: Northstar sitting for 12 years...need new springs?



the recluse
11-20-13, 09:49 PM
As the heading implies, I have a Northstar engine that has been sitting for 12 years...I was wondering that if that engine has been sitting for that long with springs compressed, do you think I should replace them before putting the motor to use?

I would hate to get valve float at high rev's because the springs are now weak...

Submariner409
11-20-13, 09:54 PM
Install the engine, run it cautiously for a hundred miles or so, do a full oil/filter change, then let it all hang out.

............ While the engine is on the bricks, pull the cam covers and soak the valvetrain with some HD 10W-30 oil. Shell Rotella or Pennzoil LongLife. Use that for the initial startup, too. If you really feel industrious, pull the spark plugs and roll the engine over to build oil pressure and fill all the oil passages - pulling the plugs lessens strain on the rod and crank bearings.

drewsdeville
11-20-13, 10:05 PM
As the heading implies, I have a Northstar engine that has been sitting for 12 years...I was wondering that if that engine has been sitting for that long with springs compressed, do you think I should replace them before putting the motor to use?

I would hate to get valve float at high rev's because the springs are now weak...

Springs fatigue with each cycle between relaxed and compressed. A constant state of relaxation or compression has no effect on their longevity. If it did, many autoloading guns, for instance, would be nonfunctional shortly after their production.

the recluse
11-20-13, 10:08 PM
Yeah, I've already split the block and resealed it...and turned the engine over while on the stand a few times...I just didn't want to think about changing valve springs IN the car , lol...

dkozloski
11-21-13, 01:47 AM
High quality springs will last a hundred years fully compressed. The enemy of valve springs is acid etching from combustion products that blow by the rings and accumulate in the oil pan.