Nick_d_TII

iTrader: (6)

I've searched and looked all over. There are multiple 'low oil press' threads, but none that I can get any useful info from so I'm going to ask!

I have an 87 13bt that I rebuilt a couple years ago. The oil pressure seems to be getting lower and lower.... Starting to scare me a little.

I jetted the eccentric shaft with weber jets, the ones bruce turrentine suggested 2mm or something, and also replaced the thermal pellet w/ a atkins bypass pellet.
I did not rebuild or replace oil pump, or the oil pressure regulators. When I first started it up after the rebuild the pressure seemed ok like 30psi at idle... and seemed fine. But a few days later it seems lower, like 20, then 10, now it hovers around 5-10 psi at 900 rpm idle but up to 60psi at ~3200. So... This is all w/ a autometer electric oil pressure gauge and a rb or mazdatrix gauge adapter under the oil filter. I tend to change the oil every 1500 miles, but the car is garaged/parked more than I drive it... But I'm ripping it this summer for sure!

I didn't lap my side housings during the rebuild as it was my first and did not have any extra money then... My oil smells pretty heavily of gas too...

So I'm going to change the oil this weekend and see if that changes anything. Do you think it so low because the jetting? I know Aaron cake said he has low pressure w/ jets in the shaft on a NA motor...

Or is it simply becoming that diluted w/ gas that its not pressurizing correctly?

I'd much rather change out the pressure regulators than spin a bearing and break some stuff...

Any information is appreciated, Thanks!

eriksseven

iTrader: (6)

One of the most notorious causes of low-pressure is the front-cover o-ring... Perhaps it was slightly pinched on install and has been deteriorating? Don't know, but that's the first place I would look.

I don't know anything personally about the jet-mods, but I would also be suspicious.

Nick_d_TII

iTrader: (6)

From what I've read a pinched o-ring will give you low oil pressure at higher rpms like 35psi low, and I'm getting like 50-60 at 3krpm, but idle is like 0-10...

today at lunch checked my oil, man stuff smells like gas more than oil? Where can gas get into the oil? Blow by? maybe the new sideseals w/ old plates causing gas to get into the oil..?

Nick_d_TII

iTrader: (6)

So I changed the oil, and its about 10psi at 1000 rpm Idle, but 60 at 3k rpm, I'm just not going to concern myself w/ it and assume its because the jets in the shaft and the thermal pellet.

I'm going to send an oil sample in to blackstone labs and see whats in it.

Brap! Pssshhh...

eriksseven

iTrader: (6)

It depends on how bad it is I suppose. I worked on a TII with about 0-10psi of pressure at idle and about 15-20psi at cruise... Turned out there was literally no sign of the front-cover O-ring when I pulled the cover off. Replaced it and wa-la, normal TII pressure.

Nick_d_TII

iTrader: (6)

I saw another RX-7 w/ about the same oil pressure, said the motor had stage 3 oil mods from Pineapple. His was 1/2 between 0-30 on the stock gauge... which is about where mine is, but at like 3k rpm im at 60 on the autometer electric gauge.

I'd really like for it to be normal, I might just take that damn cover off and look...