Software Newsletter #10 - November 15, 2000
1. Holley HP 950 Alcohol Carbs
Quay 4-Link Dragster
3. FREE Software Download
4. REAL World Technical
5. New Digital Altimeter
-- Holley HP 950 Alcohol Carbs
I've been building my own 4150 alcohol carbs for a few years now, and
it is refreshing to see that Holley is finally catching up. The HP carbs are pretty
good out of the box, but still won't work (at all!) on a drag car without some
modification. I've done a few of these carbs for some of my friends, so I thought
it was time to purchase one of my own to see if any advances have been made.
First I would like to say again that a mechanical fuel pump is not necessary.
Fuel volume is fuel volume, period. A simple flow test will reveal whether your
current fuel system is capable of delivering the proper volume of fuel. The best
method to test flow, is to take off the fuel bowls and put each one into an empty
fuel jug with the hoses still attached. This way you are testing actual fuel flow,
through the regulators and needle and seats. Run your fuel pump for 15 seconds
and then measure the amount of fuel in both containers. If each container has
a half gallon of fuel ( a total of 1 gallon), then your fuel system is adequate,
providing that your fuel cell is located in front of the fuel pump. In this location,
G-Force will actually help your fuel delivery. In the past, I have used the BG-280
pump, though now I am testing the BG-400 pump.
Holley still ships these
carbs with power valves. The only reason I can think of for doing this is that
the circle track market is larger. A power valve simply cannot be used in the
back bowl of a drag race application. A recent check of the Barry Grant catalog
stills shows that BG says that the only way to use a carb with a power valve is
to mount the carb sideways on the manifold. Maybe ten years ago, Barry! Simply
remove the power valves from both metering blocks and replace them with plugs,
Holley part #26-36. You must increase the total jet area accordingly. Holley is
using a .120 PVCR (Power Valve Channel Restriction) in these metering blocks,
an area of .011310. The carb is shipped with a .144 jet which has an area of .016277.
So, the total jet area is .027587 or about a .188 jet size. Holley always jets
these carbs rich, so be prepared to lean the thing out quite a bit, but it is
better to be safe that sorry. So, plug both power valves an install .188 jets
at all four corners to start. You also must have jet extensions in the rear bowl.
Holley now ships this carb with a notched float for this purpose. Either use the
Holley extended jets or the Moroso extension part# 65441 and use the notched float.
I recommend using two (2) bowl extensions to increase the amount of bowl capacity.
I use Moroso's, part# 65221 on both bowls. DO NOT install the foam that is packaged
with this extension!
Give the secondary idle screw about a half of a
turn in more to start. You want to have both throttle plates open about the same
amount at idle. If you don't do this, you will end up with the primary throttle
plates opened so far, that you will uncover the transfer slot, and the carb will
run too lean at idle. You can check this by monitoring your EGT. It should idle
around 450 to 550 degrees. If the exhaust temperature is hotter than this, the
engine will build too much heat at idle. After you get it running, remove the
carb and check the clearance of the primary and secondary throttle plates. If
the primary is still open too far, open the secondary a little more and back off
of the primary the same amount. That is all there is to it!
I took mine
out to test it and it was running out of fuel. A total disassembly showed that
somehow, Holley had installed three (3) float springs in the secondary bowl instead
of one! No float drop there! So we will have to go back tomorrow night and try
it again. I'll keep you informed.
-- New Quay 4-Link Dragster --
Well, we finally bit the bullet and bought a 4-link dragster. Now all the
tracks will be ground smooth for sure! Anyway, this is a really nice car. We put
a little 433 big block in it and went to Cecil County to test it. I can't understand
why everyone says that you can't get a light with a 4-link car. Really! I put
.015 in the box and the very first light out of the trailer was a .399! So, we
tried it again and went .400. Jeez, lets try it again. So we did and went .398!
So we went to Atco and put .020 in the box and out of the trailer went .406. Okay,
so you probably think we are leaving at a high RPM. Guess what? Every run was
made with a 4800 RPM chip! After looking at the DataMaster computer graphs, we
took a stab at a throttle stop factor, set the stop and went 8.880 on the very
first throttle stopped run. Killer car!
And now I can say what everyone
else has been telling me for years. WHAT BUMPS? That's right, every track is as
smooth as glass. This car rides like a Cadillac! I can't say much for the big
block. It dropped a valve on the 7th pass! I guess there is a learning curve there.
Yesterday, we dropped the small block in the car because they don't eat valves!
We'll test the small block combo tomorrow.
-- FREE Software Download
Our DataMaster Analyzer software, Version 2.0, is available to you
as a FREE download on our web site. You don't need a data recorder to test the
software and see exactly what a DataMaster Sportsman Computer does better than
any other data logger system in the world! If you have any older version of this
software, download this as a FREE update.
-- REAL World Technical
With Family Software, you'll get better technical support
than anywhere on the planet. Why? Because, I design and program all of Family
Software's products and I use them all on my own very competitive Super Comp dragster.
All of my 30+ years of experience and knowledge is available to you and our other
customers. Try to find that kind of information at any one of our competitors.
You won't be able to, I guarantee it! Family Software cares about the racer and
his/her success as a racer. The other companies just want your money!
-- New Digital Altimeter/Barometer --
We also have in stock, the best
electronic altimeter that I have ever seen. It has a resolution of just one (1)
foot. We had previously sold a unit that had a resolution of three (3) feet and
we thought that was good! The new unit is just $149.95. You just can't beat that!
To read the specs on this unit, just go to the Products page on our web site and
click on Digital Altimeter.
-- Secure Ordering --
You can safely
order directly from our web site. All of your information is handled on our Secure
you have questions or topics that you would like to see covered in this newsletter,
please Email them to me. Or,
start a new topic on the bulletin board located on our web site. I'll be glad
to join in.
Family Software - Drag Racing Computers and Software
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