1991 RX-7 - N/A Six Port Full Bridge Engine Walkaround

My freshly rebuilt 6 Port 13B. Atkins Two Piece Apex Seals, Solid Corner Seals, Bridged secondary port, "baby" bridge primary. (The six ports are difficult to port out because of the lack of material that can be removed around the port. So the primary was shaved up a little, dropped, smoothed and a thin little brow was added to create a "baby" bridge on the primary without fear of cutting into water jackets). ACT Pressure Plate, EXEDY Clutch Disc (Street Strip Sprung) SR Motorsports lightweight aluminum flywheel, Racing Beat True Dual Exhaust Manifold.




Yeah, I know it's hard to get a huge amount of power from the six ports without super light - high RPM internals or forced induction, but the simplicity and enhanced reliability can be just as important sometimes...

A Camden Supercharger is always in the back of my mind, though.

Category:

Autos & Vehicles

Tags:

• rx7
• rx-7
• fc
• fc3s
• bridge
• port
• ported
• bridgeport
• bridgeported
• six
• non-turbo
• na
• n/a

[thash1127]

so all 91's are 6 ports? and by six ports, thats three exhaust and three intakes i presume?

[igropemotoko]

All non turbos of the S4 and S5 series were six port engines. Turbos are four port engines. Four intake ports on the plates, two peripheral exhausts on the rotor housings. Basically just additional intake ports that are gated shut at low RPMs for torque then open in the higher revs for top end power.

[bosgreene36m3]

that is THE motor that is currently in my car. (the white 91 with the 10th anniversary tail lights in it) bought it from the guy you sold it to. put a haltech standalone in it, did a few more small things, soon to put a ported intake mani and dual throttle bodies in it. thats so cool you made this video.

[igropemotoko]

Awesome! How's it holding up?

[EFINIRX7]

Really nice.

Did you use any porting templates?

You should get a IDA manifold and ITB's

[igropemotoko]

@EFINIRX7 No templates. Just some educated guesswork really. There's not much porting you can do on the six port engines so we played it safe but it most def brap braps. I didn't really care at the time if it made any real worthwhile power or not. So much of what I was getting done was free in the engine dept. I just wanted the bastard to run. Haha.

[bosgreene36m3]

@igropemotoko great man. runs strong, pulls hard, sounds good. I will have to make a video for you when i can find my camera. only issue ive had with the car wasnt even the motor, the hood latch was broken and the hood flew up and bent in half, cracked my windshield and broke the sunroof. this happened on the way home from getting her tuned. hahah scared the shit out of my girl. six sigma did a great job tuning it. put down 205 hp roughly... so you did get some power from the port job.

[thash1127]

@igropemotoko oh, that's interesting, thanks for the reply. so the term "6 port" is describing the number of intakes not total of both

[JuanPapaNicolao]

Very nice

[heith85]

get rid of your factory intake manifold and throttle body. get something shorter rise your power band and work will with your porting