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1996 Range Rover P38A
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Discussion Starter #1
My valley gasket was leaking like a tea bag and i decided to do something about it, i stripped down the to valley gasket and then i saw the state of the camshaft, oh dear me.

IMG_2152.jpg The block cleaned down, camshaft removed.


IMG_2141.jpg Not the worst, but almost 0.020" missing of this follower.

IMG_2154.jpg If you look closely, the lobe is pitted and starting to break up, this lobe appears to have lost about 0.040" off the tip.

My 4.6 HSE 1996 has done 108,000 miles. It always started off the key, and apart from a bit of a wobbly tickover it's never given me any problems, i thought it was a little breathless but it is 16 years old. I had recently checked the compression pressures which seemed quite healthy at between 160 and 170psi cold. I had no idea that the camshaft could be such a major issue.

A chat to Chris at RPI reveals that this wear is perfectly normal, in his opinion these followers can wear out in as little as 60,000 miles, and certainly around 80,000 miles. I couldn't believe what i was hearing. He also told me that the cam chain would be completely shot, and it was.

I thought these motors basically lasted forever!!


The Piper Torque Max appears to be the replacement of choice and a set of OEM lifters a must. Has anybody else experienced cam failure like this?

Stripping down i found that a number of bolts were loose, mainly around the inlet manifold. The bolts holding the front cover seemed to have thread locking agent on them, on the others it was harder to tell. Is thread locker recommended?

I thought about removing the heads but have so far relented because of the issue of stripping the threads, and a new stud set is remarkably expensive even if i manage not to strip the threads in the head, i think i'll leave them alone.

I can't stress enough how well this truck drove, i wonder how many others are driving around not realising that their cams eating itself!!
 

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1970-1995 Range Rover Classic
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i think mine is starting to go as well. its going to be my winter time project with a set of new injectors. I think i'm going to have mine welded and then have a custom grind done to it. add some new lifters and drive it until it blows up. I have 120K miles on mine.

out of curiosity:

have you owned it since new?

what type of oil have you been using?

Thanks
 

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1996 Range Rover P38A
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146 Posts
Discussion Starter #3
No, i've not owned it since new, just the past 7 years. I had been using a 10/40 semi synthetic but quickly moved to 20/50 because of the leaks. The thicker oil did slow the leakage down a lot, but i wanted to sort the leaks before the winter so i could use a lighter oil.

I can't help thinking that oil is a major issue here, there's no oil feed par se, only whats dribbling out of the rocker boxes.

I'll expand a little more later, it's late and i have work tomorrow:sad:
 

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1970-1995 Range Rover Classic
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Just curious because I use full synthetic Mobil 1 10w40 in mine. It would be interesting to compare
Camshafts from those on conventional and those on synthetic to see if there is a wear difference.

I've had mine for 2 years and started using synthetic on my first oil change. I've put 40000 miles on it since then. And I don't know the service history with this one.


Sent from my Autoguide iPhone app
 

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1996 Range Rover P38A
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Discussion Starter #5
I'll put a micrometer across the lobes tomorrow and measure exactly what i've lost, but i already know it's severe. In the front casing there are two pressure release valves, i'm wondering how much of my oil is being dumped straight back to the sump because the oil is too thick and/or too cold.
For me, the bottom line is poor design, insufficient oil supply. I've seen oil sprayed direct onto the cams from spray bars, but this has nothing.

David Hardcastle has a simple mod to get more oil to the cam chain, which suffers just as bad. It involves drilling a 1/4" hole so oil draining from the rocker box can be diverted into the front case, i shall certainly employ that idea.

I have a number of books on V8's by David Vizard, on block prep and race design, i'm going to sit and study for a short while.

I didn't know you could weld cams, i didn't think you could heat treat weld, or maybe is just case hardened?

I'm going to see if i can get any technical information out of Piper Cams, see if any improvements can be made to extend the life of the cam and it's lifters.
 
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Definitely looks like a 'lack of lube' there, arudge, worn right through the face-hardening... and yes bad cam oil-feeder arrangement/design indeed, probably not helped much either if thicker oils are used.... as you know.

- I share your concerns about the viability/£ of re-facing/re-profiling the cams, are they all as bad as the one in your pictures ?

- That David Hardcastle oil-diverting mod sounds interesting/effective, any further details/photos/etc ?
 

