Megasquirt works great for a single injection point on a spridget a-
series, a
Just as the single 1.75 does so well...
Multipoint is overkill, just mix the air and gas in the right ratio
with the help of a wide-range o2 sensor and send it into the manifold.
The small difference in how much of the mix each cylinder gets because
of Siamese porting seems trivial according to my plugs.
Glen
On Aug 17, 2010, at 11:19 AM, David Lieb <72spridget@gmail.com> wrote:
>>>> What is the advantage of a crossflow head over a stock type
>>>> flowed head?
>
>>> I assume a crossflow has the intake on one side and exhaust on the
>>> other.
>
>> True, With no shared port like the A-Series head.
>
> The "siamesed" intakes on the A-Series and B-Series heads are a major
> impediment to performance. If you look at the firing order, you will
> see that the engine is inhaling through the front intake for two
> cylinders, then through the rear intake for two cylinders. This means
> that the flow is constantly interrupted and keeps accelerating and
> decelerating. I believe this is one of the reasons that the single
> 1.75" carb tends to out-perform the twin 1.25" carbs. I know this is
> one of the major reasons that it is so difficult to do a good job of
> updating an A-Series to multiport fuel injection like MegaSquirt. It
> is also one of the benefits of the 1500 Triumph engine...
>
> One of the nice things about the Pierce crossflow head is that it
> retains the three-exhaust port configuration of the standard A-Series
> head so that readily-available exhaust headers will still work fine. I
> don't really appreciate the fact that it incorporates Weber intakes,
> since this would probably make it more difficult to fit throttle
> bodies for fuel injection.
> David L
> _______________________________________________
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