This site has a great table that breaks out what should be ported and what
should come off the manifold per distributer:
http://www.mgbmga.com/tech/index.html At least it made things clear for me.
Scott
76B
---------- Original Text ----------
From: "Charley & Peggy Robinson" <ccrobins@ktc.com>, on 2/1/2001 8:22 PM:
To: SMTP@AST_SE4-1@Servers["R. O. Lindsay" <rolindsay@dgrc.com>]
Cc: SMTP@AST_SE4-1@Servers["Ptegler"
<ptegler@gouldfo.com>],SMTP@AST_SE4-1@Servers["Barney Gaylord"
<barneymg@ntsource.com>],SMTP@AST_SE4-1@Servers[<mgs@autox.team.net>]
That's what I was getting at. There are lots of different # 25D4
dizzies around. Sounds to me as if you want the #40897 and carb port,
based on your statement that you planned on "spirited driving around
town." I infer that you want midrange torque and don't plan to rev it
much over 5.5K. Since that implies full-throttle acceleration, I see the
centrifugal advance being the more important of the two because of low
vac at wide open throttle until the revs build up. That means a short
advance curve and not too much total advance. If you want more total
advance there are other dizzies..... I presume that you have the #41288
since I don't see a #41228 in my books. The specs on it are very
similar to the #40897 if you take the median of its specs, IE: 13 to 17
deg @ 1,600 is +/- 4, so hopefully it'll be 15, the same as the #40897.
Only a dizzy machine will tell.
Ain't this fun?
Cheers,
CR
"R. O. Lindsay" wrote:
>
> Ptegler wrote:
>
> > ...snip
> >
> > So ...just because you rebuilt everything to spec for your model year
> > doesn't mean it's the best setup for your aging toy.
>
> This is EXACTLY my point in asking the original question.
> I want the BEST settings, not the period CORRECT settings.
> My distributor on my '70 B-GT with the 18GH engine is a
> 25D4 #41228 using a 5-17-10 vacuum unit.
|