Date:         Thu, 7 Sep 2000 11:41:42 EDT
Reply-To:     Wolfvan88@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Robert Lilley <Wolfvan88@AOL.COM>
Subject:      Re: Thinking swap?  Engine options are only half the story...What
              about the t...
Comments: To: Bayleaf98@aol.com
Content-Type: text/plain; charset="US-ASCII"

More details...

-I used quad tip plugs to keep the flame kernel from being split by the
center single electrode.  This sends the flame to the center of the  of the
piston, rather than the edges, to reduce the sideways force on the piston
(the plug is in at an angle and the top of the piston get the force first
before the bottom). This is important because the force applied to the piston
is increased with the power increase.  The four tips ensures firing of the
plug.
The plug runs cooler because it does not stick as far into the cylinder,
therefore there is less of a chance for detonation on incoming fuel mixture.

-I also used solid rocker shafts.  The wigly clips holding on the rocker arms
seem to work OK in a stock engine, BUT they can still BREAK (on the T1 engine
this is a problem, it happened to me once, then I got solid rocker shafts and
no more problems).  When you add ratio rockers the valve travel more, puts
more pressure on the rocker arms (the arms are at an @45 degree angle to the
shaft) and increases the chance that the clips will fail.  Adding solid
rocker shafts ELIMINATE the chance that the clips will fail.

-When you add ratio rockers, the valve spring now has to push the valve train
further in the same amount of time, thus the need for stronger springs to
push the valve faster, BUT at the expense of increased cam and lifter wear
and lost HP (it takes more power to compress stronger springs)
INSTEAD of adding heavier springs, I lightened the valve train weight, so
there is now LESS weight for the springs to push, so in  EFFECT the springs
are stronger.
I did this by using cromoly lightweight cut to fit pushrods.  They are
STRONGER (90,000 psi to flex) than the stock steel and a fraction of the
weight.
To futher lighten the valv etrain weight, I am going to add lightweight
aluminum alloy, roller tip(further reduces valve stem side load, increasing
valve guide lift)

-The ceramic coatings block excessive exhaust heat from soaking into the head
keeping the head cooler, increasing its life, while keeping the exhaust hot
and promoting faster exhaust gas volicity.  The hot exhaust gases flow faster
than cooled exhaust (the exhaust pipes radiate a lot of heat).  The faster
rate helps to pull more of the exhaust gases out, allowing for the 8 degress
increase (over stock) in valve overlap on my cam and pull more intake gases
into the cylinder in a single cycle.  Overlap is when both valves are open at
the same time.


Robert