Author Topic: Strange question  (Read 1176 times)

Offline allankelly1

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Strange question
« on: September 17, 2021, 07:47:39 PM »
Just wondered out of curiosity how much oil in litres per min a CB400F oil pump displaces on tick over

Any oil pump experts out there?

Best wishes Al


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Offline McCabe-Thiele (Ted)

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Re: Strange question
« Reply #1 on: September 17, 2021, 11:35:45 PM »
I have  no idea but as long as the oil light goes out reasonably quickly I think it's enough to do the job.
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Online Athame57

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Re: Strange question
« Reply #2 on: September 18, 2021, 12:53:11 PM »

Assuming the oil pump completes it's cycle 1200 times a minute, perhaps you could find out the capacity of said pump and multiply? Otherwise you could ask those boffins at NASA?  ;D
« Last Edit: September 18, 2021, 12:54:46 PM by Athame57 »
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Offline Bryanj

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Re: Strange question
« Reply #3 on: September 18, 2021, 01:57:50 PM »
It pumps more than enough but not too much is the only answer i can give

Offline allankelly1

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Re: Strange question
« Reply #4 on: September 18, 2021, 07:12:39 PM »
Hi thanks for all the answers

Best wishes Al


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Offline Seabeowner

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Re: Strange question
« Reply #5 on: September 19, 2021, 08:14:03 AM »
Just wondered out of curiosity how much oil in litres per min a CB400F oil pump displaces on tick over

Any oil pump experts out there?

Best wishes Al


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Depends on how worn your bearings are.
Phil
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Offline TrickyMicky

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Re: Strange question
« Reply #6 on: September 19, 2021, 08:46:53 AM »
To my simplistic way of thinking, worn bearings should not alter the output of the pump. If the pump is in good order it will still pass the same amount of liquid at a given speed. Don't forget that you cannot compress a liquid, only a gas. If the pressure gets too high then there should be a by-pass valve somewhere, otherwise something will definitely break. Look what happens to the conrods and crankshafts in diesel engines when they suck in some water.

Offline taysidedragon

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Re: Strange question
« Reply #7 on: September 19, 2021, 12:39:27 PM »
To my simplistic way of thinking, worn bearings should not alter the output of the pump. If the pump is in good order it will still pass the same amount of liquid at a given speed. Don't forget that you cannot compress a liquid, only a gas. If the pressure gets too high then there should be a by-pass valve somewhere, otherwise something will definitely break. Look what happens to the conrods and crankshafts in diesel engines when they suck in some water.

Dead right. Wear in the pump itself will affect the output. Wear in the engine bearings affects the oil pressure.
Gareth

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Online SteveD CB500K0

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Re: Strange question
« Reply #8 on: September 19, 2021, 12:44:51 PM »
Isn’t there a pressure relief valve in the oil filter bolt?


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Offline Bryanj

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Re: Strange question
« Reply #9 on: September 19, 2021, 12:52:20 PM »
Thats only for if the filter blocks so oil bypasses the filter and lubes the engine albeit with contaminated oil Steve, there is an over pressure relief built into the pump itself and operates at about 65psi if memory serves

Offline K2-K6

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Re: Strange question
« Reply #10 on: September 19, 2021, 01:29:26 PM »
The one in the pump (virtually all engines have this) is to protect the oil pump drive while the oil is thicker when cold. Essentially it will hydraulic lock (dynamic and relevant to the system resistance that is normal oil flow) if revved under those conditions and risk shearing the drive arrangement.

Offline allankelly1

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Strange question
« Reply #11 on: September 19, 2021, 07:02:46 PM »
Thanks for all the answers everybody

The original reason was that I have just finished off my oil cooler installation




But  on initial checks during cranking on the starter (before firing the engine as wanted to ensure the system was flowing oil) there seemed to be less flow thru the cooler than I was expecting?

But then I remembered the there is a bypass port in the take off plate




So most flow goes direct to the engine via this port  with a percentage flowing via the cooler hence my initial worry about lack of flow of oil

Again many thanks for all the answers Al


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« Last Edit: September 19, 2021, 07:05:39 PM by allankelly1 »

Offline 400 Cafe Racer

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Re: Strange question
« Reply #12 on: September 19, 2021, 07:45:15 PM »
Thats only for if the filter blocks so oil bypasses the filter and lubes the engine albeit with contaminated oil Steve, there is an over pressure relief built into the pump itself and operates at about 65psi if memory serves

Hi Bryan, ;)

I can confirm this 65psi as I recently fitted an oil pressure gauge which tops out at 65psi when the engine is started cold. A good indication the oil pressure relief valve is functioning correctly.

Dennis
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Offline Bryanj

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Re: Strange question
« Reply #13 on: September 19, 2021, 09:31:06 PM »
Unless you arr racingan oil cooler is overkill if not fitted with a thermostatic bypass

Offline allankelly1

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Re: Strange question
« Reply #14 on: September 19, 2021, 09:33:21 PM »
No just prepping as planning to fit a 460cc lump in the future and an oil cooler was highly recommended as part of the changes when going up to 460cc


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