|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Chapter 19 Latest Entry 11/12/01 Well,
TurboStude now has a new air hat
(with sieve) which works really The advantage
to a return type regulator is that it doesn't build up back-pressure in the
fuel supply line, but rather re-routes the fuel back to the tank. This
is easier on the pump, which in turn runs cooler and presumably will last
longer. In terms of flow, a return type
regulator can provide fuel delivery unimpeded to the carb. All that
fuss we make over large line, minimal bends, and then we slam it into a
little hole in a dead-head regulator. I believe the trick with the
return type is to provide a rather large bore return line. Jon
Myer's "Spooky" Stude uses a regulator, not ON the line between the
pump and the carb, but off of a "Tee" in that line. Since I'm
not likely to be making 500 hp with TurboStude, I don't know how important
that part is.... I'll try to reproduce Oz's regulator mods on my
leaky one. I'm also keeping my eyes open for a Mallory
4309 return style regulator, as this seems to be the one most are using,
and is my fall-back if I can't come up to Oz's machining standards of
excellence. Before I sprung a leak, I did start running faster, and
began to tweak the timing. It still idles sort of fast, and this may be
timing or possibly a vacuum leak still present at the intake manifold where I
broke off that stud the night before Back-to the 50's. It may be that
bigger primary jets are still the answer at idle, at least for the time
being. The hood is
now back on, the original, without holes. The car looks almost
normal! I'll fix that with a couple of TURBO name-plates I pried off of
a LeBaron and carved a bit to remove the "fuel injected" logo
underneath. Tonight, I'll rebracket the heater fan to fit in the engine
compartment again. Then we'll see about windshield wipers.
In the spring, maybe I'll return to the abbreviated hood to make tuning easier
and upset the purists...... 11/19/01 Well, I have made the
mods to my regulator as well as some "porting" to the inside
of the regulator to allow fuel to "cross" the regulator to leave
thru the 3/8 inch return line which is plumbed straight back into the tank.
The only impedance in the line is a 90 degree bend where it enters the top of
the tank thru the sending unit. With the adjuster screw backed almost all the
way out, the fuel pressure gauge does not register, and the carb needs to
fill up its bowl by prolonged cranking, then runs until it runs out of gas.
All this talk about large return lines , but with "our"
modification, I think there will need to be some resistance on the return
line, or the pressure will not build up enough in the regulator to lift up
the diaphragm. I will add a small in-line fuel tap on the return line, and
play with resistance. Despite my pressure problem, which Oz didn't have, I
still like the idea of hogging out the inside of the modified regulator,
since the wear marks where the nipple contacted the metal part of the
diaphragm in Oz's regulator are uneven. Having equal pressure on all points
of the diaphragm (Pascal's law?) should, theoretically, raise it straight up,
and pass more fuel. I wonder whether the weaker spring which comes with the
regulator diaphragm repair kit would be better to add than more resistance in
the return line?! I can also play with the height of the nipple in the
regulator body, to create a pre-determined annular orifice when the regulator
is at rest with whatever spring is pushing against the diaphragm. Now
to fiddle. At least I don't have any fuel leaking anywhere with all the
new fittings..... 11/20/01 Of course,
when one has a pre-conceived notion of how things work, they don't follow
instructions. Though I built a great regulator, I hooked it up
wrong! The fuel should flow across the regulator body into the
carb, with the return going down the stand-pipe(center connection). Oz's
instructions were correct. Now, with the change, I get a pulsating 5.5
to 6 pounds at the gauge at idle. Spun up a nicer preload adjuster with the
boost reference tube running down the center, out of a bolt. This is
sturdier than the off-center drilled piece I was using with the soldered in
nipple. It was too dark to see the gauges last night, so I didn't go
very far with the car, but tonight I will see how the fuel pressure matches
boost. Theoretically, since the boost will be traveling up to 15#, the
fuel pressure should be 15+5.5=20.5# at about 5000rpm.... |
|||
|
|
|
|
|
|
|
|
|
|
|
