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-   -   renisis vs. 13b (https://www.nopistons.com/rx-8-discussion-19/renisis-vs-13b-56304/)

puppyslaughter 01-08-2006 05:33 PM

ok what is the diffrence between the new renisis engine and the old 13b? are the ports diffrent or something also why is the one with a standard tranny more powerful (don' get me wrong its awsome like a gift for actually knowing how to drive) but what did they do to make it change

thanks

jeff

fc3sboy1 01-08-2006 07:10 PM

the manual trans car is a 13bmsp high power motor, ie it has 6 intake ports the auto trans is a 13bmsp standard power with only 4 intake ports.



now the old 13b used perifrial exhaust ports where the 13bmsp uses side exahust ports similar to the intakes.



also note the compression of the 13bmsp is 10.0/1 where is the old s5 na motor was only9.7/1 and besides above mentioned it has alot of refinements to go along with it like better oiling and bearings aswell as harder stationary gears , even more so then the fd gears.



im sure there is other changes as well but im too tired to mention them now.

neit_jnf 01-09-2006 09:00 AM

some more changes vs older 13B's are:



different intake and exhaust port timings due to the side exhaust ports allowing for a longer power stroke before the exhaust opens, no overlap (actually there's 5 degrees of dwell where both ports are closed), lighter rotors and flywheel, "scalloped" cut rotors, finer injector spray, electric air pump and are mentiones above, harder gears, race bearings, and a lot of other changes and refinements.



the differences between the standard power and the high power renesis are basically 4-ports vs 6-ports so the standard power has slightly higher torque but runs out of breath and can't rev as high as the high power one. In Japan and other markets they offer the standard power engine with the auto as well as a 5 speed manual. The high power is only available with the 6 speed manual.

rowtareh 01-09-2006 02:05 PM

Also has 2 OMP's. Renesis won engine of the year in 03.

neit_jnf 01-10-2006 09:45 AM


Originally Posted by rowtareh' post='793029' date='Jan 9 2006, 12:05 PM

Also has 2 OMP's. Renesis won engine of the year in 03.



technically is only one OMP, but with two pistons for low and high flow rates



it won 3 of Ward's awards: Best New Engine, Best Engine 2.5 - 3.0 L (they rated it as 2.6) and Engine of the Year

puppyslaughter 01-10-2006 06:56 PM

ok well im sure that there arnt many that have hit the infamous 100k mile mark but did they make the apex seals any stronger for increased relability or are they preaty much the same

rowtareh 01-10-2006 09:44 PM


Originally Posted by neit_jnf' post='793192' date='Jan 10 2006, 10:45 AM

technically is only one OMP, but with two pistons for low and high flow rates







Seriously? Did not know. Thanks

neit_jnf 01-11-2006 03:34 PM


Originally Posted by puppyslaughter' post='793309' date='Jan 10 2006, 04:56 PM

ok well im sure that there arnt many that have hit the infamous 100k mile mark but did they make the apex seals any stronger for increased relability or are they preaty much the same





Yes the apex seals are redesigned to be lighter and stronger, they're 2-pc and since they don't have to cross the peripheral port anymore they are sure to outlast any before... unless you turbo the renesis, overboost and detonate hard which proves to be catastrophic because the seals can't go out of the engine (no p-port) so they keep bouncing around wrecking everything in their path. There's a thread somewhere about this with pictures

rowtareh 01-13-2006 11:31 AM


Originally Posted by neit_jnf' post='793515' date='Jan 11 2006, 04:34 PM

Yes the apex seals are redesigned to be lighter and stronger, they're 2-pc and since they don't have to cross the peripheral port anymore they are sure to outlast any before... unless you turbo the renesis, overboost and detonate hard which proves to be catastrophic because the seals can't go out of the engine (no p-port) so they keep bouncing around wrecking everything in their path. There's a thread somewhere about this with pictures





Yeah, it was Fe3Boost's engine that did this.

ArmyOfOne 01-27-2006 05:45 AM

I could have sworn that the RX-8 apex seals I held in my hand were 1 piece and about 5mm tall.



And yes this was from a disassembled running engine.


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