Here’s a few from the week. While I’m waiting for some parts to come in for the disk brake swap, I finished tear down on the L31 Vortec that’s gonna temporarily live in my truck. The bottom end was cherry on it. I hadn’t planned on doing a whole bottom up build but I noticed when I pulled the cam that the cam bearings had some really abnormal wear. Beings I had to pull the bearings I elected to tear it all the way down. I dropped it off yesterday at the machine shop for a clean up, hone and fresh cam bearings. Should have it back Monday or Tuesday.
It’s kind of a shame that the cam bearings were bad because otherwise the bearings, crank, and bores look brand new.
This engine was actually running on natural gas powering a small screw compressor out in patch. We pulled it from the field several years ago in favor of another compressor package. It’s amazing how long these things run and get very low wear, without the solvent properties of gasoline.
Anywhoo here’s what im going to use in the build. Other than the cam it’s mostly stuff I’ve got stashed away. I build gas compressor engines for a living so I’ve got some resources to say the least.
New Speedmaster 64cc chamber 190cc runner, .550 max lift, aluminum heads
LT4 hot cam
LS7 lifters
New GM rings
Original pistons, pins and rods cleaned and mic’d
Polished OE crank
New proper length pushrods
New plastic timing cover
Double roller timing set
New melling oil pump
Clevite rod and main bearings
Felpro gaskets and seals
Weiand street warrior vortec intake
Hei ignition
Edelbrock 1406 carburetor
Undecided electric fuel pump, fuel psi regulator
There’s probably a few loose ends I’m forgetting but that’s the bulk of it.
I’ll document the build more when I start putting back together.
I think this combo should put 400ish horsepower to the crank pretty easily. I love the idle of the LT4 hot cam
Here’s a few tear down pictures.