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69 Custom s guy

Engine Block rust removal advice please...

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I've got an engine that is full of 35 year old rusty water/coolant and I'm looking to flush clean while still intact in the car but I don't want to run it thru my new water pump and intake if possible.

I've fabricated a couple fittings for a hose connections at the front (see arrows on drawing) and was thinking of either, attaching the intake  or fabbing up some fittings for the heads.

With this setup I feel that I could power flush with an air pressure/water combo and maybe even use a pump to circulate a rust removal  product throughout the block to loosen the crap up further.

Does anybody see a problem or any issues with this contraption?  I'm sure I wont get all of the crap out but I feel any little bit would help.

P.S. I've got the heater hose nipple plugged at the block.

DerustBlock.jpg

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Quite frankly I am interested to see how this works out for you.  Be careful on your water/air pressure. You don't want to blow out your freeze plugs with too high a pressure.

The only other caution I would have is to make sure that you don't get any water into any of the oil passages or crankcase. I'd also suggest you be prepared to change the oil after you 've done this and let it settle down for a little while so everything can drain down. Putting your intake manifold back on will definitely minimize this possibility but I would still plan to change the oil anyway as a precaution.

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Justa me, but I would put the intake back on to minimize water getting into your engine. (still change oil after, as Frosty suggested) Also remember that you need to go in the reverse direction of normal water flow.  Lime scale and debris will form in ridges of the direction of the water flow. Will also hold rust and crap in the ridges.  Backflushing will work on the ridges and help remove the buildup in between.  You can pull the radiator and try cleaning the same way. Reverse direction.  That only leaves the heater core and what you wanna try to clean that. (heater core is the weakest link in the system...be gentle ) You know that has to be full of crap too.  If you don't clean the entire system it will Justa re infect the old wounds.  Good luck.

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Excellent points JUSTA!

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It's always been my understanding that you're best to leave sleeping dogs lie.  I definitely would not use air in any way.  Run the hot water heater up as high as it'll go, and empty it through the block as a clean water flush and leave it at that. No high pressure needed ... with the maze of passages, your pressure isn't going to do anything anyhow.  Thermal expansion and contraction means anything stuck to the walls is well stuck and not going anywhere. Anything else and you're poking a wasp nest with a stick.

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thanks for all your advice guys, i did wind up using an old Al. manifold however it did leak a bit but was able to flush the system both directions plus  recirculated some Gunk Rust treatment thru the block for a few hours. The water was rusty at first but after more flushing it came out clean!  Next up to remove any water that may have got into the oil passages and oil pan. I flushed the heater core with hot water as well and it too came out clear. And Radiator is next So I think I'm ready to move on.

BTW, any advise on how to evacuate any water that may have entered the oil passages? compressed air?

Thanks again,

flush1.jpg

flush2.jpg

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As far the oil galleries....would change oil..and filter.. Pull the distributor..( after you Mark everything ) use an old distributor shaft or an oiling tool...in a drill and and pre oil the engine just like you would before starting a fresh engine.... Do it for a few minutes to be sure the new oil is well circulated thru the whole system...Then change the oil and the filter again..and reassemble..Remember to turn the pump CCW the same direction the distributor rotates..Should remove any residual water. If there is any present...

Edited by TWO LANE BLACK TOP
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Ok Thanks, I flushed it again today as when I disassembled my contraption there was more rusty water, I suppose I will never get it all so now on to assembly. I'm sure I'll have more questions as I go...Thanks for all the replies.

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That's a good idea Two lane, but first you should run alcohol through the system! Motor oil won't mix with the water and the water will actually, for the most part, stay in place because of surface tension. 

After the alcohol is circulated through the block a few time drain it, let it dry a while, then run the oil through it to clean it up. Replace the filter each time like Two lane suggested.

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so Indian are you talking about putting a product like Iso-Heat in the crankcase and spinning the pump? Thats gonna suck because I just installed a new cam/lifters with all the assembly lube and I would think that would wash everything down.

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Actually I meant isopropyl, but you are correct the will wash the assembly lube away , but so will anything you pump through, even oil! You'll have to make a decision. If there is enough water, and it won't take much,  it will wipe the bearings, oil or not. If you decide to use the alcohol and the oil, when you're done, sorry I know it's a lot of work,  loosen the rocker arms, take out the push rods and lifters re-coat the cam through the lifter holes, then the bottom of the lifters. Then before you put the intake  on pour STP over the lifters. This will protect things during break in. 

Your other choice is heat the to 300f and circulated the oil at 300 till the block reachs 300. This should boil off the water. You'll still have the same issue withe the cam pre-assembly lube though.

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Ok I get it.. I'll do that then...thanks

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