erv187

can a half bridged or Full Bridge ported motor be daily driven? I'm aware Low end power would be pretty useless. however, is it still possible? Also what would be the average lifespan for a bridge ported engine? Is it even worth it? would it be better just to go Large Street Port?

Verneuil

From what i have gathered a full bridge ur lookin at like 30 to 40K miles. For daily driver Large street port. But have the supporting mods. Full exhaust and intake and carb. RB if you can afford it. Direct fire ignition and upgrade that oil cooling system. There are some ppl who have gotten very decent numbers with a stock port. Thats just my 2c

KansasCityREPU

iTrader: (9)

Full Bridge = No. Half bridge = maybe with the right carb. Gas mileage will suck.

j9fd3s

iTrader: (3)

people have run them on the street for decades. at high throttle openings, low end power is better. at low throttle openings they want to buck and snort, unless the tuning is exactly right, which is not easy with a carb.

noise is also a problem. big intake ports add power, but they are also open the same time as the exhaust longer too, overlap. a high overlap engine does not like exhaust backpressure

lifespan of the engine depends on how its used way to much to say, the port type doesn't really matter, however 9000rpms is more wear than 7000...

so if you want something to drive every day, a street port is great. weekend toy? skip the BP and go PP

Dirty 13b

30-40k is about right, depending on how cheap you rebuild it and how well the tune is.

Verneuil

you could go with a street port with a small PP. I have seen a 13B setup like that. They used the water cooling passages for the intake as the PP. Pretty sick

Siraniko

iTrader: (13)

semi-pport is the way to go since you can run factory seals

81WideMariah

iTrader: (8)

Go turbo and forget about it.... turbo cars get better mileage at cruise, and make tons of low end, comparatively speaking.

What good is 200 hp if you're only seeing it for 500 rpms and only when you rev to 9000 rpms? Plus getting 8-10 mpg... on a good day.

It just doesn't make sense for the street. Now if you're building a car for the strip, where you can leave at 9k, bouncing off the revlimiter, then yeah a bridgey or a PP make sense.

Jibaro 12A

iTrader: (8)

very good point.

erv187

yea that is very true. makes sense. thanks. since i'm on the subject, what if I were to run a port like that on a fuel injected 13b? wouldnt tuning be much easier, compared to the carbureted 13b?

81WideMariah

iTrader: (8)

tuning and driveability will be easier/better... but you're still stuck with an extremely peaky powerband and poor mileage. Bridges are known for less than stellar part throttle response.

Basically, you've got to much exhast backflowing into the intake and vice versa due to the large ammount of overlap. It's like putting a crazy lift an duraton cam na V8 and trying to drive it in stop light traffic.... not alot of fun.

Plus when you turbo a rotary there is very litle need to port the intake side as there are no valvesto get in the way. The air/fuel is going to keep cramming in as fast as your turbo can blow it. More imporant is to have big enough exhaust ports to get all that bost out.

So you get power, driveability, and mileage... it's realy a no-brainer.