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What fuel pump for an IO-360-A4K

SteveR

Active Member
This was originally an carbureted engine (O-360-A4K), we converted to injection (Precision Airmotive Silver Hawk EX). What fuel pump should be used with this setup?
 
Fuel Pump

This is difficult to "officially" pin down. The A4K is a Grumman Tiger engine with rear mounted horizontal carb.
This is further complicated by two different generations of AC style carbs, some of which are difficult to retrofit. These were not mandatory changes so early style is still being used.
Spruce and other suppliers list pressure ratings for AC style pumps.
Float carb-low pressure
Pressure carb-medium pressure
Bendix style fuel injection-high pressure.
My suggestion would be to find a pump part number for a Decathalon with parallel valve 360
 
Those are really good comments by JRS..

I recently converted an IO-360-B1A (rear horizontal induction) to an Ellison (low pressure, updraft) throttle body. My engine builder and I were a bit confused but we put a typical Lyc low pressure pump in it and everything seems fine. The issue of "early style, late style, AC laminated body", etc. seems to me to only effect clearance from the induction unit. I can go back and research my records and refresh my memory if needed, but I think "if the shoe fits wear it" applies in this case since we are not talking certificated engine applications.
 
Pump

My attempts to verify part number took me to angle valve engines which is not where I wanted to go.
Strange that they do not list Pitts S1S which is exactly what one wants.
O 360A series, parallel valve, converted to Bendix style injection became AEIO 360B4A which is basically a Cherokee 180 engine converted to fuel injection. It has the bottom mount sump that many want so just bolt on the injection and change the fuel pump.
The information on the latest greatest fuel pump states in part "taller and my cause clearance issues" or words to that effect.
Air Power at 800-247-7693 can probably help and will have a good price on a pump.
 
Pump

Looks like 41234, 15473, LW15473, 75247 and 40256 will all work. All rated at 25-30 psi. Try Chief Aircraft if you need more info.
Pump is used on a variety of Lycoming's from 320 to 540.
 
Pump

That tempest chart shows the different style arms. You will need the special fittings, lock nut and o rings.
 
The reason theO-360- A4K had a special fuel pump situation was due to interference of the fuel pump with the carburetor after the newer longer style fuel pump was introduced. So for the pump to fit with the HA-6 carb the bottom of the pump was rotated to make it so the pump woudn't inerfere with the carb. But the fittings on the pump became very close to the engine mount structure used in the early aircraft applications. So a variety of plumbing issues resulted on the Gruman American installation. It had nothing to do with anything else on the engine . So, if you convert the o-360-A4K engine to an IO-360 and leave the original sump on, you would need an adapter between the sump and the servo as the mounting pattern for the o-360-A4K Ha-6 type carb is different than the servo bolt pattern. That adapter would move the fuel servo aft and I think would reduce the concern of any interference issues with the servo and fuel pump. If you changed the oil sump to either a forward facing IO type sump or regular O-360 pointing down sump, you would use the same high pressure pump that every other IO-360 uses, without any modifications necessary. The warning about whether the new style longer pump having interference issues was due to some aircraft having cooling shrouds over the pump with a duct going to it. The interference was with the shroud fitting over the newer style pump and not with the pump and any other engine components. Hope this helps!
Good Luck,
Mahlon
 
Please Write the updated Manual of Lycoming golden knowledge!

Mahlon, I learn tons from your posts and would gladly BUY a book!

Like the Sky Ranch series.
 
The reason theO-360- A4K had a special fuel pump situation was due to interference of the fuel pump with the carburetor after the newer longer style fuel pump was introduced. So for the pump to fit with the HA-6 carb the bottom of the pump was rotated to make it so the pump woudn't inerfere with the carb. But the fittings on the pump became very close to the engine mount structure used in the early aircraft applications. So a variety of plumbing issues resulted on the Gruman American installation. It had nothing to do with anything else on the engine . So, if you convert the o-360-A4K engine to an IO-360 and leave the original sump on, you would need an adapter between the sump and the servo as the mounting pattern for the o-360-A4K Ha-6 type carb is different than the servo bolt pattern. That adapter would move the fuel servo aft and I think would reduce the concern of any interference issues with the servo and fuel pump. If you changed the oil sump to either a forward facing IO type sump or regular O-360 pointing down sump, you would use the same high pressure pump that every other IO-360 uses, without any modifications necessary. The warning about whether the new style longer pump having interference issues was due to some aircraft having cooling shrouds over the pump with a duct going to it. The interference was with the shroud fitting over the newer style pump and not with the pump and any other engine components. Hope this helps!
Good Luck,
Mahlon

This is an excellent explanation of what I was alluding to earlier..."if the shoe fits wear it". Your installation is different from mine in that I went from a high pressure pump to low pressure, and you are going the opposite direction.
 
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