OK I have to add my two cent's worth -
Michael writes -
< snip >
> A good friend of mine is planning to put two Delorto carbs (45 mm) on his
> Spit 1296 ccm - anybody on this list who has any experience they might want
> to share with me (him) on this matter? How hard is it to tune them?
> synchronize them? what other mods are necessary (cam,...)
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Well unless you've ported, polished, cc'd and milled the head to achieve
around 11 -12 to 1 compression. Port matched the manifolds, installed a
true, equal length try-Y header and 2-1/2 exhaust. Installed a roller
rocker and extremely high lift cam. Lightened the flywheel and upgraded the
ignition system. Nitrided the crank, polished and peened the rods. . . well
you get the picture. Believe me, if you havn't done most of these
modifications than you'll have one 'oooooh neet lookin' motor that will die
on you every time you step on the gas. Even with all the mod's I've listed
the motor would be fairly unresponsive below any thing under 3000 RPM, and
would have an extreem lope at idle. but above 4000, would really come to
life and around 7-8000 rpm deliver around 100 + HP. ( but wouldn't last long
). It's very easy to over carb. A eaiser and less expensive alternative is
to install a pair of 1-1/2 SU as used on the UK versions of the 1500. ( the
1300 MK III used 1-1/4) This will give you better breathing at the top end
where single Stromberg's start strangling the engine. Or if you want Webers
or Delortos because you like the look try a single 40 with as small a choke
(venturi) as possible. On my 70 Spitfire that I'm restoring I may just do
that. I have a single 40 DCOE and manifold, that I installed 28 MM chokes
in. Should be a lot eiaser to tune, and would look really cool. But then
again I have those twin 1-1/2 SU's and manifold, or that stock !-1/4 SU
setup. Hummmmm - so many choices, so little time . . .
Barry Schwartz
Bschwartz@encad.com (work)
Bschwart@pacbell.net (home)
(San Diego)
70' Spitfire (under-going major surgery) , 72'-V6 Spitfire (daily driver)
70'GT6+
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