peejay

So, for the first time since ever, I have a mechanical oil pressure gauge.

According to it, I have about 15psi oil pressure at 1000rpm, 45psi oil pressure at 3000rpm. This is with 20W50 oil below 100degF.

Haven't driven the car yet, and don't want to rev the engine higher in the building (tends to melt the exhaust hose). Haven't warmed the engine up to operating temp yet either, for the same reason.

Huh.

Should I be worried?

The main bearings were half-worn through the overlay, but I didn't worry about that since a lot of people remove the overlay as a race mod. Now I wonder if I should have worried.

Stock S4 oil pump (I think N/A, don't remember) and I crushed the oil regulator until it blew off at 90psi air pressure. I know that won't make a difference at idle, but as a FYI.

Jeff20B

iTrader: (13)

That sounds a little low to me. I have an engine that's doing that. It has an adjustable rear oil pressure regulator that I added washers to until it bypasses at 90psi. The bearings were showing copper but they were all I had at the time of assembly. Oh and a 1st gen 17.5mm oil pump (the so called high volume one from any '83-'85 12A or later nitrided 13B and GSL-SE).

The engine is eventually going in for a quickie rebuild to swap in some good used stat gears with little to no copper showing and some other mods.

As for your setup, it's a bridge or half bridge, right? That means high reving a lot of the time, I would assume, so that is where you showuld see oil pressures at 90psi. The FC oil pumps are bigger than 1st gen so your volume will be more, even if your pressure isn't. It's probably not enough to worry about until you've tested it at high RPM. If pressures never rise past 45psi, I'd start to worry.

So in the future, and this goes for me as well, if you see copper in a stat gear bearing of an engine you're building, change the bearing or throw in another stat gear.

By the way, I'm running a Camden on this low oil pressure engine and it's doing ok. Gotta use 20w50. 10w40 gives me 10psi at idle.

peejay

It was a street port. I did see super high RPM on a couple occasions but I thought high RPM bearing issues showed up as a ring around the outside of the bearing. The bearing wear I saw was literally on one half of the bearing - the half on the ports side of the engine. The bearings looked like Two-Face. I made a mental note to stop driving at heavy throttle below 2000rpm and threw it back together.

I do know that I had some issues with oil dilution. I changed the oil (Valvoline VR-1 20W50) before every rallycross but only changed the filter two or three times. There may have been dirt in the oil from the breather system, which was "open" but the hose was pointed down into a pool of oil. It's possible that dirt got ingested that way.

I did trace my odd rotor housing wear to the intake manifold vacuum leak I had, so it could be possible. This year I will pay a little better attention. For now, I wonder if I should swap out the rear stationary gear with another FC unit next time I have the trans out. Or just run straight 40w sludge.

I'm HOPING that the bridge will give me more mid range power so I don't NEED to wind the snot out of it.

Shainiac

iTrader: (7)

Did you modify the oil jets in the e-shaft? I know that kills low rpm oil pressure just because of the sheer volume they flow. On my 6port motor with a shimmed regulator, stock eshaft jets, the 13B NA oil pump, and read from a Autometer mech pressure gauge, I get around 30 at 900 rpm. I do know that I get a lot of blow by (no clue why) and the oil gets diluted with gas relatively quick. The longer it goes without changing, the lower my idle pressure is. Did you have a hard time getting the rebuild running/is it running very rich? Maybe you have a decent amount of fuel in the oil?

speedturn

iTrader: (1)

That pressure is too low for cold oil at 3000 rpm.

peejay

The engine has about 20 minutes of run time on it right now, and I changed the oil after fifteen. If the oil is diluted then I have larger things to worry about than the bearings. (And, after I remembered to plug in the computer, it kicked over and ran on the first crank. Never had a reassembled engine do that before)

The oil jets are as factory.

I do have an Atkins thermo-pellet eliminator plug, is it possible that the 3" Racing Beat front pulley is a different dimension from stock and the bolt is no longer holding the eliminator plug in place?

edit: Found a high res pic that had one of the bearings in it, cropped out a section. I wasn't terribly worried about the lack of overlay because, before I assembled the engine the first time, I used a solvent-loaded piece of emery paper to sand out some of the overlay for more bearing clearance. I figured that the lack of overlay was the just engine finishing the job because the remaining overlay was too thin to stay on the copper.

Shainiac

iTrader: (7)

Are you still using 18ga wire for coolant seals or are those just non-oem seals?

peejay

You can't see the copper sticking out?

The old ones were crispy, but they still held combustion pressure once the engine ran for more than a couple seconds. A cold start would be a little steamy.

I used green this time, to promote environmental friendliness.

Shainiac

iTrader: (7)

Kind of figured you had jumped on the green bandwagon. Obviously you are using them again, but would you recommend them for a engine that doesnt get opened up often?

peejay

Absolutely not. At least use the Mazda inners.

Quite honestly, the outer doesn't need an O-ring at all, silicone should suffice.

peejay

Well, crap. When oil temp gets up to 160f it doesn't get much higher than 30psi.

