Rotary Car Club - Dispelling Myths: Using RX-8 internals in a 13B-REW

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No, the Apex seals are different requiring milling of the rotor itself. And I believe there are some descrepancies with the rotor side landing clearances that need to be addressed

Missed the question the first time, sorry

Hmmmm...

What do you mean by side landing clearances? Did they move the side seal location to a point where it would cause a problem with the stock REW port?

Quote:

Originally Posted by Racing Beat

Rotor Clearancing

A second concern for rotors used near or above 8,500 RPM is the clearance between the sides of the rotor and the side housings. The construction and assembly of the rotor and rotor gear is such that both sides of the rotor have a portion, referred to as the “land”, that protrudes out from the rotor “side” several thousandths of an inch. For measuring purposes, detailed below, the “land” on the side of the rotor containing the rotor gear is the face of the rotor gear itself. The “land” on the opposite side of the rotor is the circular portion of the rotor surrounded by the inner oil seal. These features need to be taken into consideration when clearancing the rotor.

The first step in preparing a rotor for clearancing is to measure the thickness of the rotor housing being paired with the rotor at eight evenly spaced points to determine the minimum or narrowest point of thickness of the rotor housing. This minimum thickness becomes the “base line” for the calculation process.

Now, measure the thickness of the rotor and rotor gear assembly at three different points from the “land” on one side to the “land” on the other side. Select the maximum, or widest, thickness of this assembly and subtract this number from the base line number previously obtained. We have found that the following clearances work well:

Clearance between side housings and rotor maximum “land” width:
12A Engines (.009” +/- .001”)
or 13B Engines (.010” +/- .001”)

“Land” protrusion from rotor side: .0055” +/- .0005” (each side). This “land” clearance is obtained by machining away material from the “side” of the rotor, thus leaving the “land” extending from the rotor “side” by the specified amount.

It is entirely possible, based on the production tolerances we have seen over the years that you may need to remove as little as .001” to. 002” from each surface to achieve the recommended clearance. In other words, some of the clearance required already exists.

There is also the portion between the oils seals and the side seals that need to be addressed as well as the portion of the rotor from the side seals out.

This is all very OLD knowledge to me as I decided years ago that I was going to turbo charge my 13B-RE as opposed to build a high-revving n/a engine using the renni rotors.

What are the differences between the REW clearances and rotors sizes compared to the MSP? If there is a small amount of additional clearance, it seems it might actually be better suited for high rpm power levels?

Check the FSM's, I'm sure someone has the RX8's FSM up by now

Quote:

Originally Posted by TitaniumTT (Post 103054)

Check the FSM's, I'm sure someone has the RX8's FSM up by now

Word.

http://foxed.ca/foxed/index.php?page=rx7manual#rx8

Forgive me for my insolence, but the point of this thread is to have the info easily accessible and readable. But thanks for the link that gave me specs and such, but I have still yet to receive a complete answer. No offense meant by this, just brutal honesty, and I don't trust my engine building knowledge very much to extrapolate compatibility from specifications alone.

To extrapolate the answerd that you require is pretty simple math that is explained in the FSM. I don't know the answer for certain, so I am not going to say with any certainty in either direction. What I can do is what Nismo and I have done, give you the tools to figure it out for yourself. If you're uncomfortable with your own math/engine knowledge to make a decision, I would suggest contacting an experienced engine builder. One that has done it in the past and hope that he will devulge his secrets

what do you mean sir Brian?

http://extrapassiveincome.net/wp-con.../05/banned.jpg

but back on topic, im real curious about using the rx8 rotors.

Mad Mike, the drifter of the rx8 and 4 rotor fd. Hes running rx8 rotors in a 20b but i can't find who built his motors or his specs just that there 8 rotors. Anyone have any info on those maybe his build will help me, us, no one haha

Ah.......... yeah........... someone posted some spam, the pst was "so small" then a bunch of crappy links... so I posted "so banned"..... then I banned him

stand by for phonecall sometime tomorrow...... I hope.... was on the phone when ya called.... now I must.... so I can work tomorrow.....

Standing by.

I am enjoying the aviation brigade's final 4 day weekend... after this, it is only 3 day weekends... thanks to Fort Mother Rucker

Quote:

Originally Posted by IH8DSM (Post 149995)

but back on topic, im real curious about using the rx8 rotors.

Mad Mike, the drifter of the rx8 and 4 rotor fd. Hes running rx8 rotors in a 20b but i can't find who built his motors or his specs just that there 8 rotors. Anyone have any info on those maybe his build will help me, us, no one haha

not so much specs, but just pics, and who built it...

http://www.pulseperformancere.com/in...p?page=gallery

your welcome :D

J.