hi/lo port?

sr20ser · 01-20-2002, 01:35 AM

can someone please tell me what the hell Hi port and Lo port is?
I have no idea...I have a 91 NX2k, and a 98 200sx se-r, are these hi or lo port?

SERprise In WV · 01-20-2002, 01:44 AM

It's easy, once you get the hang of it:

-'91-93 SR20DE engines (up until about June of 1993 manufacture date) are highport engines. They have the throttle body down low, and the injectors are visible up on 'top' of the intake manifold.

-'94-up SR20DE engines are lowport engines. They have the throttle bodies up high, even with the injectors.

Think 'opposite' and you can figure it out easily: Highport = throttle body down LOW; Lowport=throttle body up HIGH.

It takes a while to get the hang of. Everybody gets it confused for a while.

sr20ser · 01-20-2002, 01:53 AM

thanks....so simple. I'm a jackass

silversx · 01-20-2002, 01:32 PM

not to mention the intake ports themselves on the intake manifold are slightly larger on the highport SR20..

Nick · 01-20-2002, 02:27 PM

i think they changed it because the injectors were prone to clogging or pooling some thing like that ? i read about it along time ago.

SmoothDaddyFig · 01-20-2002, 07:46 PM

LOOK CLOSELY:

HIGHPORT

LOWPORT

unlucky · 01-20-2002, 09:57 PM

Actually, it had something to do with emissions. The fuel would not atomize enough to burn completely because of an obstruction in the ports. The reason there was an obstruction is from a bolt that the casting had to go around. The fuel would puddle a little, and wouldn't completely burn. This caused poor emissions. So, they cut down the ports a little to make a clear shot to the valve pockets. There isn't that big of a difference performance wise between the two though.

FastNX · 01-22-2002, 01:00 AM

that pooling fuel gets sucked into the head when you let off the gas, which is why high port's make that delightful popping noise when you drop the throttle, made worse (better?) with a header and exhaust