what up, i just bought a 13b to rebuild and see that it's a 6 port. what's the difference between this and a 4 port? Are there advantages over either? I'm not sure of the year of this engine.

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I'm far from an expert, but I think this is correct:



The 6-port engines were introduced in '86 in normally aspirated cars. Early 13B's and 13BT's were 4-port engines.



In an n/a application, the 6-port is going to breathe a little better than the 4-port.

 

Looks to me like a Series 5 (1989-1992) engine. What's it going in?

 

Welcome to nopistons! I'll move this to somewhere more appropriate, you should get more responses.

 

That is an S4 NA block. It can be identified my the mechanical Oil Metering Pump on the front of the motor. The NA motors have a bit longer duration on the secondary ports with the 6ports open. BUT, when the ports are closed, the intake timing is reduced and helps low end power.

 

hey, thanks for all the feedback already! This is helpful info because the previous owner had no real history on the engine since he had bought it from someone else who had pulled it out of a junk yard. When I get it rebuilt, it's going into a beetle that i'm restoring. the flat four motors that come in them are way boring (1930's technology). Mazda rotary is way better. My plans for the motor are to tear it down, replace all the seals, port the housings (intake and exhaust), replace the efi with a carb., and set it up for my own twin turbo creation. My next questions are: is it okay to port on a 6 port? I've done some research and have found that many sites do not offer templates or services for 6 port engines. Next, what kind of apex seals would be best for my application? What kind of spark would I need, cool, hot? What's the best electronic ignition setup? I've seen some of my rotary beetle mates use a coil for each plug. What size socket do I need for that huge nut on the back of the flywheel--any tricks for a skinny guy? Finally, when I crack it open and see that the housings are rough, should I just throw the whole motor in the woods behind my house, or is there still hope for it? I paid $200.

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that motor is actually a 13B from the 84-85 GSL-SE.



they were very good actually, peak torque is at 2700rpms, and peak power is at 6500, so the powerband is HUGE.



however compared to the later engines, this one uses the heavier 3mm seal rotors (12lbs, vs 10 for 86-88, and 9.5ish for 89-2003), also the ports are slightly smaller.



for a street car, the efi setup is great, it runs hot or cold, and you can corner with it, without hiccups.

 

Ah! So I see I was incorrect!

 

oh yeah, it's heavy alright. i nearly ripped my arm off trying to get it on my engine rig i.e. milk crate.

 

sweet, I noticed when pulling the spark plugs that s2 and t2 (the back two) were black. the front two look fine.