Harv's McGee injection thread

[Errol62]

Harv FYI. Just saw this.


https://www.gumtree.com.au/s-ad/goulbur ... pasteboard


FB ute fixer upper, EK van on rotisserie

[Harv]

Very similar to my red motor set... but without the bent shaft. You can see how much they stick out the side of the throttle body casting though.

Interesting that he has a 6-port barrel valve on it. The set I have has no barrel valve, but is set up for a single-port one (it has a separate 6-port McGee fuel block).

.... must not buy more red motor stuff.... must resist temptation.

Cheers,
Harv

[Harv]

Attached below a copy of an excellent article from Speedway Classics. I'm posting the article here with permission from the copywrite owner, Dennis Newlyn. Many thanks to Dennis for both his generosity and excellent storytelling.

McGees Grinding Out History pages 1 through 4.pdf

(882.8 KiB) Downloaded 103 times

McGees Grinding Out History - pages 5 though 8.pdf

(1.29 MiB) Downloaded 95 times

McGees Grinding Out History - pages 9 through 12.pdf

(1.22 MiB) Downloaded 102 times

McGees Grinding Out History - pages 13 through 16.pdf

(1.17 MiB) Downloaded 79 times

McGees Grinding Out History - pages 17 through 20.pdf

(1.29 MiB) Downloaded 120 times

Cheers,
Harv

[Harv]

Bit of a win this week. Bought an assorted box of Hilborn injection gear, mainly for the pulleys. It came with a manky, siezed barrel valve. A little bit of love, and voila! A fully functional McGee red-motor barrel valve.

Red motor McGee barrel valve.jpg (640.36 KiB) Viewed 1212 times

This one has been worked over a bit... someone has stripped off the red anodizing, replaced the ally port caps with mild steel and replaced the brass screws with those 'orrible grub screws on the top. The good part is that the guts are in decent shape.

Cheers,
Harv

[Errol62]

Outstanding fiddling mate

Sent from my SM-G973F using Tapatalk

[Harv]

Trying to finalise some of the odds and ends so that the grey motor McGee set is ready to bolt up. One of the big questions remaining is how large the nozzles should be, and hence what range of pill sizes I will need to run. It all boils down to pump size - the more the pump puts out, the smaller the nozzles need to be. The plan will be to run both methanol and petrol, so anticipate having to run two very different nozzle/pill setups. There is lots of data available for common pumps (Hilborn, Enderle, Crower etc), but no info for the McGee stuff.

Trial and error is not a great idea for fuel injection sizing. Too lean and you do engine damage really quickly (bear in mind that mechanical fuel injection is either at idle, or flat-out... no midpoint to readily check for pinging). Changing nozzles by trial and error is also pricey - $250 worth of nozzles every time you change.

I've tried contacting McGee in the US to see if they still had info on the pump sizes. Sent lots of emails over the last 11 months, and have had limited success. Managed to get them to respond to one email nine months ago. The response was quite positive, and they remember the units well. have had no response from them since, nor any luck in getting them to pick up a phone either. If anyone is in El Dorado Springs, Missouri and wants to knock on their door for me please let me know .

Looks like I am going to have to go back to basics. Have packaged the pumps up (a round-head 6 bolt McGee pump, a later hex-head McGee pump, and a Hilborn BL420 pump) and sent them off to Lowe Fuel Systems to get them flow tested. I can then get AlkyDigger in the US to help me out with appropriate nozzles and pills.

Cheers,
Harv

[Harv]

Got the test results on the fuel pumps. Bit dissapointed that neither of the McGee pumps would flow. The grey motor McGee (sliding vane) had too much internal clearance, and the red motor McGee (gear) would not take suction. Will have to look a bit harder at the internals of these and try again.

On a positive note, the Hilborn BL420 tested up well - see attached table.

Pump sizes.docx

(15.68 KiB) Downloaded 81 times

Typically, at wide open throttle, full power, an engine requires 0.5 lbs. of fuel per horsepower every hour. A gallon of petrol weighs approximately 6.3lbs. Therefore an engine needs roughly (0.5 / 6.3 / 60 =) 0.00132 gpm of petrol per pony. Methanol needs around 2.5 times that flow, s or 0.33 gpm per pony. A standard 75BHP grey thus needs 0.1gpm of petrol, or 0.25gpm of meth. For the meth monster I want to tickle 200BHP (its a long bow, but I'll try). For this I will need 0.26gpm of fuel, or 0.66gpm of meth. The BL420 will poke out 2.8gpm, so is plenty big enough for the grey (return rate back to the tank will be 90% for fuel, and 75% for alky).

Still keen to run the McGee pumps, but the BL420 is a good backup. I've got an ally timing cover set up to run it off the cam snout, so do-able, though was hoping to use that connect to drive the tacho.

