These are pics of a whole days worth of work. Im quite pleased with the results:

*one of the streetports on the intermediate housing...the one on the other side is pretty much the same

*a pic of me working on the first bridgeport

*me...again...damn im handsome...

*my older brother decided to show up today...even tho his fb is down...so we pulled the parts for his car and he helped me with my ports a bit

*me working on opening up the exhaust port so i can get the amazing "brap brap" sound

*the finished exhaust ports...they were opened up a goodly amount

*me and my bro...you can tell who did all the work

*ahhhh...the finished bridgeport...the other looks just as sexy

Now the fun is ready to begin...im gonna rebuild this **** and put it in the rex!!!

 

looks pretty damn good, can't wait till i spit a seal or cook a water seal so i can justify opening mine up.....

 

Youve got to tell me how this runs when you get it finished. What type of induction are you going to run?

I've got several 12a cores that I'm going to pull apart and would like to do a 1/2 bp on at least one engine. I'm running twin weber carbs. check the sig for a link to pics.

 

i think when my 13b blows im gonna do a 1/2 bridgey with a turbo setup
mmmm turbo

 

how exactly did you get the postioning of the bridge though? did you use a template i didnt see?

 

no template, its not really hard to map it out though...you basically use the stock port as a guide, and cut right to the edge of where the rotor housing is. Just leave a little bridge, and you're good to go. Keep in mind, this isn't a super professional job, but its definitly a very good port job, and should produce some good power, I can't wait to hear it.

 

Hard to see from the pics but are the exhaust port lips beveled so the apex seal won't catch on them?

I'd reccomend getting the plates lapped flat and smooth before installing.

NICE work. Should make some good power.

 

Thanks guys...i should probably go back and bevel the lips of the exhaust ports...i didnt realize they needed to be...they arnt too bad right now...but i wanna be sure...

I really cannot wait until i get this thing in my car...ill let all of you know how this runs. Im gonna be usin a holley 600 with the racing beat intake and headers...then ill have it goin to a custom 2.5" exhaust.

I used duct tape for a template ...my rebuild and porting is the total poor mans everything. I have $36 to my name at the moment...all im goin new with is the soft seals. Im not gonna be able to purchase anything other than that...let alone have my irons lapped

 

I would definately go to nopistons.com and look over their porting FAQ. LOTS of Excellent info.

 

definitly very good info at nopistons on porting, and i've read alot of it (notice my shirt!)

good call on the beveling of the intake ports, i made sure he beveled the intake ports for the side seals, but we didn't focus on that when doing the aluminum, thanks for the input.

 

wow looks good! nice job!! it should run good-+

 

Is that possible? Or rather practical? I come from a (remidial) piston engine background, so bear with me here, but aren't street porting and bridge porting the same as changing the duration on a cam? I was under the impression that when a bridgeport or street port was completed you were left with "valve" timing that had a bit of overlap with exaust exiting at the same time as the intake charge was coming in for a short period of time. Wouldn't that benefit be gone with the addition of a turbo?

 

well actually with a bridge port you don't have to change the timing of the port opening at all, in my brothers case we did, not too extreme. The bridge just opens up more on the side, not on the top or bottom of the port. Even with the overlap, you can still create lots and lots of power with a turbo, you just lose a lot of low rpm power...or streetability i guess (did i make that word up?).

There are lots and lots of people that have run bridge port turbos, as for there their port timing, i really couldn't tell ya.

 

uhh yeah 1/2bp turbos are possible and quite common, and put down some NICE numbers
like im shooting for 300 RELIABLE whp

 

A bridge port does most certainly change the open timing. The bridge does open up the side more as you've pointed out. This side is actually the opening edge of the port, not the bottom. The top of the port is the closing edge. Remember that on a side port the rotor not only moves up the port but also across it. On a peripheral port the rotor only moves upward so the bottom edge is in fact the opening side on them.

 

So is this when the increased RPM range occurs?

 

You'd actually get a higher powerband. This is because the intake/exhaust port overlap causes alot of intake dilution with hot oxygen deficient exhaust gas. As rpm's rise and loads increase, the momentum of the gasses in the intake and the exhaust will keep them going in the proper direction. If you have a really good scavenging exhaust that helps to pull the exhaust out of the engine, this can actually create a suction during the overlap period and this low pressure in the engine will help pull even more intake into the engine making more power. The amount of effect this has can vary depending on the intake and exhaust system you are using. With higher overlap engines such as bridge/peripheral ports, a properly designed intake and exhaust system become very critical to good performance.

 

ill be runnin a holley 600 with racing beat headers to a 2.5" exhaust

 

As long as you tune it right, that should work fine.

 

yeah you're right with the bridge and port timing, now that i picture it correctly
thanks for keeping me in line

 

that looks like my engine....1/2 bridge 12A