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13b BP/JP or PP ?? Hp? life span? Help me decide!

Any type of technical questions or info

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MR.ROTA
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13b BP/JP or PP ?? Hp? life span? Help me decide!

#1 Post by MR.ROTA » Tue May 15, 2012 7:30 pm

Hey guys just after some info on ports, power, driverbilty and life spans on a big BP or a J port 13b.
I'm going to be fitting this into my Capella
Will be feed by 48ida webber.

Driverbilty I already know wont be the best down low.
Power? Unsure Please tell.
Lifespans unsure also (what is best seals to use).

[[/b]
Last edited by MR.ROTA on Wed May 16, 2012 8:04 pm, edited 3 times in total.



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Re: 13b Bridgeport or J-port ?? Hp? drive ability? life span?

#2 Post by (R100) » Tue May 15, 2012 10:35 pm

what is best seals to use >>>ceramics 1 pce

j port ya can make very good power but will not last long if ya go threw the water seal same as bridgeport.

bridge port 220rwhp

j port 250rwhp

pp is the way to go for max power 300rwhp 12,000 rpm on 13b motor

but i guess who builds the motor is where it comes down to and what they do to it for power wise every man is different and ya would have to make ya ida fuel bowl bigger to to keep the fuel up on ya 48ida

And who tunes it i mean to get the max out of j port motor ya would port manifold out to its limits and exhaust ports and plates.



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Re: 13b Bridgeport or J-port ?? Hp? drive ability? life span?

#3 Post by (R100) » Tue May 15, 2012 10:46 pm

Read this everything ya want to know about porting

Just remeber some peoples cars are running injected so your power figures will be less and some people say there got 250rwhp yeah at the flywheel not at the back wheels.

So don't get that mixed up :wink:




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Re: 13b Bridgeport or J-port ?? Hp? drive ability? life span?

#4 Post by MR.ROTA » Tue May 15, 2012 10:47 pm

Do the water seals have to be touched for bp or jp? Or depends on who's building it
I'm hopefully getting Rohan to do my porting, got some friends of my brother that can help me out with him.
When you say j port dosent last long
How long is not long and Is that the same for bp

Also what do the ceramic seals fetch



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Re: 13b Bridgeport or J-port ?? Hp? drive ability? life span?

#5 Post by (R100) » Tue May 15, 2012 10:53 pm

ceramic seals $1500 proberly more nrs is the way to go.

bridge port the water seal goes so close it not funny.

j port threw water seal

they use some shit putty for the water seal devcon or some crap.

and j port motor could last 10 minutes or could go for 1000 of kms just depends.

If rohan is building ya motor ask him to me a j port motor is a heap of shit.

If i wanted a motor that revs and makes good power go pp and mazda factory rotor houseing least ya dont have to worry about water seal problems and ya make heaps moroe power then bridge port or j port


J port picture http://www.google.com.au/imgres?q=mazda ... s:79,i:289" onclick="window.open(this.href);return false;

Bridge port picture http://www.google.com.au/imgres?q=mazda ... ,s:99,i:24" onclick="window.open(this.href);return false;



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Re: 13b Bridgeport or J-port ?? Hp? drive ability? life span?

#6 Post by MR.ROTA » Tue May 15, 2012 11:16 pm

Hmm don't think I'll risk a j port then
Bp or pp on the table now
But how much is a pp gonna cost me
Plugging up ports and drilling a huge hole in side isn't gonna be cheap is it (none of this is cheap I know but pp would be a lot more than a bp?)
And what's the life span of a pp gonna be?! And am I gonna be able to get it some what quite enough to not have the attention of every cop on the road



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Re: 13b Bridgeport or J-port ?? Hp? drive ability? life span?

#7 Post by Rota_Motor » Tue May 15, 2012 11:35 pm

Best bet if you are serious would be to talk to your engine builder, they will be taking your money and covering your warranty, and they will want a happy customer to spread the word for them. Definitions of ports can vary as well, what one man calls a big bridge is a small J, some people will say if its bigger than a big bridge, its just a monster and there is no definition of J port.

