Did my search due diligence - wow lots of controversy on *what* oil to use.

This is not about that.

Most engines do OK with a little more than specc'd - up to an additional quart. In fact for race motors we used to put in an extra quart on purpose (13B rotary) just to help with slosh in hard cornering - no baffles allowed in that racing class.

So if I just top off my 13' G with 6 quarts (from oil and filter change), will I get crank foaming or any other badness?

CSB - my ex had the oil light come on in her Jeep Cherokee. 4.0L inline 6, took 6 quarts of whatever. So she put more oil in. Another 6 quarts, to be exact. The problem was her oil pressure sender, but she double-filled the engine - and the crank whipped the extra oil into foam, which pressurized the crankcase to the point the engine wouldn't run (too much backpressure under the pistons). Amazingly, drained, repaired sender, filled with proper amount, ran like normal with no lasting impact. That motor had over 250k miles, was over 400k when she sold it.

 

I've always varied my fills between 5-6 qts. 6 qts actually appears to be a bit much while 5.5 is right on the money for me. 40k miles later and no issues.

5w-30, full synthetic w/ 6k intervals for what it's worth.

2nd edit...Running catch cans and they're barely anything in terms of blow-by after 3-4k miles.

 

Rotarys were designed to eat oil. Overfilling is as bad as underfilling. But .5qt wont kill you

 

My 74 Mazda RX4 certainly did. Had it seventeen years.



The fact that most Americans never checked their oil and the sharp rise in gas prices and poor MPG led to the almost demise of the rotary engine. Very light and very powerful!


Telcoman

 

Torqueless wonders. Good for racing but so mich on the street.

 

Considering that these engines can be prone to blowing out the oil galley gaskets, I don’t think that overfilling too much would do the engine any good. Maybe less than a full quart over might fly, but I wouldn’t recommend it.

 

Had an 80 CJ7 that a buddy borrowed for a trip, and he thought he was doing me a favor and did a DIY oil change and overfilled it.

Ended up stressing some seals and consumed oil thereafter at an alarming rate, like BB mentioned, something best avoided

 

I thought that's why I got the 2013 model - didn't they fix that with a metal gasket in 2011 - 2012?

 

2011 was the last year for the poor gallery gasket. But there are other seals that could be overstressed.

 

All our racing rotaries (SCCA IT-A, IT-7 or IT-S) either had the oil injection pump removed and ran premix with the fuel (like a 2-stroke) or had it replumbed to draw clean 2-stroke oil from a separate container, not the sump. We still ran an extra quart in them to prevent oil pump starvation at high cornering Gs.

 

Rotary design was nice just implementation didnt follow well. People who got rx7 rotarys who didnt know how the engine worked and had to be maintained were the biggest issues

 

Agreed. I bought a lot of parts cars of the 2nd gen (86-91) for a few hundred each because the owner had let the engine oil starve. I think I had 10-12 at the height of racing them (we had an empty field next to the shop).


I've talked to folks running in various SCCA classes that aren't rotary that do the same - the Spec Miata guys, IT-A which is mostly civics and similar sized cars, etc.

 

My miata runs an ls1 cause they are cheap to maintain

 

In Spec Miata racing?

 

Was then we used it for general track days for teaching