Curious of the different stages or things that "Real Engine Builders" do to prep a block before starting the machining. I understand the sonic process for "core shift" in the casting. What about cleaning and blasting? Also what does "Baking" do? Thanks!
Lets talk "Preping a Block"
- Thread starter Woodie
- Start date
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W-Edge
raceheads.ca
Hot tank and mag check ... Hot tank in kostic solution really cleans the metal deeply and everywhere(think water jackets) metal comes out shiny almost. Mag check for cracks. Some will rotoblast(sandblast)but I think the hot tank will do...Cleanig by hand with brushes will do too , its just more work!Donno bout BAKING unless you mean stress relieving a new casting(putting it through heat/cooling cycles)some manufacturers offer it with their castings , if your reusing or rebuilding an engine (seasoned core) no need!!!
skrews
Well-Known Member
Deburr all edges, oil system mods, chase all threads.
72Dart6pack
Harder Better Faster Stronger.
My 408 before & after. This was baked so you get a idea.
who did yours? my shop screwed me over on mine. it came out looking worse than going in.
rustycowll69
Well-Known Member
if it comes out of the hot tank looking kinda dusty, silver-white it's because the tank has become contaminated with lead from not stripping the cam bearings out of yours or a previous block
yellow rose
Overnight Sensation
The non chemical method to clean a block is three steps.
You have to bake the block. You have to heat it and then hold it there for a couple of hours to bake off all the crap. Then it goes to the blast carbonate for an hour or so. It does exactly what it sounds like. While the block is hot it spins in a fixture while steel shot is blasted all over and around the block. The third step is the shaker or tumbler. It does what it says. The block is spun and flipped to get all the shot out.
I've seen many engines destroyed because the guy running th cleaning equipment doesn't get the blocks hot enough or doesn't leave it in the shot blaster long enough. You never get all the shot out of them if that happens and the shot will come out when the engine is assembled and started. That shot does big time damage.
Baking and blasting can save a pretty rusty block or heads and make them look new. But you MUST tap every hole with a bottom tap, clean the **** out of it with bottle brushes and the decks and mains MUST be surfaced and honed. If you skip any of the steps you will have issues.
Most of the steps outlined above should be followed with any method of cleaning.
You have to bake the block. You have to heat it and then hold it there for a couple of hours to bake off all the crap. Then it goes to the blast carbonate for an hour or so. It does exactly what it sounds like. While the block is hot it spins in a fixture while steel shot is blasted all over and around the block. The third step is the shaker or tumbler. It does what it says. The block is spun and flipped to get all the shot out.
I've seen many engines destroyed because the guy running th cleaning equipment doesn't get the blocks hot enough or doesn't leave it in the shot blaster long enough. You never get all the shot out of them if that happens and the shot will come out when the engine is assembled and started. That shot does big time damage.
Baking and blasting can save a pretty rusty block or heads and make them look new. But you MUST tap every hole with a bottom tap, clean the **** out of it with bottle brushes and the decks and mains MUST be surfaced and honed. If you skip any of the steps you will have issues.
Most of the steps outlined above should be followed with any method of cleaning.
yellow rose
Overnight Sensation
I looked at a couple of the pics you posted. Getting all the paint off is not a big deal. In some states, you can't use the caustic that will remove all of the rust.
Most of the other stuff looks like it happened after the machine work was done and they pressure washed the block and didn't get it dry and didn't use WD-40 or some other protective on the machined surfaces.
The thing I can't see is if they pulled all the gallery plugs before hot tanking. That is a must.
nope. they didn't, they also didnt get the cam bearings installed correctly. Nor deck it or line hone it as paid for and they wont make it right. So I'm looking for a quality shop.
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yellow rose
Overnight Sensation
sorry, they took the one ones out, I have them, and they installed new ones, just didnt line the oil holes up. This shop came highly recommended in the dirt track car crowd, so I went to him, but he and his son, who's now doing a lot of the work I'm told, fubared the whole thing.
Which one did you deal with? (That wouldn't make it right?)
Both. Father was the worst, cussed me out right on the phone when i called about it. And this was after they increased my cost by 150 bucks and had my engine for 18 months, full write up in my build thread starting on page 5. I don't wanna steal this thread.
yellow rose
Overnight Sensation
72Dart6pack
Harder Better Faster Stronger.
Another picture of my baked block.
What did they charge..?
72Dart6pack
Harder Better Faster Stronger.
$95 to bake it and get it to look like this.
Plymouth 65
I'll be in the shop
Never sandblast a block to clean it!
Looking at the block from project 440DD that looked exactly like a 440 I had done by a diesel engine shop. That's all they do is rebuild engines, he told me that it would clean all the rust out and it didn't even take off the paint. BB's are so hard to clean out the cooling jackets, this block was so bad the rear of the block was almost completely blocked off so I took it down to my plater and we put it in the acid tank, that cleaned it down to the bare casting. The problem with that is it is so clean when it comes out it turns brown when the air hits it.
moper
Well-Known Member
I strip mine to the bare block, no plugs bearings or anything. It gets degreased, then if it's clean enough that's when it's magged and sonic tested. Then it gets padded and run through the airless shot cabinet prior to machining. Padding is simply heater hose in each lifter bore, and a larger diameter hose in the main bore. It is critical to do the degreasing well before the shot. They come out looking new cast.
j par
Well-hung Member
Mine-
heads
RAMM
Well-Known Member
Wrong. If it comes out with white/chalky residue on it then the machine shop was lazy and didn't rinse it and dry it properly after pulling it out of the hot tank.
If any aluminum is present in a true hot tank with a caustic solution everything will come out a very noticeable red and the solution will no longer work very well. J.Rob
RAMM
Well-Known Member
Why not? I roto-blast and it is far more destructive than sandblasting --if you don't know what you're doing. J.Rob
RAMM
Well-Known Member
This ^^^^^^^^^^^^^^^^^^^ right here is the real deal. I run hose in the lifter bores as well but usually keep the old main bearings in the saddles and let them get pummeled. They do come out looking like a freshly cast piece. Its a bunch of work to prep a block but when done right it will make ALL the difference in the final product. J.Rob
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