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Discussion Starter #41
Heck of a tip. Thanks. So I was surprised the gasoline with a lot of SeaFoam didn't seem to be working as aggressively as expected. In frustration, I tilted the tank and fired a can of brake cleaner in there straight at the varnish I could see. It did cut it. So I fired in another can and sprayed that all around as far as I could. Then left it in there and sloshed it around whenever I walked by. It seems to be handling the varnish well. But the top of the tank still has those tiny pepper flake sized rust flakes and that's about the top 3/4. So I got some radiator system rust dissolving solution which is safe for plastic parts. I will see if I can loosen and get rid of those flakes by filling the tank half full with hot water and the coolant solution and flipping it upside down on my metal mesh hitch carrier on the LandCruiser and then run errands with it. If that gets rid of the rust flakes, then when I flush it clear I'll be able to see if there is any varnish left and do the Simple Green trick. I already have a gallon bottle sitting out by the bench thanks to your post. Great call - thanks.
 

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Discussion Starter #42
Sixpack,

OK, I did the coolant system "rust dissolving" solution and it didn't do jack. So don't use Mac's brand Coolant Rust Dissolver #1400. I drove it around for about 90 minutes and the water wasn't even discolored. I put my borescope in and it was actually putting out little bubbles. When I poured it out the same little pepper sized flakes are in there. The gunk is gone from yesterday's two bottles of brake cleaner and a half gallon of gas mixture. So the Simple Green and pile of nuts tip will wait till my next project car. I think I'm going to have to put my entire arm in the fuel pump hole and try to brush all the rust flakes off. They're tiny and easily knocked off, so a couple passes with a stiff bristle brush and some Simple Green or Dawn should do it. For areas I can get to easier, a mild scotch pad. But there will always be a few crevices I am sure I cannot get. I'm bummed about the plastic fuel pump baffle in there as it's kept me from using something stronger on the tank, and the fact that it's only in the top 2/3 of the tank also makes it difficult to deal with. That's where the vents are, the fuel pump, and the level sender. I had to make my own cover plates to replace these, and they're plastic as well. Normally when someone's cleaning a tank, they have these perfect old fuel tanks that are featureless inside and have a huge drain in one corner so you can easily get the drift of flakes out. The Supra tank's filler tube has a tall internal flange so you can't pour water and crud out of it. The removal of the fuel pump means there's a huge hole you have to plug, etc etc. This is one aspect of the restoration I will not soon forget. So, I think I'm done with the supposed chemical solutions and will get back to simple elbow grease.
 

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Good tips, I'm also planning on restoring my gas tank this weekend while I'm in there replacing the fuel pump and filter, prolly gonna hit the inside with a brass brush and vinegar
 

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Good tips, I'm also planning on restoring my gas tank this weekend while I'm in there replacing the fuel pump and filter, prolly gonna hit the inside with a brass brush and vinegar
should replace your user name too while your at it
 

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Discussion Starter #45
I'll actually second the name suggestion. Not meant to scold or be disagreeable but I'm sure you are a decent sort and that's kinda hard to get past with the limitations of a forum. On tank cleaning you'll be surprised how much of the tank is blocked by baffles.
 

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I know your done with chemical solutions, but the tried and true industrial remover of scale and rust is oxalic acid. Known as wood bleach at the hardware store, its cheap and powerful. It should say oxalic acid on the container. Mix a few tea spoons with some hot distilled water. Then pour it in for an hour and agitate. Much better if you can get the temperature up high. Typically this is put in the cooling system and the car driven for an hour. For a tank, keeping it hot will be harder.
 

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Discussion Starter #49
OK, Sixpack - That was amazing! So I have the cleanest used Supra fuel tank on the planet thanks to your Simple Green tip. I hung a 4X4 beam off the side of my Toyota LandCruiser and suspended the tank by two corners so I could move it as I pleased. I put a quart of Simple Green, about a quart of hot water and a couple pounds of fasteners in there and went to town. Shaking it, tilting it and whipping it around. It took about 30 minutes and frankly I was thoroughly whipped and had my 19yo son take a few turns as well. I focused on the upper half and then put my color borescope in to look around. Clean! So I thought "Hmm, Sixpack said it would dissolve the gunk as well." I had cleaned the gunk already so that the floor of the tank was merely light tan but with my fingers I could not get any more off it. But thinking of you, I spun it level and left the now dirty formula on the bottom, halfheartedly moving it around but not fast enough for the bolts to work. Just as you stated, the filthy Simple Green STILL had enough power to clean the tank's bottom to shiny metal. Thanks.

So I drained all the water out, then jammed a blow dryer on high in one hole and quickly dried it to prevent flash rust. It looks phenomenal. I owe you a cup of coffee if you're even in beautiful Coeur d'Alene, Idaho!
 

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Discussion Starter #51
Well, back on the engine, and a frustrating delay. I test fitted the aftermarket pistons and was not happy with the pin fit. So I brought the to a machine shop to get a second opinion and I also brought the original pins and pistons as well. He immediately discounted my concern on the factory pins with the faint lines/grooves which I'd assumed were bad damage from the carbon and original HG blowing. Seeing my continued skepticism, he went to a half full 55g drum and grabbed a healthy handful of random piston pins (that drum is just for pins - must have been thousands in there). Every single one had similar marks.

Then he measured things and felt the fit and agreed with me the original pins and pistons would be his choice and they're totally fine. So I went home happy and proceed to screw up the project.

I heated the pistons to assemble them temporarily so I could hand the rods on the crank and plastigage the clearances. The last two pins did not go in easily even though I've fastidiously kept track of parts with sharpie marking and bags. I tapped one back out with a brass drift, not noticing that I dinged the pin bore with it and then when I assembled, it did not feel smooth. Hmmm. Being part Irish, I thought "I'll figure this out on final assembly". And proceeded to do the exact same thing with the last piston. Argh.

So back to the machine shop for advice. He laughed when he saw me pull back in in my classic yellow VW Van and came out to the parking lot. He took a look, said "yep, order a flex hone and fix it." So that's on order. I'm feeling frustrated but will get over it. I moved the engine back to the garage as temps are now warm enough. When the hone comes in, I'll clean up the two piston bores and proceed. Hope this teaches others. The machinist lent me the proper tool for pounding out piston pins which has a center tip that prevents it contacting the bore. Awfully kind of him.

Tank is ready for the new fuel pump and I'm going to open the fuel sender and clean up the wire sensor per the post elsewhere here on the forum suggesting it. More later...
 
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