Anyone Ever Bridgeport a GSL-SE motor ??
 

So i'm building a motor for my 84 gsl-se and i want to port it, since i didn't do any porting on my 94. I'm looking for as much power as possible without PP, so i figured a bridgeport. I've been searching the 1st gen section and found plenty of 6 ports, but none from an SE. I have a spare rear iron, so i thought i would do some practice. I've read that most of you use a couple shapes of carbide burrs on a dremel tool. I got a couple bits from the hardware store and went at it. when you do a bridgeport on a 6 port, does your bridge go from the primary to the aux. port
? Here is what i have now, keep in mind i have never done any porting of any kind before and this is pretty much junk.....
http://pictures.sprintpcs.com/mmps/0...ut=255,255,255

Do you make a small bridge for the primary and a small bridge for the 5th or 6th port, make one big bridge that covers both, or make only a bridge on the primary ?? It seems I have 3 options and no clue.....any advice would be much appreciated !!! Pics wouldn't hurt either.....:icon_tup:

sorry here is the pic......
http://c4.ac-images.myspacecdn.com/i...8cd5f49af7.jpg

That iron is junk...

EDIT: I hope I didn't come off as an ass. You just made the bridge too big, and the side seal will not be supported, so it gets sucked into the port and then into the next combustion chamber... etc etc.

Also, if the housings are -SE, I would just get 12a Irons, and port those. Equivalent of a 13b 4 port, and you won't have to worry about the aux ports.

http://img363.imageshack.us/img363/1...0320280rz2.jpg
http://img363.imageshack.us/img363/p...jpg/1/w640.png
83-85 6 port plate, water grooves in housing , aux port smaller, primary plate smaller than the s4/5 NA engines

get a template if contemplating a bridge !

for your 6 port plates
you can cut full bridge, or you can leave a minor section to separate the aux runner bridge from the secondary runner bridge
- i suggest the latter may be advantageous in increasing air speed into the engine
when the rotor's closing interacts to separate the two runners into separate speed airflows

when you cut in the water groove does the housing need to be cut also, it would seem that way ?

When you cut into the water groove? If you mean the coolant seal, then you run some silicone sealant around what is left of the iron to the water/coolant port. If you cut through the whole iron and into the coolant port itself, then you block it off with Devcon or similar metal additive to make a seal.

If you cut through the coolant seal, you will start to have major longevity issues. If you stay about 1mm away from the coolant seal, you have a more usable power band and better engine life.

Also in the picture you posted: if you cut a port like that, the aux port flow will be compromised. The aux ports are designed as to when the rotor closes along the primary, the 5th/6th port will gain pressure and force more air/fuel mixture in (more than what the engine would pull in, take a look at the RX8 intake). When you go and add a bridge to it, the timing messes with the aux ports.

If you are wanting to go bridge, then bridge the secondaries and primaries, and leave the aux alone. But if you want more power, get 12a Irons and bridge thoses, with your -SE housings and rotating assembly.

sounds like i either need some 12a irons or just do a streetport on the -SE irons, thanks for the help everyone......

Out of curiosity, how much porting can an SE take using the stock EFI setup? At full flow, does it ever suck the AFM door all the way open? If there's some door travel left, is there still some duty cycle left on the stock injectors?

i have a J&W intake manifold for a 6port, so i was gonna try to run a carb setup. I couldn't see why it wouldn't work, i'd be nice to run an E&J TB with a haltech system but i can barely afford one and i've got 2 !!!

what you need to do is educate yourself by reading up in the Tech and Performance section.... there is a TON of info in there that can help you. lots of people have bridge ported 6 port plates

How much low end do you care to retain for street manners/driveability? If you want/need some, street port the primary and secondaries, then bridge the aux ports. I would also keep the aux ports functional for better low end streetability Read through the 'Rotary Engine Building and Porting' section over at NoPistons.com. Read through bridge ports for the NA FCs. Pay particular attention to any posts by Judge Ito, BDC and Lynn E Hanover. You need to make the support bridge wider and bevel the housings. Best suggestions is purchase a porting template.

