Prepping a stock block for racing

Apart from sonic testing, magnafluxing & Torque Plate honing, what prep work do you do to make a factory block race ready? I was deburring my 400 block, cleaning up all the casting flash & generally smoothing my block, when a Chevy friend looked at what was doing & said I was wasting my time. Do any of you guys that work on stock block racers do any cleanup of the block? I coated all the inside surfaces with POR15 to make for a smoother surface for oil return, am I going too far?

Chase every thread and blow them out with air. Deck and line bore check while at machine shop. Modifying oil pickup to 1/2" I think is still up for debate but I would recommend it.

Chevy guys don't have to do any of that stuff because they drive a Chevy.

Paying attention to detail is often the difference between winning & losing. Deburring gets rid of any slag that "might" break off in the future and smoothing & painting helps quicken oil drainback and reduces places where dirt/wear, etc. can hide. I believe that the #1 important item is cleanliness - scrub, rinse, blow-dry.....repeat. That's especially important when painting to insure the paint doesn't flake.

It's the little things that add up, whether it's looking for efficiency, HP or reducing weight. Each little thing you do may seem insignificant by itself, but the cumulative effort will show obvious benefits.

Word!

I agree with all said above. If you are running an external oiling pickup you wouldn't have to worry about the internal pickup.
Bushing lifter bores would be a nice luxury, but not absolutely needed. Depending on cylinder head, you may want to consider oiling mods to the heads. The factory oiling strategy uses the #4 main feed to oil the heads. The cam is drilled to intermittently feed oil from the #4 main in "pulses" to the heads. This is done to limit the amount of oil "robbed" from that main bearing (and the 2 rods it feeds).
The problem with this method of oiling is it sends a very limited amount of oil to the heads. If your heads are oiled through through the factory valley drillings, I suggest you do this...
Drill a 1/8" hole to intersect the valley drilling to the main galley drilling. This will feed the head with a nice plentiful supply of oil without risk to the bottom end. Then open up the hole to thread a 1/16"npt thread to plug the hole in the valley. Rotate the #4 cam bearing, drill a new hole in it to oil the cam journal only. Rotating the cam bearing blocks the drillings to the heads. This simple mod evens out the supply to the mains and rods, while improving valvetrain oiling.

How will you know if you didn't completely gassed out all solvents, petro products, LocTite, etc?

You'll drive over the crank when the paint film reaches the pump.

The factory paints the race blocks also.. I've
been doing it for years also.. never had any issue
of driving over the crank

I use a 1/2 fill of hard block. I break the sharp edges of the main bores, I chase all bolt holes and have good machine work done and I double check everything I can.

I would never ever use Por15 but that's just me. Heck I won't even use that crap on the bottom of my cars any more after it peeled of mine and several other Friends cars.

Same here.. I use Rustoleum .. I used Chassis Saver
and POR15 on my chassis.. that stuff SUCKS.. it peels
off in sheets... then I sprayed it with Rustoleum ..
still holding great

All the above mentioned suggestions are good advise.To make the job complete the block should be squared front to back,pan rail to deck,align bored if necessary,align honed, decked,bored and honed(with plate)all this indicated off the centerline of the crankshaft.Make sure your machine shop has a BHJ or similar fixture to do this.

Dont forget main studs.They have to line hone after they are installed but add strength.Degree cam also.Balance and clearance is important also.Rocky

I kinda got carried away on this one but my time is FREE and I am in my happy place at the track, at my porting bench, or with my hands inside an engine. This 360 block is going on its 4th rebuild this Winter with hundreds of passes on it. Its gone 9.73 so far and should run some 9.50's in 2016.

I like to hand file, then stone the sharp edges of the main saddles. Just something I been doing since my 1st 440 back in 97.

The difference: how do you know yours is as clean as a new block?

Have it hot tanked... then spray it with brake
cleaner.. blow it dry.. spray paint with Rustoleum
that has worked for years now

How would I know a new block is as clean as mine? Clean it once, clean it again and then when you got it clean, Clean it again.

well i've done most of what you guys have mentioned but it didn't get hot tanked but it got the degreasing from hell, complete with cansx2 of carb cleaner to dry out any residual oil in the casting. i've never witnessed any failures with the POR15 as you guys have mentioned. i've given a few blocks this treatment it's never shown any sign of peeling. after i've finished degreasing the block i let it sit overnight, our humid semi tropical air creates a faint layer of rust which helps POR15 stick, i think maybe it's how your prep for that product that makes the difference. here's my block now ready for trial fit of my parts.

LOL.. its funny you use a screwdriver on the stand
just like I do

X2

Alot of machining steps involved but the main ones are:
Make sure decks are 100% square and parallel to the corrected crank center, bush lifter bores to make sure they're correctly positioned and aligned with the cam lobes, make sure the crank throws are indexed correctly and the journals have proper radius and clearances, bore and hone with torque plates and main caps installed (ideally at operating temp).

When you clean up after machining make sure you remove ALL galley plugs and thoroughly scrub all passages with strong detergent and rinse with hot water then blown dry with compressed air - repeat until brushes come out clean and no debris is blown out.

And somehow they can't drill the hole so the engine sets straight up!

mine is actually a 1/4 drive screwdriver but the ball bearing fell out years ago so the sockets don't stay on it. but it recycles real nice in this job. many a time i've thought about cutting it down but i never seem to get around to it.

You can never go too far. All the above mentioned plus any sharp edge in the block and caps should be rounded off to prevent stress points

One other thing I do is to glue screen into the
intake valley.. that way it keeps any top end
parts from getting down to the bottom.. I use
JB weld to glue it in.. then I paint the valley
area.. I cover the screen when painting

1 step ahead of you Mr P. I've made a couple of these in the past but I'm going to reallocate this one from the dead block it resides in.

Looks nice

Have the block sonic checked before doing anything else.

Personally - I like a old block baked then shot blasted - versus the old method of chemical hot tank. But regardless in the end it has to be washed clean - then cleaned again with brushes and all the thread chased clean. New or old makes no difference cleaning is the same - the more you clean it the better it will be! painting the inside is a personal preference - I go with unpainted.

I clean them with really strong degreaser like red-hot or bleach-white for cleaning brake dust off wheels and tires, let it soak but don't let it dry, then I hit it with hot watter from my pressure washer, a couple times of this and it is ready to check out and machine if it checks out OK, dirll 1/8th drainback holes in lifter valley to drain oil puddles right onto cam lobes (all 16 if possible), then wash it same way a couple more times when back from machine shop, then test fit everything, adjust grind where needed dissasemble it and clean a couple more times and set up a big heater under the block to help it dry quickly, then mask it off and paint then assemble.