As for what is a bridge, a J or a monster, different people have different views because they are all variations of a bridge. Many years ago there was quite a long thread that got onto the topic of port naming. The general agreed definitions that most people were happy with were:
Bridgeport - has a bridge to support the corner seals, but only goes as far as the edge of the rotor housing, without the need to chamfer the housings.
J port - bigger version of the BP, and goes out past the edge of the rotor housing, but only to the inner edge of the inner water seal so it does not compromise sealing integrity, requires a chamfer on the rotor housings to utilise the extra surface area.
Monster port - biggest possible side porting style, requires cutting of the inner water seal and therefore compromises the water sealing integrity of the engine and is likely to lose water into the combustion chamber sooner rather than later. The previous linked picture indicating a J port is what people were referring to as a monster port.

As I said this was a while ago, but alot of the regular users before the young rotor groupies turned up ;) it seems these days what alot of people are calling bridges are more to our definition of a J, and not many people build engines further out that require cutting water seals, mainly because street cars are usually turbo, and most racing classes outlaw cutting the bridged port further than the inner water seal.

As further evidence of the J not going past water seals, the engine in my 1300 is labelled as a J and built by a workshop, and it has never had a water loss issue for all the years I have had it.


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Re: 13b Bridgeport or J-port ?? Hp? drive ability? life span?

#8 Post by MR.ROTA » Tue May 15, 2012 11:58 pm

I do believe we are on the same page for the jp and bp
How long has your jp lasted (km) and on what seals? What power figures and all that jazz

Rota_Motor wrote:Best bet if you are serious would be to talk to your engine builder, they will be taking your money and covering your warranty, and they will want a happy customer to spread the word for them. Definitions of ports can vary as well, what one man calls a big bridge is a small J, some people will say if its bigger than a big bridge, its just a monster and there is no definition of J port.

As for what is a bridge, a J or a monster, different people have different views because they are all variations of a bridge. Many years ago there was quite a long thread that got onto the topic of port naming. The general agreed definitions that most people were happy with were:
Bridgeport - has a bridge to support the corner seals, but only goes as far as the edge of the rotor housing, without the need to chamfer the housings.
J port - bigger version of the BP, and goes out past the edge of the rotor housing, but only to the inner edge of the inner water seal so it does not compromise sealing integrity, requires a chamfer on the rotor housings to utilise the extra surface area.
Monster port - biggest possible side porting style, requires cutting of the inner water seal and therefore compromises the water sealing integrity of the engine and is likely to lose water into the combustion chamber sooner rather than later. The previous linked picture indicating a J port is what people were referring to as a monster port.

As I said this was a while ago, but alot of the regular users before the young rotor groupies turned up ;) it seems these days what alot of people are calling bridges are more to our definition of a J, and not many people build engines further out that require cutting water seals, mainly because street cars are usually turbo, and most racing classes outlaw cutting the bridged port further than the inner water seal.

As further evidence of the J not going past water seals, the engine in my 1300 is labelled as a J and built by a workshop, and it has never had a water loss issue for all the years I have had it.



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Re: 13b BP/JP or PP ?? Hp? life span? KEEPING IT QUITE FOR ROAD

#9 Post by Momus » Wed May 16, 2012 5:56 pm

What Rota_ is saying is on the money regarding port definitions. The first Australian bridge ports started appearing in the 70's and where apparently developed from British designs that were a refinment of the Mazda factory 'saw tooth' long inlet duration design of the late 60's. they had small 'eyebrows and never went beyond the red combustion/water seal in the classic housings. Monster ports where a hog out that involved a lot more compromises for no extra timing and probably on most very little extra inlet flow and thus power. I know this to be the case from first hand experience with each pedalling winning cars racing circuits in the IP/ClubCar/Road Registered category. Extend Ports are a modest enlargement of the std port that doesnt change the timing or flow a great deal.


The skill, intelligence and experience of the engine builder will have a huge influence on the BP motors durability and driveability.
The amount you are prepared to pay for high quality aftermarket parts and brand new OE stuff is also a key factor. The tune will also matter. If you are using a Weber you need a good man who has been around and knows about the progression circuit modifications, accelerator pump cams and emulsion tubes. He will probably own a set of jet reams and vernier guages and have access to a lathe and a good supply of jets.
Usually ports are made far bigger than they need to be.

