Removing surface rust from crank

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DentalDart

DentalDart

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I got a 4in Scat Crank for a 360 and all the parts to build a stroker only problem… the crank has a bit of surface rust on it, besides sending it into the machine shop, what’s the best way to remove it? Brake cleaner and shop rags?

I’m not 100% sure on the pistons and what heads I can use, old owner was going to do W2 heads but I don’t have W2 headers. I have everything for aluminum heads… I’d just have to buy another set of aluminum heads lol.


I want this to cost as little as possible. First time ever building a motor and I have all the parts… hopefully. I got a book to help.

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Watch Evaporust on the polished surfaces. The Dana 60 powr-loc carrier I'm trying to sell, in soaked it in Evaporust and all the polished surfaces are stained. My bet is 2000-4000 emery cloth will polished it back up. But who knows.
 
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DentalDart said:
I got a 4in Scat Crank for a 360 and all the parts to build a stroker only problem… the crank has a bit of surface rust on it, besides sending it into the machine shop, what’s the best way to remove it? Brake cleaner and shop rags?

I’m not 100% sure on the pistons and what heads I can use, old owner was going to do W2 heads but I don’t have W2 headers. I have everything for aluminum heads… I’d just have to buy another set of aluminum heads lol.


I want this to cost as little as possible. First time ever building a motor and I have all the parts… hopefully. I got a book to help.

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Double check the crankshaft stroke and piston compression height. The KB190 pistons are listed as 1.675 compression height, which would be for a 3.58 inch stroke crankshaft. The 1.675 compression height is not compatible with a 4 inch stroke crankshaft.
 
Bobzilla said:
Double check the crankshaft stroke and piston compression height. The KB190 pistons are listed as 1.675 compression height, which would be for a 3.58 inch stroke crankshaft. The 1.675 compression height is not compatible with a 4 inch stroke crankshaft.
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Good eye! The box is clearly marked "360" too, isn't it? Wow.
 
WD-40 and scotch brite pad on the crank weights. A quick touch with Crocus Cloth on the journals with WD-40.

Then rinse with WD-40, blow down and wipe clean.

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☆☆☆☆☆
 
Bobzilla said:
Double check the crankshaft stroke and piston compression height. The KB190 pistons are listed as 1.675 compression height, which would be for a 3.58 inch stroke crankshaft. The 1.675 compression height is not compatible with a 4 inch stroke crankshaft.
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Idk what any of this means lol. I have a box that says “408 stroker” and these are all the parts in it, I was just going to put it together for ***** and giggles while I wait on the painter.
 
DentalDart said:
Idk what any of this means lol. I have a box that says “408 stroker” and these are all the parts in it, I was just going to put it together for ***** and giggles while I wait on the painter.
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It means you may have the wrong pistons for a stroker crankshaft. You know what THAT means, right?
 
If you use "scotch brite", make SURE you clean the oil holes completely multiple times. If any pieces of the pad goes through the oiling system it will scar up some bearings. Ask me how I know.
 
Hope you have the good stuff to measure everything with... ye ole engine builder...you!!! Get 'er done''' but its gotta be right! Right!?
 
DentalDart said:
Idk what any of this means lol. I have a box that says “408 stroker” and these are all the parts in it, I was just going to put it together for ***** and giggles while I wait on the painter.
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Piston compression height plus rod length plus half of crankshaft stroke gives you a length. That length must be close to the the engine block deck height.

Small block Mopar deck height is a given number, around 9.58 inches to 9.6 inches from the center of the crankshaft journal to the top of the deck surface were the head sits. This number depends on LA or Magnum block and whether it has been machined or left where the factory set it.

Small block Mopar rod length is usually about 6.123 inches from the factory and same length is generally used in a 4 inches stroker setup.

Add the rod length to half of the crankshaft stroke length and you get 8.123 inches. Subtract that 8.123 from the deck height of about 9.6 inches and you get 1.477 inches. That 1.477 inches is how much piston compression height will now fit in the block above the crankshaft and connecting rod. So, most Mopar small block pistons for use with a 4 inch stroker crankshaft will have a compression height of around 1.465 inches.

Check if the pistons have a part number inside of them or measure the approximate compression height of the piston.
Check for a casting number or stamped part number on the crankshaft itself.

Hopefully the parts match and the part number on the piston box is not what you actually have.
 
Bobzilla said:
Piston compression height plus rod length plus half of crankshaft stroke gives you a length. That length must be close to the the engine block deck height.

Small block Mopar deck height is a given number, around 9.58 inches to 9.6 inches from the center of the crankshaft journal to the top of the deck surface were the head sits. This number depends on LA or Magnum block and whether it has been machined or left where the factory set it.

Small block Mopar rod length is usually about 6.123 inches from the factory and same length is generally used in a 4 inches stroker setup.

Add the rod length to half of the crankshaft stroke length and you get 8.123 inches. Subtract that 8.123 from the deck height of about 9.6 inches and you get 1.477 inches. That 1.477 inches is how much piston compression height will now fit in the block above the crankshaft and connecting rod. So, most Mopar small block pistons for use with a 4 inch stroker crankshaft will have a compression height of around 1.465 inches.

Check if the pistons have a part number inside of them or measure the approximate compression height of the piston.
Check for a casting number or stamped part number on the crankshaft itself.

Hopefully the parts match and the part number on the piston box is not what you actually have.
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They are definitely KB190s. I guess I’ll look for some pistons.

That kind of is a bummer. I was just going to try and put it together for ***** and giggles.

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Made a mess. Have another set of rods and pistons but neither of them have much information on them except part #s

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Ok well I will start another thread called “Finish my engine” where everyone can debate what “cheap” pistons and camshaft I should get for my cheap stroker build.
 
Bobzilla said:
Did you check the crankshaft yet for any numbers?
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This is all I have found, it looks like it reads 258 and 213

Then the guy wrote on it with sharpie, but he wrote 2.82, I think he should have written 258 if he was trying to write what was etched into the crank.

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You can measure the throw accurate enough with a tape measure.

It will either be close to 4 like the pen says or it will be closer to 3.6


((Main OD/ 2) + Distance between red lines)X2 = throw


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DentalDart said:
This is all I have found, it looks like it reads 258 and 213

Then the guy wrote on it with sharpie, but he wrote 2.82, I think he should have written 258 if he was trying to write what was etched into the crank.

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The 2.82 number is is their rough measurement of the main diameter and the 2.13 is their rough measurement of the rod journals.

From your rough measurements it does appear to be a 4 inch stroke crankshaft.
 
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