Head tensioning. Correct torque for worked High compression motors.

[epod]

G'day all.
In the past I have been a bit lazy becuase my torque wrench has broken, thus tensioning Lifan heads by feel. Using stock head gaskets this did not cause any problem with leakage. However since runiing a bigger barrel 150cc combine with aliminium (how do you spell it, you know what i mean) gasket, oil leaks to the outside of the head as happened twice with 2 different gaskets. Motor is still running ok with a bit of a lose in power however oil is not leaking into the cylinder as the engine is running clean.
What is the correct torque to apply to a worked head with high comp piston? I have been doing them about 20 - 25 pounds. Answers in NM is ok also. Thanks.
P.S I shall Buy a new torque wrench before the rebuild.
Ride on.

 

[coolmodee01]

ma that should be way to tight

from memory requirements are only like 8lbs/ft or maybe 8nm cant remember exactly

in either case 25lbs is mass over kill yeah
maybe the over tightening is whats killing your gaskets dunno

cactus aka guru swarmie will know for sure i cbf lookin it up sorry for the lazyness

 

[themountain]

first off...make sure your studs are completely seated in the bottom...taking out the head several times certainly loses them and when you put the head back on, its still loose ,even when the nuts are forced on it to the end!!
second ..use copperspray for the gasket next time...it seals the gasket to the head properly and third buy a torquewrench!!!!...lol
15ft/lbs for your studs!!

 

[epod]

Thanks alot mountain, interesting point about the studs coming lose from the case. Thanks for the torque setting. Will definatley use a gasket bond spray also.
Peace , ride on.

 

[Cactus Jack]

I try to not stick my beak in wherever others are taking care of the subject ... All I'd add is to make sure to tighten the head gradually in stages in a cross hatch pattern ... starting from the oil gallery stud (bottom right hand stud) and as has been said ... make sure the stud threads are at their full depth in the cases first ...