olddragger

iTrader: (3)

the difference that can be seen on the piston -imho does indicates its moving a good bit?
thinking about this in regard to the entire system
1- front bypass is opening sooner than we thought---why? cold start ups? reducing pressure to the coolers?
2- coolers "thermostat" and system further reducing flow and pressure as previously discussed
3- rear regular/bypass may not be the one reducing the pressure/flow in the way we originally thought.
4- oil filter bypass may be activating with thicker oils/cold start/ambient temps.
5- no oil pan magnet

OK--now here is my pre mod pressures:
1- cold start up with 15w/40 oil i see 82psi at 1500rpm (ambiet in the low 40's)
2- at engine temp of 160-170F (oil and coolant) I see a idle pressure of 30psi (my idle is 1.1K)
3- same temps at 4K (instate cruising) I see 65psi
4- @3K i see 63
5-7.5K i see 78psi.

I Itake my pressures from a relocated oil filter plate. My lines that are on this relocation kit are 10 or 12an (i forget!) SS approx 2 ft long. I run a moble 1, #1110 filter.
Once i received the modded rear bypass and the correct shims for the front i will report my finding once more.
Oh by the way my 1st eoa sample will be sent this week.
olddragger

ayrton012

1. Cold start...Are the the S2 coolers stronger, as the S2 has not got front regulator? Maybe. I don't know, but those have different parts number.
2. Yes. I don't want to believe in it, but maybe Mazda did not does comprehensive test on the system pressure, or they changed the cooler's constructions ( for example the thermostat's type) in the last minutes before throwing the car to the market, and they didn't test the system pressure again. I don't know.
3. I don't think it.
4. I don't think it, it has not affect on max oil pressure.

It's a pre mod, and it did not does so much change in max pressure, like the full mods ( without regulators mod.).

ayrton012

Here are some new shots about the end screw of the front regulator cylinder. The wearing marks shows that the spring coils are moving up and down (as the piston) inside the screw (cylinder). I think it is a good proof of it.





The spring can't turning in the cylinder, because it is always in pretensioned mood.

ayrton012

Some more shots about the cylinder. Sorry mates, these are not a good ones.

bse50

During the cold starts my oil pressure gauge shows 6\6.5 bars as well and then goes down when the engine reaches its operating temperature.
Could it be that the front bypass opens during the start-up only?

PhillipM

Definately moving, and quite a lot looking at that.

Brettus

iTrader: (2)

Yes
I've not really followed this thread so sorry if it has already been stated what the front bypass is for . It basically bypasses oil to reduce pressure at cold start up . It is common for race prepped rotaries to remove this bypass but for a street machine removing it will result in excessive pressure at startup and increased warmup time.
So my engine builder tells me anyway ....

ASH8

I always thought Any Oil Pump By Pass is for engine start only, so oil will go where it is needed immediately (like bearings) and stops flow to oil coolers for only a very short period of time....like 15 seconds...once it stabilises valve moves down further allows oil through coolers.. well this is how it works in Banger engines and I don't believe it is any different in rotaries.

ASH8

Gee..Does Mazda Europe Stock ANY PARTS???...

But it does show you that they are not a large seller...(Valve Springs)

Edit...see if they have 0839-14-115 Plunger/Piston, this is still used in the RX-8 (S1), it will show you your Piston is not that badly marked at all....almost normal...please don't get too confused about the markings, I recall...(going back 20 years) I order a new one (same part number above) and was surprised to see all the marks already on the piston..it is not perfectly smooth or shiny.

jmc23200

I wonder if the Pure Power Oil Filter would help increase oil flow. It is a reusable stainless steel oil filter using steel mesh and two 1 inch earth magnets as its filtration medium. A typical paper oil filter is rated to allow 2-6 gallons of oil flow per minute while pure power's filter allows up to 22 gallons per minute. I'm curious to see this thing in action.

https://www.rx8club.com/rx-8-discussion-3/pure-power-lubricants-187250/

ASH8

Yes, the S2 has a FRONT Relief valve...it is in the OIL PUMP assembly, it also has a TWIN Spring, and inner and outer by the looks of it...why would they do that??

