V8 cylinder head torque settings for modified engine

DamianZ28

DamianZ28

Active Member
Hi,

I've recenlty finished the engine rebuild on my 72 P6 V8, I have 3.9 skimmed heads with composite head gaskets fitted.

I've torqued them down as per workshop/factory settings: 70lbs inner 10 bolts and 45lbs outter 4 bolts, these are for the standard factory settings with original P6 heads and tin gaskets, so should I be using a higher setting on the torque wrench? I ask as I stil get a bit of blue smoke on start up when the engine is hot but say been switched off for about 15 mins.

With expansion when the block is at running temp, would there be a 'gap' for oil to run into the bores once engine is off & before it cools down ?

Thanks very much Damian
 
Standard P6 heads with tin gaskets were 65-70ft.lbs for all 14 bolts, it was only the intro of composite gaskets that saw the reduction in the setting for the outer row of bolts, so if you have later heads, and composite gaskets then use the torque settings that were recommended where those were standard equipment. P6 settings have no relevance.

I can't see oil running across the head gasket and into the bores.
 
Hi Harvy,

Thanks for the info, I've added this to my resto thread but I'll add it here: 'One thing I noticed is when I accelerate from say 40 to 60mph, I can hear a metallic sound under load, almost sounds like its pinking, timing perhaps, its set to 6°BTDC, when I rev the car by hand when stationary, no noise, I guess it has to be under load. Also notice a vibration when accelerating from say 50mph upwards, one thing I did was to mark the location of the torque converter in relation to the flywheel before unbolting it, this I forgot & did not align the two up when refitting, would this create the vibration or inbalance or is my BW35 auto box on the way out?
I do have the 5-spd manual to go in for my next project.

cheers damian
 
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