Time to Rebuild Bottom End
#71
Way back in the day I wrapped my exhaust from block to tailpipe except for the cats on a 1995 Corvette that I tracked and drove daily. I finally sold it in 2015. It still had that exhaust wrap on it.
Still had the original cats on it. Never warped the headers. Never a problem.
Who knows. Your mileage may vary. If this new gold exhaust tape screws up I'll post it up on this board. I can be your test dummy. Emphasis on dummy.
Anyway...
Today I lubed and installed the 53229 Crower low-end performance cam from Summit.
Installed my nicely machined crank and its new Main bearings. The Mains and rod bearings are .020 oversized to match the machine work from the shop.
At this point you have to test the machine work so you try to rock the lubed crank. Passed that test. No forward/vertical rocking.
Then with everything coated in assembly lube you gently try to rotate the crank. Passed that test.
If it rotates too easily then you have clearances that are too big. Problem if so. Passed.
If it doesn't rotate at all then you have a problem if so. Passed.
So at this point it is reasonable to think that the machine work on the crank matches the oversized bearings and that the motor will actually work when finished.
Basicly the cam is straight, the crank is straight and not out of round, and the block is straight and squared internally.
Hooray!
So I installed all 8 pistons with new piston rings, then finished installing the rod bearings (lubed) +end caps. Then I matched up the dots on the new timing chain+cog+sprocket to time the cam to the crank.
Rotated the crank again. She rotated. Passed! And the dots remained aligned every two turns. Passed!
Packed the front oil pump/cover with vaseline.
Tomorrow is installing the oil sump+pickup tube, oil pump+cover, heads, and fuel rails as time permits.
Whew!
This turned out to be a large project. I don't think that I'd recommend pulling and rebuilding your own Disco2 motor to any fellow amateurs like myself in the future.
Just my time alone for what I've done makes Buying a pro-built 4.6 motor for $7k look like a bargain instead of spending my time on this rebuild.
It didn't seem like such a bargain before I began, but my thought process was stairstepped. At first I was just going to pull the oil sump and replace the front pump/cover with the motor still in the Disco2, and then just replace the rod bearings and main bearings from underneath the vehicle, leaving the old cam bearings, old crank, old camshaft, old tappets, and old piston rings.
...but at each step I kept talking myself into doing the job "right" instead of taking my usual short cuts so one thing led to another thing and I ended up spending 4 days to pull the whole motor out and now it is completely rebuilt.
Guys, go buy a rebuilt motor! Don't copy what I've done here.
Look, I've got gold exhaust tape on my headers. You can't copy a guy who puts gold exhaust tape on his headers!
#73
There should be radiant barrier between the cats and the floor, if not some thin aluminum will do the job, about 98% radiant heat reflectivity. I actually wrapped the cat on the passenger side in aluminum ductwork, so it only emits 2% radiant heat and the heat shield reflects back 98% of that 2%. I mostly did it to lengthen the life of the driveshaft u-joint.
#75
Thought about it, but the crank felt right when seated so I didn't bother.
Keep in mind that I bought this truck for $500 so a lot of my thinking is that either something works good enough or else "Move on."
Even so, I still caught myself blueprinting the ring gaps. Good grief. Who spends that much time on a $500 truck?! Apparently me, sometimes...
Anyway, when I thought about the plastigauge, I asked myself, Well, what you you change if the plastigauge showed you a fitting out of tolerance?
And my answer was "Nothing, I'd just see if the old truck motor ran passibly anyway."
Keep in mind that I bought this truck for $500 so a lot of my thinking is that either something works good enough or else "Move on."
Even so, I still caught myself blueprinting the ring gaps. Good grief. Who spends that much time on a $500 truck?! Apparently me, sometimes...
Anyway, when I thought about the plastigauge, I asked myself, Well, what you you change if the plastigauge showed you a fitting out of tolerance?
And my answer was "Nothing, I'd just see if the old truck motor ran passibly anyway."
#76
[QUOTE=No Doubt;638255]Thought about it, but the crank felt right when seated so I didn't bother.
Keep in mind that I bought this truck for $500 so a lot of my thinking is that either something works good enough or else "Move on."
