I had previusly modified my oil pressure regulators in my 85 12a motor.. i crushed one and shimmed the other... i got a new (different) motor. 87 TII 4 port.... i put the 12a regulators in it... is this acceptable? whats my best option... its going to be running a 35r on a raceport and about 20-25 psi...

 

Usually shoot for 100-120psi on our street motors and 140-160 on the race cars.

What was the pressure before with that regualtor? It'll prob be a tad but lower now due to the diff in oil cooling system.

 

Get the FD regulator which gives about 110 psi, and also place a couple thin washer spacers in the front/safety regulator.

Then rework the oil pump scavenge area in the front side housing for better oil flow.

 

what are the first gen regulators rated at? and with one crushed and one with two washers shimmed in it? I have the first gen everything on it... i just plugged most of the other oil passages in the block... is that ok?

 

everything except the FD and 2009 Rx8 has the same 71psi regulator in it. the FD is 110psi. i do not recall what the 09+ Rx8 runs, but its in the manual...

the FD part list price is like $28 too, so its cheap!

 

I crushed the fc regulator and shimmed the front cover I get 80-90 psi above 3k.

 

I have a turbo 2 motor with a raceport.. gt35r and will be running 20-25 psi... will i need more oil pressure than 80 - 90? it is an Fc engine...

 

one of the key updates that Mazda did going from the FC engine to the FD was to bump the oil pressure to the same level as the racing engines. so you should too.

 

Wont the 80-90 psi be better than the stock FC? I know that 110 would be ideal but will 80-90 be ok. I will be only running about 15 psi this year and about 350 rwhp since i need more fuel...

 

We strive for 100psi+ for any engine making over 300rwhp.

 

Mazda ran 110psi on everything over 250hp...

 

Crap

 

Hmm, maybe I should do high oil pressure?

 

what were you doing jeff?

 

Doing a quickie rebuild of my REPU's engine to make it appropriate for boost. I've got an adjustable old school oil pressure reg so I can add washers to up the pressure.

 

you are doing both front an rear right? i smashed one and shimmed the other like previously told... this is the first ive heard of have to have over 100 psi...

 

Honestly I highly doubt 100+ psi is a necessity on a street car. There have been MANY builds exceeding 300whp w/o oil pressure that high. On a race car, it might be a different story.

 

I won't be going that high. I'm thinking 90psi, maybe 95. I've got an old school oil cooler and hoses here.

I'd rather pay attention to things like the oil cavity where the oil pump sits, and the other sharp edges along the oil's path. A little smoothing here goes a long way when it gets there.

And I won't add any washers to the front reg. Why? It already is set to like 140psi. I just look for the tallest spring in the collection and throw it in. I try to not be pretentious about this stuff.

 

Imm using the fd rear reg, shimmed the front, and still idle oil pressure is at 40psi, revving the car it stays put. What am I missing here? I gotta have this sorted since I will be driving to Dallas next week for tuning.

 

Something is definitely wrong, even the stock regulator should increase pressure when you rev it. Is the oil pressure sender hooked up correctly ? what about the oil level? I hope its not the case, but that front cover o-ring has been known to cause oil pressure problems...

 

I thought about the front cover o-ring, but i was meticulous when assembling it since i knew i would be pushing this motor. I got a cheap oil pressure gauge im gonna hook up to see if its not the dash gauge itself. Gonna try a different sending unit as well. Any other tips are appreciated and can benefit the thread!!

 

Even meticulous execution can lead to negative results if one is following an incorrect procedure.

What series is the front iron/front cover? did you use a teflon ring with the o-ring? gasket or rtv to seal the front cover?

 

Front cover is 85 13B, s6 irons. Using teflon ring and gasket. Used same setup and had flawless pressure, 65avg at idle and 110 at 12 psi WOT (street tune).