Roller Rotary

[sickofpistons]

Could anyone please explain any pros or cons to this idea ? ? ? ?

9526

[vex]

Why bother using them in the first place?

[low compression]

Im not an expert on bearing technology, but im not sure a bearing of that kind can handle the load against it as well. If it was a good idea im sure the small block chevy would of had a crank bearing like this a long time ago. Only reason i meantion a s.b.c crank is because we all know that engine gets all the minds in the world wanting to better it.

[vex]

Im not an expert on bearing technology, but im not sure a bearing of that kind can handle the load against it as well. If it was a good idea im sure the small block chevy would of had a crank bearing like this a long time ago. Only reason i meantion a s.b.c crank is because we all know that engine gets all the minds in the world wanting to better it.

I don't think that's correct. Racing teams look to do this for removing friction, however using such bearings causes another issue: Survivability. This is an interesting read: Link (http://www.eng-tips.com/viewthread.cfm?qid=115281&page=10)

If it goes, what's to stop it from having the needle bearings clogging the oil passages? Where as compared to a regular journal bearing, if it fails, what's going to clog the oil passages?

[TitaniumTT]

Where is that from? Website, links, more infor..... is that from a 16X? Seems pretty wide to me.

[RETed]

Less friction = more efficient engine
More efficient engine = more power using less fuel

Or course, the downside is that needle bearings are less reliable versus journal bearings.
I'd imagine service interval is a lot shorter for these needle bearings versus journal bearings.
If you're building a "race engine", this is not going to matter.


-Ted

[NoDOHC]

The big advantage to roller bearings is that they do not suffer accelerated wear for short periods of non-lubrication (if they get hot, it is a different story). This is good for starting (no oil pressure). The biggest problem with them is as stated above, there are more wear parts than just the oil film. Thus changing the oil does not completely replace the wear items in the bearing. The journal bearing is truly awesome for longevity under high loads and high speeds.

The picture that is shown is from a small air-cooled rotary that has no pressurized lubrication system (mixed oil in the gas). This is why the roller (or needle) bearing is required.

[C. Ludwig]

If it was a good idea im sure the small block chevy would of had a crank bearing like this a long time ago.


They are. Needle bearings for cams and crank shafts are common place in high end circle track engines.

[sickofpistons]

I only googled roller ratary in images and came across it. It was a link to ausrotary.com.

[sickofpistons]

Im not an expert on bearing technology, but im not sure a bearing of that kind can handle the load against it as well. If it was a good idea im sure the small block chevy would of had a crank bearing like this a long time ago. Only reason i meantion a s.b.c crank is because we all know that engine gets all the minds in the world wanting to better it.

The reason they didnt have one for the S.B.C or any other piston motor was because they couldnt hold oil pressure because they were a two piece design. They have them now in high end sports cars like the {bugati} i geuss is how its said? I think this needle bearing design would increase response and horsepower do to less friction. Its like hydraulic cam vs roller cam. If there was a way to machine these bearings for the 13b, would you have to mill down the e-shaft or bore the rotors and stationary gears?

[sickofpistons]

Less friction = more efficient engine
More efficient engine = more power using less fuel

Or course, the downside is that needle bearings are less reliable versus journal bearings.
I'd imagine service interval is a lot shorter for these needle bearings versus journal bearings.
If you're building a "race engine", this is not going to matter.


-Ted

What would make the needle bearing less reliable vs journal?
Thanks.

[C. Ludwig]

Needle cam bearing in a V8.


http://image.hotrod.com/f/9512434+w750+st0/p140491_image_large.jpg

[j_tso]

That look very much like a rotor from Woelfe Engineering's Aixro rotary kart engine.
http://www.woelfle-engineering.com/

It's a 294cc single rotor engine that gets about 40hp. The housing is water cooled and the rotor and bearing are cooled by the air/fuel/oil mixture, like NoDOHC said.
Here's an illustration from K. Yamamoto's Rotary Engine book:
http://homepage.mac.com/jolocho/intakeCooled.gif

[TitaniumTT]

40 hp???? I think thaty would work well on my riding mower :reddevil:

[RETed]

What would make the needle bearing less reliable vs journal?

It's inherent to the design...
Less parts = better reliability
This is why journal bearings are used in the most inaccessible locations.

Anyone who has lost a pilot bearing on their RX-7's knows what I mean...


-Ted

[Judge Ito]

on my own personal 13B I tried roller bearings on the front and rear stationary gears over 6 years ago. there is pros and cons..

[TitaniumTT]

Still running? Die a painful catostraphic death? Pics? Care to share more of the first hand experience?

[FC Zach]

I'm curious as well.

[vex]

Judge Ito is such a tease :p. Count me in on wanting to see the aftermath of the roller bearings/engine.

[2gslse]

Pics or it didn't happen!!!

[sickofpistons]

I found this information if any dedicated rotary fan is interested.....check it out!

http://www.precisionenginetech.com/tech-explained/2009/05/22/camshaft-needle-bearings/

http://www.southshorebearing.com/bearings.htm

http://www.daltonbearing.com/iko/iko-needle-bearings.aspx

http://www.directindustry.com/industrial-manufacturer/needle-bearing-60788.html

Has anyone ever had a radial trust bearing fail in your engine? There are to many bearing designs, so there has to be a better alternative that will reduce friction and increase HP! Im only tryin to contribute to the forums knowledge and FLOW of IDEAS.

[My5ABaby]

If they're better, why wouldn't Mazda use them?

[vex]

If they're better, why wouldn't Mazda use them?
Price.

[sickofpistons]

If they're better, why wouldn't Mazda use them?

Faster production....? Lower costs, and more money in there pockets... i geuss. Lol wouldnt you think so? :dunno:

[TitaniumTT]

Longer service life and quieter too

[sickofpistons]

Well i found a donor car NA 88 I think it has a blown coolant seal. But anyway im going to try and cheap bastard rebuild, lmao with different bearings and see what happens. Im fasinated with rotaries and would love to contribute to any design or improvement. If anyone needs any designs of parts im proficient with AUTOCADD, so hit me up!

\,,/_ _\,,/ GIGADY

[NoDOHC]

Hey, you can't argue with that - does the ideation and the testing.

Good luck with the build!

(Ideally you could dyno it with journal bearings and roller bearings).

[sickofpistons]

Thanks for that, what would a 13b na basic bone-stock have with HP just to compare after this Ideation and testing?

[vex]

Depends on a lot of factors. Port size, geometry, compression, measuring location, flywheel weights, etc, etc, etc.

[NoDOHC]

My S4 NA stock ECU with 7 degree advanced timing and 4 clicks lean on the AFM made 138 WHp per my G-Tech (which I have found to be pretty accurate).

I think (although I didn't copy the run to excel - so it's just from memory) that the S4 NA with a manual transmission did about 118 WHp with stock timing and stock AFR.

My S5 Automatic with stock timing and stock AFR (can't adjust S5) runs 102 WHp per the G-Tech. Made 120 WHp with 7 degree advanced timing.