Unless you are running some SERIOUS compression and camshaft, you
probably won't be able to get the mix lean enough. 3 two-inch carbs are
a whole lot more than you need on one of these 2.5 litre engines. SU's
have a great number of needle profiles, however, they don't have the
tune-ability of DCOE's.
Burlen fuel systems, in the UK, who makes and distributes all the SU
parts, suggests 3 inch and three-quarter carbs for high performance
in-line six cylinder engines of up to 3.0 litres displacement. 3 two
inch carbs are suggested for in-line six cylinders of 3.5 - 4.5 litres
(ala big Jaguar sixes). I guess between 3.0 and 3.5 is a gray area.
I have three 1.75 inch carbs on my TR6. The compression is just above
10.5 and I have a fairly high lift camshaft (Goodparts GP-3). A friend
of mine used a Triumptune S-4 cam with close to 12:1 compression. He
used two HS8's on his after opening up the stock manifold to accept the
larger bore. He had extremely favorable results.
To get back to your question; Burlen fuel systems would be your best bet
for finding a proper needle profile. Give 'em a try and good luck.
http://www.burlen.co.uk/
You might have to e-mail them your question and cross your fingers.
Shawn Loseke
1972 TR6
Fort Collins, CO
http://www.loseke.net/shawn
On Tuesday, October 8, 2002, at 01:26 PM, ROVER827@aol.com wrote:
> Does anyone have experience using HS8 2-inch carbs on a TR6?
> I just installed three on my 1971 TR6 and, of course, it runs extremely
> rich. I need to know which needles/jets work best.
>
> Richard Truett
> Detroit, Mich
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