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Discussion Starter #1
Ok, so this problem started after the first head gasket replacement. Upon breaking down the engine (@114,000 miles), my buddy mechanic (an off shift LR tech) noticed how some tappets/lifters had square wear marks (signs of needing replaced according to RAVE) and my camshaft was also worn a bit, nothing excessive but about right for 114K miles. So I was convinced to replace the camshaft, tappets/lifters and while I was at it, the timing chain, along with all the typical head gasket related materials. All parts were ordered through Atlantic British. Everything seemed fine and the truck ran well, until about 1200 miles later. Excessive misfiring (cylinder 6) and very loud rattling of the lifters was noticed, along with a backfire noise through the airbox. I never overheated the engine, but I did have to limp it 20 miles to a buddy's house since I was in rural area.
After getting the truck towed to an actual rover shop this time, so the work could be warrantied, it was discovered that the backfire through the airbox was due to the exhaust valve not opening, therefore the cylinder combustion was backfiring through the inlet valve. This was due to the fact that the #6 cylinder camshaft lobe was completely gone. It had been completely ground down to the shaft. So there was nothing to open the exhaust valve. It was believed that the lifter had seized and basically beat the lobe down to nothing. So now the top end of the engine was completely redone again, new camshaft, new lifters, all the appropriate head gaskets etc..., new plugs, and even a new water pump just because.
So now after the second rebuild, everything seemed fine. We drove to the Outer Banks,NC on vacation, and had been driving it to work for almost 2 months.
Now approx. 2000 miles later, I had another misfire and that all too familiar sickening sound of lifters rattling. I immediately took the truck to the shop. After getting a phone call back this afternoon, it seems the exact same thing has happened, except this time the problem is with cylinder #2. WTF? I mean if it was the same #6 cylinder it would make a bit more sense, but since now the camshaft lobe is completely gone on cylinder 2, I'm completely confused.
When the shop did all the work last time, they checked all of the valves, and pushrods and everything seemed in order. The shop is confused as well. That's two camshafts my engine has eaten is less than 4K miles.

So this thread is asking for everyone's help in figuring out what in the hell is going on? Please just give me any possible causes or solutions to this problem!!
 

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I'm no expert in engine rebuilding, but I have read comments by experts... LOL If an entire cam lobe has been ground down, that strikes me as introducing a hell of a lot of metal shavings into the engine block and all the oil passages. With that much metal getting pumped around, all the block's oil passages should be given an extremely thorough flushing. If flushing isn't really practical due to the design of the engine, then the block should be considered scrap and should not be rebuilt. I think it possible that metal shavings have contributed to your problems. But, now that I think of it, that doesn't really address the first episode of grinding down the cam after the first top end job... Regardless, it seems there may be an oiling problem, and possibly the block should be scrapped, unless it can be confidently cleaned of all debris.

The various brand new Range Rover block options are really reasonably priced versus a rebuild. I would strongly consider buying a new block this time.

My engine is at 105,000 miles. Having just seen one of my lifters due to a recent head gasket job (overheating due to my negligence) and noting its pristine condition, I have to winder about your comments about expected wear and expected necessary replacement of lifters at just 114,000 miles. Here's my post showing a picture of the lifter.

viewtopic.php?f=3&t=32128&p=248693&hilit=lifter+pic#p248693

Based upon my observation, I don't think I would expect the wear.

Brett
 

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Look closely at lubrication, understand that if a cam bearing is not carrectly installed or shifts, or a passage plug is missing then lube is cut off. Flush the passages and blow them out. Also check oil pump bypass and pick up screen. It is posible that if the pan was not removed when the cam failed, all the metal would go to the screen as well as any gasket or carbon scrapings that fell in while cleaning.
There are so many variables, but the above are some of the most common causes of cam wear.
To help you diagnose if is an lube issue or a defective product: Oil flow usually goes into the pump, past the main bearings through the crank and rod journals, up to the cam bearings and lifter galleys, through the push rods, and flows out the top of the push rod dripping down the rocker arm lubing the valve train and returning to the pan .
Scrutinize every oil passage and bearing position if re-using this block.
Good luck :wink:
 

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Discussion Starter #4
Thanks for the replies guys, keep them coming.
The pan was dropped on the last rebuild, and the mechanic looked for metal shavings since the lobe was sooo bad, but didn't find much at all. The pickup screen looked pretty clean, and I was told it seemed as though oil was flowing fine across the head. I haven't gotten to see the lifters etc. as it sits right now, but could a lifter not rotating be part of the problem?
A lifter not rotating I assume would be due to it not getting propper oil?
 

