Fast Eddie
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Why did Triumph dispense with the splayed head in favour of the parallel port head on the T140E in 1978 ?
Anyone know ?
Anyone know ?
Thanks LAB but unfortunately the question still stands...
A ‘revised head’ due to ‘emmisions’ as quoted in the article is a tad vague on detail.
As far as I know, the head changes where:
1. A move to parallel ports
and
2. a ‘revised combustion chamber’.
What I’d really like to know is why they did those.
I always thought that twin carb heads and single carbs heads were a different casting, having differences around the intake port areas.
it finally got a composite head gasket in place of the prehistoric copper one.
Was there something wrong with the prehistoric copper head gasket?
Was there something wrong with the prehistoric copper head gasket?
L.A.B. said:Quote from 'Triumph Service Bulletin 9-79' (Jan. 79) :
"... the Klinger cylinder head gasket was introduced to prevent failure to which the copper gasket was prone."
I thought that cylinder head was the earlier single carburettor version modified (manifolds) to take twin Mk2 Amals not a new for the 1978 model item in total but the Mk2 fitment might have been ?
There was some mention of the straightened inlet port adding to swirl as far as the splayed exhaust port but that might have been wishful thinking after the fact.
Possibly swirl induced by the splayed inlet ports directed incoming flow to exit straight out the exhaust port during the valve over lap period, not good for emissions
The straight inlet ports would send the intake charge at the exhaust valve face and not at the open area of the exhaust valve inducing tumble instead of swirl