Bridgeporting a rotary is the Wankel equivalent of putting a racing camshaft and big valves in a piston motor. With both, unless the modifications are properly designed and the rest of the engine and it's support systems are up to it the results can be disappointing.
To get good power from a long timing rotary you need a long primary exhaust; 7' or 8' is a starting point, with probably 1-3/4" bore stainless tube. The quietness is an issue. I have made, reluctantly, quiet mufflers for road car bridgeports. They were multi pass and the size of a small suitcase, and heavy and very expensive and required that the spare tyre well be removed.

Cheers Marcus



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Re: 13b Bridgeport or J-port ?? Hp? drive ability? life span?

#10 Post by Rota_Motor » Wed May 16, 2012 6:27 pm

MR.ROTA wrote:I do believe we are on the same page for the jp and bp
How long has your jp lasted (km) and on what seals? What power figures and all that jazz
Cant accurately tell you how many km it has gone, admittedly it hasnt been on the road alot, but always has had fluids in it, and started fairly regularly. I have no idea what seals as I got it as is for a sing due to 'low compression' which ended up being a fucked carby and badly adjusted points. Also hasnt been anywhere near a dyno, but is appreciably faster than a stock port and I think it is still being strangled by the exhaust, it is loud but I also think restrictive. Again I didnt get the exhaust built for the car so not sure what its got, but it doesnt look expensive.


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Re: 13b BP/JP or PP ?? Hp? life span? KEEPING IT QUITE FOR ROAD

#11 Post by Dazz » Wed May 16, 2012 7:48 pm

Just remember if you are running a proper close ratio gearbox, frizby flywheel and small diameter clutch, decent injection and a non road legal exhaust, looking at big rpm bridge / J-port styles is somewhat self defeating.

You can build a good 13B BP with very sensible porting, a well set up Weber and SII electronic dizzy that will make good strong mid range power with a good flat torque curve that will pull better than a big top-endy style ported motor with the same inlet and exhaust combo.

There's a huge difference between a basically unrestricted IPRA style BP that will never be close to road legal noise wise, and a motor used for the road with all the compromises that go along with it. One porting style does not suit all needs, and porting designed to work from 7,000-10,000rpm with injection and all the good shit will be a shit of a thing with a Weber, normal clutch and g'box, quiet exhaust etc. You'll have all the shitty driveability with none of the power.

At the end of the day do you want porting to impress your mates, or performance to impress yourself?


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Re: 13b BP/JP or PP ?? Hp? life span? KEEPING IT QUITE FOR ROAD

#12 Post by MR.ROTA » Wed May 16, 2012 8:01 pm

Well I'm not trying to break any records or anything
I'm not after trying to impress my mates (although impressing my self with the power would mean my mates would be to I guess)

I was thinking this over a bit before I'm after power that's is very impressive and I'll be happy with what it can give me when I give it some. What port that is I'm not sure, but I do want to get the near most I can out of the engine with out having to upgrade every little thing (like i said I'm not tryin to break any records).
I want to do good port, dowl it if neserccery and modifie my webber to suit, my header size I will be making to what is neserccery for best flow
I'm Also happy with a pretty high up power band as Im willing to rev this thing to 9-1100rpm



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Re: 13b BP/JP or PP ?? Hp? life span? Help me decide!

#13 Post by RX2-12a » Wed May 16, 2012 8:35 pm

Y dont u jus go 13bbpT. An be done with it? u can pic up a s5 13bt for cheap enough these days that's what I'll be doing around Xmas



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Re: 13b BP/JP or PP ?? Hp? life span? Help me decide!

#14 Post by MR.ROTA » Wed May 16, 2012 8:42 pm

RX2-12a wrote:Y dont u jus go 13bbpT. An be done with it? u can pic up a s5 13bt for cheap enough these days that's what I'll be doing around Xmas
Don't want to go turbo and can't even if I wanted to



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Re: 13b Bridgeport or J-port ?? Hp? drive ability? life span?

#15 Post by Glassmancanada » Sat Jun 09, 2012 10:42 am

(R100) wrote:ceramic seals $1500 proberly more nrs is the way to go.
Even better I'll sell him them for $1145 including springs for 1pc


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