Which Rover V8 head gasket?

[Chris Wilson]

[This followup was posted to uk.rec.cars.maintenance and a copy was e-
mailed to PJ]

In article <ant31192...@tarags.demon.co.uk>,
p...@tarags.demon.co.uk says...
> There is an idea floating around that Rover's method of fitting and sealing
> the heads on the 3.5litre V8 is not all it could be. The theory goes that the
> engine gets it's reputation for leaking oil (which reputation is this, BTW?)
> from the fact that a combination of the tin head gasket and uneven bolt
> layout causes the cylinders to leak pressure into the valley between the
> banks, thus pressurising the crankcase and forcing oil out all over the
> place.

<snip>

"Leak pressure into the valley"??? What pressure? Combustion pressure
leaks = blown head gasket. Oil leaks? Oil leaks from the head gasket
into the valley just run down into the sump, internally. I don't
follow just what pressure they claim to be leaking. I find a semi
cured bead of silicone is preferential to end gaskets on the valley
ends of V8's. In fact most US V8 engine makers (the car manufacturers)
have gone away from conventional gaskets in such locations in favour
of a silicone bead.

The usual cause of Rover V8's (standard early engines) leaking oil
externally is blocked breathers, allowing a build up of crankcase
pressure from the normal and inevitable piston ring blow by. Adding
adequate and clear breathers, or restoring the efficacy of the
existing ones usually puts this right. In most cases any leak from
crankcase pressure build up (gaseous) is from the crank rear main
seal, in my experience. Not a seal fault, purely a breather fault.
--

Best Regards,
Chris Wilson

(Race car preparation and development)
http://www.formula3.demon.co.uk

[Phillip Dodds]

I have just stripped two RV8's and both were fitted with tin head gaskets,
both having done over 100,000 miles each and no signs of leakage across the
gaskets, and don't forget if you use the composite gasket you will need to
reduce the rocker shaft pillars by the according amount or use adjustable
pushrods/rockers.
just a thought.

[Andy Dingley]

PJ <p...@tarags.demon.co.uk> a écrit :

>may just be that the omission of the bolts was a byproduct of the new head
>design, rather than that they were omitted specifically because they may be
>problematic.

Land Rover claim it's deliberate, to solve the head blowing problem.

I don;'t think I've ever stripped a Rover head that hasn't shown some
evidence of gasket failure here.

--
Smert' Spamionam

[Andy Dingley]

PJ <p...@tarags.demon.co.uk> a écrit :

>Aha! Do you have a specific source for this?

Not offhand I'm afraid. It was a Landie document for their dealers at
the release of the 4.6 (it also talked about cross-bolting the mains)