Fhooom.....
Turbo Mini Forums

Vegard's right ! I always re-torque the head after running the car for a while. The recheck after a few miles driving, i've always found they need time to settle and often need a slight re-torque.
Haynes quotes 55ft/lb for Turbo engine.

Phil.

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the advice given is retorque after running the engine

(ie) HOT and reseting the valve clearences.

the normal figure is 50 ftlb on cold and then when HOT

which pulls the head down further and compresses everthing as it should be.

the figure 55ftlb is slightley higher on a harder working motor say 16psi of boost

which gives a slightley better tensile load
dont worry about ruining the head gasket this wont happen untill excessive amounts are applied.

surley you could torque the head up higher on say a 4psi boosted engine

but whats the POINT as opposed to say a engine which runs 16psi

you need a greater tensile load! on the 16psi engine

lets say an engine was torqued up to 50 ftlb and run 10psi of boost

then we adjusted the boost pressure to a "hypothetical" 100psi of boost we would need more tensile load, hence somethings going to go.

the point i was making is all too often people fall into the trap of not retorqueing the head when the motors hot

i have come over dozens of A series engines over 30 years with premature head gasket failures due to the above

theres the point phil retorque the head ................

in the early days of the A series some 30 years ago

it was stated that the head bolts should be torqued up to 40ftlb

then along came the COOPER S which they stated should be torqued up to 45ftlb......................

then along came the turbo and what have we got ???................

50 or 55ftlb depending who we believe! or which book we have read

that says it all!

Edited by BENROSS on 18th Mar, 2005.

As i said Haynes quotes 55ft/lb for the Metro Turbo.

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The difference is not boost pressure it has got to do with head gasket type and bolt type. The A+bolts are of MUCH better quality than old A series ones.

I believe that it has got NOTHING to do with boost or compression.

A head gasket will perform it's best only at ONE fixed compression. That means 45 is too little and 55 too much if it' supposed to have 50.

Hmm hokay. So let me chek this with you ben - 50 lb/ft is the cold figure, so i should re-torque to 55 when hot?
The usual advice is to retorque after 100 miles or so (a few heat up/cool down - lets the studs and head bed in).
RE valve clearances, what are people using (HOT) and (COLD)? with what kind of tolerances?
(I'm sure this is covered elsewhere)

Cheers people,
Ed

Ive torqued mine up to 50, do i need to re torque it to 55 or leave it at 50??

over the years there have been masive amounts of conjecture!
wrote about torque figures and applications of this.

there has been and allways will be people who will argue the toss right to the last 000000000000.1ftlb

am not prepared to do this

its up to you who you belive!

im not going to argue the toss!

enough said!

Up to you but i'll say it just one last time - "Haynes quotes 55ft/lb for Metro Turbo"

Make your own mind up .................

WWW.TURBO-MINI.COM

haynes may quote 55ftlb for the turbo metro

if thats the case .................................

it still does not get a way from the original point of re torqueing the head after the engines been run..............





any way am taking my ball in LOL

On 18/03/2005 15:03:59 benross said:


any way am taking my ball in LOL

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I always retorque my heads up when cold.
I agreen on 55lbs/ft for the Metro, I don't agree on 60lbs/ft for a higher boosted engine :)

vegard well thats your oppinion buddy

and everones a right to there oppinion