Cheers,
Harv

[FJWALLY]

Got the test results on the fuel pumps. Bit dissapointed that neither of the McGee pumps would flow. The grey motor McGee (sliding vane) had too much internal clearance, and the red motor McGee (gear) would not take suction. Will have to look a bit harder at the internals of these and try again.

On a positive note, the Hilborn BL420 tested up well - see attached table.

Pump sizes.docx

Typically, at wide open throttle, full power, an engine requires 0.5 lbs. of fuel per horsepower every hour. A gallon of petrol weighs approximately 6.3lbs. Therefore an engine needs roughly (0.5 / 6.3 / 60 =) 0.00132 gpm of petrol per pony. Methanol needs around 2.5 times that flow, s or 0.33 gpm per pony. A standard 75BHP grey thus needs 0.1gpm of petrol, or 0.25gpm of meth. For the meth monster I want to tickle 200BHP (its a long bow, but I'll try). For this I will need 0.26gpm of fuel, or 0.66gpm of meth. The BL420 will poke out 2.8gpm, so is plenty big enough for the grey (return rate back to the tank will be 90% for fuel, and 75% for alky).

Still keen to run the McGee pumps, but the BL420 is a good backup. I've got an ally timing cover set up to run it off the cam snout, so do-able, though was hoping to use that connect to drive the tacho.

Cheers,
Harv

Could the internal cylinder be sleeved or it it more likely gear wear?


Sent from my iPhone using Tapatalk Pro

[Harv]

Hard to tell - I stripped, cleaned, and reassembled with new seals, but did not check any clearances. No factory specs to check them against, and the McGees are hard to get hold of.

The pump construction is relatively sloppy for both. Can possibly tweak the rotors along the shaft of the grey one. Need to do my homework first.

When I got the magnetos done, I also got a spare Vertex shaft/base made up to suit a Ronco angle drive. It will slip into a grey block, and let me run a magneto sideways to clear the Repco head. I intend to run the McGee angle drive, but this gives me another option. The Tepco head guys would love to have it The Ronco drive has the same problem as the McGee pumps... slightly sloppy fit up.

I’ll see if I can work out where the slop is in both pumps and angle drive.

Cheers,
Harv

Cheers,
Harv

[ardiesse]

Harv,

You gotta love arcane non-SI units of measurement: brake specific fuel consumption is expressed in pounds of fuel per horsepower-hour.

But it makes sense, particularly for aircraft engineers: If such-and-such aircraft requires P horsepower to cruise at n mph, is equipped with Mr So-and-So's engines which have a BSFC of x lb/hp-hr, and has a fuel capacity of w pounds, how far will it fly before gliding into the sea somewhere in the South Pacific?

As an aside, one of my favourite methods of tormenting the junior engineers at work is to ask: "Calculate the conversion factor from pounds per horsepower-hour to kg/J."

Rob

[Harv]

I taught Grace to convert between weird units. It was like watching a lightbulb turn on once she got it.

Cheers,
Harv

[FJWALLY]

Could you try a light surfacing of the cap and volute ring to take out the end play of the rotor - like Fred has done on the Wray as if there is any end play the fuel will leak back over the rotor end - same result in a grey oil pump the end clearances need to be very tight?

[Harv]

I suspect the drama on the grey motor one is the clearance between the “lid” and rotor. The shaft/rotor can move closer/further pretty easy... not much holding the shaft in position other than bearing race friction.

Cheers,
Harv

[Harv]

I got a call out of the blue from a good mate, and the chance to buy some McGee gear from an old Speedway gentleman. Hard to say no, but had to draw the line at a set of McGee injection to suit early Falcon 6 (even I have limits... mostly ).


Box of assorted McGee pills. This will be damn handy for tuning the meth monster. Screw-in like Enderle, but different thread. Also has some adaptors to connect NPT hoses to McGee injectors.

EFE4188C-B205-4A0D-9215-059FCDC99522.jpeg (94.89 KiB) Viewed 1098 times

McGee angle drive to turn the dizzy sideways. Invaluable for the Repco heads, where clearance to the inlet manifold is nasty. This one has snapped the spigot and had it rewelded, just like my first one. Needs the driven shaft made up out of an old grey motor cam (see below).

0B3EA619-FB50-4383-95A0-5D00B7B636C5.jpeg (3.01 MiB) Viewed 1098 times

Pump belt drive.

F58D39D7-E58D-4587-A097-366DDC450FA3.jpeg (90.13 KiB) Viewed 1098 times

Bronze angle drive, this time with the driven gear (this is what I will need to get an old cam killed down to to finish the earlier one). More robust than the ally ones, but mucho heavy.

6E65103E-8025-4A2E-8139-10E713364713.jpeg (119.5 KiB) Viewed 1098 times

Hex-head fuel pump, red motor era.

AD869DBE-A590-4C47-8965-329DC587383D.jpeg (118.6 KiB) Viewed 1098 times

Cheers,
Harv

[Blacky]

some nice goodies there mate