Hi guys. I am considering getting a used slant six and freshening it up before I use it in my truck. Here is what I am considering doing to it before I use it:

Disassemble

Hot tank block

Mike cylinders and hone to get back to a round/straight hole and reuse same pistons/rods with new rings if possible

Install new cam bearings

Mike and check rod and main journals, install set of new rod/main bearings if possible

Not planning on a head job unless necessary

New timing set

New oil pump

Gasket set of course including new rear main seal and timing cover seal


What do you think? Obviously I am trying to get a good sound motor without going to the expense of having to buy a set of pistons or do any grinding on the crank, if the used components are found to be serviceable. Am I being penny wise and pound foolish? I work at a NAPA store with access to a machine shop so I think I can do all this pretty economically if I am lucky with being able to use the old pistons and get away with just new bearings and no crank work. Your opinions would be welcome. Davey

By the way, which main bearing is the thrust bearing? How critical is setting crank end play? Is it done with shims? Davey

I would do the head also. You could wait, but you will get much better results if the rebuild is equal throughout. It is good to have the valves seal as well as the rings. I would also do the bearings. There is so much labor in in taking it all apart, it is much more efficient to just go ahead and put new bearings in. I think the third bearing back is the thrust bearing. If it was a stick shift car, that will be worn more than if it was an automatic. Keep in mind that the newest of these engines is now 20 years old, and most are in the neighborhood of 30-40 years old.

Sam

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If everything is in spec, there is nothing wrong with re-using the pistons and crank. Don't try and "get by" on marginal pieces though. You will end up with an oil burner for sure.

Also, I would have the head gone through now. It will save headaches later.

I'm having brain fade on the thrust. I just saw one apart a couple weeks ago too. IIRC, it is the #3. Clearance is kinda go-no go. I've never seen one with too little, and if there's too much the crank needs fixed.

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Official Cookie and Mater Tormentor.

Numbe three is the thrust bearing. I have never seen the end play to be out of spec, unless the crank was really toast. In that case the crank has ro be repaired, anyway. Some manufactures, did have "select" fit thrust bearings available at initial assembly, but I don't know if Chrysler was one of them. They did use undersize main and rods bearings on occasion.
I have some OEM 1/2 thousenth under mains on the shelf.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
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I would plan on doing the head also. The guides and seats in most engines are usually tired before the rings are. A ring job on the bottom end should be fine, but as already pointed out, make sure everything is within specs.

Pay attention to the ring side clearance, it will probably be fine but check it. Make sure the ridge at the top of the bore is removed completely, sharp new new rings hitting the ridge will be ruined . Only hone it enough to remove the glaze and put a complete pattern on the bores.

I would not try to re-use the bearings. Even if they look good, they will have some debri embedded in them and no matter how carefully and thoroughly they are cleaned they will not likely seat back in exactly the same.

Read through Doug Dutra's article on BLOCKS, and consider his comments on testing and preparation. A little work on the oil circuit might pay off. Smoothing sharp external edges also makes it a little nicer to work around.

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
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