Er... if it's 90 degrees off, it spun! And if that journal was no longer getting oil because the bearing was blocking the passage, then neither were rods 6 and 7.
Rear main ALWAYS looks like that on an SBC, even one with no apparent issues. The nanobeavers are always at it.
An aside, that's the first 4 bolt main LT1 that I've seen. Corvette block I assume. All of the Camaro and Caprice engines I saw were 2 bolt main. Apparently it's not that big a deal, considering.
Cleaned and lubed and skillfully inserted the bumpstick.
And I pulled a rod cap to see what type and size rod bearings are in this engine.
King brand bi-metal, which I've heard are pretty OK. I need one rod's worth, but I haven't seen these sold separately. They're pretty cheap though, so I might just buy a full set. Then again, I could be super-challenge-guy and pull the best one out of my broken engine.
In reply to Pete. (l33t FS) :
I've been told all Corvette LT1s have 4-bolt mains.
I've never had a Corvette LT1 apart
I've also never seen a Chevy spin the mains. This is kinda weird. Were all the cap bolts tight, and the caps tight in the registers? They should have required a lot of finagling to get them out of the block, supposed to have a mild press fit.
If they were loose in the block, you may have had detonation issues. Or the previous owner did.
In reply to Pete. (l33t FS) :
One outer bolt on one of the middle mains (I think it was #3) did not take as much torque as the others to break loose, but they all had that satisfying "pop" when they broke loose. All caps were snug in their registers.
This bottom end had about 208k when it became a challenge car. It spent a bit of time in the buy here pay here world prior to my ownership, so who knows what kind of life she led.
Here are the components of an LT1 hydraulic roller lifter. I'm taking them apart one by one, to flush / clean / inspect / lube / reassemble / install them. 2 down, 14 to go. EDIT: I'm not pressing the roller shaft out of the main body. There's enough clearance to give the roller a good flush.
And here's some more Chevy Orange. I really hope the B-Body pan clears my crossmember. I designed it around the Corvette pan. They are pretty similar forward of the sump, so it should be OK.
Using Plastigage to check crankshaft bearing clearances. In-service spec for mains is 0.0008"-0.0028", which I'm calling 0.001-0.003". In-service spec for rods is 0.0009"-0.0029", which I'm also calling 0.001"-0.003".
Plastigage is cool stuff. It's like a string made of wax. It is a known diameter, so a cross-section is a known area. Place a short length on a clean dry bearing as seen here (the green line):
and torque the cap to spec. Then remove the fasteners, remove the cap, and compare the width of the squished Plastigage to the scale printed on the packaging. Because the area of the cross-section is "constant", and because the squished cross-section is approximately rectangular, the scale relates the squished width to the thickness, which is the bearing clearance. In this case, clearance is 0.002", dead center of the in-service spec:
From #1 to #5, the main bearing clearances are:
- 0.002"
- 0.002"
- 0.0025"
- 0.0025"
- 0.003"
After lunch, I'll check the rod bearings.
preach
UltraDork
6/25/24 4:40 p.m.
Sweet!
Man I love building an engine.
Installed new bearing shells on #1 rod, and checked all rod bearing clearance (inches):
- 0.001
- 0.001
- 0.0015
- 0.0015
- 0.0015
- 0.0015
- 0.0015
- 0.0015
Verified torque on all main (75 ft-lb) and rod (45 ft-lb) caps. Verified torque on oil pump bolt (65 ft-lb). Replaced rear main seal and torqued fasteners to spec. Installed timing set and torqued cam gear bolts to spec. AK1 and AK2 were here for dinner so we had delicious Thai.
Currently putting away tools. Tomorrow I will:
- finish cleaning lifters and rockers;
- clean heads;
- install timing cover;
- install oil pan;
- install oil filter adapter;
- Install heads;
- install intake:
- Install Opti;
- install water pump;
- install flywheel;
- install clutch disc and pressure plate;
- Install balancer;
and that's probably about it for one day. Honestly, I'll be lucky to get most of that done tomorrow. Doing it all is probably a bit of a stretch.
Mr_Asa
MegaDork
6/26/24 6:24 a.m.
