What, if any, would be the advantage of a 20B over a 13B?? Or vice versa??

please include cost, maintenance, parts, service, customization, performance, etc.

thanks

pro's:

low end power

you can have 300+hp with out opening the motor



cons:

its not cheap

expect about 11-16mpg



mike

Whats up. Im new here, this is my first post in fact. I as just wondering how much a 20b motor will cost and if it bolts up to the stock RX7 tranny. Thanks.

about $3500 and it will bolt up although you need a flywheel for it since all 20B's are automatic....

Can you use the 13B flywheel??? Also can you guys help me out, I'm new to this rotary thing and I wanna build my own motor. I was wondering if there are any books or anything out there I can look at. I know regular engines and could build them all day but I never did a rotary so I need to learn. Thanks guys.

the stock mazda flywheels have a balance wieght cast into them, the automatics have a counter wieght, that bolts to a seperate balance wieght.

all the after market flywheels bolt up like the flexplate, and mazda never made a 20b flywheel



mike

wow, 300hp w/o even pushing it yet. i want one of those

yah, thats why i did it. i can have vosko speed without having to pull the motor out of the car....



mike

engine too heavy for a 510 huh? or how bout a rx3?

my turbo 2 wieghs 10lbs more than stock, and the only thing i did was ditch the ac and ps



mike

Hey whats the max you can boost on a 20B???

max boost is relative to max fuel which is relative to how much you have tuned...... https://www.nopistons.com/forums/pub...DIR#>/wink.png

Ok say you got the tuning all G. Whats the highest you cna go on pump gas before you blow it up?? I heard the cooling and lubrication are the limiting factors in the rotary engine. Well those and the apex seals. If you run a big radiator and a big oil cooler will it help??

about 18psi, it depends on the intake air temps, among other things



mike

Koo koo. So I guess I'm gonna have to be running a fat intercooler on my car then.

once the air intake temps go over 45-55c then it will be more prone to detonate.



mike

20B's are only automatic!? awwww maannn. is there anything you can do to make it stick? :rant:

Easy. Ditch the flex plate and bolt up a aftermarket flywheel. Stick a Turbo 11 box on

Oh, don't forget a good clutch https://www.nopistons.com/forums/pub...IR#>/smile.png

Funny that Mazda said 20B were all auto because there was no manual to take the torque but the Turbo 11 box is fine, even at 350 hp

about 18psi, it depends on the intake air temps, among other things



mike[/quote]

RPM is the big killer with std apex seals. Stick to 7000 and they will be OK

Add detonation at high boost & RPM tho and you are asking for tears!

detonation will kill the seal no matter the RPM...

The stock seals (they're all pretty much the same from 86-Current) will take a shitload of power, and some high RPMs.

Don't look down on the stock Mazda Apex Seals. They're very good. https://www.nopistons.com/forums/pub...IR#>/bling.gif

and oh yeah

Most of the std Mazda rotary bits are xlent

Our 362 rwhp FD race car is internally stock.

It's a 13J!

tain't a 13G, there are 4 rotors in there

Have you been drinking? https://www.nopistons.com/forums/pub...IR#>/smile.png

Not yet it's only 3:31 PM here. Did I miss something? https://www.nopistons.com/forums/pub...IR#>/dunno.gif

I'm so cool!

wtf, i just noticed it had 3 plugs per rotor.

I'm scared :(

Why? That just means peripheral port.

Do Mazda Factory PPort housings all have 3 sparkplugs per rotor?!?

Not all. R26B housings had 'far trailing' plugs as an aid to fuel consumption at Le Mans

Van says all Factory 13B PPort housings have em.



Survey Says...

sorry, van better luck next time. you do get some wonderful parting gifts....



mike

yeah umm Van NO https://www.nopistons.com/forums/pub...DIR

*looks at genuine Mazda PP housings bought in 92 still in boxes covered in dust*

I was gunna say I got ripped off, wheres me third plug?

They never got put in an engine........

'I ain't putting THEM in a MOTOR to like GET USED........do you know how much they WERE?????'

OK Ok settle down....how bout we just look at them now & then, OK? https://www.nopistons.com/forums/pub...1047683894.gif

*looks at genuine Mazda PP housings bought in 92 still in boxes covered in dust*

I was gunna say I got ripped off, wheres me third plug?

They never got put in an engine........

'I ain't putting THEM in a MOTOR to like GET USED........do you know how much they WERE?????'

OK Ok settle down....how bout we just look at them now & then, OK? https://www.nopistons.com/forums/pub...1047683894.gif[/quote]

haha, i have stuff like that too. its like the housings are so much its a shame to use them



mike

Then wtf did those pictures come from. I can't remember lol

3-plug PP Quad has to be a Endurance racer of some sort dunnit?. Altho Racing Beat had some 3 plug housings too