bolt torque

Sounds...ok... dunno that I've ever bothered torquing manifold bolts, sust a good firm pull...not quite 'half a grunt'

But re-check 'em once the engine has got hot/cold a couple of times and every thing has settled, that's probably the important bit.

I'm sure one of the UK guys will pull a torque figure out of the bag for you...they just havn't got out of bed yet! ( We get a 5 hour head start of course !)

20-25 ft-lbs is correct for Grade 2 (no head marking, or marked A-307). Grade 5 (3 radial hash marks on the head) should be 30 ft-lbs and Grade 8 (6 radial hash marks on the head, or marked A490) should be approximately 45 ft-lbs.

Also, follow Cat's advise and recheck after several thermal cycles.

I always torque em' til I hear a little squeak. I wonder how many ft lbs that is?

thanks to all who posted. i'll start with 25 and see how it feels after 500 k

johnkelsall

http://www.erl.dot.state.ia.us/Apr_2005/IM/content/453.08ab.pdf

http://www.roadmasterinc.com/pdfinst/1420-1.pdf

joshua

thank you for posting and blessings for being able to post tables

johnkelsall

Spend a few bucks and buy a repair manual it will give you the correct procedure, -- under 20 bucks -- don't do a grunt and then check again -- a new exhaust manifold is pretty pricy unless you have a lot of junkers of the same model the fool around with.

This is auto mechanics not "Rocket Science" DOH -- remember you don't have to re-do a "Rocket repair" just simple stupid "Auto repair"

I am so surprised to see the responses to this question.

The Hanes manual was on sale for 12.95. And shows the bolt grades and the specs for each grade and size but the bolts i have to deal with have a stud sticking out of the bolt head exactly where the grade marks would be. This stud is to attach heat shields and o2 or air injector supports and 25 ft/pounds sure is light compared to the torque required to loosen those same bolts after being cooked in for 10 years. Yes, you are right it isnt a job I want to do again.

thanks

johnkelsall

I alway purchase Haynes and Chiltons. Between the two, I have been very well informed and instructed.

cr3

I have rebuilt a few engines in my lifetime and I agree with Del. The w/shop manual will give you torque loadings for all the nuts and/or bolts on an engine.

However if you uuse the correct sized spanner, not a 300mm shifter, for a particular size nut/bolt and tighten it up tightly you will have round about the correct torque. Spanner design ensures this.(one does not put water pipe over spanners to increase mechaical advantage)

Of course when tightening important bolts I use tension wrenches, stretch gauges or hydraulic jacks and dial indicators. These important nuts/bolts would include such things as head bolts, big end bearing bolts, main bearing bolts,etc.

The proper rule is, "tighten it until you strip it, then back off half a turn."

-A-

Been there, done that, the trouble is that that the whole thing comes undone........then you have to hold the nut on with "super glue," or what fishermen use for everything, either sikaflex or chockfast.

There's another good thing professional fishermen have in their tool kit,that is a complete set of spanners 4inch - 24 inch adjustable spanners or more commonly called shifters, they fit any nut on board....... but then .......there's the 36 or 48 inch stillson wrenches, just in case.

I would use copper nuts for exhaust manifold.

copper nuts. From the delicate Copper Tree of southern Kentucky.

The big stillis are called hammers aren't they?

I was taught the same way!!!!! Same teacher?

I use similar method for cooking...stop when it's burnt and go back a bit!

Glad I don't have to work behind you guys. Be a nightmare getting everything working proper again. You guys must work for big outfits where the only work is fixing your own repairs again and again and again .........

Hey I invented the term MBR

'Mended Beyond Repair'

Hopefully, you did not miss the ?

The components being put assembled are iron and steel parts. A torque of 18 ft lbs establishes a 45,000 psi preload in the fastener. A torque of 24 ft lbs establishes a 60,000 psi preload in the fastener. The 18 ft lbs torque is appropriate for the cash iron threads. The bolts you are using are most likely not alloy so after pulling them to 24 ft lbs, you should discard at next disassembly. PS use a copper or nickel based lubricant on the threads, makes disassembly easier whenever.