Healey BT7 Engine Turn-over Torque Required

[mwagon]

If a BT7 engine has been rebuilt properly, compression 165 psi, using a Torque wrench to turn over the engine with & without spark plus installed, what ~ torque max. value would you expect to see? Its taking 35 ft-lbs to turn over my newly rebuilt engine without spark plugs installed.

 

[Randy Forbes]

There's a lot of drag on a newly assembled engine; I've never made an attempt to quantify the value, but the ring drag alone is considereable. Add to that grease (versus oil) on most all rotating and sliding parts, including the oil pump, if packed with white lithium, and it's not unusual to require a substantial force to rotate a freshly rebuilt engine.

A brand new BMW engine (in a new car, not a rebuild) takes several thousand miles before it revs freely. This is very noticeable in driving; one day it's just a completely livlier engine!