CCarlisi

I have a couple questions related to this:
1. What did the apex seals look like?
2. What were the symptoms?
3. How many miles were on the car?

Thanks,

-Chris C.

mad_7tist

i saw a housing at pettit that was said to have failed because the "pfc does not controll the omp very well" the housing was scored and had wear groves around the entire housing in nice straight lines. i know cam does no sell the pfc and uses the haltec so.... fwiw. i did not see any apex seals though

CCarlisi

Interesting. My friend's motor begins wearing down apex seals when his boost is raised over 13psi. His MOP has about 120,000 miles on it. I am wondering if the pump is outputting enough oil volume to raise oil line pressure above 13psi.

mad_7tist

how old are the lines? one of mine broke it was clean inside but i have wondered if they become clogged. pre mixing wouldn't hurt.

CCarlisi

I believe the lines are also original (120k). He has broken 3 motors with the same symptoms. The housings were not damaged. Motor #1 was assembled with a new reman core and had new oil nozzles. I believe these were reused in motor #2 and 3.

I'm going to take a close look at the lines and nozzles. later this week.

I would be very helpful to learn how an oil metering problem effects the apex seals. The crown on my friend's seals has been reduced to a sharp ridge. The seal tops are black in color.

mad_7tist

apex/rortor clearence? if they don seat right it will drag at a poor angle and wear. what about the springs are they binding?

CCarlisi

That's possible, but the builder is very reputable and apparently double checked all the clearances on motors #2 and 3. Also keep in mind that the parts came from a new reman core. It seems unlikely, although still possible, that the grooves on the reman rotors were so far out of spec that the motors would fail after 800miles in vac + a handful of dyno runs.

I am not sure. How can we determine this?

A little more background info:
-All motors run fine at 12psi, but once the boost is raised above 13 they lose idle vac with each dyno pull. Based on this I think we can rule out high RPM as the sole cause of the damage.
-Afrs are in the low 10s.
-Timing starts around 10 and raises to 16 at 7800 rpms at 13psi of boost.
-we pulled plugs after just about every dyno pull and they looked identical-both wet
-fuel pressure is rock solid with no roll off.
-between motor #2 and #3 the following was replaced:
--primary injs cleaned and flow tested
--secondaries replaced
--main harness replaced with new mazda harness $680 ouch!
--timing verified with a light gun

Thanks a lot for your suggestions guys, keep them coming.

mad_7tist

was it ported?

CCarlisi

Yes. The builder has assured us that the exhaust port lip is bevelled. The wear mark across the seal is approximately 6cm wide. That entire section is black. The remaining 2cm (1cm on each side) has no signs of wear.

mad_7tist

what kind of apex seals? are they worn down upon dissassembly? or just scored?

jspecracer7

I've seen first hand what a motor will look like without OMP. The Apex Seals fuse themselves to the rotors...we never got them out of the grooves...

CCarlisi

Motor #1: mazda 2 piece 2mm seals
Motor #2: mazda 3 piece 2mm seals
Motor #3: mazda 2 piece 2mm seals

mad_7tist

in the pics it looks filed sharp in spots not rounded

CCarlisi

That's correct. The 'crown' has been reduced to a sharp ridge. The damaged area is 6cm wide. The edges of the seal are fine. We have been told by a couple builders that the discoloration and wear is indicative of high seal temps.

Potential causes of high seal temp:
-faulty coolant system (not likely given his water temps were always fine)
-faulty oil cooling system (not likely for the same reason)
-lean afr (we have wide band data that says otherwise)
-clogged oil jet (one of few parts that all 3 motors have in common)
-faulty MOP (one of few parts that all 3 motors have in common and the pump has over 120k on it).

mad_7tist

ever verified flow omp at all? did the car use any oil during the break-in period?

Mr rx-7 tt

iTrader: (5)

Nope...It was probably a bad 3mm cut job.

ZoomZoom

iTrader: (2)

Anyone have pictures of housing and seals with an OMP or oil cooler failure?

RICE RACING

I have the same issue in an engine I just pulled down from another builder, traced fault to faulty/inadequate OMP flow rate.

pomanferrari

iTrader: (1)

When I was redoing my 100K motor, I replaced the OMP and also the lines. Think about it: an electric motor operating for 11 years. It's bound to be inefficient and may inadequate.

obviousboy

premix

93BlackFD

yeah, premix...


and i've seen an engine fail from OMP nozzles not being installed correctly, WeaponRX7's reman was installed without crush washers on the banjo fittings from the OMP lines to the OMP nozzles, so they torqued them down w/ out teh washers, which pushed the inside of the rotor housing surface torwards the rotor, it eventually caused the apex seals to burst in the centers

interesting eh?