Date:         Sat, 17 Nov 2001 10:13:07 -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: How much power can a stock FI make?
Content-Type: multipart/alternative;


Chris Stann wrote 
I am considering building a 2.1 long block with some minor performance
enhancements such as ratio rockers, lightweight valve train and
ceramic-coated heads and pistons, aircraft-grade head bolts and some other
anti-leakage measures.  I would install this 2.1 in place of my 1.9 since I
am just over 150K on an untouched motor.
The question:  How much can my stock 1.9 fuel injection handle?  What
improvements can I make before I need to replace/upgrade my FI system?  Am I
looking at larger injectors and or just a fuel pressure regulator?

Chris 
    I have just completed a 2.1 big valve conversion into my 1985 camper.The extra power has allowed me to power up the hills of Vermont and New Hampshire 
at 70 mph with no problem. I had five people the dog and a 25 pound turkey with the fixings in the van at the time. There was enough power left to increase my speed to 75 mph and beyond.
 The Digijet fuel injection system is not what is limiting the available power. What does limit the power is the ability of the engine to breathe and that darn rev limiter that's built into the ECU. As a gear head I have spent allot of time pondering this truth. The question then is how do you make the engine breathe without loosing longevity and drivability.  Using aftermarket camshafts with huge amounts of duration and lots of lift. is an example of how to loose low end power and over all drivability
    My method of increasing power threw out the power band was to add 3 MM larger valves, blending the valve seats with a Serti style cutter and minor porting work. when I say minor I mean the intake port where it meets the intake seat was made only .050 ths larger to match the new intake valve seat.  With the aid of a flow bench I was able to increase the air flow by 20% throughout the travel of the valve. (ratio rockers don't even come close to this) I have posted the flow charts on my web page see the stage three engine and look for the link. The other internal changes are a minor regrind of the OEM cam, more spring pressure and increased clearance in the cylinder to allow the piston to grow.       
The rest of my vans cooling system and fuel injection is bone stock. I would not consider changing the heads studs from stock, ceramic-coated heads and pistons or counterweighing the crank. Mr. Lilley has never proven there value to me. 
I invite you to drive my van and see for yourself the increase in power.

Bob Donalds 
Gear Head Deluxe
http://www.bostonengine.com
as always all right reserved 


   

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