Magnaflux vs dynaflux

[mikehaugen]

I have an ls engine that has either a bad head gasket or cracked head. I plan to pull at least one of the heads, probably both to inspect, but while heads are off I would like to check for cracks. They are aluminum heads and was considering either of these 2 dye penetrant type kits... is one better than the other? The dynaflux is roughly 1/2-1/3 the price.

I completely rebuilt this engine about 40k miles ago so I don't know what happened, maybe my mistake, maybe the felpro MLS gaskets... idk. This time I bought oem Delco gaskets, maybe I will have better luck.

Another question, has anyone ever done this without disassembling the heads? I was planning on it but maybe I can get by without?

I suppose there is a slim chance the block is cracked (it's aluminum and I had it bored .020 over even though it's not recommended) but I'm really hoping not.

 

[webscrounger]

I think magnafluxing only works on ferrous materials, not aluminum but I'm no expert.

 

[Steve_P]

Magnaflux is only for ferrous materials as said prior, and not a typical dye penetrant test. And they may, but I'm not aware, have a dye penetrant test kit that they market under their name. but if they do, it's not "magnaflux" other than by their name. Magnaflux is a magnetic test for checking for cracks in ferrous materials.
If you need to check for cracks on aluminum look into a true dye penetrant test. It's very simple, two spray cans.... I'm sure Zoro has what you need.

 

[webscrounger]

I'm guessing that if your aluminum cylinder has a steel liner, Magnafluxing would work for that, but not the aluminum block.

 

[mikehaugen]

Yes, I was referring to the magnaflux branded dye penetrant kit not actually "magnafluxing." I was just curious if anyone knew of a difference between different brands. Magnaflux brand (spotcheck) is around 200-220 for their kit, dynaflux and even Radnor (probably rebranded one of these two) is around $80.

I am not interested in checking the block really. If the heads and gasket check ok then I'll start to worry. I'm assuming if the gasket is leaking it will be noticeable visually?

I will probably also call a couple machine shops, their price to check them may not be too bad considering the cost of the kits.

 

[MitchL]

like you said Magnaflux is a brand not a testing method. I have worked with magnaflux materials (MT and PT ) extensively for over 15 years. I prefer the magnaflux materials better than most of the other brand I have used, but I would say it is only marginally better at best. (Ardrox, radnor, etc) You might be able to save some money by not buying the cleaner as non- chlorinated brake cleaner will work just as well for your application. Use the dye very sparingly as a little goes a long way. (I would spray dye into a plastic cup and use an acid brush to paint on). It might be worth inquiring with your local NDE companies as they might be able to test fairly economically especially if you don’t require a full code report for the work.

 

[cvairwerks]

I’ve used Zyglo for aluminum inspection for most of my career, until we went almost exclusively to eddy current testing.