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Discussion Starter #1
:mad:

So I pulled the valve cover last night “just for peace of mind” - it's been a few months since I replaced the wiped cam from the previous owner. I mean, there is no way the cam is wiped after 600 miles…. Right?

Wrong. It is already showing signs of being wiped. UNBELIEVABLE. THIS IS CRAP!

600 miles ago.....

• New OEM cam and rockers
• Valve lash measured/ adjusted to .012+ on all valves
• All parts slathered in assembly lube
• 300 miles of break in driving without hitting the big cam
• Bypassed the oil coolers – removed the sandwich plate
• Mobil 1 5w-40 Turbo Diesel oil
• Always waited ten minutes AFTER coolant temp shows 185 to get on big cam

600 miles later the cams are getting wiped.

This is crazy. I’m a mechanical engineer in my mid 40’s. I run a factory of over 700 people. I am not some dumb kid that makes stupid mistakes. Over the last 20 years I have had Porsches, BMW's, Mercedes – all maintained myself, all driven “as they should be” – including track time, with ZERO major issues. I am meticulous, organized, and I research like crazy before I take action. I can’t get this damn lotus (With a Toyota motor!) to last for 1000 miles.

Please Help ! What am I doing wrong ??? I’ll sell this POS if I have to replace cams every 1000 miles. What really gets me is no one really knows what the root cause of this problem is, so you are just guessing on corrective action. Ridiculous.

Fed up.
 

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I have heard that some have done a quasi analysis of the oil shower lines above the head do not actually shoot oil where it should be.

It's random thought, but I have a Lotus member out here who needs help with the same scenario... He is on his 3rd I believe...

You even did it right the first time and replaced all the rockers and everything. Maybe investigate exactly where the oil goes pressurized. No idea where that thread is? If it was not on LT it might have been on newcelica.org




Just a possible lead. The thread in question even had technique to be clear where oil was going. I think he just used pressurized water or something and did a plot that matched the head. The spray on more than one aperture was def going the wrong way. It is one possible cause to investigate for those with multiple cam wear issues... If I recall he figured what the correct angles should be and enlarged the openings in the correct way so that the oil was going where it was designed to go.
 

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Metallurgy

Do you have any metallurgy contacts that you could work with. It looks to me like the cam is not hard enough. If that's the case, then the supplier needs to hear about it.
 

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I have heard that some have done a quasi analysis of the oil shower lines above the head do not actually shoot oil where it should be.

It's random thought, but I have a Lotus member out here who needs help with the same scenario... He is on his 3rd I believe...

You even did it right the first time and replaced all the rockers and everything. Maybe investigate exactly where the oil goes pressurized. No idea where that thread is? If it was not on LT it might have been on newcelica.org




Just a possible lead. The thread in question even had technique to be clear where oil was going. I think he just used pressurized water or something and did a plot that matched the head. The spray on more than one aperture was def going the wrong way. It is one possible cause to investigate for those with multiple cam wear issues... If I recall he figured what the correct angles should be and enlarged the openings in the correct way so that the oil was going where it was designed to go.
The sprayers are so close that the general consensus is that the angle of spray shouldn't matter.
 

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Discussion Starter #8
One "solution" that I am considering is installing MWR Stage II cams and upgrading the valve springs. Has anyone wiped a MWR Camshaft ? I've read that they test significantly harder on the rockwell "C" scale.
 

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One "solution" that I am considering is installing MWR Stage II cams and upgrading the valve springs. Has anyone wiped a MWR Camshaft ? I've read that they test significantly harder on the rockwell "C" scale.
It seems any of the aftermarket cams are more highly regarded than OE
 

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Arch. Project Manager
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What he said:popcorn:
 

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One "solution" that I am considering is installing MWR Stage II cams and upgrading the valve springs. Has anyone wiped a MWR Camshaft ? I've read that they test significantly harder on the rockwell "C" scale.
I would like to hear about this option also. Does anybody have any first hand experience with aftermarket cams in a otherwise stock motor?
 

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We did a lot of Rockwell testing years back (JCR and us, the royal "we")... tested the rockers, the cams, OE and aftermarket. Yes, the aftermarket cams are much harder... There is a happy medium as we took the efforts to fortify the stock cams with various treatments to improve the surface durability. The problem went the other way and our super OE cams ate through the rockers... The hardening process certainly impacted the lubricity of the material.... Nevertheless, it's rare to see aftermarket cams fail. Not unheard of, however, but rare.

People celebrate the Yamaha head. I've never figured out why... That said, the lions share don't have cam problems, so there's that too...

-Phil
 

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The synthetic diesel oil was generally accepted as a standard going ack to something like 2013 and before due to it having slightly higher ZDDP than gasoline oil. We've used Redline Race oils for years and the reality is that we've seen the cams wipe with every oil imaginable, with and without ZDDP additives, etc...

The issue does not seem to be linked to oil.

-Phil
 

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My second head likes to eat cams. I ran .018 clearance all around. Ate mutiple stock cams and one stage 3 intake cam.
Roller rockers solved that problem. Running wide lash solves most wipping. .012 is too tight IMHO . My first " stock " head
didnt wipe cams ( 13,000 miles ) .
 

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George B.
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Did I overlook something? After reading the Wiped Cam Threads, I decided I would always replace the little O ring that fits on the pipe that feeds the shower in top of the valve cover. I called my local Toyota parts Man, he's unable to find the part, and says there's no picture of an O ring, nor is there a part number for it.

So I look at two 'on line' Toyota parts catalogs, and sure enough, it's not shown or mentioned. I used 2005 Celica GTS and confirmed 2ZZGE Pictorial was what I was looking at. It does make me wonder how often they get changed, but the chance this has much to do with failures is small I guess. If anyone has the number for a proper O ring, I'd appreciate knowing same.
 

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George B.
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Just one more swing at extending the life of this thread? from a quote above: "I keep thinking I should pull my valve cover and look at my cams...and I keep chickening out because the car runs fine and I have enough car projects going on....". I took my car to My local Lotus Dealer, The Service manager drove it, thought all was fine. Two of my intake high lobes were wiped, and unless I was able to break a rocker on the way home in heavy traffic, the rocker was broke too. I suggest you look, I'm glad I did, what was going to break next?

With this said, I had a spare head with what looks like a real nice intake cam and rockers. They're now installed in my engine and careful attention was made to keep the lobes and rockers mated. How will they get alone on the new rocker shaft? We'll see... BTW, the rocker shaft in the car looks absolutely new, the shaft in the used head has wear marks, so I'd guess that the used cam and rockers were doing fine for far longer than my failed cam.

Are some heads kinder to Cams? With Modern CNC and such incredible tolerances, that's hard to believe, but I just got here...
 

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On a stock motor, can we just upgrade to stage 2 cams and call it a day? Or would we need additional tunes/parts/etc. I thought MWR only offered stage 3 or you had to have a modified engine ... correct me if I'm wrong please.
 
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