AngryCorvair (Forum Supporter) said:
Honestly, I'll be lucky to get most of that done tomorrow. Doing it all is probably a bit of a stretch.
Dont worry, buddy. I hear it happens to most folks when they hit retirement.
With LT1s, is it still good practice to tack weld the oil pump pickup to the oil pump like an older sbc?
With LT1's, it is good practice to yoink that pile of parts and replace it with an LS. Just my experience
maschinenbau said:
With LT1's, it is good practice to yoink that pile of parts and replace it with an LS. Just my experience
Next time. When this one E36 M3s the bed, or when I can't possibly keep it under challenge budget, it'll get an aluminum block truck LS.
Today I have an early quitting time. Now. I'm happy to report that all required steps back have been taken, and I've recovered to where I left off last night.
You see, the OBD2 LT1 (my replacement short block) has a crank sensor target wheel between the timing gear and the balancer hub, and the key for that combo has a longer raised portion than the OBD1 LT1. See below:
Backdating is easy, just remove the target wheel and use the appropriate timing cover and balancer hub. Oh, and use the correct key. Well, I don't want to take the crank timing gear off the new engine to swap the key, and I can't install my balancer hub as-is. Solution: get sketchy! See below:
Yep, I'm gonna trim back the key with the death wheel.
i had to remove the oil pan to remove the timing cover, then remove the cam gear and chain. Next, I set the oil pan back in place and covered everything in overlapping sheets of aluminum foil:
The death wheel made quick work of the key mod, and a healthy hosing with brake cleaner got everything clean.
Then I reinstalled the cam gear and chain (cam gear bolts 18 lb-ft), the timing cover (100 inch-lb), the Opti (106 inch-lb), and the oil pan. Can't torque oil pan bolts until RTV sets up.
I didn't get to clean any of the top end parts today, so I know what I'm doing tomorrow.
Cleaning cylinder heads. Nothing wrong with them, no service required, just getting rid of sparkly stuff.
Yusss! Why is 2025 out of the question? You are closer to done than you were for 2023 and 2024 already. You showed up both of those years.
wvumtnbkr said:
Yusss! Why is 2025 out of the question? You are closer to done than you were for 2023 and 2024 already. You showed up both of those years.
Life reasons, not MonZora reasons. And all of them are good.
Mr_Asa
MegaDork
6/28/24 5:46 p.m.
AngryCorvair (Forum Supporter) said:
wvumtnbkr said:
Yusss! Why is 2025 out of the question? You are closer to done than you were for 2023 and 2024 already. You showed up both of those years.
Life reasons, not MonZora reasons. And all of them are good.
I was gonna say "who can't use an extra year to dial in a Challenge car?"
Got a bunch done today. Installed oil filter adapter, balancer hub, water pump. Cleaned and installed cylinder heads. Disassembled, cleaned, and installed 8 of 16 roller lifters, plus cleaned and installed 8 of 16 pushrods and rocker arms. I've got brain damage from having my hands in mineral spirits and brake cleaner for the last six hours. Where I left off:
Because I'm a dork, I disassembled and cleaned each lifter over a coffee filter, so I could see how much bottom end metal was inside each one. It wasn't a little:
7AM run tomorrow, then either a nap or a cup of coffee and moar lifter cleaning.
7:25PM, 90°F in the garage, I think I might throw in the towel for the night. This morning's run was rained out, so I'm getting up early to knock out some sunrise miles. Off topic to this thread, but here's the summary of my Thursday run:
If my first mile was a 10:30, it would have gone 11:00, 11:30, 11:52, 12:12, 12:17 or something similar. I really have to be careful on mile 1. I used to do this route at an 8:45/mi average. I'll be happy when I can average 9:45 again.
Where I actually knocked off, 9:30 PM:
Valve covers are just sitting there to keep dust out. I still have to do initial valve adjustment before they get cinched down. Also, I think I might replace this vacuum cap:
AngryCorvair (Forum Supporter) said:
In yesterday's mail:
Can you send me, or post here, a pic of where I finished and the little blurb with it? I don't subscribe to the paper copy anymore.