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Date:         Sat, 9 Feb 2002 19:46:07 -0800
Reply-To:     Walter Evens <wrevens@MYEXCEL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Walter Evens <wrevens@MYEXCEL.COM>
Subject:      Re: '85, 1.9 timing questions (cont)
Comments: To: Robert Donalds <bostneng@fcl-us.net>
Content-Type: text/plain; charset="iso-8859-1"

Someone mentioned in a post earlier this week about advancing the timing 5 degrees as a way of getting a little more OOMPH out of a Water Boxer. It's been some time since I've used timing adjustments as a way of gaining power (way back in my younger days with Chevy V-8s).

I'm new to VWs and the list so I hope this doesn't sound too stupid. If my timing is 5 degrees AFTER TDC, would the advancement be to 10 degrees AFTER or TDC?

I have never in my life heard of an engine firing ATDC. Why would they do that?

Thanks for your input. I was almost going to get rid of my Vanagon with the blown engine (my wife was playing with the tape deck and dropped it from second into first at 45 MPH coming up a steep grade) right after I got it back on the road. Then instead of having that engine rebuilt, I let her talk me into buying another one for $800. Only this one runs.

Now that I know I have a support group and many gigabytes of info in the Archives, I may just exchange all my vehicles for Vanagons. Let's see, keep a GL for the family, buy a Westy for the weekends and a Transporter to replace my Jap pick up. One manual covers them all!

Walter Evens Hesperia, CA, USA 2-85GLs

----- Original Message ----- From: Robert Donalds To: Walter Evens Cc: vanagon@GERRY.VANAGON.COM Sent: Saturday, February 09, 2002 9:30 AM Subject: Re: '85, 1.9 timing questions

Walter wrote Hello Vanagoneers:

I timed my 85GL the other day based on the info the guy at the shop gave me. He showed me a picture in his Bentley which is actually backwards from my GL. The manual shows 5 degrees being to the right of TDC and on my pulley it's to the left. Can anyone explain the difference? Is it a typo?

I find it runs better at TDC than at 5 degrees. I tried to set the timing mark even with the place where the crank case comes together. However if I move it a little too much past that, the idle goes way up and the mark moves way to the left. Can anyone tell me why this happens?

I read another post where someone mentioned TDC as being a better setting for a little extra power. How will this effect things like, emission controls, etc, for those of us living in a state with Smog Controls and Smog tests?

By the way, I did remember to unplug the temp sensor before setting the timing.

Walter

the missing piece to the 5 degrees question is that the 2.1 engine has the timing set to 5 before top dead cente5r and the 1.9 is 5 after top dead center. as for the emissions I saw no differace underload you might see some at idle set it to stock when you go in for a sticker. The messages below are posts from the list a few weeks ago

hope this helps

B. Bob

Chuck Mathis wrote >About a year ago, I measured carefully and added a notch to my pulley for >what should be 5 degrees BTDC on my '85 with about 50K miles at the time. >Bearing in mind Boston Bob's early dyno let down with his big valve engine, I >will only say the engine seems to pull stronger from a stop and seems to run >stronger through the full RPM range

That was not a let down it was a learning curve and I shared it to show my fellow learkers that even thought I thought the engine ran great the air fuel ratio was way off. I was also tring to make the point that tuning can no longer be done without checking fuel pressure and setting the injection system up with the help of some kind of sampling of the exhaust gases!!!!!!! In the first round of testing the big valve engine made more power cold and made less power when warmed up due to the fact that tas it warmed up it ran leaner. This was compared to my 84 std valve 2.1 engine that I had used as a standard base line for the 2.1 power compassion I posted the note below after my second dyno session and Have not post more about the final numbers because the numbers are in question due to the method used for correcting weather factors on different days. I feel the software that came with the Chassis dyno is flawed so that I can not use data gathered on different days for comparison to each other I am however confident that tests done on the same day are valid. This means that I have to retest the big valve engine on the same day as the van I used for the base line reading. I can tell you that I am very happy with the power the big valve engine makes and I am going to redo the testing in the near future. I have also found others that are willing to participate with tiico conversions and stock vans to test on the same day so that comparisons to stock 1.9, 2.1s,and big valve and in line 4s can be made Bob 1/30/02

posted on 1/15/02 As you know I have been testing engines on the Chassis dyno. I finally got my 84 2.1 big valve engine running correctly and tested it this past Tuesday. I four pulls (tests) and made one change after the first two pulls to see if more timing made more power and it did. let me recap I have installed a 2.1 big valve engine in my 84 camper I kept the digijet fuel injection system and left the stock dist and pulley. when I changed the timing from the stock setting of 5 ATDC to about 4 or 5 BTDC I found two things first the dist tended to kick in more advance due to the increase in RPM if I went past this point. by this I mean the timing moved more than I was turning the dist. I did not check but I think the centrifugal advance was engaging. the second thing I found was that the engine made about 10 % more power throughout the power range Keep in mind this is a 2.1 engine in a 84 with digijet. I need to be clear that all the old time tuners say not to believe any flash reading on a dyno with changes in timing!!!!!! I have found that changing the timing makes the engine run hotter this can take time and might only happen under constant loads (highway driving) hotter engines CAN loose power and melted pistons can be a result At this point I am still going threw the #s for all the tests and will offer my finding when I am confident that I have the correction factors for the different days of testing correct and the HP #s plotted on a spread sheet with the torque included. Bob Donalds http://www.bostonengine.com As always All rights reserved


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