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Should I use oil on head bolt threads ?


Noddle

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My builder said the Datsun torque values are dry values. If you lubricate then you adjust the values. I do not know where Jon is getting his info from.

 

WHOA!!!!!!!!! Please do NOT EVER torque head bolts dry!!!! :nono:

 

(Steve. Please don’t take offense to my post here, :) I’m merely only protecting/educating those newbies, and you as well, who might be reading this thread for technical advice and that advice about dry head bolts is entirely incorrect. My guess is that you must have misunderstood your builder when he was discussing this with you. Anyone that is an engine builder knows to NEVER torque bolts dry, EVER!).

 

 

Head bolts 101, NEVER :nono: EVER :nono: should ANY head bolt on ANY engine from ANY manufacturer be torqued dry. PERIOD!

 

With factory head bolts, use standard engine oil with the factory recommend torque specs, no special synthetics or moly paste bolt lube, unless you have the proper torque spec for that bolt using that particular special lube, or you WILL have head blot/gasket issues….

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I've been using PST (Pipe sealer w/Teflon) with decent results. I used to use the moly lube, but I made good friends with a guy who owns an 8-second mustang and said he's been using PST for years with good luck. I've never really talked to a machinest about it, though. BRAAP, opinions?

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Head bolts 101, NEVER :nono: EVER :nono: should ANY head bolt on ANY engine from ANY manufacturer be torqued dry. PERIOD!

 

With factory head bolts, use standard engine oil with the factory recommend torque specs, no special synthetics or moly paste bolt lube, unless you have the proper torque spec for that bolt using that particular special lube, or you WILL have head blot/gasket issues….

 

 

Thank you for the information,

I did know that there is a difference with dry and oiled threads, but was not sure if that was the case here, since I could not find that information in my book.

 

Nigel

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Head bolts 101, NEVER :nono: EVER :nono: should ANY head bolt on ANY engine from ANY manufacturer be torqued dry. PERIOD!

 

That is not what the GM service manual says for a 2002 Camaro engine::

 

-----------------------------------------------------------------------

 

Clean the engine block cylinder head bolt holes, if required. Thread repair tool J 42385-107 may be used to clean the threads of old threadlocking material.

Spray cleaner GM P/N 12346139, P/N 12377981, (Canadian P/N 10953463), or equivalent into the hole.

Clean the cylinder head bolt holes with compressed air.

Check the cylinder head locating pins for proper installation.

 

Install the NEW cylinder head gasket onto the locating pins.

 

Important

when properly installed, the tab on the left cylinder head gasket will be located left of center, or closer to the front of the engine, and the words "This Side Up", and the engine displacement, will be visible.

 

Inspect the gasket for proper installation.

 

Install the cylinder head onto the locating pins and the gasket.

Install the NEW cylinder head bolts.

 

Notice

Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

 

Tighten the cylinder head bolts. Tighten

Tighten the M11 cylinder head bolts (1-10) a first pass in sequence to 30 N·m (22 lb ft).

Tighten the M11 cylinder head bolts (1-10) a second pass in sequence to 90 degrees using the J 36660-A .

Tighten the M11 cylinder head bolts (1-8) to 90 degrees and the M11 cylinder head bolts (9 and 10) to 50 degrees a final pass in sequence using J 36660-A .

Tighten the M8 cylinder head bolts (11-15) to 30 N·m (22 lb ft). Begin with the center bolt (11) and alternating side-to-side, work outward tightening all of the bolts.

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I've been using PST (Pipe sealer w/Teflon) with decent results. I used to use the moly lube, but I made good friends with a guy who owns an 8-second mustang and said he's been using PST for years with good luck. I've never really talked to a machinest about it, though. BRAAP, opinions?

 

 

Zeeboost,

In regards to PST, I’m not sure how slippery it is compared to Motor oil though I have heard of people using the PST with good results. Sorry I can’t offer any more info than that.

 

 

 

 

 

 

 

 

That is not what the GM service manual says for a 2002 Camaro engine::

 

-----------------------------------------------------------------------

 

.........

Notice

Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application.

 

Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure.

 

Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners .... blah blah.. blah....

 

 

 

Popnwood…

 

Hmmm… There could be a couple explanations for that. In the section I quoted from your post in bold type, it mentions sealants etc. In that “service procedure” section, is there by chance mention of using sealant or thread locker on the head bolts?

If GM doesn’t want the assembler to apply any sort of lube or sealant to the threads of the head bolts, then there is a good chance that GM applied a coating of some sort on the treads already.

 

In a quick search online about LS-1 head bolts, I was only able to find this from RHS which states to use anti-seize on head bolts in aluminum threads to prevent thread damage.

 

http://www.racingheadservice.com/Products/InstallationNotes/GenIIIHeads.asp

 

 

I still stand firm that EVERY head bolt needs some sort lube, no matter what! If you do not have some sort of lube or even sealant on the bolts, even aluminum, you will not have consistent bolt stretch values and there is a VERY good chance the threads will gall.

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That is why I cut and pasted the entire head installation procedure.

 

I wasn't sure what "GM P/N 12346139" was. Thought it might be lube, but turns out it is brake cleaner. But when searching for that info I found this snippit from a Helms manual

 

http://www.ls2.com/boggs/torques/headboltinstructions.htm

 

It specifically states the M11 bolts, which are fastened with angle gauge, must be set dry.

 

I guess the moral of the story is to always read the manual.

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