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Do you use the proper running in procedure and use proper camlube when assembling?
 

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Discussion Starter #6
I didn't actually do the assembly myself, but yes they did use cam lube, and I believe the correct break in procedure.
Isn't it something like running the engine around 2K RPM for about 15-20 min? And this was done on both of the last two rebuilds.
 

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1. the rockers may have been inadvertently installed incorrectly ... they may look OK but if they're in wrong order... -> oil starvation and ... :crybaby2: check the order of the rockers ..i.e. the way they're pointing ...very carefully!!

2. Don't use synthetic oils... they are not optimum for "old fashioned" pushrod engines such as GEMS/THOR. For modern roller cam/roller rockers... synthetics are great stuff...

3. While going up/down, pushrods and lifters are designed to also rotate so as to spread the wear pattern ...synthetic oils are too slippery and reduce the rotation... hence the rectangular wear pattern you observed on the lifters (from being hammered in the same spot by the cam lobe). Stick with a high quality 10w-40w mineral based oil

4. The 20 mins running in @ 2000 rpm at first start up is critical...don't let the engine idle. If you need to stop it, cut the ignition, make adjustments then fire it straight up to 2000rpm again when you restart

there's extensive discussion on this in other posts... it's worth a search

good luck
 

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Hoges said:
1. the rockers may have been inadvertently installed incorrectly ... they may look OK but if they're in wrong order... -> oil starvation and ... :crybaby2: check the order of the rockers ..i.e. the way they're pointing ...very carefully!!

2. Don't use synthetic oils... they are not optimum for "old fashioned" pushrod engines such as GEMS/THOR. For modern roller cam/roller rockers... synthetics are great stuff...

3. While going up/down, pushrods and lifters are designed to also rotate so as to spread the wear pattern ...synthetic oils are too slippery and reduce the rotation... hence the rectangular wear pattern you observed on the lifters (from being hammered in the same spot by the cam lobe). Stick with a high quality 10w-40w mineral based oil

4. The 20 mins running in @ 2000 rpm at first start up is critical...don't let the engine idle. If you need to stop it, cut the ignition, make adjustments then fire it straight up to 2000rpm again when you restart

there's extensive discussion on this in other posts... it's worth a search

good luck
Could also be that the pushrods aren't rotating like they should and maybe that's where some of your previous metal got to, plugging the pushrod. Also, if the lifters did not get checked for cupping from previous failure OR at least trued on a flat emry stone that may have contributed to the second lobe lunch. It may also be that the particular lobe that went away on the second cam was just not hardened as well as the lobes that were fine, meaning that none of your valve gear was at fault and it was just an unfortunate and unavoidable coincidence.

Like the man said, a lot of variables.

Good luck with number 3.
 

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Camshaft and lifters should ALWAYS be replaced as one part.
If you've used old with new, that's why your camshafts are selfdestructing.
 

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q-rover said:
Camshaft and lifters should ALWAYS be replaced as one part.
If you've used old with new, that's why your camshafts are selfdestructing.
Absolutely, I don't know what I was thinking. Just realized he had 1200 on the set anyway. However, some have had the luck of fools and gotten away with that (a long time ago in a galaxy far, far, away...) But no matter, even if you pulled them just after break in (2000/20) they should still be replaced as one part. My bad for even suggesting you used the used. :doh:
 

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Discussion Starter #12
Thanks for more input.
Yes on both of the last 2 rebuilds, I had new lifters and a new cam installed.
You wouldn't think this would be the case, but everyone in my local Rover club, along with the shop, and other hotrod enthusiasts I've talked to all believe it to be a camshaft parts quality issue. It does seem that I've had piss poor luck and that on both of the last two cams the hardening wasn't done correctly or something. Because all of the other lobes look perfectly fine, and then the exhaust lobes (#6 first rebuild, #2 on this second rebuild) were completely ground down to the shaft. I've heard some opinions, and read posts across the internet that Britparts has some quality issues with their products. I'm not sure where AB is getting their cams, but this has really got me wondering now.
And I'm not try'n to give AB a bad name either, don't get me wrong, but I won't be ordering cams from them again.
I've been assured that oil is getting across the head just fine, the lifters are rotating like they are supposed to, and the rocker arms are operating properly. I've now decided to go with either a genuine cam and lifters, or cam/lifters from D&D Fabrications. From reading up on Rover forums and talking to other enthusiasts in the know, they provide quality replacement parts for our Rover "215" engines. http://www.aluminumv8.com/engine/engcomp.htm
 
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