olds 307 and 403

First, it actually looks very clean inside and out. One thing to address is the light rust on the outside of the block before paint the block. Should I use something like Naval Jelly or Evaporust? Any negative to using Evaporust before paint? I know Naval Jelly needs neutralizing with something basic like Baking Soda or it continues to react even under paint. I still need to get a mirror to check the plug near the distributor gear for a spit hole, the one near the the timing chain has one. I was going to pressure wash the block. Now I wonder if I should just use cloth rags or pick up gun cleaning brushes to see what grime comes out. Thoughts? I still need to blast the oil filter adapter, easy now it is off the block. I will also blast the oil fill tube as well. I may pick up aluminum oxide to help get the little bit of rust and make the paint stick better. Thoughts?

67OAI

I personally never trust an engine block that has just come back from the machine shop being thoroughly cleaned. You don't have to invest in gun cleaning brushes, pick up some cheap small "bottle" cleaning brushes at a flea market, squeeze the round end a little flat so it will pass through the oil galley easily and pull it through with a brazing rod or a coat hanger that has been straightened. (I can supply a picture if you wish) Copious amounts of GUNK SC (super concentrate) mixed with either kerosene or diesel fuel (mix instructions on the container) and then hosed off thoroughly; hint here, it helps to leave the engine block out in the hot sun for a few hours to warm up before cleaning. Have plenty of lint free rags available to wipe dry the bores after hosing off. Yes, you will have to remove the oil galley plugs for cleaning. If it is just flash rust on the surface, wipe it down with lacquer thinner; for heavier rust, use wire brushes or wire wheels. I don't like to bead blast anything with a mechanical insert such as the oil filter adapter. A good soaking in that GUNK SC mixture followed by a good scrubbing with various brushes should be fine. I have found that for me glass beads works fine for abrading the metal surface for paint.

oddball

ALWAYS clean and clean again!
Like said, remove the oil galley plugs and push brushes all the way through. I find the engine cleaning brush kits to be very useful and they're not that expensive.

Carefully clean the bores and wipe down. Keep doing it until the cloths don't show any grime. I use ATF to keep the bores from rusting.

A tip from Dulcich which I'll try next time is to use a solvent sprayer and mineral spirits as your cleaning solution. Means you don't have to worry about rusting near as much, but it's hard to get the big volume of fluid to wash away junk.

Don't worry about the quick flash rust on the outside. The paint will still stick just fine. I assume the shop hot-tanked/cleaned the block, so we're not talking about scaly stuff - just flash rust.

Phoenix8990

I'm assuming the block is unassembled? In the 70's I worked in a machine shop, the guy who did the real machine work built motors for serious people, drag racers etc. He used an old dishwasher to make sure they were clean. Somehow i think I would need to put an extension on my dog house if I tried to bring a blosk in the house.

redoldsman

I have seen many folks use soap (like Dawn) and water and then dry them down when they are done. I have used it several times. Dawn is a good degreaser.

Sugar Bear

Engine cleaning brushes work well. Used to use the hottest water I could tolerate along with liquid laundry detergent, others mentioned Dawn, that is probably better. Flush, flush, flush the oil galleys, wipe the bores until the cloth wipes clean and oil the bores.
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Good luck!!!

olds 307 and 403

The 350 block in question. 4.100" final bore, decked
.016" to bring flat and align honed with ARP studs.

skyhigh

I no its to late to mention this now, but when I dustless blast, I use a product called "holdtight" that you add to the water, this will give you a few days grace before it will flash rust, but I always prime the same day if I can. It has very minimal flash rush so a quick wire brush, blow it off with air and give it a wipe down with some thinner that will flash off quick, I would use M.E.K cause I have access to it, Then prime it up

olds 307 and 403

Thanks Dave, I will look it up. I don't know how much I will get done today, 35C today. I hate hot weather, probably work at it early tomorrow morning. With this heat and no rain, harvest might be happening mid August. Hopefully I see the rods soon and the machine shop grinds the crank to confirm bearing size and get it sent for internal balancing. I will tap and blow out the main bolt holes and install the ARP studs in the block first.

olds 307 and 403

Dave, where do you find Holdtight down in Ontario? Is it only available in 5 gallon pails? Not paying the $500 Amazon Canada wants with shipping.

skyhigh

not sure, the supervisor does the ordering. I can ask Mon.

olds 307 and 403

I used a 7/16" tap, cleaned after each hole on 1 through 4 mains. I installed them hand tight like ARP instructions stated. Then did ,#5 with a 1/2" tap then a die on #5's main bolts. I will be tapping all the bolt holes and hitting with carb cleaner and compressed air

olds 307 and 403

I tapped all the bolt holes in the block. I cleaned the intake end rails, timing cover gasket surface, oil filter adapter area and pan rail gasket surfaces on the block the finer 3M conditioning pads on my Dewalt drill. I also carefully treated the outside of the block with rust converter, wiping even tiny drips off the machined surface immediately.