Technical > Spud Miller's Cave
scott super slot injector
dreracecar:
What is pictured with the lines is a distribution block and not a BV, the fuel from the BV goes to the dist block which then send the fuel to the nozzles. The fuel metering valve is at the front of the injector and is opperated by the throttle shaft.
DeSoto:
Thanks again. I think I'm with you now. So the barrel valve used is in the scott casting.
The barrel valve would have to be changed to the hilborn type to have been used with a
hilborn pump or the scott barrel valve would have been retained if they stayed with the scott
pump.
I am beginning to think it wasn't run with a hilborn pump and they just added the block, extra nozzles and lines for some reason?
If I take the barrel valve out and post a pic. Would you be able to tell me if it is a Hilborn or correct for the Scott.
Sounds like this is very important and would give me a clue as to how it was run last.
GlennLever:
Did a little surfing on the web
http://www.scottfuelinjection.com/pump/
Scott Centrifugal Pump
Why was the Scott centrifugal pump superior to others ? Here’s how
Scott explained it on the cover of his catalogues:
Scott Fuel Injection uses a completely different type of pump than any other
injection system on the market. Other Injectors use a positive displacement type
pump, with return lines, etc. Scott uses a diffuser centrifugal type pump (no return
lines), which has a much wider pressure range than the positive type pump. It also
can pump twice the volume.
The reason we want a wide pressure range is on a blown engine for example, with
say 300 cu. in., turning 2000 RPM, there is no blower boost yet, so in order to have
a fuel air ratio of 12 to 1, you need 11 GPH of gas, and with the engine turning 7000
RPM and 15 lbs. of boost, for a fuel air ratio of 14.3 to 1 you need 63 GPH. In order
to achieve this the pump must pump 9 times the pressure at 7000 RPM than at 2000
RPM because a jet or nozzle will allow .6 times the volume to pass when you double
the pressure. This is due to a pressure drop through the jet or nozzle.
The Scott pump is designed to give a fuel pressure of 8 lbs/sq. in. at 2000 RPM
(when driven at crank speed) and about 92 lbs. at 8000 RPM. This rate of pressure
build up is a little less than the square of RPM; but the pressure curve is typical
of a cetrifugal pump. Scott pumps use no by-pass return lines. All the pump pressure
goes right to the nozzles. Result is a fuel flow that is nearly proportional to RPM,
so the cylinders get virtually the same volume of fuel per suction stroke at 2000
RPM as at 6000 RPM or 7000 RPM. Load control is accomplished in much the same
way as the other competition systems – that is, fuel flow to the nozzle passes through
an orifice and metering valve assembly that is linked to the throttle pedal. This cuts
down the pressure at any given RPM as you close the throttle. The valve is operative
over the full range of butterfly travel.
The graph below speaks for itself !
The Scotts also sent me an article from Dr. Robert H. Goddard (volume 3: 1938
-1945) which goes into great detail about how the cetrifugal pump is superior due
to it’s high volume and dependability. E-mail me for a copy of this if you like. (info@madmaxcar.com)
http://www.madmaxparts.com/
This is a look alike EFI unit
I found no pictures of the pump, do not believe this is correct
Best I can tell the pump was off the crank
here is a post on the HAMB
A little more poking around might find additional stuff.
another HAMB post
http://www.jalopyjournal.com/forum/threads/scott-injector-hat-need-a-photo.599907/
dreracecar:
You cannot use the Scott metering valve with the Hilborn pump. Metering valve and barrel valve ,although have the same purpose, they are not the same. Glenn provided a pic of an oval blade injector with what appears to be a BV off to the side and linkage to the throttle shaft. This is the correct way to construct a system if one plans to use the Hilborn pump.
Glenn that is the correct pump picture, the best way to describe it as a "washing machine pump" and only has one moving part and that is a vaned impeller
GlennLever:
You could easily get hook on this, so c-101 or c-202 pump.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version