John Karlsson posted the following query to the British Cars list:
>I find that parts for the original Solex carburetor (OOOPS! I
>mean carburettor.) are no longer made, and after about a quarter
>of a million miles and several rebuilds, my carburettor is about
>ready to be replaced. I'm considering the Weber conversions
>offered by Atlantic British, and I'd appreciate any suggestions
>from any of you out there who may have experience with these.
>
>They offer two different Weber models. The single barrel
>apparently mounts on the original manifold via an adapter plate,
>and the two barrel comes with a new manifold, air cleaner, and
>claims of 15% increase in performance.
>
>Several issues come to mind in considering these conversions:
>
> 1. The new manifold that comes with the two barrel doesn't
> bolt to the exhaust manifold like the original. Does this
> result in icing, such as I experienced when I installed a
> home made header? And does it avoid the characteristic
> problem of cracking of the exhaust manifold?
>
> 2. How does the header sold by Atlantic British (Part #
> 2899) affect icing, since there seems to be no provision for
> heating the carb?
John,
There are actually two ways to mount the two-barrel Weber carb, a full
custom manifold and an adapter piece which allows mounting on the stock
Land-Rover manifold. I believe both are made by Pierce manifolds in North
California:
Phone: 800-874-3728 or 408-842-6667 or fax to 408-842-6673
I suspect that Pierce's price may be lower than that of ABP and suggest that
you give Pierce a call. I believe that British Pacific (800-554-4133) may
also have a lower price than ABP.
If you use the full Pierce manifold (undoubtedly the higher-performance
set-up) you will lose the heat-riser connection to the exhaust manifold. So
you might as well go with the headers and, as you say, eliminate the
manifold cracking nemesis. Then, so I have read, to get the full
performance potential from the set-up, you need to go to the cam-grind
profile for the 2.5-liter Land-Rover four-cylinder engine. Improvement in
performance? Yes. Worth it? Hard to say.
Yes, you will have cold-starting and -running problems with this set-up,
unless you build and install a heat-riser set-up (of sheetmetal) to capture
sufficient heat from the headers and pass it to the manifold. It seems to
me that another approach would be to modify the air cleaner set-up (in
which, by the way, the Pierce kit normally replaces the oilbath with a K&N
dry filter) to have an air pickup which incorporates a heat riser. Several
cars that I have had have had such a pick-up and some have had summer and
winter settings with a damper that you can move to determine whether the air
is cold or hot. I believe one even had a thermostatically controlled damper
and that would seem to be the ideal solution.
Regarding the single-barrel Weber, it works O.K. but I am skeptical of the
performance claims. I have run one and felt that I lost performance,
slightly, compared with the Zenith carb which it replaced (on a 1970 Series
IIa 88"). There has been considerable discussion on the Land-Rover-Owner
discussion group (LRO@team.net) about both types of Webers. Some owners who
have used the single-throat Weber have felt that it gave a performance increase.
If you pursue one of these modifications, please keep us "posted"
on the Land-Rover list (lro@team.net). If you are not a member of this
excellent Land-Rover discussion group, I encourage you to join. You can
e-mail me for further details, if you wish.
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[ G.B.Pool(Redwood Vly, CA, USA)Appraiser,R/W Agent,Land-Rover aficionado ]
[ e-mail: mcdpw@pacific.pacific.net ** Ph:(707)485-7220 H,(707)463-4265 W ]
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