Author Topic: Oil Injector  (Read 184 times)

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Flying Frenchman

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Oil Injector
« on: December 03, 2017, 10:59:29 AM »
Hi Guys its been a while.  Now that harvest is over and there is snow on the ground its time to start thinking Race sleds.
Just got my 340 invader engine back from getting ported and the heads done.  Was wanting to run Premixed C12 fuel in it but still want to run the injector pump in the idle position to lube bottom end.  Does anyone know if I plug the injector lines to the intake if the crankcase will get to much oil?  As in the extra oil that should go to the intake would flood the bottom end?  Any Advise would be appreciated.

mswyka

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Re: Oil Injector
« Reply #1 on: December 03, 2017, 11:17:20 AM »
Each of the  injector discharge ports are fed by discrete alignment of  the pump barrel with the discharge port.  When the pump barrel rotates to be in alignment with the port, the pressure reserve is released into that port.  While I have to believe that more oil will be distributed per pulse if there are no other outlets, the pulse duration is so short that the variation would likely not be much.  The only way to know for sure would be to take a measurement by the procedure in the manual.

The feed from the pump barrel comes through the holes in the side of the barrel.  These holes are visible in the attached photo - which happens to be of a worn pump.  Pumps in good condition will show no wear at the hole location.

« Last Edit: December 03, 2017, 11:18:56 AM by mswyka »

Teherr

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Re: Oil Injector
« Reply #2 on: December 03, 2017, 06:58:26 PM »
I have a invader motor that uses pre-mix.  You have to drill equivalent holes for the inside bearings as the outside bearings have.  The motor appears to have been designed for either as the there are indents where you have to drill. 
2 440 Invaders
440 LTD Monohead
Liquifire
80' 4/6 
250 & 340 Enticers

jskal

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Re: Oil Injector
« Reply #3 on: December 05, 2017, 08:42:17 AM »
I am working on building a 440 LTD Monohead, also converting to pre-mix - was happy to see this thread.  Just got the crank out yesterday and sending it for balance.  Similar requirements?  Would a chamfer on the piston skirts achieve the same oil bath for the outer bearings?

Interceptor398

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Re: Oil Injector
« Reply #4 on: December 05, 2017, 06:26:39 PM »
Why would you prefer pre mix to oil injection?  Just wondering as it seem like one more step.

kawhead

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Re: Oil Injector
« Reply #5 on: December 06, 2017, 08:23:58 AM »
I don't get it.....my 550 went over 7400 mi before rebuild....seems pretty reliable to me

gixxer6

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Re: Oil Injector
« Reply #6 on: December 06, 2017, 09:54:09 AM »
Mixing gas is towards the top of the list of my least favorite things to do... 

If the oil pump, tank, and lines could be removed I could see an argument for weight savings but the crank must be oiled, so the injection system must stay.  I can't see a reasonable reason to delete it. 

jskal

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Re: Oil Injector
« Reply #7 on: December 06, 2017, 10:11:16 AM »
My project is entirely experimental and it seems like I'm always fighting with that oil tank.  Not sure what Flying Frenchman has cooking.

kawhead

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Re: Oil Injector
« Reply #8 on: December 06, 2017, 12:56:44 PM »
driving the invader waterpump is a issue with no oil pump......

Boomologist

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Re: Oil Injector
« Reply #9 on: December 07, 2017, 06:21:34 AM »
When running pre-mix you have one oil/fuel ratio throughout the entire throttle. Pre-mix doesn't take into consideration the needs of the engine. At idle it's rich with oil and at top end, where the engine needs the most lubrication, it's lean for oil.
Also, running pre-mix will change your fuel to air ratio because instead of pure fuel going through the jets in the carb you now have some of that fuel being replaced with oil.

Oil injection allows a variable ratio as oil is needed. At idle the gas to oil ratio is 100 to 1. As throttle is opened and the engine is working harder the ratio changes with engine needs. At 3/4 throttle and above the engine gets about 25 to 1.
This is one reason we can get such high engine mileage for a racing engine.
There is absolutely no good reason to partially block or remove the oil system.

Flying Frenchman

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Re: Oil Injector
« Reply #10 on: December 17, 2017, 11:16:29 AM »
Good Morning Guys,  Thanks for all the input.  The reason i am thinking of running premix is for two reasons,  1.  I have just spent quite a bit of money getting this engine race ready and want to make sure it doesnt pile up due to a faulty oil pump or something like that.  2.  I have 3 other race sleds in my trailer on race weekends and we all run C12 race fuel and those sleds all run premix so it would make the pit crews lives easier if there was only one jerry can. 

kawhead

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Re: Oil Injector
« Reply #11 on: Today at 08:21:01 AM »
I see your point....how will you drive the water pump?