Engine block crack check

[afazz]

There is a mark on the head gasket surface of my cast iron block (4cyl CW), and I need to determine if it's a crack or a scratch. What type of test should I use? Is this something an automotive machine shop can check? The block is still assembled and painted.

 

[pop pop]

Yep.

 

[PAToyota]

Google "magnaflux" and you'll get enough information to either take it somewhere or do it yourself - your preference.

 

[rsanter]

You can do a dychem test with spray on chemicals

Bob

 

[EvilWelder]

Dye penetrate test kit, 3 part kit. It is available at your local welding supply for about 50 bucks.

 

[welder4956]

Soak it well with kerosene or diesel fuel, brush it on and keep it wet for about 10 minutes. Then take a clean, dry shop towels or wipes and dry it off. Do not use any solvents or cleaners to wipe it down. Then sprinkle talcum powder on the surface you are checking and allow to sit at least 5-10 minutes. The wet spots in the powder will show if a crack exists.

This is the original liquid penetrant test method developed on railroad car wheels. This later evolved into the dye penetrant test. I like dye penetrant testing, but if you can't get your hands on a kit, the above method works just fine.

 

[afazz]

Thanks for the info! I bought a dye penetrant test kit this morning, and it is only a scratch. False alarm! I'll keep the diesel/talc test in mind for the future, I figured there was a home brew method.

 

[BillK]

afazz,
Just make sure it is not in a location that will affect the head gasket sealing properly. Post a pic if you want and I will take a look.

 

[afazz]

While I'm posting pics, here is the kit I used

There are a few smaller scratches that the camera exaggerates, I think it will be fine for a stock-ish NA motor.

I tested it on a real crack, and this is what showed up:

 

[coolreed]

Just looking at the picture it looks like a crack. But it does not look like it is in a critical area. You might consult a reputable machine shop and have them look at it. I doubt if they would charge you just to look and make a suggestion.
Good Luck and hopefully it is not a serious issue.

 

[BillK]

The red arrow is pointing to what looks like a crack to me, but that is a strange place for a block to crack. Green arrow is scratches. If you are not sure have your machine shop magnaflux it for you. It only takes about ten minutes with a dry powder magnaflux and will give you the peace of mind. Even if they charge you it shouldn't be much. I would probably charge you $20 at most, depending on how good of a customer you were

I personally have never liked the die test kits for finding cracks. They might be ok on aluminum aircraft parts but I just dont like them for engine parts.

 

[welder4956]

If that were a crack, it would have bled out like a stuck pig with the developer on it. Looks like a scratch to me.

We use dye penetrant daily to check welds on piping, pressure vessels and cast steam turbines. I have a lot of confidence in it's ability to reveal cracks on this type of work.

 

[Spectre32]

PT isn’t exactly the best method for checking for cracks in steel. Its mostly reserved for Non Ferrous Materials. It will work and it can be used on normal C.S but there is a reason MT was developed. On C.S parts PT is the least "sensitive" in terms of all of the suited NDE for Carbon Steel. Florescent PT would be a step in the better direction towards better characterization of the flaw.

 

[MoonRise]

Dye penetrant testing is certainly used for both ferrous and non-ferrous NDT for cracks.

http://en.wikipedia.org/wiki/Dye_penetrant_inspection

(yeah, yeah, I know, wikipedia. But it gives a decent overview of the process.)

http://www.magnaflux.com/Products/PenetrantInspection/SpotcheckVisible/tabid/82/Default.aspx

http://www.contech.com/Dye_Penetrant.htm

http://www.aws.org/itrends/2004/01/it0104-17.pdf

Looks like a scratch. You did a penetrant test (as long as you were reasonably following the directions) and found out it is just a surface (but pretty deep) scratch. Move on.

 

[Canadian Cowboy]

I have used D/P many times your fine, make sure you clean the block surface really good you don't want any imperfections on the gasket mating surface clean all traces of the D/P film.

CC

 

[Spectre32]

Dye penetrant testing is certainly used for both ferrous and non-ferrous NDT for cracks.

http://en.wikipedia.org/wiki/Dye_penetrant_inspection

(yeah, yeah, I know, wikipedia. But it gives a decent overview of the process.)

http://www.magnaflux.com/Products/PenetrantInspection/SpotcheckVisible/tabid/82/Default.aspx

http://www.contech.com/Dye_Penetrant.htm

http://www.aws.org/itrends/2004/01/it0104-17.pdf

Looks like a scratch. You did a penetrant test (as long as you were reasonably following the directions) and found out it is just a surface (but pretty deep) scratch. Move on.

I never said it wasn’t, I said its just not the best solution for checking for flaws in Ferrous Materials. IT can and is used for Ferrous materials applications when MT cant work, due to parts configuration and or magnetizing the material will have a unwanted effect. It is a nice go/no go kit but if you actually had to map out and excivate that repair PT'ing it would be equivlant to use a borad brush, were an MT or Fluorescent PT would be significantly finer....which is what you would want since you typically want to remove as little of base material as you can and then repair with whatever method is applicable.

 

[Skandsen]

Just make sure you are sure It ***** to slap it together to find out you have a crack after all. AMHIK