[TR] Inlet Manifold Question

Tony Gordon triumph at 2simpleusa.com
Fri May 16 19:14:11 MDT 2008


I have been looking at the early/late head question for some time, and now
have a late head (many thanks to Colin Grimes ... who has a really tidy late
71 TR6, and is a really good bloke with a delightful wife to boot!).

In a recent exchange with Ibsen Dow on this question, as I was sending him
some information from Chris Witor, I noticed that he (Chris, not Ibsen) had
made reference to the fact that he has gas flowed all the big 6 heads (and I
have his table of head characteristics ... but alas, it lacks the flow rates),
but what is interesting is the fact that he has determined that cyls. 2 and 5
are underfed with the standard 2 Stromberg manifold ... have a look at the
tables in his analysis (this was on the sixappeal website ... but its gone
from there, so I've echoe'd it ...
http://www.2simpleusa.com/triumphlist/Witor.mht).

Any idea what Chris did to rework the inlet manifold to balance the gas flow?
Kastner is NFG since he dealt with PI or webers only, and William's doesn't
reference any fine tuning of the standard 2xCDS manifold in his Tuning TR250
and TR6 book ...

I could call Chris (and since I bought some of his work-of-art oversize 1.6"
SS inlet valves - undercut and looking like they will add 10BHP just sitting
on the workbench ... NFI but I'd recommend the workmanship and service) I
think he might share, but I thought I'd see what the list thought first!

Incidentally, Witor and Pumford (the Lucas PI guru) appear to be the top folks
in terms of their art in the UK, where there are very many more Triumph big
6's running strongly, but not in TR250 or 6 bodies!

**************************************
Tony Gordon
72 TR6
**************************************


More information about the Triumphs mailing list