Time to Rebuild Bottom End
#51
When you reassemble the engine don't forget to use truck loads of assemble oil, it's better than ordinary oil as it's slightly thicker and gives the engine some lube when starting up. It sticks like the 'proverbial to the blanket'.
https://www.google.fr/search?q=engin...tPSigWItSaR9M:
https://www.google.fr/search?q=engin...tPSigWItSaR9M:
Finished cleaning all 8 pistons. Lots of brake fluid and scotchbrite rubbing. Also cleaned all 8 rod end-caps.
Tomorrow is leak testing the valves/heads. Maybe Thursday (ha!) I'll get my crank back.
Got a tool to install piston rings.
Still need to clean main bearing end-caps.
What does a large "B" stamped onto my pistons mean??
#52
Hmmm... This 4.6 Rover engine overhaul guide might come in handy!
https://www.scribd.com/document/2689...6l-V8-Overhaul
This guide says:
NOTE: Pistons fitted on production are graded ’A’ or ’B,’ the grade letter is stamped on the piston crown.
Production piston diameter:
Grade A = 93.970 to 93.985 mm (3.700 to 3.7002 in)
Grade B = 93.986 to 94.00 mm (3.7003 to 3.701 in)
Grade B pistons are supplied as service replacements.
Worn cylinder liners fitted with grade ’A’ pistons may be honed to accept grade ’B’ pistons provided that specified cylinder bore and ovality limits are maintained.
https://www.scribd.com/document/2689...6l-V8-Overhaul
This guide says:
NOTE: Pistons fitted on production are graded ’A’ or ’B,’ the grade letter is stamped on the piston crown.
Production piston diameter:
Grade A = 93.970 to 93.985 mm (3.700 to 3.7002 in)
Grade B = 93.986 to 94.00 mm (3.7003 to 3.701 in)
Grade B pistons are supplied as service replacements.
Worn cylinder liners fitted with grade ’A’ pistons may be honed to accept grade ’B’ pistons provided that specified cylinder bore and ovality limits are maintained.
#55
#58
This was weird. One valve spring was rubbing against part of the head. The head had been drilled to have an indentation behind the spring. In the pic, you can see the shiny area where the spring was rubbing some of the fragments of the (factory?) drilling for that indentation.
There were tiny metal fragments in the spring groove.
I do wonder if that made some sort of ticking noise at idle.
...anyway, I shaved the area a bit so that the spring no longer rubbed the head.
There were tiny metal fragments in the spring groove.
I do wonder if that made some sort of ticking noise at idle.
...anyway, I shaved the area a bit so that the spring no longer rubbed the head.
#59
Today I've been installing piston rings. There are 3 ring grooves in each piston, but the oil ring groove actually holds 3 rings inside it.
Then there are 2 compression rings & groves above the oil groove.
So, 5 rings per piston times 8 pistons equals 40 rings to install.
Well, you have to soak each ring in engine oil first, then hand insert one at a time to the top of the cylinder that it will be installed in, then you use the piston for that cylinder to push the ring down about 1/3 of the way into the cylinder so that you can insert a feeler gauge into the ring gap to verify that the gap is large-enough that the piston ring wouldn't bind up when heated and actually installed into its piston ring groove.
All but 3 of the 40 rings were within spec out of the box, which is pretty cool since I'm doing the 2nd rebuild on this motor (first for me!) with 177,000 miles on it and since it also has the larger B pistons/liners.
I had to then grind a larger ring gap into those 3 to bring them into spec, then buff down the gap to prevent any burrs from scratching the cylinder/liner walls, clean with brake cleaner, then re-oil...and *then* I could install the ring into the piston.
Then there are 2 compression rings & groves above the oil groove.
So, 5 rings per piston times 8 pistons equals 40 rings to install.
Well, you have to soak each ring in engine oil first, then hand insert one at a time to the top of the cylinder that it will be installed in, then you use the piston for that cylinder to push the ring down about 1/3 of the way into the cylinder so that you can insert a feeler gauge into the ring gap to verify that the gap is large-enough that the piston ring wouldn't bind up when heated and actually installed into its piston ring groove.
All but 3 of the 40 rings were within spec out of the box, which is pretty cool since I'm doing the 2nd rebuild on this motor (first for me!) with 177,000 miles on it and since it also has the larger B pistons/liners.
I had to then grind a larger ring gap into those 3 to bring them into spec, then buff down the gap to prevent any burrs from scratching the cylinder/liner walls, clean with brake cleaner, then re-oil...and *then* I could install the ring into the piston.