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1996 Range Rover P38A
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Discussion Starter #7
Had a chat to the lads at Piper cams today. I had some ideas about further lubrication with which they agreed, but I also asked about welding.

Welding cams is not something they advocate or would do. However, their cams are hardened to 56/58 roc and I have rods at work rated at that.

Personally, looking at how much time it would take me to TiG up 16 lobes I'd have thought it would be cheaper to buy a new cam, but if you were after something radical I can't see why it can't be done. I've never hardness tested the hard weld, we use it to create cutting edges, but I can testify its f***ing hard!!

I'm going to work on my oil mods and I'll post again when I have something to show.
 

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1996 Range Rover P38A
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Discussion Starter #10
IMG_2160.jpg This the oil modification suggested by David Hardcastle, it is simply a hole drilled through the casting to allow oil that is pooling in the valley to flow into the timing casing, and therefor giving the timing chain some oil along draining the oil a little quicker.


IMG_2159.jpg I decided to pull the main shell bearings to check their condition, oh dear. 108,000 miles and completely worn out. My local mechanic said he wasn't surprised, a little premature but not unremarkable. They will get changed, the crank is ok but i wonder how many rigs are rolling along with their owners thinking everything is just fine.

I now need to know if a better oil is the answer, but i'm told that everything i've found is considered normal.
 

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i don't know, i've torn down quite a few motors. some with 200K miles and the bearings haven't looked that bad. another reason i use synthetic oil.

are you going to just stick new main bearings in there and call it good, or are you going to tear it all down and rebuild?
 

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I'm in a similar situation... been dealing with Piper cams direct...Rpi's flippant response left me cold. The torquemax is expensive for what it is and a new standard cam from Turner engineering and standard chain set is all that's needed. Spend the cam savings on a set of ARP head studs rather than the TTY bolts. They now have a specific kit for the 4.6L ... The part number is 157-4301 and it is available.
cheers
 

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Discussion Starter #13
Getlost4x4.
I don't have sufficient funds for a full rebuild, this was only supposed to be a valley gasket change!

On the one hand i want to remove the heads, check the valves, do a little work on the ports, on the other i want my truck back on the road. I think what i'll do is leave the heads for now, but get a couple to work on from the breakers, work on them and fit them at a later date.

I'm going to go with the fully synthetic oil. The engine is clean, all the oil gallery's have been flushed out, the oil cooler has been drained and cleaned, oil pump and pressure relief valves cleaned out.

I'm also going to "T" off the oil pressure switch and fit a gauge, see what pressure we get compared to rave.

Hoges.
Thanks for contribution. Chris at Rpi is something of a character, i don't blame you for walking away.

I don't know too much about cam profiles, but i do know a fair amount about hardening steels and heat treatment. We have a lot of issues with heat treatment, sometimes it can be a bit hit and miss. On this occasion i'd rather stay with a quality product because i can't test the hardness, i could at my last place. I just don't trust cheap cams, the money is in the steel, not the grinding.

I couldn't find the studs you referred to, i'll give them a ring in the week.

Thanks again.
 

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i don't think there is anything wrong with throwing some new bearings in there and calling it good as long as the rest looks good. rebuilds can cost a lot. just check your surfaces on the crank to make sure they are still in spec. i've thrown bearing in a motor to get by for awhile and had good results..
 

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My valley gasket was leaking like a tea bag and i decided to do something about it, i stripped down the to valley gasket and then i saw the state of the camshaft, oh dear me.

View attachment 11760 The block cleaned down, camshaft removed.


View attachment 11761 Not the worst, but almost 0.020" missing of this follower.

View attachment 11762 If you look closely, the lobe is pitted and starting to break up, this lobe appears to have lost about 0.040" off the tip.

My 4.6 HSE 1996 has done 108,000 miles. It always started off the key, and apart from a bit of a wobbly tickover it's never given me any problems, i thought it was a little breathless but it is 16 years old. I had recently checked the compression pressures which seemed quite healthy at between 160 and 170psi cold. I had no idea that the camshaft could be such a major issue.

A chat to Chris at RPI reveals that this wear is perfectly normal, in his opinion these followers can wear out in as little as 60,000 miles, and certainly around 80,000 miles. I couldn't believe what i was hearing. He also told me that the cam chain would be completely shot, and it was.

