V8 Head Bolts

[oldcobber]

Hi guy`s,

Nearly ready to bolt the heads back on after a full (ish) rebuild. I noted in the manual that it states using thread sealer / lubricant on the bolt threads.

I`ve got some sealer that I used with the front cover / water pump bolts, and I`ve got some assembly grease / lube.

What should I use?

Thanks

Bob

[TINKA]

I used the assembly grease that came with the bolts, The reason for this is the torque figure quoted is not supposed to include the friction of the threads you would have if you use nothing. :thumb:

[oldcobber]

Thanks Martin,

Thats exatly what I thought, lube not sealer. I assumed that the head gaskets do the sealing and could not see a reason to seal the bolts.

Thanks

Bob

[Sidecarbod]

Don't forget that its not just the friction in the threads that can effect the torque reading. You must put some lube between the head of the bolt and the washer!

Regards,

Pete

[wilf]

Hold on a second.

On some engines, the cylinder head bolts go throught the block deck and into the water cooling spaces. Ford 289W comes to mind, not sure what others.
Anyway - in those cases, a thread sealant is needed to stop water from getting up the threads and rusting the bolts solid in the block. (or leaking out through those threads).

[Sidecarbod]

Originally Posted by wilf leek

Hold on a second.

On some engines, the cylinder head bolts go throught the block deck and into the water cooling spaces. Ford 289W comes to mind, not sure what others.
Anyway - in those cases, a thread sealant is needed to stop water from getting up the threads and rusting the bolts solid in the block. (or leaking out through those threads).

Hi Wilf,

I presume that as Bob (Oldcobber44) has put his question in the Rv8 section then he is talking about a Rover V8, in which case it is OK to use lube. Having said all that you still have a point.


Regards,

Pete

[wilf]

Pete - you are right, I had missed that, and I can't recall if RV8 head bolts go through the deck or not. However, now that I AM aware of it, there is another issue - stopping the steel bolts from corroding into the ally block, and Rover specified some special gunk to do that.

Really must stop to see where in the forum I am someimes!

[robinj66]

Wilf is correct (as nearly always )

Austin Rover manual says to "coat each cylinder head bolt thread with 3M EC 776 Lubricant-sealant" on the SD1 RV8.
Best I could come up with was loctite stuff from Partco.

:thumb: Robin

[Sidecarbod]

Originally Posted by wilf leek

Pete - you are right, I had missed that, and I can't recall if RV8 head bolts go through the deck or not. However, now that I AM aware of it, there is another issue - stopping the steel bolts from corroding into the ally block, and Rover specified some special gunk to do that.

Really must stop to see where in the forum I am someimes!

Hi wilf,

I was being a bit of a smart ar5e! and anyway from what Robin say's you need a special lube/sealant so we are both right and wrong in a way!

Pete

[wilf]

Many people have commented that I am "not right". Still, what do they know?