Rub20B

If you connect the line coming from the oilfilter to feed the front bearing at the top of the engine where the turbo oil feed starts instead of drilling a hole @ the 90° bend, wouldn't that be easier, from thereof there's only 1 90° turn to the bearing..

frode

[quote name='banzaitoyota' date='Jun 7 2005, 05:46 AM']No, you still need flow to the front relief. The O-ring problem is currently being engineered out of existance. Stay tuned


[/quote]



I ran my 13BT on the brake dyno without the front relief. No problem there. Oil passage to the front cover plugged, no o-ring and oil discharge to the oil cooler tapped at the same place you have done.



regards,

frode

crispeed

Just a little tip from my experience when doing this mode. Don't use pipe thread. The front housing in this area is very weak and prone to cracking. Pipe thread expands from the base to the top. Your best bet would be to either use AN or Metric thread and use a sealing washer of some kind. What I do is metric thread with a countersink so I can use an o-ring along with a sealing washer.

I've being doing this mode for some time now mainly on extreme street/race high hp+rpm turbo motors and have not experienced any negative effects in doing so. Also this mode is a little tricky when you're still running A/C because the A/C bracket is in the way of the oil feed for the front main/stationary gear bearing. You'll have to modify the bracket a little for clearance. On street cars I feed this galley from the RB oil temp/pressure adapter they sell for use that's place under the the oil filter. For race I'll have a remote oil filter where the outlet is Y'd between the fornt and rear mains. Tee's and sharp 90 deg fittings should be avoided when plumbing oil systems to prevent cavitation and pressure drop.

It's strange that I missed this thread before or else I would have commented earlier!

diabolical1

i'm interested in trying this with the engine i'm currently building, but i have a couple of questions.



1. is it safe to assume that there will be a change in pressure when you do this mod?

2. if so, how drastic and would it be bad for an engine that spends most of it's time on the street?

diabolical1

okay, does anyone have any photos of a 12A (or old 13B) ported oil pump passage. i just want to make a comparison to mine. in order for me to get the kind of curvature that the ones posted above have, i think i would have to remove too much material and i'm not comfortable doing so. any help is appreciated.



thanks.

1Revvin7

That was my understand of the oil pressure relief valve. I've done this to 3 engines so far, with eliminating the front cover O-ring/relief valve. However they aren't running yet. Atleast one should be shortly.

Chris1966

I've just cross drilled the main journals of the eccentric shaft for my 12a/Turbo ll hybrid engine. The 12a eccentric shaft was extremely hard but I managed to get through the surface with a diamond burr. I also opened the rear oil passage in the main journal so it is the same diameter as the front journal oil passage. I doubt this will weaken the shaft appreciably and I want to try and balance the oil flow to both bearings.



The reason for this is that I'm going to do the loop line mod....but with a difference. I've removed the plug from the front iron and have tapped it as Lynn has said. I've also removed the plug and tapped the oil pump discharge gallery in the front iron. I want to go from this outlet directly to the oil cooler and then back to a custom dual filter mount. This mount will be single inlet and double outlet. One outlet will feed directly to the front iron main bearing via #10 line. For the rear iron I plan on fitting a cover over the filter mount and having both the up line from the banjo and the rear main bearing line connected. Both will be supplied by the other #10 line from the filter mount. Connecting the up line from the banjo and the rear main bearing line in the cover should allow the rear oil pressure regulator to do its job. This mod should provide the least possible turns in the oil path. I wont be using the oil path through the dowels.



Other engine mods include opening up the main bearing galleries and passages through the stationaries. The stationaries will also be machined for multi-window bearings front and rear. The 12a rotors will be machined for extra side clearance. The irons are secondary bridgeported and the primaries are extend ported. Maximum RPM is 9000 but I doubt I'll see the high side of 8000. Do I really need 100PSI oil pressure? I wont be running the front regulator as the front cover will be blocked and only a 0.040" hole supplying the oil metering pump drive shaft. I don't need to supply the oil metering pump as I use synthetic oil and two stroke via an OMP adapter.



The engine is a bit of a strange setup but I can't legally run a 13B Turbo in my RX-7. I am stuck with the 12a capacity. The law doesn't say anything about which irons I have to use. Only thing I'm unhappy about is machining the brand new rotor housings down to 70mm wide.



Any comments on what I propose to do would be appreciated. I can't see how it could be worse than the stock oiling system!



Chris.

ArmyOfOne

If you are doing all that then just remove the OMP drive gear and anchor the shaft in there. Now you have one less thing to turn, hence one less thing that can fail.

Chris1966

I can't do that as I need to drive the OMP still. I'm just using a rotoary aviation adapter to supply the OMP with 2 cycle oil.



Chris

Mark T.

I'm building an old 13B RX4 race car running premix. Can I plug the OMP oil gallery and remove the shaft completely?