> This is exactly the setup I have. Of course, I don't know how well it works,
> because my '73 Midget doesn't yet run (it does gush fuel from the front float
> bowl).
Sticking floats or badly ovaled holes will do that, as will dirt in the
needle valves between the valve and the seat. (Um... remembering some
damn stupid thing I did ten years or so ago, so will hooking the
fuel line to the vapor recovery tube, I think. I have vivid memories
of the smell and the look of gas gushing out of the carbs.)
> Do all PCV's operate on similar principles? That is, do they all vary flow
> in inverse proportion to vacuum?
Again, after reading the manual and looking at the pix in two different
books (Bentley and Haynes), M.G. engines from about 1970 to 1974 use
the same principle as the gas jet in an SU carb -- the air going past
an orifice pulls stuff through that orifice, in this case the crankcase
vapors. So it's in direct proportion to velocity. And in the case of
SUs, which are constant-velocity carbs, it must be pretty constant...
> > This is a 74 Midget....and as far as I can tell from the manual....this
> > set up (apart from the PCV valve ) is correct.
>
> Which manual? I've got the Haynes, and I couldn't find a decent picture of
> the setup.
The Emissions Control Supplement in the Bentley Complete Official M.G.
MGB 1968-1974 has great pictures of the Midget -- as I said, you can
clearly see "1275" cast into the side of the block, and you can see the
funny little canister hooked onto the timing chain cover (since the
1275 lost the removable tappet covers on the side). Also, the HS2s
used on the Midget have the brass fittings oriented inboard, where the
MGB's HS4s have them on the outboard sides of the carbs.
--Scott "If you know what you're doing, it isn't research" Fisher
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