looking for tips/tricks for smoothing a block?

Any HAMB'ers got some good tips and tricks for smoothing the rough casting on an engine block? Also - does anyone sell a "kit" that has most of the abrasive rolls and discs in it? I'm nickle and diming myself to death buying these things onesy-twosy...

 

I think Eastwood sells a kit.

 

Hey Neighbor.

for knocking the rougher areas on a block you might want to try one of those 3-M (shameless local company plug lol ) paint and rust removal discs. i bought one to strip and prep the frame and x-members on my '54 tudor, but found they are too agressive for what i wanted to acomplish. they leave a ground down look with scratches, but the surface is very smooth and would clean up nice with a very light sanding. i only gave up on them for my frame as i did not want to go over the thing again with sandpaper before priming an painting it. ended up just wire wheeling the frame instead.

the thing seems to hold up better than i had thought tho... for being a plastic structure with impregnated abrasive. think "scotch brite pad" only real stiff with larger abrasive in the shape of a wheel. i think they come both with the mandrel mounted for use in a drill (the kind i bought) and one for use on a grinder.

Traves

 

I completely smoothed out my Chevy 292 'six' block and heads before painting it Candy Apple Red.
Prepare to spend a lot of time, and some money to do this. First I used a 4" grinder with a stone on it to cut off the major protrusions. Casting flash, numbers, parting lines, etc. I then went in with a carbide burr, on a high speed die grinder, to get in all the nooks, crannies, and corners that I couldn't get with the big grinder.
Next comes the beginning of the smoothing operation. I again used the 4" grinder, with a flap disc to get all the larger flat areas, and accessible stuff. I started with 60 grit and finished with 120. Next was the die grinder, again. The best thing I found doing this job was being able to get the same type of flap disc in both 3 and 2 in. sizes. They have a "Roloc" mounting to go on a regular sanding disc attachment for the die grinder. They were a real savings of time and sanding discs. After doing the flap disc things, I got in all the corners with those sandpaper cylinders that you get for head porting. Rough grit first, followed by 100 or 120.
After that I did a quick run over it with 220 grit. I used the DA, the 4" grinder, and the sanding cylinders. Didn't spend a lot of time on this step, though, just the worst sanding scratches.
Then to prep it for paint, I put on 3 coats of HOK epoxy primer..good for filling, and doesn't sand too badly, and will hold up to the heat. I let it sit a couple nights, and then guide coated it, and blocked it out with regular sanding blocks, paint sticks wrapped with wet-or-dry 400, and rubber fuel hose wrapped with sandpaper as well. Another primer job , and it's ready to go, unless you have to 'correct' problems. I used a bit of polyester glaze to fix some minor problems, and it's holding up so far.
That's it! I estimated I spent close to 40 hours before I put on the first primer coats. Probably spent 60-80$ on flap discs, and resin discs, and cartidge rolls, and holders.
Good luck...and wear a dust mask, and goggles!

 

Has anyone done a post on the proper primer and paint to use on an engine? I'm getting ready to drop a 235 in my old chevy and want to give the engine a nice coating that will come close to the color that will eventually be on the car.

 

Hey, John, how are you?
As for paint, you can use almost any paint you'd use on a car, just avoid lacquer based products. I've used, on different engines, catalyzed Centari (acrylic enamel), Imron (polyurethane), single stage Uro, base/clear, and HOK's Candy urethanes. Just put enough on to get good color and shine, don't over do it, excess thickness will eventually fail.
For primers, I've used Vari Prime (self-etching primer), Epoxy, and once, I used POR-15, as the engine was a bit rusty, and I couldn't spend the time to de-rust it completely. That's regular POR-15, not their engine paint (tho I have used that, as well), and you MUST paint it when it is still tacky, don't let it dry! Just don't use lacquer primer. In a pinch I've used spray can engine primer.

 

Are you talking about the inside of the block? I used a "air" metal rasp or burr, whatever you call it, on an old pontiac engine I built up. I smoothed off all the rough casting crap and enlarged the front oil drain.
That thing could be used to smooth out the outer block I imagine. However I think a 4" grinder would cut the time in 1/2 or better. Dremel might make something. They have attachements for just about any project.