Author Topic: Oil pressure 1W  (Read 8598 times)

Offline scully

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Oil pressure 1W
« on: July 01, 2015, 06:17:52 pm »
Hi,

I have a 1W luying around, and I'm thinking of using it, just for the oil squirters, and making a 1341 out of it. It seems to me that the oil squirters must have an effect on the oil pressure. Do I need to compensate that, or is the difference negliable? Does anybody know what the oil pressure difference is between a PY and a 1W?

Offline Alexiskayak_7

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Re: Oil pressure 1W
« Reply #1 on: July 02, 2015, 10:31:36 am »
It won't have pressure difference at all...
What makes you think that?

Offline Yoof

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Re: Oil pressure 1W
« Reply #2 on: July 02, 2015, 12:52:35 pm »
It won't have pressure difference at all...
What makes you think that?

You assumption is based purely on the fact there's additional capacity in the relief circuit of the oil pump. Do you know this for fact, or is it a guess?


Offline scully

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Re: Oil pressure 1W
« Reply #3 on: July 02, 2015, 01:17:03 pm »
It won't have pressure difference at all...
What makes you think that?

I'm thinking there will be a lower pressure with the 1W, because with the oil squirters, the oil has 4 extra easy way outs in comparison to the normal PY oil circuit. This will lower the pressure the same way as when you have a puncture in your tyre, right?  :-\ Can you please explain why there will be no difference at all?

Offline dubstar

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Re: Oil pressure 1W
« Reply #4 on: July 02, 2015, 05:20:43 pm »
piston crown oil jets.

Offline Yoof

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Re: Oil pressure 1W
« Reply #5 on: July 03, 2015, 07:32:54 am »
It won't have pressure difference at all...
What makes you think that?

I'm thinking there will be a lower pressure with the 1W, because with the oil squirters, the oil has 4 extra easy way outs in comparison to the normal PY oil circuit. This will lower the pressure the same way as when you have a puncture in your tyre, right?  :-\ Can you please explain why there will be no difference at all?

Oil pumps are generally sized to provide adequate oil pressure in the worst case condition, which is usually a high oil temp, hot idle. As the mechanical pump is directly coupled to the crank, the relationship is fixed to engine speed. Once the pump size has been determined for worst case, it is then over sized for other speed points. This is regulated with a pressure relief/bypass on the pump, to ensure there is a smaller pumping loss and oil pressure isn't 10bar at 7,000rpm.

With that in mind, if you add 4 holes to the circuit, providing the pressure relief valve remains open (i.e. it is still bypassing excess oil back to the sump) then the pressure remains the same.

The quantity of oil the pump moves remains constant with or without oil jets/squirters.

However (and this was my question to Alexiskayak_7) this assumes the oil pump has additional capacity, and I'd like to know if this has been tested, or is a guess.

Offline Alexiskayak_7

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Re: Oil pressure 1W
« Reply #6 on: July 04, 2015, 11:50:56 pm »
I have tested a costumers 1.4d 1w a year ago due to random oil pressure warning in the dash.
The problem was a oil pressure switch, but i have tested the oil pressure of engine to be sure that it wasn't any oil pump issue.
Measuring the oil pressure at different oil temps the pressure was similar with my py engine.

The only thing i mentioned was that above 80 degrees the oil pressure was slightly more stable than my g40... I have no idea if the 1w has different oil pump

Both on 10-40

Offline scully

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Re: Oil pressure 1W
« Reply #7 on: July 05, 2015, 06:43:03 pm »
I wasn't aware of the pressure relieve valve, so thanks for that.  ;)

Offline Yoof

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Re: Oil pressure 1W
« Reply #8 on: July 05, 2015, 06:55:42 pm »
I have tested a costumers 1.4d 1w a year ago due to random oil pressure warning in the dash.
The problem was a oil pressure switch, but i have tested the oil pressure of engine to be sure that it wasn't any oil pump issue.
Measuring the oil pressure at different oil temps the pressure was similar with my py engine.

The only thing i mentioned was that above 80 degrees the oil pressure was slightly more stable than my g40... I have no idea if the 1w has different oil pump

Both on 10-40

So it's a guess, based on information that isn't relevant.


Offline benh999

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Re: Oil pressure 1W
« Reply #9 on: July 05, 2015, 10:04:59 pm »
Hi,

I have a 1W luying around, and I'm thinking of using it, just for the oil squirters, and making a 1341 out of it. It seems to me that the oil squirters must have an effect on the oil pressure. Do I need to compensate that, or is the difference negliable? Does anybody know what the oil pressure difference is between a PY and a 1W?

Is the 1w block not already a bigger cc than 1341? Surely you can't carry this out?

Offline scully

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Re: Oil pressure 1W
« Reply #10 on: July 06, 2015, 04:02:28 pm »
I need custom pistons for that, and I do not want to exceed 200 hp with regards to the drivetrain, so for that reason I choose for the smaller capacity.

Offline benh999

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Re: Oil pressure 1W
« Reply #11 on: July 07, 2015, 10:52:58 pm »
I need custom pistons for that, and I do not want to exceed 200 hp with regards to the drivetrain, so for that reason I choose for the smaller capacity.

I'm still lost, how do you make a block whose original capacity is approx 1400cc into a 1341cc

I may be missing the obvious here?g

Offline scully

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Re: Oil pressure 1W
« Reply #12 on: July 07, 2015, 11:28:39 pm »
By putting in the PY crankshaft, conrods and pistons?

Offline xandyx

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Re: Oil pressure 1W
« Reply #13 on: July 08, 2015, 01:11:29 am »
You'll need 1w crank due to different stroke..

Offline youngprodigys

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Re: Oil pressure 1W
« Reply #14 on: July 08, 2015, 12:48:24 pm »
You'll need 1w crank due to different stroke..

Read the original post. He only plans to use the block so all his internals will be using the G40 crank in order to create 1341. He would only require the 1W crank if he was creating for example a 1471cc engine - which he is not.

The oil pump has a pressure reducing valve built into it as it can create more pressure than the required level. The oil squirters will not impact the delivery of the required pressure.