you may want to mention the way the stock apex seals should be put in for a half bridge. i always turn mine around on the rear rotor so the triangular piece is away from the side with the bridgeport, the fronts can be installed normally.

for a full bridgeport you should use a solid apex seal.

 

^ yeah that is a smart idea! i never thought about that but it makes complete sense! wouldnt you want to use 3mm seals and solid corners...?

 

I totally forgot about that, I just do it so that is why i forgot.

This is true, just turn the rear rotor apex seal backwards, this puts the corner seal to the inside away from the cut rotor housing and bridge.

Good Info

 

Sticky!!!

 

nice avatar

o and sticky!

 

The problem with turning the seals around (assuming you are using 3 piece apex seals) is that they aren't designed to be run that way. The edges between the top and bottom pieces of the stock apex seals are angled. When installed properly these help hold the top piece against the rotor housing. When you turn this around backwards, it isn't doing this anymore and it is actually forcing the apex seal towards the back of the groove but away from the housing. If you have 2 piece seals then by all means turn them around but do not do this with 3 piece seals.

 

Easy solution use two piece seals. You don't have to use one piece seals on a bridge it just depends on how big of a bridge port you go with. As long as you don't have to cut a relief into the rotorhousing then you can use two piece seals. I like to cut the secondary ports with a large bridgport and the center plate with a smaller bridge and just flip the rear apex seals.

 

rotary god, your right but they were not talking about 3mm seals. yes the one side is beveled and the other side has corners that would dig into the housing. so yes do not turn the 3mm seals around!

 

Shouldn't you also leave out the rubber plugs?

 

oh, no, this thread is turning bad. yes, turn the 2-piece 3mm seals around on the rear rotor on a hallf bridgeport especially if you cut the rotor housing.

rotary god you have to think about how the apex seals are in the engine when you are talking about 3 piece 2mm seals.

picture yourself inside the engine standing next to the apex seal on the front side of the seal then picture youself on the back side of the apex seal. so actually when they run, the front side of the apex seals becomes the back and the back side becomes the front. it is easy to see this if you picture the rotor in the position right before ignition occurs and full compression has been acheived. imagine how the apex seal nearest the leading spark plug is facing verses the apex seal nearest the trailing spark plug is facing. the compressed gases are actually pushing against the back side of one apex seal and the front side of the other apex seal. the apex seals are slamed against both sides of the apex seal groove while the engine is running.

i would just toss the 3-piece and use 2-piece apex seals.

the rubber plug is supported by the bridge so you can leave it in.

 

if one is going to go through the time, effort and coin to build a motor like this, why not just use solid corners?

 

All Right People this is a GUIDE TO PORTING not to putting the motor together or what you need to run in the motor.


Lets try and keep this on track

 

I don't want to mess up your Thread but is'nt a Bridge suposed to be cut at an Angle?

I noticed yours was square to the Plate?

 

I like the idea of Cutting your own Bridge (Takes *****) i have always been a little put off by some of the really Poor Pictures you see on the Forums (e.g. https://www.rx7club.com/rotary-car-performance-77/advice-bridge-port-i-have-done-532587/) but this is Inspiring.

What do you think of the Hole method of Bridge Cutting? (Drill a series of holes first and Joing them up with the Grinder) ? You just make it look so easy to cut the Hole out.

 

you can cut them at an angle if you want but you need to grind the port runner to make the lip of the bridge stick out like it looks in that first drawing. just cutting on an angle isn't going to make that protrusion.

even if you don't cut it on an angle the bridgeport will still have air pushed into it by atmospheric pressure.

i always scribe a line where the drill bit center goes so the drill bit doesn't slip while trying to make the holes for the bridge. you just move the template out and use it as a guide for your holes line.

 

There is angled but not drastilly

 

I supose if its cut by hand it would make it alot harder to cut much more angle?

 

Keeping it up top

 

Your large images with easy to follow steps please the rotor gods.

Seriously...nice job on the post. Good stuff, keep it coming.

 

Now that is a real port job.

 

Thanks!!!!

 

sticky!!

 

theres tons of material that could be ported away with your ports, I see your using a racing beat old style template designed for old style 4 port engines. If you notice your intake opening is way late. porting any engine is much more then intake opening and intake closing. when you port any engine, your looking for FLOW. your looking to increase the amount of CFM available to cruise in and out the ports. something that your not doing here.

you need to concentrate inside the runners, you need to port away the factory venturi, but later ported rite back. also pay attention to the bowl inside the port, tons of gains are made here. U have the basics down, but you need to step away from the intake opening n closing and pay alot of attetion to everything else. also the back cut of the eyebrow, you left it stock. If I was to grade this job I would give it a C no offense, just trying to give some constructive critizm.. and make sure you have atleast a 2mm bevel on your closing edge of your exhaust port. I didnt see much..

 

sweet deal! sticky kinda confused about the apex seal

 

wow, this gives me more confidense about porting my own motor. i'm afraid to bridge port because of the emissions in Ma. but this is definetly helpfull, and i will keep it bookmarked to refer to when i get there.