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Discussion Starter #1
The two rear bolts nearest the firewall LH side ( and maybe someothers) holding the heads ARE NOT BUDGING with my impact driver, so I was considering using a cheater bar to remove them. Im not a full time mechanic and Im hoping that will work and not break the bolts. Anybody have an opinion on that issue? I hit them hard with a chisel to release tension on the threads a couple times. Ill try that again before twisting them again. The one in the head is partially submerged in oil so it probably pretty wet. They've not been removed in known history before. Engine is in vehicle, a '95 4.2L.
 

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I would usually loosen all the bolts first then remove them...but I use a breaker bar not a impact ...
If it does snap hopefully it is high on the bolt so there is still something to grip onto after you remove the head...
Sometimes tightening the bolt a hair will break it loose...and if you pulled all the bolts as you go... the last ones may be in a bind...
 

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1970-1995 Range Rover Classic
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Did you soak w/ PB Blaster? The other thing you could try is to heat, then cool, but that should be done w/ engine out.


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Discussion Starter #5
I would usually loosen all the bolts first then remove them...but I use a breaker bar not a impact ...
If it does snap hopefully it is high on the bolt so there is still something to grip onto after you remove the head...
Sometimes tightening the bolt a hair will break it loose...and if you pulled all the bolts as you go... the last ones may be in a bind...
Thanks ya'll.. Here is the out come. The 1995 Rover 4.2L , 265,000+ miles:
I went back to the job this afternoon determined to get it done! I put the breaker bar on and popped each one.. the impact I have, a 24V Kobalt, didnt do squat. In the end I learned it's a matter of using an impact (hardened) socket, the shortest extension possible, keeping the drive VERY square on the bolt, a breaker bar with a pipe extension, and elbow grease... then a POP! A few times I thought "OH SNAP!", literally, but its just the 25 years' release of built up tension. Just go for it and be congnizant of what's going on and double check the driver position on bolts! Yeah! The manifold bolts were much less stressful if not harder to access.

Pictures are the proof!
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Completed heads removed!

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Right Hand side looks very clean, after sopping up the coolant, which didn't leak past the rings.

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The Left Hand side looks ok too, with the exception of #7...which is slightly different, carbonized and burnt looking

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Cyclinder #7 is the only different looking one of the bunch.. what does it mean?


These next two are 1 and 3. You can see the original boring on the walls. Its amazing the piston stamps are still very easy to see.
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A closer look at #7. Burnt.

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The Left Hand side perspective, A/C connected and Power-Steering still in circuit.
 

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Looks like a fun job...
Does your cam kit come with a new timeing chain.?
 

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Always wonder why these engines get so dirty inside? Must be some design issue, poor ventilation maybe.
What made you open it up? Looking pretty good otherwise.
 

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Discussion Starter #12
Always wonder why these engines get so dirty inside? Must be some design issue, poor ventilation maybe.
What made you open it up? Looking pretty good otherwise.
I had the PowerSteering gear box replaced. The guy who did it said I had some pretty bad rod knock and that he was afraid to test drive it afterwards...but did. He said engine needed to come apart but that it all hindged on the front cover being reusable... So I pulled that off to check the pump.... And while I was at it, might as well go all in..
Here's the link to my other post, Is it Really that bad....,related to the tear down. Ill be updating it with the bearing job or start a new thread.
 

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Discussion Starter #13
Looking for some "next steps advice" and what will make the rebuild go smoothest with respect to what order I should be putting this all back together. I need to take the heads somewhere (near Austin, TX) to get reconditioned. The bearings still need to be replaced ... both MAINS and rods. I plan on putting back the standard sizes. Should I put the top end back together, before doing that work, OR replace the bearings now, before the timing chain is removed and cam replaced (since it will hold the crank shaft in place)?

I believe the liners are fine and that the engine is in rebuildable condition with no need to remove it at this point. Looking forward to the next quarter million miles or MORE!
 

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How was your oil pressure before you took it apart? Might be good to mic the crank for peace of mind, be a bummer to put it all back together with new bearings and have weak oil pressure. I'm curious about what makes them dirty, mine was actually surprisingly clean inside (no idea why), despite not being supremely well taken care of before I got it. I'd definitely get all the gunk off those heads for sure if you aren't planning to have them rebuilt. I did see some services that do rover head rebuild exchanges, really not bad, about $600 for the pair. How did your old cam look when it came out? Mine had a couple lobes that were almost worn flat!
 

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As you have the engine stripped that far is it not worth putting in new rings? You will have the caps off.
I would not hold the crank up with the timing chain, your gonna have to take it all off anyway!
you would have to loosen all the main bearing bolts if you intend to leave it in situ and try to slide the bearings in Hopefully you will get enough clearance at the gearbox end and it doesn’t damage the rear oil seal, how will you clean the journal’s? don’t forget one pair has side thrusts as well.
are you also renewing rocker shafts and rockers as well...
 

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Yes of course I recall this case! Good to see you are making progress.

If you are going for new rings, you have to hone the cylinders so they bed in right. All doable but adds a whole new level of complexity since when you hone the cylinders you need to really really clean it well to get rid of any abrasive materials (with the engine in situ) then you have to bed in the rings, change the oil a few times etc etc. If the compression was good and all the honing is fine, which it seems to be I would leave them be. Just replacing the rings without honing can give you all sorts of compression and oil consumption issues

Heads I agree would be worth dropping off for cleaning, skimming and rebuild. Not too expensive easy and gives you that piece of mind (and the shiny look).