Even so, I still caught myself blueprinting the ring gaps. Good grief. Who spends that much time on a $500 truck?! Apparently me, sometimes...
Anyway, when I thought about the plastigauge, I asked myself, Well, what you you change if the plastigauge showed you a fitting out of tolerance?
And my answer was "Nothing, I'd just see if the old truck motor ran passibly
Bearing ends can be filed if the gap is too big, much like if ring gap is too small.
If the gap is too tight, a new and likely oversize bearing is needed.
The small things do make a difference in how well an engine runs or lasts.
Even if the truck was free, you're still spending money in it.
There are better ways than plastigage, but for a low revving engine, it's good enough, and definately better than not doing it. Considering how small tolerance ranges are, you'll never tell by feel, it needs measured.
If you have one tight or loose rod or main bearing, be prepared to re-do all of what you just did, and sooner rather than later.
No point cutting corners with a complete dissssembly.
Keep in mind that I bought this truck for $500 so a lot of my thinking is that either something works good enough or else "Move on."
Even so, I still caught myself blueprinting the ring gaps. Good grief. Who spends that much time on a $500 truck?! Apparently me, sometimes...
Anyway, when I thought about the plastigauge, I asked myself, Well, what you you change if the plastigauge showed you a fitting out of tolerance?
And my answer was "Nothing, I'd just see if the old truck motor ran passibly
Bearing ends can be filed if the gap is too big, much like if ring gap is too small.
If the gap is too tight, a new and likely oversize bearing is needed.
The small things do make a difference in how well an engine runs or lasts.
Even if the truck was free, you're still spending money in it.
There are better ways than plastigage, but for a low revving engine, it's good enough, and definately better than not doing it. Considering how small tolerance ranges are, you'll never tell by feel, it needs measured.
If you have one tight or loose rod or main bearing, be prepared to re-do all of what you just did, and sooner rather than later.
No point cutting corners with a complete dissssembly.
#77
Installed the pickup tube today with new, lubricated o-ring, oil pan, and heads torqued in 3 stages per book.
Installed a new crank sensor.
Tried to clean up the old valve covers but they didn't want to polish up.
Tomorrow I do the rocker arms, pushrods, and new lifters that have been soaking in motor oil tonight. Then valley gasket, valve covers, starter motor, fuel rails, and intake manifold.
Might be able to begin the motor installation back into the Disco tomorrow night and finish Monday.
Installed a new crank sensor.
Tried to clean up the old valve covers but they didn't want to polish up.
Tomorrow I do the rocker arms, pushrods, and new lifters that have been soaking in motor oil tonight. Then valley gasket, valve covers, starter motor, fuel rails, and intake manifold.
Might be able to begin the motor installation back into the Disco tomorrow night and finish Monday.
Last edited by No Doubt; 02-24-2018 at 11:18 PM.
#78
Got the motor off of the engine stand and back onto the hoist+chain.
Installed the ring gear+flex plate onto the back of the motor, too.
Tested the tensioners/pulleys. Passed. Didn't test the AC pulley, power steering pulley, or alternator pulley.
Cleaned the transmission center shaft. Installed new Hayden fan clutch onto the fan blades... but not yet mounted to motor.
Installation back into the Disco2 begins tomorrow, along with new spark plugs, oil change, and new coolant.
Might be able to get the AC, power steering, and alternator back on, plus the intake manifold tomorrow, too.
Sheesh! This is a big job. Someone should have warned me that a full engine-out rebuild is such a giant project!
#79
Installation back into the Disco2 begins tomorrow, along with new spark plugs, oil change, and new coolant.
Might be able to get the AC, power steering, and alternator back on, plus the intake manifold tomorrow, too.
Sheesh! This is a big job. Someone should have warned me that a full engine-out rebuild is such a giant project!
Might be able to get the AC, power steering, and alternator back on, plus the intake manifold tomorrow, too.
Sheesh! This is a big job. Someone should have warned me that a full engine-out rebuild is such a giant project!
Got one exhaust manifold mounted onto one downpipe.
Disconnected the motor hoist and stored it. That felt good!
Might be driving it tomorrow if all goes well.