Retorque Aluminum Heads?

[CobraEd]

If I were to re-torque the Edelbrock aluminum heads on my 302, would I back off on the bolt first and then retorque in order to break the thread lock first or just tighten to proper torque? They have been on for about two years and 5K miles.

I am getting some goofy temp fluctuations that I believe are due to the crappy Classic Roadsters radiator, but I thought maybe there is a slight head gasket leak.

Ideas?


Ed

[blykins]

Just torque them to the spec that you torqued them to when you assembled them...and follow the torque order.

[Rodney]

Ed
Your correct, loosen "one" head stud nut at a time, and then torque it to 95ftlbs or whatever your engine builder recommended. Do this in the torque sequence as described in the assembly manuals. This method will give you the most accurate torque. Also if you have an old torque wrench get it calibrated or just buy a new one!
hope this helps.

[cobrashoch]

I wouldn't back the head bolts out if I were you. Most (not all) head bolts stretch a bit after a aluminum head heats up from its first heat cycle on the original build. The right thing to do is to replace the bolts with new ones, or if you are insistant on using the old ones just re-torque them in sequence with the engine HOT. Aluminum heads grow a bit when they are hot and this will effect your settings if you do it when your engine is cold. But again, the right thing to do is use new head bolts esp. on a two year old engine. Remember too, most engines see heat cycles parked in garages even if they are not ran.
cobrashock

[Woodz428]

Back them off one at a time in the tightening order and re-torque. Retightening without loosening will give a false reading because of initial drag.

[cobrashoch]

Backing them out without cleaning the dried locktight off the bolt and the thread holes will stlll give you uneven torque settings. Better to just snug them up. Again, the right thing to do is use new bolts, lock/tighted and one at a time. Don't forget to run the new bolts in and out to "chase" the threads before you locktight and torque em' in.
cobrashock

[super_kit_car]

you need to do a cooling system pressure test to determine the problem. there is a pump that screws on where your radiator cap was. you pump it up and look for leaks. if it is the head gaskets, you will see fluid come out at the bottom of the heads near the exhaust manifolds. if you find a leak correct the problem. also, are you losing water or is the gauge just jumpish, could be a faulty ground or gauge. if you are not losing water, it's the gauge or ground.