I thought these motors basically lasted forever!!


The Piper Torque Max appears to be the replacement of choice and a set of OEM lifters a must. Has anybody else experienced cam failure like this?

Stripping down i found that a number of bolts were loose, mainly around the inlet manifold. The bolts holding the front cover seemed to have thread locking agent on them, on the others it was harder to tell. Is thread locker recommended?

I thought about removing the heads but have so far relented because of the issue of stripping the threads, and a new stud set is remarkably expensive even if i manage not to strip the threads in the head, i think i'll leave them alone.

I can't stress enough how well this truck drove, i wonder how many others are driving around not realising that their cams eating itself!!
Thank you for posting these photos -they are most helpful. Am in process of gradually dismantling mine to change the head gaskets and the cam etc. I am about to remove the radiator. Is it possible to remove/replace the cam without disrupting the oil cooler and aircon heat exchanger? Thanks and regards
 

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1996 Range Rover P38A
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Discussion Starter #16
Thank you for posting these photos -they are most helpful. Am in process of gradually dismantling mine to change the head gaskets and the cam etc. I am about to remove the radiator. Is it possible to remove/replace the cam without disrupting the oil cooler and aircon heat exchanger? Thanks and regards
I pulled everything out, but i had issues with the A/C so i had no qualms about breaking the A/C lines.

However, i've loose laid the A/C exchanger back in to see if it can be done.



IMG_2168.jpg The cam won't quite go back in, but not by much, the smaller cooler is the transmission cooler and is not an issue. You may have to unbolt the A/C dryer to give yourself a little more movement with the A/C heat exchanger but you may have enough as the flexible connecting hoses have a fair amount of movement.




IMG_2167.jpg As you can see, the fans are still attached, with these removed i'm sure you'll have enough room to pull the rad further forward and then pull the cam out.



A word of caution if i may.



IMG_2146.jpg This is the connection to my transmission cooler after i tried to undo it, the action of unscrewing the joint tore the thread clean off. I've since leaned this is common, but there is no need to remove this cooler so leave it well alone. The engine oil cooler is the same but you can break the joints on the timing casing with ease, the timing casing has to come off anyway so you may as well remove the hoses first, don't even consider the joints on the oil cooler itself. The cooler is aluminium, the fittings are steel. It's not the only mistake LandRover made.

If you need anymore pics please do ask.
 

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This is why you remove the engine for any in depth repairs/upgrades. The block is so easy to remove on our rigs it really is not worth the back aches, poor access and frustrations to leave it in place. Block stands and hoists are dirt cheap to rent and far worth the minimal cost.
 

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This is why you remove the engine for any in depth repairs/upgrades. The block is so easy to remove on our rigs it really is not worth the back aches, poor access and frustrations to leave it in place. Block stands and hoists are dirt cheap to rent and far worth the minimal cost.

I agree with you...regretably however, back aches, poor access and frustration are part and parcel of my "now" situation... as my only available secure work space provides approx 35cm (14") between the front bumper and the wall and less than that between the rear bumper and the roller door which opens onto the street /:( though there are a couple of metres of clearance either side... however there is insufficient room to manouver the truck in "sideways" so an engine crane etc is out of the question.
 

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this is the connection to my transmission cooler after i tried to undo it, the action of unscrewing the joint tore the thread clean off. I've since leaned this is common, but there is no need to remove this cooler so leave it well alone. The engine oil cooler is the same but you can break the joints on the timing casing with ease, the timing casing has to come off anyway so you may as well remove the hoses first, don't even consider the joints on the oil cooler itself. The cooler is aluminium, the fittings are steel. It's not the only mistake LandRover made.

If you need anymore pics please do ask.
Many thanks indeed...I will be careful!!
cheers
 

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Discussion Starter #20
I agree with you...regretably however, back aches, poor access and frustration are part and parcel of my "now" situation... as my only available secure work space provides approx 35cm (14") between the front bumper and the wall and less than that between the rear bumper and the roller door which opens onto the street /:( though there are a couple of metres of clearance either side... however there is insufficient room to manouver the truck in "sideways" so an engine crane etc is out of the question.
I'm in the very same position, at least i have a garage to work in.

IMG_2172.jpg A little compact, but enough.

IMG_2171.jpg I have roll the car forward to even open the door!
 
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