If you have any questions or need help with the porting, PM me. Since you have a standalone available, you may wish to consider going with a complete S4 intake swap. You'll need the 2 extra injectors Nice job on the FD rebuild, not fond of the lime green but I do have some fluorescent lime green powder coat. :lol:

thanks, i'm not really that big on the green either, it was leftover from my friend painting.......on.......my 240.......from a can..........long story. I think i'm going to buy a pineapple streetport template for these irons, which i don't plan to use if i continue on my PP motor side project. I'm not really worried about street driveability, the car will most be at the strip !!!!

If the engine is for track use only, go for a full bridge along with one piece carbon apex seals. I would also suggest using 12A end irons and making it a 4-port. Fun part is sourcing the needed intake mani and going carb instead of FI.

I just had a question about gas mileage. I was told that anything beyond a street port/large extend port really compromises gas mileage and streetability. Is this true?

^^ Yes. Well, anything bigger than stock and you lose MPG.

yes. any kind of porting will decrease gas mileage its just MUCH more noticible with a bridge.

increase in air = more gas being burned = more power = less mpg. (more or less) thats pretty much a basic automotive concept

The 1/2sp-1/2bp 12A in the widebody, I've gotten as low as 8.5 mpg in the winter with short trips and extended warmups when I had the Mikuni 44 PHH. I've also gotten 23.5 mpg running 60-65 on the highway with the the dual DCD Webers that's on the engine now and it's still running a bit rich. It comes down to your driving habits and tuning.

So after using that funny little search box and doing some reading, this is what i've come up with.

http://c4.ac-images.myspacecdn.com/i...02e9c13d43.jpg

I'm waiting on my template to come in, so the ports are stock for now. I think this is a little more workable. The bridge is one line past the 1/4" line and the port right at the 1/8" line on a tape measure I still laugh every time a see that junk iron.....what a mess.......let me know what you guys think of this try.

I currently have a GSL-SE that is ported but I've also had ported 2nd gen 6 port motors and 4 port motors with both stock and custom built manifolds. I will say that the GSL-SE intake is the single most restrictive of all the fuel injection manifolds. The air flow meter is smaller than the 2nd gens by 20% in area as well. It's quite noticable as the SE has pretty nice low to midrange power but is on it's butt around 7K.

A bridgeport absolutely needs a free flowing intake which is what the stock one is not. A bridgeport is a complete waste of time. More is not always better. I am of the personal opinion that a bridgeport is a waste of time on ANY 6 port motor regardless of setup but that's just me. If it's not a dedicated track car, it shouldn't be bridged. I don't really care who has what , who likes it, or who tolerates it on the street. I have higher standards and don't like driving cars that feel like crap around all day so other opinions may differ and yes I've driven other porting styles.

The stock ports on your motor aren't even as large as the 2nd gen 6 port engine's are. I'd buy a Racing Beat or Mazdatrix template, and do some nice work with that. You'll be happy doing some other things as well. The Racing Beat Street Port exhaust system (long primary) has been the best performing system I've ever had on that car. I still regret selling it but then again I like experimenting. Converting the distributer over to direct fire is also a nice mod. Finally a lightweight flywheel makes it accelerate noticably faster. The car is light so all of this adds up to a pretty nimble and quick little car that's fun to drive. Later on you can get into an aftermarket ecu and intake manifold.

You'd be surprised at how nice this combo is. I currently have a Megasquirt and an S5 intake manifold and it's pretty nice. Ignore the bridge idea. It's crap and people here keep spreading the word that it's doable on those engines on the street. Doing it and having it work and having it work nicely are 2 different things. Most of the people here can't even hit 200 rwhp for some reason on streetports which isn't hard to do so take advice on the subject of porting these housings at your own discretion.

I will not be using the stock intake. I have a j&w intake mani from a 2nd gen 6 port. The template I'm waiting on is coming from racing beat. I've also been looking at their intake manifold kits, but so much $$. I was going to run a holley or edelbrock 650 for now. I need a header and have 2 full sets of stock gsl-se intakes that someone needs...!! anyone ?

