Hey guys I am wondering what dose half-bridge means on a rotary engine? What are the difference between street port, half-bridge, and other types if you can list them.

Thanks In Advance!

 

it means half of a full brdige... there are also many types of bridges. j and d. i'm currently running a full j-bridge. it's a rough motor, but it's QUICK

 

a half brige is a motor that has street port primarys and street port secondarys with the brige aded above like a eye brow

 

There are a few sites that list, show and describe the different porting styles, don't recall any off hand though. A 1/2 bp simply means that either the primary or secondary ports, usually secondarys have a bridge or eyebrow cut in addition to the streetport. A full bp has all 4 intake ports cut with an eyebrow.

The engine building and porting section at NoPistons.com covers porting and building much better than we do here.

 

I remember reading some good information on this subject last time I searched for it. Not trying to seem like an ***, Im just too lazy to find a link. lol

 

Yep, and then a street port, the more popular option, is just expanding the size of the existing ports, not adding any extra.

You'll sometimes hear added on words like, small, mild, or large to better describe the size of the streetport.

And the last type I know of is a peripheral port, which is where the regular ports on the side housings are sealed shut and a new intake port on the rotor housing is machined in. So now the intake port would be directly above the exhaust port. This is a crazy setup, and is mainly used in race setups.

 

I c, thanks guys this helps a lot, I had no idea after reading and hearing people talk about this options. Now I have a general idea of what it is so this helps.

 

I am thinking about doing just that to a 6 port that is sitting in my garage. Thing needs a rebuild badly anyway, so might as well dive in there. On No-Pistons there is a guy getting about 200 hp at the rear wheels on a 6 port with bridged working secondaries. I think with a bit wilder street port on the others he could see a bit more.

 

The usual half bridge has:
Center iron housing is street ported
Front and rear iron housings bridge ported

Must have a 4 barrel carb or other seperate throttle intake system (Not a 2 barrel carb)

The goal of a half bridge is to have more low rpm torque than a full bridge motor, yet have more top end power than a street port motor. The half bridge will not make as much top end power as a full bridge port racing motor, but it can be operated on the street (if the intake system is done right) and also was popular for rally racing 20 years ago.

To meet that low rpm torque goal, then the intake system must not feed the front and rear housings at low rpm/part throttle conditions; the intake system must only feed the center primary ports at low rpm/part throttle conditions. A 2 barrel carb will not give the desired low rpm torque, since a 2 barrel feeds all the ports all the time.

 

what abou the cheese/drill port?

 

must have 4 bbl? what carb are you running trochoid? a 2 bbl? does it low end torque? i didnt think so. lol i disagree to say the least.

 

Speedturn is correct in his asssesment of keeping morelow end with a 4 barrel, of done right. And I am running a 2 barrel and low end sucks.

Cheese/drill ports are worthlesss.

 

Less said about those the better. lol