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Head re torque


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Errr no, you dont loose paste seal IF its done as soon as poss,

wid engine hot, as its still soft.

can easily get another full turn on some

go figure why

 

And, as most ev run their engines wid coolant in em at start up

then 100% chance its not got hot enough t,melt the goo

nee coolant on fust start up, simples

 

 

 

M

Edited by GT6M
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Only to add to the options/debate/argument ;) and this doesn't apply to composite gaskets as I don't use them as I have a few original Payen copper ones.

 

But my father many moons ago taught me to remove the gunk on Payen gaskets with thinners so its spotlessly clean and then fit with a good smear of LM grease on both sides. Torque normally and run engine, then retorque cold,

 

Why bother? because when you come to take the head off next, your nice (and now expensive and hard to get) Payen gasket will come off complete and intact and all it needs is another clean with thinners and can be reused. The advantage on reuse is that you won't need that re-torque as any compression has already happened. My current Payen is on its third head off cycle and is as good as the day it was first fitted, another slight bonus I find is that provided you don't strip and keep the valve train in exact order, you will find magically that all your tappet clearances on rebuild are almost exactly what they were when you stripped it!, ok need checking after initial running, but will be very very close.

 

Never had a head gasket leak using this method (although I'm not running super high compression) and the longest time I have had a head gasket come off clean was from an engine in a car that had been in storage (still full of coolant) for 25+ years. I didn't actually reuse it (but think I could have) but do have it hung on the wall.

 

Not suggesting that anyone copies building an engine that you hope will be together for an extended time frame, but if you think more frequent rebuilds are likely it works for me, especially as if/when they come up a NOS copper Payen is north of £50.

 

I suspect my fathers reasoning was also financial as they were running methanol Hydroplane engines (on a shoe string) and I seem to remember the engines being stripped and rebuilt every other event or so.

 

Alan

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Hi Marki,

My own personal experience. I started out on the last RBRR with a newly rebuilt engine. 1000 miles later I had lost a litre of water 1 pint of which found in the catch tank. Re-torqued he head and all was fine.

Everyone in the car park said don't you know you should re-torque after 500 miles. I do now. B)

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Guest ntc

Load of boll!!!s you should see white residue at the joint after 500 miles clean it off, if you torque it again a stud will turn and the seal is gone,the block will rust around the stud hole and crack safe bet number 2 or 5.

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I use Payen or in the modified engines the ELMESO

custom made for 78mm bore.

 

I torque them to 10mkg with Moly paste on the washers and retorque them

cold after some miles when I set the valve clearance again to 10mkg.

 

I do not think retorque is essential but its an easy job when valve cover

is already open and rockers are quickly removed

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Check the torque after 500 miles. Re-torque if required. Standard Workshop practice.

 

Back in the 1960's if you had any work done by an ST main agent on the head then you had to take to car back in after 500 miles for them to check the torque.

 

Dave

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Guest ntc

They would at a cost? I have built many 6 pot engines over the years strait to the dyno then in the car,never had one fail.If you need a cracked block I have plenty.

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Indeed it did, and I've never damaged a TR or any other block by checking torque at 500 miles or thereabouts.

 

On the other hand, I can think offhand of 3 occasions when I omitted to check the torque at 500 . . . . and paid the penalty of a blown head gasket.

 

Block damage is more likely to be caused by an inaccurately calibrated torque wrench, or by erroneous technique - and I've seen both a few times.

 

Cheers,

 

Alec

Edited by Alec Pringle
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+1 for DaveR

 

I worked for Coopers/ Payen/Halls Gaskets in the 1960/1970s and that was the requirement, as Dave says! Also to expel another myth the varnish that was applied in the last op of manufacture was put there for anti-stick purposes only! But did not work very well on the TR7 for instance! Many types of varnish formulae were tried to cure this sticking on of the head gasket/ Cyl. Head/Block.

 

Bruce.

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Sorry, I am now confused.......all bar one say " do retorque ". Neil, you say "don't" .....but confirm you have lots of cracked blocks. Is that possibly because you don't retorque ????

 

Is anybody else been able to confirm the theory that not retorquing leaves you with a cracked block ?

 

Cheers !

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I have never had a block crack due to re torquing on 1.6, 2.0 and 2.5 six cylinder engines and 948, 1300, 1500 four cylinder engines over the last 50+ years. You are only ensuring the torque hasn't reduced, if it has you then set it up again to the correct figure. This was a Standard Triumph (ST) laid down process. If it was cracking blocks ST would have stop stipulating this requirement and found another way of dealing with the changes in torque.

 

If you don't check the torque and it has reduced then the gasket may blow and or the head could warp.

 

Bolts stretch, the gasket compresses, things change after use which can cause the torque to reduce.

 

Dave

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Dave

 

Thanks for putting me right. So perhaps going forward, if Neil does retorque......no more cracked blocks ?

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Where's Stuart when you need him???

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Stuart's probably keeping his head down, out of the firing line of a difference in views which is unlikely to be resolved ! :rolleyes:

 

Neil has his own way of doing things, Dave and yours truly prefer a more TRaditional approach.

 

Think leopards and spots, dogs and tricks . . . . . :P

 

The idea of a shed full of cracked blocks is mildly boggling . . . . . fixing them is a costly specialist welding task, and hardly cost-effective as long as there's no great block shortage. And they're a bit big for door stops . . . .

 

Cheers,

 

Alec

Edited by Alec Pringle
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Alec, I enjoy following and learning from the posts. But when a dozen agree and somebody resolutely doesn't, we should try and encourage debate, but of course........you can lead a horse to water.......or indeed........habits die hard......

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"you can lead a horse to water"

 

Commonly quoted Peter with it's attending line, however when you talk to an agricultural community the "extra" line is commonly appended

 

"but you can salt it's food" which actually works pretty well !... just the same as eating salted peanuts in a pub.!

 

Mick Richards

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Mick

That's a bit like the old adage

"You can't polish a turd"

 

"But you can roll it in glitter"...........

 

And I get that comment just before going out of an evening !?!?!?

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