp makes contact. The only solution I can think of other than replacing all the rockers ($$$) is to either have new wipers brazed on the rockers or regrind the current ones. The only problem I can think of with regrinding or brazing them is that they have to be done as a set, so all three line up correctly with the cams centerline.
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97 Type SH; Type S H22A, Crower stage IIa, Mugen Showa.
06 Accord V6 6MT; H&R OE Sports
Keep in mind after skimming the specs of Crower, Skunk2, Eibach, JUN, and Webcam the Skunk2 springs are the stiffest of the bunch. I'm only assuming it's to accomidate their high lift cams.
Though was the damage done solely due to the valve lash being off by such a high margin?
Originally posted by bb6flier I had that problem with my rockers at 80k..... I was running Type S cams with the stock valve train. It leaves a very faint line on wiper where the lobes ramp makes contact. The only solution I can think of other than replacing all the rockers ($$$) is to either have new wipers brazed on the rockers or regrind the current ones. The only problem I can think of with regrinding or brazing them is that they have to be done as a set, so all three line up correctly with the cams centerline.
A faint line is fairly common. I have seen this on stock engines with 50k+ miles on them (stock as in stock cams, stock springs, etc. etc.).
These rockers that I looked at this weekend (and my own) have divots in them that are at least 0.5mm deep.
As for repairing the rockers, AFAIK, they are hardened, so you really can't "fix" them. A new set is the best way to go. IIRC, that'll run about $850.
Originally posted by paulyg Do you think this could also be an affect of the type of oil used?
Do we know what type of oil was used in the failure cases?
I started thinking about that last night. I used 5W30 when I had my problems. I don't know what Mike was using in his car. I was thinking that an oil that has a thicker film might work better, as the cam literally scrapes on the rockers. Maybe something as thick as 15W50? I have no idea what that would do to the rest of the engine, though. Maybe a straight 30 weight race oil would work better. Who knows without actually trying it.
I do recall a tuner (I really forget who) that recommended the use of dino oil in a straight 30 weight (i.e. racing oil).
How much lift do you think you can put on the Vtec rocker before the lost motion assembly bottoms out??? I just havn't seen any data concerning just how much lift they can take.
Plus... when you look at it, in Vtec the center lobe is the only one making contact with the cam when the valve is open. The Vtec lobe is forced to push the valves open farther, faster, and with alot more spring pressure than stock.
As far as the oil type used, I would think that a thinner oil would be better since it will lubricate the head faster on cold start-up.
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97 Type SH; Type S H22A, Crower stage IIa, Mugen Showa.
06 Accord V6 6MT; H&R OE Sports
Originally posted by bb6flier As far as the oil type used, I would think that a thinner oil would be better since it will lubricate the head faster on cold start-up.
I was kind of thinking the same thing, but . . . . **shrug**
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This is why I'm a fan of the Mobil 1 0W-40 synthetic. This oil is the best of both worlds since it passes the GF-3/engergy conserving standards in addition to passing rigourous European valvetrain test standards. It's the best oil I've ever seen.
After saying that, though.... This is a boundary layer lubrication issue, so maybe 15W-50 is your best bet. From my experience, the Valvoline VR racing series oils might be the best solution since they have more zinc/phosphorus (ZDDP or ZDTP) than newer oils for antiwear. This will cause you some power, but with a good MoDTC or MoDTP additive like Mugen MT105, you might have the best protection/power balance you will ever get.
I would think that something as heavy as a 50 when hot would have drawbacks that would outweigh any benefit (being a lot heavier).
Billy, my guess is that MikeD was running 10W30. Most lube shops put that crap in cars in TX because they think it protects the motor better. I still don't think it does any better in the heat and serves to increase wear on startup.
bb6flier, the problem here appears to be just on the VTEC lobe- so unless you're VTEC'ing on startup, it shouldn't be an issue for that. My concern on startup is the increased valve chatter as the valvetrain doesn't seem to lube up as fast.
Has anyone cryo'd rockers? Think that a cryo job, or some kind of improved surface hardening would help?
Originally posted by Justwakin he is running mobil 1 synthetic 5w 30.
According to Justin, he was running 5W30, the same that I ran.
As for cryo treating, the cams and the rockers are surface hardened from what I know. Cryo treating might help, but they are supposedly hardened already from the factory.
The lost motion assembly is a good question. I don't think anyone has looked at how much lift the lost motion assembly can handle without binding. However, in this case, stock cams were being used, so the valve lift that the lost mostion assembly can handle is a moot point.
I think at this point, everyone agrees that spring pressure and lubrication (or lack thereof) on the rocker pads is the problem.
Perhaps the only way to run lightweight oil with aggressive cams and springs is to use a roller rocker setup.
billy and todd as you know mike is really talking about selling the car. stuburn bastid.
here is my question. todd you give him 10k more miles untill there is real damage correct? if he went thicker oil for now how much tiem would that save him? and if he went back to stock springs do you think things would be fine or still be bad because the pads have worn down so much? im trying to talk him into getting a new head and just stay with the car but it doesnt look like he will.
Originally posted by MC_HondaRacing This is why I'm a fan of the Mobil 1 0W-40 synthetic. This oil is the best of both worlds since it passes the GF-3/engergy conserving standards in addition to passing rigourous European valvetrain test standards. It's the best oil I've ever seen.
After saying that, though.... This is a boundary layer lubrication issue, so maybe 15W-50 is your best bet. From my experience, the Valvoline VR racing series oils might be the best solution since they have more zinc/phosphorus (ZDDP or ZDTP) than newer oils for antiwear. This will cause you some power, but with a good MoDTC or MoDTP additive like Mugen MT105, you might have the best protection/power balance you will ever get.
I always wondered why Honda puts 0W40 in my car here... now i know.
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1999 Prelude 2.2 VTi 4WS
I speak fluent typo
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