hey guys,

i'm rebuilding a LT1 and its a 355 with forged speed pro pistons and stuff. i dont have a crank hub yet so i've been turning the assembly by hand...well i finished the pistons today but its really hard to turn teh crank using the lobes and stuff. i'm wondering if i screwed up anything. i'm using plenty of assembly lube and i donno....

please tell me it should be hard to turn the assembly by hand with no leverage!!!!

 

The complete assembly? Depends how strong you are, from under the car its a little herky jerky for me with no leverage.

 

the engine is on a stand....... and everything is in.....pistons....rods...crank!!!!!


i can turn it....but its really tough.....

 

Mine was pretty hard to turn over at first with no heads on it, with the heads, it got tough as hell. After the engine got running and broke itself in, it's much easier to turn. Just realize these parts have made no contact with each other to create any kind of wear pattern, plus the fact you have the assembley lube in there, which isn't the thinnest of stuff

-Shannon

 

A good rule of thumb is 5 ft lbs per cyl and 5 ft lbs for the crank by itself max.. This would be a max. of 45 ft lbs for a completed 8 cyl. maximum. I typically install one rod then check the turning torque, it shouldn't be higher than 10 ft lbs (crank + 1 piston/rod) then move on to the next and recheck. Use a beam style torque wrench. Typically you will come in less than 5 ft lbs per cyl., more like 2-4 ft lbs. I think my last engine was 35 ft lbs total. If you are turning it by hand then you should be ok. The spec. doubles if you have the heads on.