Thread: Spitfire / Hemi build

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I miss the days of the old caustic hot tanks. Years ago all the local machine shops went to Jet Washes. They do OK on dirt and grease but don't touch rust. Exterior rust on blocks and heads can be bead blasted off, but it's virtually impossible to clean the water passages.

I've used citric acid to de-rust other stuff and have wanted to experiment on a block and heads.......this is the perfect candidate.


I bought a 5 pound bag off Amazon and the largest plastic tub Walmart carries.


Y Citric by M Patterson, on Flickr


The first batch to go in was the spare set of rockers and shafts, main caps and HEMI heads. All this stuff had been sitting in the trunk of the Imperial for 40 some years and was coated with a hard rust. Five head bolts were rusted solid into the rocker stands on one set of rockers.


Y RP by M Patterson, on Flickr


I put the first batch in the tub filled it with enough water to completely submerge everything and mixed in about 2 pounds of the citric acid.


Y Soak by M Patterson, on Flickr


It took about 4 days and during that time I eventually added about another 2 pounds of the citric acid. I suspect it would have only taken a couple of days had I done this in the summer when it was warmer........It was only getting into the 60s during the day and almost freezing at night.


I took the caps and rockers out after the 4 days (decided to give the heads an extra day). Those parts came out rust free and the head bolt tapped out with no problem. The rockers are still a little stiff on the shafts so I'm hitting them with penetrating oil before I take them apart.


H3 by M Patterson, on Flickr



As I said main purpose of going thru this was to get the rust out of the water jackets and I'm pretty happy with how that turned out.

WJ by M Patterson, on Flickr


The Poly heads are currently in the tub (with the same solution) and they should be ready to come out about the time I get the block out here.



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