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The mkiv Supra Owners Club

Engine rebuilding for dummies


Jake

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I have a few questions about engine rebuilds:

 

In readyness for my next engine blow-up I'm thinking about rebuilding my spare engine, the one that overheated on the motorway and sounds like a bag of spanners now.

I've taken the head off and it all looks ok, bores are like new, piston crowns and combustion chambers are unmarked.

When I take the sumps off I'm expecting to find a bit of a mess.

 

Other than visibly, I have no means to check the crank (or knowledge how to). If it looks ok (Not scored) where the rod and main bearings go would I probably be alright to just bung some new bearings in? Or must I take it to an engineering place to have it checked for roundness (not sure of the right word there)?

 

If I take it to an engineer's I presume they'll need the block, rods, caps and crank - is that right?

After machining will they be able to tell me what size bearings I'll need? Or is that something I'd have to measure somehow for myself?

 

 

Thanks for any help.

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Only way to know for sure is take it to an engineering firm and get everything checked. If it overheated all sorts might be out by very marginally and not visibly.

The crank should be checked for balance I guess, plus measured to check it's round as you say. May require some grinding. You may need to know what types of oversize bearings you can buy first too for matching.

This is all from experience of rebuilding my old Pinto - this JZA80 kit is way more advanced than that but basic priniciple remains.

If it were me I'd just hand the lot over and leave it with them.

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:blush:

 

Yeah I did. I think it's broke again. :D

 

 

Thought I might as well do it properly this time.

 

LOL

 

as said, it over heated jake, you will need to get the head checked for warpage and pressure tested. If its ok get the facing cleaned up, get the VS oil seals done and the ports decoked and cleaned up,get the valves recut and get a set of Arps for bolting it down with a descent headgasket of you dont want to go the stocker route.

As for the block, Youll need to get it checked aswell, they will also clean out all the oil and water gallerys, the crank journals will need to be measured and reground if needed, all the rods checked including the bearings etc etc. The bores will need to be checked too. If everythings ok then kust replace the big end and small end bearings and the oil pump.

But as you said, it sounded like a bag of spanners so i guess the big ends or something give up the ghost.

 

Better leaving it to a decent engine builder and give him the info on what you want done, unless your 100% in knowing what to do and how to do it man :)

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