ayrton012

What was the oil temp at that pressure?

ASH8

Well, as the Mazda Factory Series 2 Service Highlights says Oil Pump "Relief valve opening pressure" is 156.6 PSI, compared to 64-71 PSI on Series 1.

Given there is no other Oil Pressure Relief Valve apart from this one on Oil Pump for S2's, the Oil Pumps Oil via OCV to the two EMOP's at a max of around 20 PSI with a flow back oil tube from EMOP to Oil Filler neck back to Oil Pan.

The stats by Phillip appear to be in-line with the factories numbers.

PhillipM

What'd be interesting would be to see what the pressure figures are on a car with the stock oil cooler setup and see if the S2 setup comes closer to our figures than the S1 did as standard.

ayrton012

Yes, but I don't always believe to the factory numbers, so it is better that Phillip verified it.

ASH8

Yes, well I do believe the factory figures they use "their" industry standard equipment and are the makers this engine..
And with all due respect to Phillip, he uses an RX-8 engine, not an RX-8 engine in a RX-8 body with factory Oil Coolers, etc, etc.

PhillipM

Yeah, that's why I thought it might be interesting to see what a standard one gets, it'll show whether the oil cooler system is still restrictive or not.

ayrton012

Don't wait interesting datas, we know how much PSI is losing away in the factory system. About 10 PSi. I've got about 10 PSI more pressure at lower rpm, where the regulators even don't play too much, with my single cooler system.

Now I use -12 diameter oil hoses, and connectors from the engine, because I "threw" away the factory "banjoed" pipes, and screws. I made -12UNF adapters instead of the factory banjo screws, so I could use the -12UNF reusable connectors and oil pipes from the engine block.

PhillipM

I meant off an S2 rather than a modded S1. The oil circuit is different. Lots more pressure lower down too on this engine (it idles at more pressure than you're showing at 3000rpm). We just made a press in adaptor for the engine block itself so ours is on -12 hoses right from the get go.

I'll have the gauge calibrated next week (it's a new one, and only a cheap one as we're getting a digital dash over winter, so it's probably +-10% at the minute), and hopefully get some milage on the engine and report the pressures back if anyone wants them.

ayrton012

Of course, we want the pressure datas!

DocBeech

iTrader: (1)

I'm interested to see if the temp drops to low in the winter.

ayrton012

Here is around 60F outside now, and the oil temps are usually 158F at the filter, with the 176F oil thermostat.

PhillipM

It's 45F outside here at the minute, but I don't think the oil'll go much under 195F in our case :D

ayrton012

That's not bad from a WOT or "idle" used racing system. :-)

I got 200F at the very twisty uphill roads of the Alps.

9krpmrx8

iTrader: (46)

I had my single cooler through last winter here in Texas and it wasn't and issue, the Oil never really got cooler than 175F at cruise and i am measuring temps on the return after the cooler so I am sure it is plenty hot coming into the cooler. In a really cold environment you would probably have to block it off to avoid over cooling but that would be simple.

I get over 200F everyday whenever I get anywhere above 7,000RPM. But it is in the 90's here.

PhillipM

Had the gauge calibrated and dropped some fresh oil in her today, idle is at 77psi, (but idle speed is up slightly due to some mapping tweaks) 100psi by 2000rpm...
She's only putting out 261bhp this time though, but - she's gets to peak power earlier and holds onto it for longer with the tweaks, so I'm guessing the only reason she's down a few ponies on the dyno is either just differing conditions + the engine being tight (it's done less than 1000 miles after all).

The S2 engine definately runs a lot cooler too.

ayrton012

Do you think that the faster oil flow (by S2's higher pres.) has that effect on cooling?

PhillipM

Quite probably, the water pump is different though as well, but the oil is running a lot cooler - to the extent where I think we're going to have to spend a lot longer warming the car up before the races.

ayrton012

Last week I modified my single oil cooler system. I moved the oil thermostat from the "fender" to the battery's place, and turned upside-down the oil cooler. Now the oil cooler system is more central located than before, and the oil pipes are shorter...but here are the pics:

carbonRX8

iTrader: (1)

THis is interesting and all and I am considering something similar.

But I have to say that mathematically linking FLOW with PRESSURE is only so much BULLSHIT. It just doesn't fly. I don't buy it.

9krpmrx8

iTrader: (46)

Looks good man, I am over a year or so with my setup and all is good. I like what you did with the oil thermostat, I have been meaning to relocate my battery so i may have to steal that idea. I am using Taylor Push Lock hose and it is holding up very well. The stainless stuff is tough to maneuver.

I took delivery and will be installing the Racing Beat lines on a stock RX-8 soon. So look for a new thread with before and after oil pressure and temp readings.

ayrton012

Thanks! It was working well in the first position, but there was problems with the stainless pipes. If they touched anything they caused loud vibrations. Now I use special rubber holders for the pipes and the thermostat (under that) so the system is quiet.
I will looking for your new thread!

9krpmrx8

iTrader: (46)

Yeah I have worked with SS lines in the past on previous cars and it is just a pain. The rubber hose I use is very durable and will last years. It is also very easy to route and I don't have to worry about vibration damage either. If you use SS lines the rubber boots on them is a must.

ayrton012

If somebody could tell it to me earlier! Now I learned it on my own example.

Other:

The other reason why I turned upside down the oil cooler, that if the car was standing more than a day, at the first start-up there lasts 1-2 sec to get oil pressure, because some amount of oil drained back from the system while standing. So I always have to cranked 3-4 minutes at full WOT (no fuel injection) to fill the oil cooling system with oil, before started the engine. Strange that if I used the S2 oil filter, more oil drained back to the pan at standing. Maybe there are weaker drain back valve (ring seal) in the S2 filter, because it is almost upside-down position in the S2, so in that engine the oil could not drain out from it after shut down.

Anyway after that I turned upside-down my very tall (34rows) single oil cooler, this draining back symptom has gone, even with the s2 oil filter.

9krpmrx8

iTrader: (46)

Makes sense. That is why I positioned my cooler so that it drains back some what. I tried to keep the lines around the same height as the stock lines.

ayrton012

Today when the engine got started I felt so again that the oil pressure built up later (+1 sec). Maybe I'm just worry too much, but I begin to loose my confidence in using S2 oil filter on S1. I think it could not hold the oil for longer times in upside down position when the engine is not running. Anyway later I will test a filter outside of the engine.