ZCar Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
Hi guys, i have a 74 260z with 80000 miles on it (not sure if i should believe the odometer) and i have the engine pulled out and i am cleaning it up. Do you guys think the connecting rod bearings should be changed? The engine was running great before, just simply cleaning it up and giving the block a fresh paint. Not sure if its worth replacing, i will note that i saw some sediment at the bottom of the oil pan (most likely iron deposits) but i cant be sure. Any advice or things that need attention before i put the engine back? I am replacing the oil pan gasket (due to minor leak in gasket) as well as the valve cover gasket (as i will be polishing it and putting it back.
 

·
Registered
Joined
·
58 Posts
Was there any sludge in the cylinder head or oil pan that made you think oil changes weren't performed regularly? While the engine is old, it has low mileage. I'd be more inclined to just let it ride, and reinstall as-is.

But if you already have the pan off, it wouldn't be too difficult to check a random crank bearing.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #4
Was there any sludge in the cylinder head or oil pan that made you think oil changes weren't performed regularly? While the engine is old, it has low mileage. I'd be more inclined to just let it ride, and reinstall as-is.

But if you already have the pan off, it wouldn't be too difficult to check a random crank bearing.
That's true, checking one would make sense but i didn't notice much sludge at the bottom of the pan. But I definitely should check the head to see the condition of it. Thanks for the advice
 

·
Registered
Joined
·
759 Posts
It's optional at this point. If you want to check, you can pull one crank bearing cap, check the bearing visually and re-install, torquing to spec. If you're feeling particular, you can Plastigage it as well.

I am not aware that the Z engines are prone to bearing problems, but if you have reason to think oil changes may have been neglected, this is absolutely a great time to check. If you're not in a rush, I'd probably check it.
 

·
Registered
Joined
·
2,023 Posts
Leave your bearings alone. They aren't usually a problem. A tip on the pan, NEVER pry them loose, always cut them loose. When you're tightening the pan bolts remember that they only take 12 inch lbs, not 12 foot lbs. Any tighter than that and you'll warp the pan. If the head has not been rebuilt OR if you don't know one way or the other then it would be advisable to pull the head and see if it still has brass intake valve seats. If it does then have it rebuilt and by all means surface the head before you reinstall it. Z man of Washington
 

·
Registered
Joined
·
116 Posts
ZMan --- great to see that you are still sharing your vast knowledge of Datsun Z issues with new owners that are struggling. We have done business over the years but my aging body told me it was time to sell my Series I 240Z to a neighbor who has a vast car collection. He has been bugging me for 10+ years. Being the original owner of this unmolested, no accidents, original eng
106800
ine and drivetrain, classic, I sold the car in April, 2018 ---- a generous offer that was hard to refuse. A stunning vehicle after painting it for the first time in 2009 with 2007 Nissan 350Z Daytona Blue.
 
1 - 8 of 8 Posts
Top