I say boosted 5.3, but that's only because I don't have to pay for it.
406 rebuild, MOAR compression! Let that big SBC cackle. Boost is the new fad = lame. And cast iron heads? That is sooooo early millenium!
I'd say you really need to pull the engine to see what damage has been done. That may answer the question for you. But if it's repairable, I vote to rebuild it and put it back in.
Schrapnel sure sounds like a German word. Turns out Henry Shrapnel was the British inventor of the Shrapnel Shell, a hollow cannonball filled with shot that would burst in midair.
Check out the image of my Crower hydraulic roller lifter. You'll note that some important fragments are missing. Those pieces are now buried deep in the engine.
There's only one right way to handle this: The engine needs to come out so that we can gain access to the crap hiding in the Canton road race oil pan. Some people may have blindly installed a new roller lifter pair and hoped for the best, but that would almost definitely lead to catastrophic engine failure.
The big question is: Should this engine be reinstalled after freshening? It's a great powerplant based on a high-nickel-content 1971 400 block with Milodon billet main caps, a Scat 4130 forged crank, Manley rods, a JE/SRP piston, ported cast iron World Products Sportsman II heads with Manley Pro Flo valves, an Edelbrock Victor Jr. intake manifold, and a hand-built, custom-calibrated Holley carburetor. It also features 10.5:1 compression and a Crower 236 duration hydraulic roller cam. Output is reasonably estimated at 1.2 horsepower per cube--a total of 480 ponies. It's a great engine. The alternative is an "undesirable" and therefore affordable 5.3-liter LS engine with just enough boost to yield 550 horsepower.
Let's hear some feedback: Gen 1 406 rebuild or boosted junkyard 5.3?
I hope to pull the engine and have a look inside the pan on Sunday. I expect the bearings to be okay, but the cam lobes to be trashed.
I'm not one for fads, but if value and efficiency generate popularity, so be it. I'm wondering if I can produce 550HP and 20 mpg for under $5K with all brand new hardware except for the core 5.3 take out. I will talk to Joe and the crew at Precision Turbo (http://www.precisionturbo.net) next week. Thanks /Steevo
VTEC, yo.
Sorry to hear about the ailing engine. As I type this, there are a bunch of great American Iron and AIX donor cars running past me on the massive front straight at Miller Motorsports Park. However, I think they're going to need their engines for their NASA Championship race.
Gonna have to do just as much work to build a 5.3 that will be reliable under boost, especially in sustained high-RPM situations. I'm also assuming this means you would be going EFI and putting in all the wiring etc associated w/ an LSX.
Therefore, just teardown, freshen, and rebuild the 406.
Damn this is an expensive hobby!
I'm pleasantly surprised by the volume of feedback in favor of the Gen 1 406. Makes it easier to fix and reinstall.
I have a new Barry Grant Road Race carb to test and share. And I would like to try out Holley's new standalone EFI system in 2011.
So let's fix it and reinstall it. I have some excellent "File Under D for Duh" forensic tips to share in the coming week. Like "Don't rotate the engine on the stand to remove the oil pan. Keep it right-side up or all of the fragments will fall back into the engine." Duh.
We found a needle bearing and some cool looking crap on the magnetic drain plug. I try to get a decent pic.
Refresh the 406, add blow through carb, and boost it! high compression? Keep boost reasonable, and tune for E-85.
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