It is in the 09 service highlights...

olddragger

iTrader: (3)

i dont think increased oil pressure is going to be an issue with a flat plat cooler like the oems or those beefy banjo connections.
The oil coolers restrictor/thermostat will have a more difficult job however. But all in all i dont think a slight pressure bump like the mods we speak of is going to cause any leakage?

With this new info on the front bypass IMHO the shims and mod on the rear bypass will increase the lower rpms pressure also? Hope mine hurries up and gets here-----PAUL??lol
OD

madcows

Is the valve intended for cold starts only? Possibly. Is it affecting OP once warm? Also a possibility. But by the looks of those markings on the inside of the bolt, the spring is moving.

I'm also a bit curious about that dual spring setup in the S2 pump. I wonder if there is any recession in the piston where the small spring partially sits in.

od, I have a feeling that the bypass mods won't affect low RPM OP (except perhaps when cold), but I've been wrong before....once. lol


jmc, I would have to imagine that the oil filter you're referring to *might* allow for slightly higher flow, but any OP measurements taken at the sandwich plate would actually show a decrease in oil pressure.

ayrton012

If that would be a start-up moving only, then we should see this max pressure (around 92PSI, 6,3 Bar) with warm oil, at least 9K.

ayrton012

They usually haven't got this kind of special parts. We had the FD only for 3 years here (1991-1993), so the old rotary parts market is not so strong for them.
Maybe if I order these parts, they will have it in 2 months. from Japan, But I won't wait so long, so only the shims stay.

ASH8

Here is a link to Shim the REAR BY PASS VALVE in an RX-7...this is the same unit used in a Series 1 RX-8....Mazda # 3648-14-250.

This procedure is by using two washers, NOT Crushing the Valve as Pineapple Racing Video shows...

I thought there was another way as Mazda makes the spring and valve available as replacement parts (0221-14-115 and 0221-14-116), all you have to do is remove the roll pin to disassemble..

So you do not have to have a Hydraulic press to crush the end of valve if you want to upgrade or increase OP..

NOTE:The regulator really only opens up above 3000 RPM or so because that's when the oil pump starts producing enough volume to create higher pressures

http://www.aaroncake.net/rx-7/shimoil.htm

ASH8

ALSO SOME VERY IMPORTANT AND INTERESTING INFO ON THE FD RX-7 REAR VALVE WHICH YOU CAN BUY AND FIT INSTEAD OF MODDING...

If you want this REAR FD valve...here is the Mazda # N3A1-14-230

You can BUY from Montgomery's for ONLY $28.90 US...plus shipping
http://www.trademotion.com/partlocat...?siteid=214264

ayrton012

Good find! Anyway I think this mod won't has effect on the S1 RX-8 max oil pressure (with original 2 OC's), without the mod of the front regulator. I think so. We will know it at least then, when I will take shims under the front reg spring, because I won't mod. the rear reg. in the first step.

ASH8

I don't agree, I think you should do both, even the guy in this article say..

He also says on the rear valve, and I agree..

So, IMO the reverse would apply by only shimming the FRONT...to high OP and the REAR will be permanently By Passing..

Remember this example link has the exact same Valves and OIL Pump as the S1, except the Front Spring and Twin Oil Coolers. (except Australia and Japan have one Oil cooler)

PhillipM

1. The assembly is stiffer, so there'd be less wear on the housing from the spring.
2. Twin springs offer some internal damping, to stop the plunger bouncing if it opens or shuts with any force.

ayrton012

Yes, but I would like to reach the non modded rear bypass opening pressure (about 92 PSI) at first.

olddragger

iTrader: (3)

my "kit" is on the way. Should be here this week. Install this w/e.
results to follow. My oil pressure gauge maxs at 100psi. This kit may peg that?
olddragger

madcows

With the front and rear modded, I have a feeling you'll be able to hit over 100psi. We'll know for sure soon enough

9krpmrx8

iTrader: (46)

I'm not sure why but my max psi has gone up a little from 90 to about 93PSI. Maybe my oil is breaking in

PhillipM

Exactly where mine is :D