<VV> timing

[Mark Durham]

True, Bob, or he could just change the timing 2 degrees at a time and
go drive it! Mark Durham

Sent from my Windows Phone
From: BobHelt at aol.com
Sent: 12/20/2011 11:10
To: kovacsmj at sbcglobal.net; virtualvairs at corvair.org
Cc: fastvair at yahoogroups.com
Subject: Re: <VV> timing
Mike,
The answer has to be "IT DEPENDS".

This is a rather involved and technical subject so i am just going to hit
some important determenents. First, for each and every engine speed of any
engine using a particular fuel there is a spark timing point BTDC that
develops  maximum torque. This is called the MBT or the maximum best torque
point.  If the spark occurs before that point or after there is a loss  of
torque. So for total maximum torque at each and every engine speed, the  timing
must follow these MBT points. Now if your distributor does follow these
points, then you already have the max acceleration already available
to you. If
not, then you may get better acceleration at one engine speed and maybe
worse  accel at another engine speed depending on the MBT curve. You would need
to know  both the MBT curve and the dist advance curve.

Same for fuel mileage, EXCEPT that the vacuum advance takes over at all
cruise speeds and maximizes gas mileage independent of MBT.
Regards,
Bob Helt.



In a message dated 12/19/2011 5:07:02 P.M. US Mountain Standard Time,
kovacsmj at sbcglobal.net writes:

Just a  quick one. If an engine timing is set at  factory 10 degrees BTC,
which
will give it a bit better acceleration? 8 degrees or 12 degrees. This a
bit
generic, but would apply to a Corvair.

Same question about fuel  mileage. Will retarding (8) or advancing (12)
tend to
improve gas  mileage?


MIKE  KOVACS

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