Help with a new to me 408

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bigtooth

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Hi All,
Been a while since I sold my Duster due to good old life changes, but recently picked up a '82 W150 with what I was told was a LA based 408 in it. I got a ton of help from this group when I had my Duster, so figured it was a good place to start.
What I know about the motor:
Cam: Comp Cams 20-225-4 https://www.summitracing.com/parts/cca-20-225-4
Heads: Performer RPM 8077
Intake: RPM AirGap
Was told it had a forged crank, but still need to identify exactly whats in it.

Cool rig, pretty good shape, its swapped to a 5spd out of an early magnum. It seemed to be running strong when I parked it for the winter.

rear main had a pretty good leak so I tore the oil pan off and the fun begins. Quite a bit of RTV in the pan/pickup and some lovely remnants of a spring that I'm trying to identify and some other bits of some very soft metal along with small metal cone shaped piece. At this point I'm going to pull it for the ease of working on it and take a deeper look at things. Pressure relief spring/valve/cap all seemed intact. Any ideas of what I'm looking at here?

labeled_carnage.jpg
 
Looks like someone didn't clearance the oil pump to the longer stroke crankshaft
 
the soft/flexible metal shavings, are they nonferrous? if so, likely bearing material...

to me, that's a lot of trash and would warrant further investigation. at least you already have the motor out...
 
Those spring peices look like the retaining clips from several lifters?
The cone could be a prod tip or a plunger from a lifter maybe?
Makes me wonder if the flexible bits aren't check valves and discs from a lifter too. I'd be pulling that intake for a much closer look. Wouldn't hurt to go around and check lifter preload, and rocker hold down bolts as well.
I'm guessing you're going to find a bit of rework to do.
 
Had a bit more time to work on things. I cleaned everything up and slapped the pump an pan back on with some cheap oil to do a compression test before I pulled it. Plugs all looked sooty and black.

Yes, the metal pieces seem nonferrous, smooth and malleable.
The cone/tip piece turns out to be quite hard but will break apart with enough pressure. I found one of the rubber prongs from the oilpan gasket (in the pic) was broken off, it almost looks like that piece, but petrified.

Compression test readings were 192, 192, 200, 165, 175, 185, 185, 175

I hope to get it out and on the stand tonight.

oilpangasket.jpg
 
Any thoughts on what I have here? Comp cam adjustable rockers with stock hold downs? I read about grinding down the hold downs to gain clearance on the shaft. But those rough sides in pic #2 and #3 can't be right..

20240222_211729.jpg


20240222_211735.jpg


20240222_211743.jpg
 
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I never could get rear main on mine to seal until I put thin film of RTV between rear main cap and block. Otherwise high oil pressure pushes oil out between cap and block appearing like a seal leak.

No way I would build an engine with flat tappet lifters given the risk of wiping a cam. Roller lifters in my engines only I don't need that level of grief. Wipe a cam back to square 1 total tear down start over
 
340sFastback said:
No way I would build an engine with flat tappet lifters given the risk of wiping a cam. Roller lifters in my engines only I don't need that level of grief. Wipe a cam back to square 1 total tear down start over
Click to expand...
The cam lobe on that worn lifter doesn't look obviously flat, but I have to imagine its safe to say that things shouldn't be put back together with that cam in it. That leaves my options at trying a flat tappet again or going down the road of putting rollers in my la block.
 
I run those rockers, Comp, they are steel and are bushed. I ran the previous generation that wasn’t bushed. I’m happy with them. With all the trash, I would make sure to clean EVERYTHING. Including the rocker shafts. As to the hold down, they do wear, but you can just make them flat again and shim for side play
 
hold downs don't look too bad honestly. it's not like they were precision machined from the factory. i'd dress 'em with a file or some paper so there's no high spots or potential places to snag or gall and then shim everybody tight and ship it.

time for a new cam. with a stroker... why not go solid roller? *evil laughter ensues*

x2 on furry's advice: clean everything and then, when you think it's clean enough, clean it again.
 
Plus, it sure looks like your geometry is off with roller rockers to valve stem.
 
Those lifters sure do look suspect........
If you stick with a FT cam, find some 25 yr old or aftermarket lifters & have them re-faced. I believe Oregon cams does it, may have some on the shelf [ re-faced ].
 
Oh, the top lifter is trash. Doesn’t look like it was spinning. My personal opinion would be solid flat tappet or roller depending on performance goals. I am currently running solid flat tappet EDM lifters. Would not hesitate to go that route again. If you do, attention to detail is highly important. With the lash set and intake off, all the lifters must spin while turning it over by hand. If not, move them around (if new) until the do. Find out why they are not spinning. High zinc oil. I like the EDM lifter.
 
It would be the same deal with sol lifters: find some 25 yr old lifters.....& have them re-faced.
 
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