Rebuilt engine hard to turn over

[mopar367]

I have been rebuilding a 440 engine. It is mostly stock with a few aftermarket parts. But I just installed my rocker arms and pushrods. When I turned the engine over it was great! All the valves opened and closed and it took about 35 ft lbs on the torque wrench to turn the motor over.

Since I have installed the spark plugs the engine is a lot harder to turn over, I can hear slow hissing coming from the ports, But If my lifters weren't Primed up would this cause this? or is it because my engine has higher than stock compression? I used the this head gaskets.

Any tips would be great.

 

[Meep-Meep]

So all the valve train is installed and the plugs? Sounds like you did a good job. You are just fighting compression because the chamber has to be completely sealed on the firing stroke.

 

[mopar367]

Ok, Maybe its just sealing well. And I am used to turning over tired old small blocks lol

 

[ArtH]

Most engines are hard to turn over by hand when the spark plugs are in and the valves are properly sealing the combustion chamber this is normal and a good thing. With an 8 cylinder engine there is a cylinder coming into full compression every quarter turn (90 degrees) of the crank. If it's hard turning over with a starter motor, then you may have a problem.

 

[Cranky]

And the hissing that you are hearing is the air escaping past the rings and valves. It's new and not yet broke in so the leakage will be less later on but will never be perfect.

 

[lewtot184]

I have been rebuilding a 440 engine. It is mostly stock with a few aftermarket parts. But I just installed my rocker arms and pushrods. When I turned the engine over it was great! All the valves opened and closed and it took about 35 ft lbs on the torque wrench to turn the motor over.

Since I have installed the spark plugs the engine is a lot harder to turn over, I can hear slow hissing coming from the ports, But If my lifters weren't Primed up would this cause this? or is it because my engine has higher than stock compression? I used the this head gaskets.

Any tips would be great.

it should be hard to turn over with the plugs in! your compressing the air the cylinders.

 

[moparmarks]

35ftlbs open and harder than heck sealed up? Sounds good to me.

 

[mopar367]

Right on guys, sounds like its all good then.