wwjessedo

I've been reading threads on streetable bridgeports for no less then an hour now and haven't gotten anywhere. Some people say it can't or shouldn't be done and others say it's not a problem.
I own an '88 NA. It's got 203,000 miles on it and the engine finally needs a rebuild. I want more power out of my engine but don't have the money for a turbo setup.
What would I need? I'll be doing the work myself. I'm aiming at a partial bridgeport. User Kurgan mentioned that street porting the primaries, and bridgeing the secondaries is quite feasible. Does this sound right? Does anyone have experience with this setup? How much power could it make? I would ofcoarse give it an intake and full exhaust. I will be driving this car everyday but don't have a problemwith 1000-1200RPM idle or the noise it makes. Any help would be apreciated. Thanks in Advance!

Bridgeported

I think full bridgeport's are streetable, so partial bridgeports are definitely streetable. They are a good compromise of power and streetability.
I would expect power potential on an NA engine to be about 210-250 rwhp.
Besides doing the actual porting, you will need to upgrade your ECU or change over to a carburated system, upgrade your fuel system, exhaust system, intake, ignition system. Remember, how open your exhaust is is probably the main factor is how much power you are going to make with a bridgeport, so if you can deal with the loudness, then let 'er rip!

Crashunit

they just dont really like to idle well, so stalling and dying out sometimes become a problem, but if you dont mind, then you can drive it.

Gearhead

iTrader: (1)

All of them I've been around idle fine. You just have to have them set up properly. As far as upgrading the engine, I believe you will need all the high RPM upgrades, such as hardened gears, clearanced rotors, 3 window race bearings, upgraded oil pump... and... some other stuff that I can't think of off the top of my head. I really don't know how much cheaper (if any) the BP will be than a turbo, especially considering you can buy a Jspec ser. 5 motor for 950, and it has turbos etc on it, and you will be able to match the N/A BP peak power. You SHOULDN'T have to rebuild the Jspec, either.
I may be off on this, though.
Don.

SPZ510

Are you guys forgetting he has an 88 with a 6 port? Bridgeporting is out of the question unless you want to be the first and try something that others have only talk about on this forum. If you have an 88 and you want more power, I feel you have two choices. A-streetport it with a potential of 220-230fwhp. Or B- sell it and get a TII. The second option is much less work and probably the smartest. You can go my way and build a 4 port but trust me the time and frustration it takes to build a BP is just not worth it unless your racing a class that makes it necessary. Do a search for my post and you'll see me cursing myself all the time for not going turbo. Damn, Damn, Damn!!! It's just too easy.
I spend probably 2-3hrs each port on a BP. The time it takes me to hog out the main port witch is similar to a streetport is about 20-40 min. And the possibility of messing up a housing doing a streetport is a fraction compared to a BP.
As far as the motor, built and running, I have no complaints. Idle- no problem, 1100rpm and is fine. Powerband- decent. Starts at 4.5k and pulls until 9.5k, and when your on it, thats where your at anyways.
Good luck with your choice.

Crusader_9x

http://www.teamfc3s.org/forum/showth...5&pagenumber=1

kinda long but this guy claims to have a partial bridge 6 port. kinda interesting and makes since in my opinion that it can be done.

Bridgeported

Oops, I didn't know he had a 6-port engine.
Well you can still do the bridgeport, it just means you should (or kind of have to) do this first....
GET A 4-PORT ENGINE

It is possible to b-port a 6-port engine - but not worth it. You can't make the bridgeport big enough for serious power, and there is not enough material around there to be strong enough so it lasts.

Node

iTrader: (1)

Itoport it!
http://www.jrsrotaryperformance.com/ go to porting and then look at the N/A 6 port. That but with a bridge on the 5/6th ports.
Ito is making one now and hopefully there will be pictures soon.

enfini3

I wouldent bridge port unless you have rebuilt severl motors already and don't mind the time and work put into the porting. By the way wont you have to port the hell out of the intakes to make it worth wild anyway?

$150FC

Keep in mind, also, that one person's definition of "streetable" can be much different than yours.

madas7

bridge port sounds like a good idea, relatively cheep upgrade. You dont need any high rpm upgrades internaly unless you want to build a le-mans endurance engine. bridge the secondary mains and primarys but not the sleved six port. The factory manifold will be fine, the throats tapper down radicaly at the block end which can be massarged easilly with the diegrinder to port match your ported plates. Run a good exhust a pair of 12a 810cc or 13bse 720cc injectors in the secondarys for extra fuel at high rpm. factory ecu should be fine, they can run huge stage II's , try to find cheep fuel only ecu and run ignition on dizzy to keep cost down. may need larger fuel pump.
stage II engine is easyier to build but my first engine was a bridge and it went hard!!
ps change flywheel too seriuosly light aftermarket one. this is a cheep but huge preformance apgrade.

