I saw this in issue 140 of the Stag Owner's Club newsletter and, since
it also applies to TR7s, thought it might be of interest. The "Triumph
V8" is the Stag engine, not the Rover engine.
This is an extract from a December 1974 service note, presumably the number
of vehicles with blown cylinder head gaskets was reaching the sort of figures
that could not be ignored. Quote:
The specified cylinder head tightening torque for the Triumph V8 and
slant four engines is 55lb ft. The yield figure for the head
attachment stud and bolt material is 60 lb ft (editorial comment: !!).
>From this it can be seen there is insufficient lattitude to consider
increasing the tightening torque (ed: typical brit understatement), but
in any event it is generally considered that the introduction of the
latex coated gasket should bring about the desired result of reducing
leakage problems.
(ed: Anyone ever see a "latex coated gasket"?)
A January 75 service note has more information:
Whilst it may not be a complete answer to cyulinder head gas leakage
problems on the Stag, Dolomite and Sprint models, it is suggested that
the use of Hylomar jointing compound in aerosol form could reduce the
number of repeat failures in service due to leakage. Hylomar jointing
compound is available in aerosol cans under Unipart No. GGC101. Hylomar
in tubes is not recommended for use on cylinder head gasgets for these
models owing to the difficulty in applying a coating of even thickness
over the whole of the gasket. Uneven distribution of jointing compound
can result in unequal distribution of the clamping load across the
gasket face. In addition to the application of Hylomar in aerosol
spray, it is recommended for cylinder head bolts and studs to be
retorqued when the engine is cold after first being run up to its
normal working temperature. Retorquing of the heads and studs should
again be carried out after 1000 miles as stated in Service Sheet 371.
Service reps are asked to implement the above procedure on any problem
cars in their area and report on the effectiveness following a suitable
evaluation period or mileage.
End quote.
Anyone ever try using that Permatex copper spray-a-gasket for this
application? Any other thoughts on this? How many of you have
checked your torque wrench calibration recently? :-)
Anyone have access to the Triumph service note file? It would be
*very* interesting to read through that stuff.
--
Paul Amaranth Manager User Services - office: (313) 370 4541 (also voicemail)
(internet) amaranth@vela.acs.oakland.edu | WANTED: Clever saying
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