Cam n Lifters
#21
#22
Lifter Noise 1997 Discovery GEMS motor
Hi Folks,
I have a 1997 Disco SD with a GEMS motor with 158,xxx miles on it. Same ol' comments, I am getting the tapping in the morning when cold then it goes away when warm or if the RPM's are increased. But the tapping comes back indicitave of bad oil pressure. Performance obviously is crap and feels like the lifters or something has collapsed in the valve train. Truck has a new fuel pump, injectors, fuel rail clean, battery, alternator, computer, plugs, wires, coil banks, air filter, MAF etc, etc.
I am getting ready to tear it down and had a couple/few+ questions.
1. Pretty sure the piston sleeves are not slipping How do you test? (Visual?) Carbon pattern should be uniform at the TDC for each piston.
2. If the oil sump pickup is loose, which may cause bad oil pressure, Is there a better one to buy other than stock? along with fasteners etc.
3. Camshaft, If worn, where can I get a good perfomance Cam with better lift and duration?
4. Lifters, I can get a set set of replacements from my local junk auto parts store but wondered if anyone has tried a roller setup in these motors?
5. Rockers, do they fall out of tollerance normally from 150K wear? get sloppy etc.
6. Engine sludge in passageways, does it make sense to do some kind of seafoam exercise before tearing it down? I am planning on dropping the pan and will have it cleaned sandblasted and painted before install.
7. Headbolts and gasket kits, ARP? or what is the best "Quality" set of replacements for not only the "foo foo" gaskets but the best metallic head gaskets.
8. And last, Heads? who does the best job for a rebuild? I have a local guy that says he knows what is what... but I am looking for someone that has been around the block and has done a three angle valve job with quality stems and valves if needed, in addition to seals and all the other goodies.
I am planning on keeping my rig long term and was curious, if given the money based on my situation would be ideal, in your opinions. I have built many GM motors and wondered what was/is compatible. It seems to me that the rover power plant is based off the buick 231 only made lighter in aluminum form and wondered what fits?
Sorry for the book report but I am planning on dropping a fair amount of time and money into this thing and want to get it right!
Scott
503.737.7120
I have a 1997 Disco SD with a GEMS motor with 158,xxx miles on it. Same ol' comments, I am getting the tapping in the morning when cold then it goes away when warm or if the RPM's are increased. But the tapping comes back indicitave of bad oil pressure. Performance obviously is crap and feels like the lifters or something has collapsed in the valve train. Truck has a new fuel pump, injectors, fuel rail clean, battery, alternator, computer, plugs, wires, coil banks, air filter, MAF etc, etc.
I am getting ready to tear it down and had a couple/few+ questions.
1. Pretty sure the piston sleeves are not slipping How do you test? (Visual?) Carbon pattern should be uniform at the TDC for each piston.
2. If the oil sump pickup is loose, which may cause bad oil pressure, Is there a better one to buy other than stock? along with fasteners etc.
3. Camshaft, If worn, where can I get a good perfomance Cam with better lift and duration?
4. Lifters, I can get a set set of replacements from my local junk auto parts store but wondered if anyone has tried a roller setup in these motors?
5. Rockers, do they fall out of tollerance normally from 150K wear? get sloppy etc.
6. Engine sludge in passageways, does it make sense to do some kind of seafoam exercise before tearing it down? I am planning on dropping the pan and will have it cleaned sandblasted and painted before install.
7. Headbolts and gasket kits, ARP? or what is the best "Quality" set of replacements for not only the "foo foo" gaskets but the best metallic head gaskets.
8. And last, Heads? who does the best job for a rebuild? I have a local guy that says he knows what is what... but I am looking for someone that has been around the block and has done a three angle valve job with quality stems and valves if needed, in addition to seals and all the other goodies.
I am planning on keeping my rig long term and was curious, if given the money based on my situation would be ideal, in your opinions. I have built many GM motors and wondered what was/is compatible. It seems to me that the rover power plant is based off the buick 231 only made lighter in aluminum form and wondered what fits?
Sorry for the book report but I am planning on dropping a fair amount of time and money into this thing and want to get it right!
Scott
503.737.7120
#23
If the liners are moving it will sound like a pile driver at idle. The 4.0 and 4.6 are, underneath it all, pushrod V8s. The heads are typical OHV and most any competent machinist will give you good results. They respond well to port matching on the intake side and a clean up on the exhaust side.
The stock cam timing and lift is a good compromise, and the only performance cams I've heard of produce more top end and are available from the Brits. You might consider installing a Gems 4.6 - LR used a juiced up 4.6 Gems in a special edition 99 Range Rover at the same time they were switching over to the BMW stuff.
The stock cam timing and lift is a good compromise, and the only performance cams I've heard of produce more top end and are available from the Brits. You might consider installing a Gems 4.6 - LR used a juiced up 4.6 Gems in a special edition 99 Range Rover at the same time they were switching over to the BMW stuff.
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