There aren't many members that I take their porting advice to heart, rotarygod is at the top of the list of those that I do. From his post, it sounds like you'd get more performance, and definitely better driveability, by changing to an S4/5 intake and a decent street port.

My personal opinion is that if you want to bridgeport an SE engine, your better off using 12A end irons, but then you run into problems finding a 13B 4-port intake mani that will fit. I would also keep it FI, going with a 2nd gen intake and MegaSquirt for a standalone ecu.

Hey rotorgod... I have built a bridge and driven it on the street. No problems.

I never said it can't be physically driven on the street without any problems. I'm sure that a Cessna could be physically rolled down a street under it's own power without breaking or suffering any mechanical issues aside from the stares of drivers going by or the cops not appreciating a spinning propeller and wide wingspan trying to go under lightpoles.

A bridgeport and peripheral port are not streetable. They never have been. This doesn't mean people haven't physically done it. That doesn't make them streetable. That makes their owners tolerant. There's a difference. If you like loud exhausts, poor gas mileage, and jerkiness at part throttle such as cruising, go for it! No one can argue that they take more finess and are more finicky than milder types of porting. They are! That's why they're at home on the race track. You don't run under those conditions. In the same fashion I wouldn't tell someone wanting a dedicated race engine to use a stock port with a conservative tune and a quiet exhaust manifold and hope that it works well on the track. It wouldn't. You could drive it but you'd be pretty slow.

Porting is not generic. No porting style works well in every driving situation. Sadly enough many people think that more is better when this is almost always contrary to reality when it comes to engine building. Go as much as you need. More than that isn't always better and often times it's worse.

How many people here that drive a bridge or peripheral port on the street have actually changed their transmissions to closer ratio units to take advantage of the narrower, higher powerband of those ports? Anyone using a stock transmission with anything more than a streetport is wasting power! You've got it on a dyno chart but you don't have it at the wheels when you need it. The same holds true for those porting styles and stock manifolds, exhausts, ecus, etc yet we see people do it all the time.

I have a simple saying (among many). "Years of experience mean nothing when it's been done wrong the whole time." What this means is that just because certain information is passed around over and over again doesn't mean it's good information. In the end it's up to the individual to figure out who they think is right. If people want to take my advice then cool. If they want to take different advice from others, that's fine to. It's their choice and no matter what at least they'll learn something. I for one just try to pass on what I have more often than not learned the hard way over the years so people don't make the same mistakes I have. Here's a little secret as to how I started porting engines. The very first 2 porting styles I tried were the aux bridgeport and hogging out the 5th and 6th ports to one big port. Here's a hint at how well that worked, I currently have a streetport and those old housings are in rotary heaven somewhere along with many other experiments I tried including just about every conceivable exhaust combination I could think of.

I don't want to come across as criticizing anyone directly. I am more against a mentality in the rotary community as a whole where much bad info is the norm and the good stuff stays secretive to a select few. I want those secrets to become common knowledge and I don't care who I piss off by telling it.

Not to dispute your years of tried and tested experience, but one thing of interest that I found about my 1/2sp-1/2bp is carburation can make all the difference in the world. I started out with a 2 barrel Mikuni and it was a pita to drive on the street. Couldn't cruise below 3k without the herky jerky, sometimes had to use 4th gear on the highway, power band began at 4-1/2k, took off like a bat at 5k.

Then I installed a set of RE dual DCD carbs. Made all the difference in the world. During most driving the secondaries are closed off due to the way the carbs are designed. In essence, driving on the primaries is the same as driving an sp, until the secondaries open up. I have my idle set around 1500-1600 rpm, I can turn it down to 800 and it will still idle, but it's quite lopey. I can also now cruise at 1500 rpm, smoothly and the transition when the secondaries open up is quite smooth. Something I could never tune into the 2 barrel Mikuni.

I was pleasantly surprised with the difference between the 2 and 4 barrel carbs. Fuel mileage is reasonable too, I can live with 23-24 mpg on the highway, but I have to be gentle with the throttle. Opening up all 4 barrels can suck quite a bit of fuel. My only regret is that I didn't do the high rpm mods to make use of the rest of the untapped power above 8k.