Date: Thu, 20 Dec 2001 19:20:22 -0600
Reply-To: "Smola, Tony" <TSmola@TRIBUNE.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "Smola, Tony" <TSmola@TRIBUNE.COM>
Subject: Dyno day for Boston Bobs
Content-Type: text/plain; charset="iso-8859-1"
I know this might too much too ask, but do you ( Robert ) have the
opportunity to put one of your own 1.9L
flat fours on the dyno with stock timing ( 5 deg ATDC ) and then advance the
timing to 6 degrees BTDC at idle.
I swear by this advance and I've been driving with this performance ignition
timing ( better bottom end and wider power
band) for years without harming my motor ( 135K and still going
strong......orig everything, but h20 pump)
Malibu Tony 85' Westy 1.9L 6 degrees BTDC
78 911 SC
ORIG MESSAGE:
Date: Thu, 20 Dec 2001 10:25:10 -0500
From: Robert Donalds <bostneng@FCL-US.NET>
Subject: Boston Bobs day at the dyno
fellow learkers and so forth mores
I spent the day testing vanagons on a chassis dyno with mixed results. =
The truth of the matter is that everything I thought I observed by the =
seat of the pants method was wrong. First on the dyno was the big valve =
engine in my 84 camper first run to warm the engine up made 50 hp at =
3000 and a max reading of 77 hp at 4600 RPM thats a nice start but the =
air fuel ratio was a little lean second run fully warmed up 3000 RPM 41 =
hp and max power of 70 hp at 4500 RPM the fuel air ratio is now off the =
scale its way to lean. Thats huge loss of power amost 25 % at 3000 RPM =
from the one thing that nobody seems to check air fuel ratio. OK the =
day is young so we can take this in stride and I am sure this engine has =
the potental to make alot more power because the 20% increase in air =
flow threwout the valves lift . after checking the fuel pressure we =
desided temporarily boost the pressure used the adjustment screw on a =
pair of vise grips clamped to the return line and we got the gauge to =
read a steady 35 pds under load. (dont try this at home) and we did =
another run no differance in power or the air fuel ratio. OK I now have =
a problem that is more than I want to sort out on the $100 an hour =
chassis dyno and its time to move on to the next van. I brought out the =
family van blue bell with a stock 2.1engine it a stock 1984 7 passenger =
plan Jane quick as a bunnie and Im sure its not as fast or as powerful =
as my race camper. First run bang 3000 RPM 55 hp max hp of 74 hp at =
4600 RPM air fuel ratio right on the money mid 13s same thing second =
try. thats not what I exspected but I keep repeting the things I am =
learning so far #1 fuel air ratio is VERY important #2 the meter is =
running when you are on the dyno.
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