Full-flow oil circulation for flathead

Lubrication System (oil feed pump and scavenger pump, reservoir, filter, and lines)
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greg

Full-flow oil circulation for flathead

#1

Post by greg »

what does it mean and how is it done on my WL?
sleeper
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Re: Full-flow oil circulation

#2

Post by sleeper »

Greg, a book you must have is Bruce Palmer's "How To Restore Your Harley Davidson"
Anyway, your oil tank =right tank gravity feeds the oil pump on your cam cover, thru an oil line & is pumped thru the pinion shaft & thru-out the motor & to the wheels & crankpin & is flung off, as well as scraped off & collected in the rear scraper & fed to the lower Scavenger pump & is pumped thru an oil line back up to the oil tank. This is explained in your shop repair manual
You should have at least both these books. The answers are in there...
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Re: Full-flow oil circulation

#3

Post by Jack_Hester »

Greg -

Billy covered this one well. Palmer's book, and a reprint of an original manual, are readily available on the Internet. The shop manual has a very good picture and a flow diagram. Also, I don't know how stock your bike is, but an oil filter is a must. Yours did not come with one. But, they can be retrofitted, easily. Billy and I both are advocates of oil filtering. Your scavenger pump is more than capable of pumping oil thru a filter. If stock appearance is what you want to maintain, you can hide a filter somewhere on the frame, and splice it into your return line. There is an abundance of metal and carbon that floats thru your engine, when it's running. Some of it settles in pockets and screens, in the gearcase. The really small stuff justs keeps floating.

Hello, Billy -

Not much activity here, on the WL forum. It seems to be growing, though.

Jack
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Re: Full-flow oil circulation

#4

Post by sleeper »

Hi Jack, I seem to run into you everywhere, [kidding] ;D
Yeah, I hope this is growing, anyhow, Yes on the Oil Filter, hide it anywhere if you need to, But add one to your system. Very Cheap Insurance to protect the motor.Just because they came this way, doesn't mean we can't improve on many things, like this &
add A Magnetic Drain Plug for Extra protection..
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Re: Full-flow oil circulation

#5

Post by panhead »

I was told, long ago, that placing an oil filter in the return oil line would create too much resistance for the oil pump. So that is not true?
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Re: Full-flow oil circulation

#6

Post by 57stroker »

As I seem to recall, the discussion involved using a car oil filter on a Harley, as the car filter has a much higher rated by-pass valve (if there is one at all!)
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Re: Full-flow oil circulation

#7

Post by panhead »

Yes, that was the issue
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Re: Full-flow oil circulation

#8

Post by Jack_Hester »

All -

The scavenger (gear) pump is more than capable of pumping oil through a filter. However, choice of filters is very important. I make sure that any filter I consider has a bypass of less than 10 pounds pressure required to open it. There are many filters on the market with these specifications. That way, when it stops up (which I hope that it would be changed often), it will open the bypass and pump straight to the tank. It's going to do this with cold oil, anyway. A good rule of thumb is that if you don't know, use the Harley spin-on filter, as it bypasses at less than 10 psi. I believe it is the same as most small car filters, in that it bypasses at 7 psi. And, the Harley filter is good for down to 10 microns, which is a high quality filter. Most comparable automotive filters run for about $2 or $3 dollars less. This combined with a magnetic drain plug is the best insurance that you have little or no metal floating throughout the engine.

Jack
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Re: Full-flow oil circulation

#9

Post by sleeper »

I have friends that have been using oil filters in return line with oil coolers also, for years. With very good results. And these 45's get ridden hard & often..
Seems the "Full Flow" conversion is more. My initial response was incorrect, I stand corrected.. :-[
But this is not for my motors.
The procedure is outlined below.

Seems the Full-Flow conversion is more. It involves grinding a groove around the pinion shaft bushing, so it feeds oil constantly to the crank-pin. As opposed to getting it's oil as the feed hole in the pinion shaft passes the feed window. My concern would be for the lessened oil supply for the cam bushes. Some people like this conversion, some don't.
Such is life.... :
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