Judge Ito

I bridgeported a 6 port engine in a serious manner. I ported the regular 4 ports.I ported really large the 5&6 ports with a super nice angle since so much metal is available to port without going over into the water jacket. Then I bridgeported every single port. The regular 4 ports and the 5&6 ports have a seriously large bridgeport. I match ported the 5&6 port sleeves and installed the pineapple racing better flowing inserts. The engine is using a Racing Beat header for now, later I will modify the exhaust to help this engine make some nice power. goal horsepower is 250rwhp. Right now the car was finished about 2 weeks ago, Rx7 runs alot better then before at low rpm cruising(more power and little effort of the gas pedal to make the car run fast) We have a nice video of the idle and having fun with a pretty decent burnout. The Rx7 looks fast coming out of the burnout. I was thinking of posting some of this info. on this forum while I was doing this proyect for my customer, but for other reasons I decided not to. When I read a couple of forum members thinking it was a waste of time to bridgeport a 6 port engine I had no choice but to reply. This Rx7 with the new bridgeported 6 port engine has some serious power and is a really fun car to drive. Idle is something left to a serious rotorhead. The brap,brap,brap is a little aggressive. Mods so far are.
1)intake
2)header
3)750cc secondary injectors
4)a seriously nice bridgeported 6 port engine with 2mm Atkins apex seals. because the big bridgeport I could not use the factory 3 piece 2mm apex seals. Engine runs great with out any over heating and no problem using the stock ECU for now. Later Ill upgrade to a better EMS

karism

This might not be a bridge,but this is the way we do it here.The pics show 12A housings.

It has been running 2 years now,and is in a Flat track racecar.Shift point is set at 13200 rpm,at which it makes 235,with the class relevant class restrictions on

88fc3sw/HX83

Whats your interpretation of "Streetable", I know of cars, driven on the street, running a Peri-port.

E6KT2

karism, What do you do to make the engine live at 13k? I am looking at a raised redline for my rebuild and I would love some pointers.

ShortBusRiot

yea i want to know too!

madas7

karism, 13k? 2 years?......... you must have double sprung roller rockers and solid lifters runing short stroke rods. right!

Rotortuner

13k ??? My PP12a does not even pull that and a PP12a is is a high rever. You must have a super large monster bridge or your just BSing us.

CJG

Node

iTrader: (1)

kinda looks like it could be photoshoped (solid black)
I don't see any sign of a bridge either
Please do tell.

RICE RACING

13k for two years

**** man don't do that to me ! I am fragile and can't take falling from my chair onto the hard floor boards at home in a fit of laughter

Gearhead

iTrader: (1)

13K does sound a little high. At what RPM do you guys recommend running the high RPM goodies? I've only built 2 engines using this stuff, and 1 was a PP, and the other was supercharged. Funny now, the Atkins S/charger starts running out of steam at 6k. Somebody sent him the small one after charging him for the big one.

karism

The pic was edited,your right on that.The reason i did that was :we dont have digicams here..if i had one,i could even post a pic with the dimensions and all.

3 window bearings,running 180+psi oil pressure,the clearances on the rotors to housings are half of the size recommended by Mazda.Extensively lightened,and balanced to within 0.5 gram.51 IDA with 340 mains.everything you can think off,is done to the engine.The guy had only been able to build one.Another one was built to exactley the same specs,but it lasted only 2 months,and then it destroyed the sidehousings and rotors,broke the stasionary gears(please note,not chipped off the teeth,there wasnt any teeth left).

Does sound unrealistic doesnt it?I thought so too,and i then saw the figures,heard it and saw it go.It`s been club champ for 2 years now,in the same class as the 500 hp nitromethane V8`s

Other than the little info i gave,i`am not allowed to tell anything more,sorry the competition wants the info,and there is some in this club

Node :Its not a bridge,it use to be a Six port in its previous life.The reason its not a Peri ?It was banned of the track in 1986...the Monster port was then created.

Just for reverence :The intake flows 25% more than the engine can use!

peejay

25% more than the engine can use?

That sounds like a foolish waste of port velocity. Peak power looks great but you need to come up through the rest of the rev range to get there. If you're kicking butt in your competition, congratulations, however your competitors are likely to put together a more realistic combination that will leave you in the dust.

RICE RACING

That realy is the biggest mother load of crap I have herd in a while

buzz

Hi Judge,
getting this thread back on track -
You wouldn't happen to have any pics to show what the bridged 6port plates look like? My latest car has a stock six port and a 48ida weber - and I'm debating whether to pull the bridged 4port from my other car before I sell it or plan a bridge when this engine dies in the bum.
Mail me off-list if you like.

Mark / buzz