Date: Tue, 2 Jun 1998 14:23:07 -0400
Reply-To: Derek Drew <drew@INTERPORT.NET>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: Derek Drew <drew@INTERPORT.NET>
Subject: ECU CHIP AND ROCKER UPGRADE (Dennis Haynes on...)
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The update on this potentially explosive topic from Kyle can be gleaned
from this forwarding of a private post from Dennis Haynes. Dennis is
worried about premature engine wear, but seems willing to test the setup
from Kyle, particularly if somehow it is obtained for free.
I think we all knew you don't get something for nothing. This post from
Dennis Haynes discusses some of where the tradeoff may be appearing. It
seems likely that if we could get the roller rockers in this setup then
we'd have solved the problem Dennis is concerned about.
How about it Kyle, roller rockers?
>From: "Dennis Haynes" <dhaynes57@email.msn.com>
>To: <vwmaster@VOLKS-MOTORSPORTS.COM>, "Derek Drew" <drew@interport.net>
>Subject: ECU CHIP AND ROCKER UPGRADEconcerns as per Dennis
>Date: Wed, 15 Apr 1998 22:45:41 -0400
>X-Mailer: Microsoft Outlook Express 4.71.1712.3
>
>Derek and Kyle,
>I think this approach is a great idea but I have a number of concerns and
>possible observations.
>
>Of this combination, I believe the greatest Horsepower increase is from the
>ratio rocker arms. Not only does this method increase lift, but it also
>increases the duration. The down side of this is increased valve guide wear
>from the increased valve travel and the increase operating angle of the
>rocker working against the valve. I have worked with both ratio rockers and
>hi-lift cams so I have first hand experience with the increased wear this
>can cause. In fact, many cars (stock) that still use rockers are going to
>roller rockers to solve the valve side loading problem. My beetle running a
>Cam with 40k on the engine is getting ready for a valve job now due to
>guides being worn and the backs of the valve stems being all pounded out.
>
>As for the chip, what is it actually modifying? The fuel mixture, timing
>or both? Is the mixture being modified at all speeds or only at full
>throttle? I'd like to get more details. Partly for emissions compliance,(We
>start testing under load for NOx here in November) and concerns of damaging
>the catalyst. For what it's worth, using a Digifant FI system with a
>matching distributor seems to greatly increase the power of the 2.1 engine.
>I've done a number of 2.1 conversions and I can't believe how well they run.
>Another trick I've done is add some .3 volt dropping diodes in series with
>the O2 sensor. This enriches the mixture slightly which smoothes operation
>and eliminates that idle miss-fire.
>
>As part of this upgrade, I suggest some type of free flow muffler. This is
>probably the greatest restriction to the Vanagon engine's performance.
>Maybe some type of glass pack would do the trick. Just need a way to mount
>it.
>
>Anyway, I would be happy to assist in this venture. I can't justify $900
>right now but maybe I could go half. I would really like to see a roller
>rocker set-up if that is a possibility. My camper engine now has 155K on it
>so I sort of hate to start abusing the valve train now. It;s never even had
>a gasket problem YET!!! Send me more details. Also, I am paying close
>attention to the 2.0 inline engine that should still be offered by Overland
>parts. This should be very promising as this is a long stroke engine which
>can offer the torque that the wasser-boxer is missing.
>
>Dennis
>
_____________________________________________________
Derek Drew New York, NY & Washington DC
ConsumerSearch
drew@interport.net
212-580-6486 (W)
212-580-4459; 202-966-0938 (H)
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