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Re-torquing heads - Mercruiser 7.4L

R

rnace

New member
Should I re-torque my head bolts after top-engine rebuild on 7.4L Mercruiser FWC Engines? I have 25 hrs on the engines since the work was performed and new head gaskets were installed. I'm also wondering if re-torquing the heads would disturb the thread sealant already on the bolts protruding into the water jackets and cause leaks.
 
With modern head gaskets that's not as necessary as it used to be. You might try re-torqueing a few bolts, as a test case, that do not go into the water jacket I believe the ones on the exhaust side of the head do not.

Jeff
 
Most holes are wet on the big blocks, for sure on my 427 which is NOT a tall block. Jeff is correct, new gaskets in the last 20 or so years, are not needing retorque. In the 60s and 70s I did retorque. Then got sold on McCord and Felpro. Never retorqued another head. Gotta take the motor halfway apart to get to the bolts anyway. I like to check decks on the big Chevs, have had a few problems over the decades.
 
The last upper rebuild I did, Once and done! I also used a thread lube from ARP. Great stuff! Use it on my motorcycle head bolts also (aluminum casting so torquing is even more critical.....again one and done!
 
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