Re-torquing head

[draenog]

Hi,

Firstly apologies for bringing up what looks to be an age-old question, but I can't find any answer for my situation.

When I got my +2S I had lots of teething problems which eventually got sorted after being returned to the dealer twice (further issues I ended up fixing myself). During this time the garage sent the head off for some work. I can confirm it does look to have been worked on (the inlet ports have been cleaned and are shiney).

So I've currently got the cam cover off (replacing it with a refurbished Weber cover). My question is, assuming the head has been off, should I take the opportunity to re-torque the head bolts? My temptation is to just leave it alone (visions of breaking a head bolt) but the engine does leak oil (after several runs I have a small pool on the garage floor) and I was wondering if it indicated the head needed re-torquing.

I've done considerably less than 1000 miles since getting the car although this does include many short runs.

Thanks,
Rob.

P.S. When re-torquing, is it worth slackening the bolts off a 1/4 turn, or just torque (in sequence) to 60 ft lbs?

[rgh0]

It is unlikely your oil leak is from the head to block join - there are plenty of other opportunities in a twin cam for an oil leak before that

Yes I would re-torque the head bolts. Ideally I would do it after the first couple of engine heat cycles when I am just checking the engine for leaks and setting the carbs and timing, then at around 100km of use after running in the engine and then at around 500 to 1000 km of use after the first oil change. Normally I find you get a little movement the first couple of time but usually nothing the last time.

The bolts should not have seized in the block after such a short time if the blots and threads were clean and lightly lubricated, so you should be able to get a good tightening without having to slacken off and retighten. If I am concerned about this I would normally only just slacken then a few degrees just to "crack" them free and then re-torque, No need going a quarter of a turn.

cheers
Rohan

[draenog]

Hi Rohan,

Thanks for replying.

It is unlikely your oil leak is from the head to block join - there are plenty of other opportunities in a twin cam for an oil leak before that

Looks like you're right! On closer inspection what I thought was an oil leak isn't. It's sticky, and appears to be dried oil, or some sort of sealant (wellseal?) but not a leak...

The bolts should not have seized in the block after such a short time if the blots and threads were clean and lightly lubricated, so you should be able to get a good tightening without having to slacken off and retighten. If I am concerned about this I would normally only just slacken then a few degrees just to "crack" them free and then re-torque, No need going a quarter of a turn.

OK, I'll just try re-torquing them. Wilkins and the Sept 74 workshop manual says 60-65 ft lbs, while the Sept 69 workshop manual gives 55-60 I'll try 60 ft lbs, as the bolts have GKN on them which from another post indicates they're originals?

Thanks,
Rob.

[draenog]

Follow up post.

OK, I'll just try re-torquing them. Wilkins and the Sept 74 workshop manual says 60-65 ft lbs, while the Sept 69 workshop manual gives 55-60 I'll try 60 ft lbs, as the bolts have GKN on them which from another post indicates they're originals?

According to the workshop manual new head bolts were introduced at engine no. 18820. As my engine no. is F21598, I'm assuming it has the stronger bolts so I decided to torque to 65 ft lbs.

Out of the 10 bolts 8 tightened up OK, moving almost a 1/4 of a turn. One didn't budge - I slackened this one a couple of degrees and retorquing to 65 moved it slightly beyond it's original position. The last bolt during torquing made a slight pinging noise but tightened up to 65 ft lbs Finally, I went over the bolts again to make sure they were holding torque.

I expect this is all old hat to seasoned hands, but for me it was pretty scarey stuff

Rob.

[draenog]

Worry worry worry. I'm now wondering if I really did slacken off that bolt and retorque it, or if it simply didn't move Would it be OK to have another go at it, out of sequence, or should I just leave it?

[collins_dan]

I had a bit of a coolant leak and still had original bolts on my S4. I ended up removing them one at a time in proper sequence and replacing with new ARP bolts. I sleep better now. I found it scary as well. There is no sound like that crack when a head bolt releases. Good Luck. Dan