I repeat my earlier question: Does anyone know if the single-groove Racing Beat pulley is a different length than a standard pulley? If it is longer, then my thermo pellet bypass plug isn't seating and that could be most of my problem.

peejay

Apparently I don't know how the thermal bypass thing is supposed to work. Googling around got me this page.

When I installed the Atkins eliminator plug, I didn't put any springs in there. (It didn't come with any directions, it was just the part in a Ziploc)

I wonder if this is a good chunk of my oil pressure problem, but I don't quite see how it would make a difference, as the spring would seem to be forcing the plug in the wrong direction.

And, yes, the aluminum pulleys are apparently a different depth than OEM.

PvillKnight7

iTrader: (16)

So the aluminum plug is free to move around inside the end of the e-shaft? That's not right. You need the spring.

peejay

I thought the bolt held it in place. Further, looking at how it is laid out, I'd think that you'd want the spring between the plug and the bolt instead of between the shaft and the plug.

Unfortunately, I don't have any thermal pellet parts lying around that I am aware of. I'm fairly sure that I pitched all that a while back.

Fun fun fun.

Shainiac

iTrader: (7)

I've always reinstalled the spring with Atkin's alum pellet. I have a couple laying around at home, but Im not at a couple hours from home at school. If you dont get a hold of one by next weekend, I can send you one once I'm home for spring break.

peejay

Believe it or not, I found the spring in the first box I looked in.

I'll try that first, if that doesn't work, I have some good main bearings from a GSL-SE block that I will throw in. I assume that all pre-FD stationary bearings are the same.

peejay

....yeah, that made no difference.

The funny thing is, when I pulled the bolt out, the plug was stuck to the bolt. So, apparently the spring is mainly there for belt-and-suspenders action.

The funnier thing is, when I was road testing it, I took an off-ramp to turn around and head back to the shop, when something broke clutch-wise. I think the pivot ball punched through the clutch fork.

The car isn't tuned well enough to start the engine in gear.

I did find, however, that 1st gear synchro is strong enough that 3000rpm and two hands on the shifter will make the car roll fast enough that I could drop it down to idle and stuff it in gear. Yes, my transmission hates me now But then the 3-4 shift fork is bent, I think the splines on that hub are folded a little, and 5th hasn't had a synchro since 2006...

edit: OH WAIT PETE YOUR LYING A HALF BRIDGE IDELS AT 4000RPM AND DOESNT MAKE POWER UNTIL 12000RPM

PvillKnight7

iTrader: (16)

Haha I'm sorry to hear your having compounded problems. I would check the front cover o-ring. Maybe the o-ring is out of place. While the cover is off I'd inspect the oil pump.

rotarygod

iTrader: (1)

You've got such a small bridge I don't see why you'd have idle issues at all which I guess you don't. Years ago Paul Yaw had a repu that had a small bridge. It was a TII block with S5 na rotors and a carb. He had a mild street port with a bridge on the secondaries only. That bridge was only from the middle to top of the main port. That truck could out accelerate a stock 3rd gen to 60 which was probably a sight. He said that engine had all kinds of low end towing power. Not very relevant to your problem but still cool to know.

peejay

I know for a fact that the front cover O-ring is in place. I have a foolproof way of assembling the engine that prevents any issues with the O-ring or the thrust washer stack. (Stick it on the flywheel!)

The idle problems are strictly due to the fact that I have an engine tune that assumes a 17"Hg idle, and the engine now idles at 8"Hg, so the PCM is assuming that much more air is flowing through the engine than is actual. It's actually funny. When cold, a mist of raw fuel/oil mix comes out of the exhaust, and when it's warmed up, at low RPM/load it still runs so rich that it blubbers instead of running like a bridge port should.

My laptop's backlight is dead, and the laptop that I can borrow couldn't find the wifi so I could download Megatune. I downloaded it with his desktop to burn it to CD, but he hadn't installed any burning software yet. And I didn't have any of my USB drives with me. Fun fun fun

Under cruise, with the wrong tune, it drives better than my streetport did with the 6-port intake manifold. Ya rly.

rotarygod

iTrader: (1)

What intake and exhaust are you running? Just curious.

peejay

I am not sure.

The intake is a T2 manifold that I'd removed all of the little bumps and ***** from the lower, which required a dose of JB Weld since I ported into air when I did that. Upper is untouched.

I don't know if it's Series 4 or Series 5. I have two uppers, and the other upper required some hefty filing of the outer bolt holes to make it fit the lower.

Exhaust-wise, it's what everyone tells me is a Mind-Train header, slotted and ported to fit a 13B, blowing into this thing:



that I may be taking back out again. After that is a 2 1/2" Thrush glasspack, some 2 1/2" pipe, and a 2 1/2" Ultraflo with a 1 7/8" restrictor in the end for noise abatement.

peejay

Well...

The front cover O-ring was gone. Missing. No idea where it went.

The front bearing measures out at 1.700. The one I'm putting in measures at 1.693.

diabolical1

iTrader: (3)

glad you found the source of your issue, it was really kind of weird seeing you ask for help.

t_g_farrell

iTrader: (1)

See this is why the internets are so dangerous

Lol! It was stange to see you of all people post a thread like this. Of course
it shows we are all humans.

Glad to see you got it figured out.