Hi guys; wich is the best rust preventive or treatment to a marine block it was used on salt water now will to street use. thanks

If it is just a block at this time, I would think having it hot tanked would remove the rust.

muriatic acid and then a good baking soda and water mix

The rust will start the inside of the cylinder walls to start flaking off unless it is already doing do.

Not sure how bad yours is but I had one that I cleaned out thoroughly prior to a rebuild and when it was apart a year later due to a cam failure the rust inside the block was even worse so I didn't use the block again. I did not think to use any treatment so don't know if that would help.

I would avoid a marine block for this reason.

Just my $.02 worth.

Mark

many modern machine shop have abandoned the old caustic soda based vats because of the problems disposing of the crud in the bottom. Those things never were much good for rust anyway. Some shops now have a "bake and blast" setup. the bare block with all plugs removed is baked in an oven at like 800 degrees to carbonize every thing on or in it. Then it's blasted with steel shot. It comes out looking a lot like new, even in the water jackets. It still needs to washed with hot soap water, many shops do this after the bore/hone and other machine work is done. Downside to this is that the shot blasting is hard on the machined surfaces. Depending on how long they leave it in it may need to be decked and align-honed afterwards if you're picky about that kind of thing.

Tom

I had a 454 Marine block "shake and baked" a few years ago. They didn't shoot any steel shot at the machined surfaces, as they appeared to be in the same shape as they were prior to baking. The motor had a ton of rust scale in the water jackets, and the shake and bake cleaned it up pretty well. There was still a tiny bit of rust in the block passages that would find its way out once the motor was run and a coolant flush was performed. I had the block magged and sonic checked, and there were no thin spots or cracks. It was then hot-tanked. That is the only way too go with a used marine block. Have it checked out before buying your other parts!