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Old 05-21-2003, 01:46 AM
Richard Wooldridge Richard Wooldridge is offline
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Join Date: Dec 2000
Location: Battle Ground, WA
Posts: 576
How was it driven?

Hi there,
I have had at least six Nissan products (4 280Z's and 2 PU's), and every one I've taken apart has shown no wear anywhere except the head. The blocks wear forever, and the cranks hold up well also. The only place I've seen any real problems is valve guides - they seem to wear enough to allow the stem seals to leak and cause oil consumption. They are replaceable, and I still have a set or two in the parts cabinet. New ones will hold a valve for a minute or two with a slight oil film, before allowing it to slide out. I think your twin turbo has a forged crankshaft and heavy duty rods. I suspect they are in fine shape, but it always is good practice to send them in to be checked for bend and torsion. I doubt they would need resized. You can check bearing crush to verify, though. My factory manual says they should have less than 0.05mm (0.002") per 100mm (3.94") bend or torsion. I would spend some time inspecting the head - make sure the valve seat inserts are in good shape and the guides are still serviceable. (less than .1 mm or 0.0039" clearance stem to guide) Check the head for warpage. Remember that with a turbo engine you don't want to rev the engine until oil pressure has built up to avoid destroying the turbo bearings, which are plain aluminum bushings. If you drive it hot and hard let it idle a bit to cool the turbos before shutoff. My cousin has a barrel of turbos that failed left from his airplane business, mostly due to inexperienced pilots failing to observe one or both of these simple rules.
Good luck with the rebuild/freshen up!
Richard Wooldridge
'82 300D/4.3L V6
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