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Mercruiser 260

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54_corvette

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Can anyone tell me the correct

Can anyone tell me the correct torque settings for the Cylinder Heads and Intake manifold on a 1983 Mercruiser 260. The manual I have with the boat says for a 5.7l engine 80 and 25 ft/lbs. The guy that rebuilt the heads says 60 and 35 ft/lbs. Thanks!
 
1977-84 305-350 Head 65; Ro

1977-84 305-350 Head 65; Rod 45; Main 70; Crankshaft 60; Flywheel 60; Intake 30;
 
"Thanks, well I have done the

"Thanks, well I have done the head to 80, what do you recommend, leave as is or back off and re-torque to 65??"
 
"By over torquing the head you

"By over torquing the head you may have ruined the integrity of the head gasket.

I know you do not want to hear this BUT

remove the head, buy new head bolts, buy new head gaskets, reassemble and use some oil on threads of new head botlts befor installing and torque down in

THREE STEPS!!!

first round should be ~ 25 ft lbs
second round ~45 ft lbs

and last round your final setting of 65 ft lbs.

My opinion. OH AND BUY A SERVICE MANUAL INSTEAD OF LISTENING TO SOMEONE WHO MAY OR MAY NOT KNOW!!!"
 
"Further: "you may have ru

"Further: "you may have ruined the integrity of the head gasket."

... and over stretched the bolts. Tightening a bolt to its specified torque intentionally stretches the bolt, which is why Kghost also said..

" buy new head bolts"

... and a service manual so you will know what sequence if any is specified for torquing the head bolts."
 
"Thanks for the comments. I ha

"Thanks for the comments. I have followed your advice and re-done the gaskets etc. I feel better now! Having said that I fired up the engine yesterday, yeah! and after letting it run for maybe ten minutes did my usual feel around of the risers exhaust pipes etc. When I did the rebuild the rubber exhaust connection from the riser to the pipe, about 16 ins long had delaminated inside and was effectively blocking the exhaust on that bank (1,3,5,7). When I showed it to the hose guy he said it had 'cooked". My feel around discovered a very "hot spot" on the new rubber pipe. Close to the riser about 3 ins by 1.5 ins all the rest of the pipe was cold. any ideas what may be causing this? This is presumably what caused the original hose to fail. Thanks"
 
Did you get the elbows cleaned

Did you get the elbows cleaned at a radiator shop? Water passages may be narrowed/blocked and not enough water is dousing the fireball from the exhaust. If all the exhaust is original then get all of it cleaned and pressure tested or replaced. If its only been in fresh water then cleaning should take care of it.
 
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