Date:         Tue, 1 Jan 2002 12:11:38 -0500
Reply-To:     Robert Donalds <bostneng@FCL-US.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Robert Donalds <bostneng@FCL-US.NET>
Subject:      Re: B. Bobs day at the dyno and the importance of fuel air ratio
              update
Content-Type: text/plain; charset="iso-8859-1"

Fellow vanagon types
Let me recap in my own defense 

I tested the big valve engine I had built, to promote the increase in power it makes.But as of yet the I have not been able to make the engine produce the power I am sure it is capable of due to a lean running condition. I have learned allot along the way and will retest once the engine is sorted out 
     I had briefly hooked the tail pipe to a exhaust gas analyzer and the engine was running a little lean I thought the converter was doing a great job and knew when the engine had a few more miles on it I would need to go back and fine tune it and I left it at that. 
    When It came time to chassis dyno test on 12/19/01 the air fuel ratio meter on the dyno went from lean to very lean (air fuel ratio 15.00 ) as the engine warmed the engine leaned out (air fuel ratio 17.00 ) (I think 13.5 is Ideal) and the power dropped  almost 25 % at 3000 rpm ( 9 hp)  50.68 first run verses 41.73 warmed up. At 3500 rpm the difference was 61.19 hp verses 53.84 hp warmed up. At 4000 rpm 4500 rpm first run 77.07 hp verses 70.23 hp warmed 
I also tested my almost stock 2.1 1984 plan Jane 7 passenger van (blue bell)  with 40 k on the engine as a stock engine base line with an air fuel ratio of 13.5 it made 55 hp at 3000 rpm 62.84 hp at 3500 rpm 69.86 hp at 4000 rpm and 73.89 at 4500 prm 
  
what's new
I have braved the cold this past week and looked over the fuel injection system in my 84 camper with the big valve engine. As I previously reported I inspected each sensor and every wire as I installed the engine and all of its components. I carefully cleaned and installed the ground wires on the drivers side head and I would have replaced the connectors if I had thought they looked at all like they had a problem. (can you see where I am going with this) I did the pin test in the Bentley book page # 24.20 as recommended by Greg at Greg's repair and I found that the ground wire from the NTC coolant sensor was not grounded to the head causing the engine to run lean I hope. the connection looked great the terminal it was nice and clean and I could see there the wire was neatly crimped but it was as if the terminal was not even touching the bare wire. Once the new terminal was crimped and in place and retested I took the van for a drive and the seat of my pants impression ( that by the way has been wrong consistently ) was that the engine has more power after warm up and less throttle is needed as I go threw the gears. I will now check the mixture and report back ASAP

  I'm sharing my learning curve with the list to point out a couple of things. First I am sure the engines with poor connections and the lean settings is not that uncommon!!!!!!!!!! Pin test pin test pin test. Second  my mileage has been in the 15 16 and 17 mpgs on the highway and with the proper air fuel ratio and the increase in hp that goes with it I would think my mileage will increase. The reason would be less pedal for the same amount of work and lastly the engine has a better chance of staying together longer because the chance of abnormal combustion from the lean condition hopefully has gone way down. Can you imagine how long an air-cooled van would last if the engine was left this lean with the higher head temps. can you say melted piston.
    Please contact me by p mail if you are interested in a chance to dyno your van or car I am trying to arrange a Saturday In January the location would be Hampton NH just across the Ma. border and  8 miles off of interstate 95 the cost is $75 for three to five pulls. 
 
stay tuned pun intended 
Bob Donalds 
http://www.bostonengine.com
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