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Options, if any, for a crankshaft that has out of spec circle runout

Engine Building Fundamentals

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Hi all,

First post here. I picked up a (cheap) 1FZ-FE block, as I have a 100 series Landcruiser, that I bought as a learning tool(diagnose issue for experience). The issues found were the center journal on crank circle runout was 0.26mm(thus bent). According to FSM 0.06mm is the "throw it out and buy a new one" limit. The end journals on the crank had a circle runout were 0.01mm and journal 3 and 5 were about 0.10mm. The bearings under end caps 3,4,5 were crushed, and as expected parts were found in sump and on the pick up. Can this crank be salvaged, say by machining + nitriding or some other process? Is it even worth considering(after testing for cracks)?

Hi Jason i rang a good friend of mine and he has many many years of building these engines and I fully trust his advise, he said do your self a favour and buy a good one before it ends in tears. now i trained this young fella many years ago and he is the tightest little man you've ever met so he would know if there was a viable and worthy option other than renewing something.

I hope this helps

Cheers Ross, thought that may be the case. It was bought with the expectation parts will be a write off(crank and block were only things that I thought may be salvageable), and that I could get some experience so, I'm happy to source another crank shaft. Getting useful parts from this will be a bonus.

Thank you for the advice there. Now time o see if block is salvageable(got a crack treating kit), and where to source a decent crankshaft and block (as the rest of internals I want to replace).

Going to come down to what you can buy a new/good used crankshaft for and what it'd cost you to get the crank straightened.

Back in the day some of the surface treatments required lengthy immersion in hot salts, and it wasn't unusual for the crankshaft to come out 'bent' - traditionally the correct proceedure was to, literally, hit the crankshaft with a large hammer* using, I believe, close fitting copper or lead 'V' supports and drift to avoid damaging the crankshaft surface. DO NOT try and straighten with a press as this would frequently just break the crankshaft.

Doing some checking for where you can get this done, I came across this process, that may be of interest - https://www.crankshaftgrinding.co.uk/crankshaft-straightening-insitu.html

You could have the mains re-ground, if the undersize bearings are available, but there are two other things to bear in mind. a/ because the main part of the crank mass has been moved of centre, it will now be unbalanced and b/ the crank throws will be lifted/dropped with the bend and this will affect deck heights and compressions. Those may, or may not, be significant, but will need to be taken into account.

Something you may like to try, if the crank is otherwise a loss, is 'shrinking' the crankshaft in a similar manner to 'shrinking' panelwork - heat and quench to draw it back. Not something I've ever tried, but rather than having an unusual lanp stand, it might be worth trying.

Before you do anything, if you do decide to try, get it crack tested - no point in spending money on something that is already scrap iron.

Thanks Gord for the reply.

I'll look into if there is a place that does a straightening process in Victoria (Australia), and find out the price if available. I've already purchased a chemical crack test kit and going to try on block, head and crank, again for a learning exercise.

To me, what I've gained in confidence and knowledge from the process of dismantling the block, was worth the (relatively) small cost of the block/head. I wanted something I could, if I buggered it up, not feel an attachment to (if it was on the block that is running fine in the vehicle I'd be unhappy). Now I feel I could tackle a rebuild.

Ah, smart chap - I always advise people to build a 'spare' engine, rather than the one in the vehicle, primarily because it always takes longer and is more expensive (those are often related) than expected. This is especially important if the vehicle is going to be available for the work in a limited time frame. Heck, even with a POS engine, you can practice assembling and disassembling it, as you get the hang of setting up cam drives, measuring clearances, using torque wrenches, etc, without worrying about messing something up as, if you do, it doesn't matter.

You could try these chaps - https://www.crankshaftrebuilders.com.au/ NOTE, I don't know anything about them, other than their inter-web site came up, so you may need to do your homework on how good they are.

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