I changed the bearing shells in a few engines in situ and is not that hard to do. I did it my 3.5 about 5000mls ago and it was good. You can use plasticgauge to check for clearances, but if the shells are really worn, just putting new standard size bearings in would already make a big difference. You can pretty much spin the crank everytime you fit new bearings to feel if they stick. Use a lot of oil during installation.

From what I understand on these engines low oil pressure could also be caused by warn camshaft bearings or rockers which then waste a lot of oil pressure. Replacing the camshaft bearings is a bit more involved as you need a tool to push them out and in.

Ideally you build up pressure before you turn the first time, or at least you spin it without spark plugs. For the older models you can use a drill to spin the pump, on the serptine engines there is another trick, but i need to find that.. will post here.
 

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Discussion Starter #17
How was your oil pressure before you took it apart? Might be good to mic the crank for peace of mind, be a bummer to put it all back together with new bearings and have weak oil pressure. I'm curious about what makes them dirty, mine was actually surprisingly clean inside (no idea why), despite not being supremely well taken care of before I got it. I'd definitely get all the gunk off those heads for sure if you aren't planning to have them rebuilt. I did see some services that do rover head rebuild exchanges, really not bad, about $600 for the pair. How did your old cam look when it came out? Mine had a couple lobes that were almost worn flat!
A local guy in Austin who has lots of experience with RR Discovery heads (because of know issues back in the day) said he would recondition the heads for $450, I provide the 16 seals. I clean the lifters part and reuse.
I dont know the pressure as I couldnt find the fitting for the harbor freight test kit to fit the figging sensor hole. All those measurements are good to do but at 265K miles the bearings are shot and will kill the oil pressure for sure ... I have #3 out of the main and all the babbitt is gone but the journal(?) looks fine.

Im obviously confused as I dont want to remove the crankshaft because I thought it couldnt be removed with out pulling the engine... but once all the caps are removed then it would just fall out? Going with the premise of MasterRoverTech rebuilding and using standard bearings.
 

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Discussion Starter #18
Yes of course I recall this case! Good to see you are making progress.

If you are going for new rings, you have to hone the cylinders so they bed in right. All doable but adds a whole new level of complexity since when you hone the cylinders you need to really really clean it well to get rid of any abrasive materials (with the engine in situ) then you have to bed in the rings, change the oil a few times etc etc. If the compression was good and all the honing is fine, which it seems to be I would leave them be. Just replacing the rings without honing can give you all sorts of compression and oil consumption issues

Heads I agree would be worth dropping off for cleaning, skimming and rebuild. Not too expensive easy and gives you that piece of mind (and the shiny look).

I changed the bearing shells in a few engines in situ and is not that hard to do. I did it my 3.5 about 5000mls ago and it was good. You can use plasticgauge to check for clearances, but if the shells are really worn, just putting new standard size bearings in would already make a big difference. You can pretty much spin the crank everytime you fit new bearings to feel if they stick. Use a lot of oil during installation.

From what I understand on these engines low oil pressure could also be caused by warn camshaft bearings or rockers which then waste a lot of oil pressure. Replacing the camshaft bearings is a bit more involved as you need a tool to push them out and in.

Ideally you build up pressure before you turn the first time, or at least you spin it without spark plugs. For the older models you can use a drill to spin the pump, on the serptine engines there is another trick, but i need to find that.. will post here.
No new rings, no push rods... . the car never smoked or used any oil. I dont have the tool to press the cam bearings and heard it was really involved.... engine has to be removed? I did see pics of walked bearings and mine dont appear to be... need to look harder as I turn the crank and see more internal. Not all things need to be done perfectly to make this work is my opinion... not a perfectionist here... practical-ist more like it. Thanks for the input... keep it coming. Ill not put another quarter million miles on the rebuild most likely.
 

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Crank won’t just fall out,, the flywheel or flexi plate is bolted to the gearbox end of the crankshaft with the clutch or torque converter (depends if it’s manual or auto) bolted to that, then then into that either the gearbox shaft will be in the clutch assembly and crankshaft spigot bearing or the torque converter bolted to the flexi plate will be engaged in the auto gearbox pump..
 

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Discussion Starter #20
As you have the engine stripped that far is it not worth putting in new rings? You will have the caps off.
I would not hold the crank up with the timing chain, your gonna have to take it all off anyway!
you would have to loosen all the main bearing bolts if you intend to leave it in situ and try to slide the bearings in Hopefully you will get enough clearance at the gearbox end and it doesn’t damage the rear oil seal, how will you clean the journal’s? don’t forget one pair has side thrusts as well.
are you also renewing rocker shafts and rockers as well...
Hey CortinaMk2... good points.
The rear pair has side thrusts, is that right? YOu think Ill have a time with those? Nothing is easy apparently. I think they will all be a bear.
I was going with the write up from MasterRoverTech when he did the Disco rebuild with the crank in block, from underneath, on a lift. MRT said use a surgically clean towel to clean the journals... and slip the bearing in carefully. I dont have a lift but it is up on ramps... gonna take some muscle...
If the timing chain is left in place until the bearings are done then it can hold the crank and since it is stretched alot, hopefully it will make the difference... It is supported on the transmission end too.
If I tried to remove the crank I would have to remove the engine is what I was thinking... I have not done that.
I read that the seal is not pressed in anyway really and wont be a problem..
Any other issues Im not aware of?
 

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