Okay just when I thought that I had the answer I look at Mazdatrix site and see that their bridge port on the rotor housings is cut into the water seal groove. How is the seal used? Mazdatrix bridge-port

 

Its a J port they are showing in the photos.

 

okay....so on a j-port how are the water seals used? JB weld? I cant imagine any other way.

 

Yip, JB Weld is used.

J-port is normally used in a class where PP is banned/not allowed.Normally the life span of a Jport is very short compared to other port configs,as the water will start leaking into the housings after some time.

 

What's the difference half bridge compare with full bridge. Is that idling 1.5k rpm above problem for full bridge?

 

full bridge has the primary and secondary ports bridged, half bridge only has the secondary ports bridged

 

A half bridge engine is built for a compromise between a street port and a full bridge port, for situations that need more low rpm torque and driveability. The porting is as Bucky says above.

To make the half bridge deliver more low end torque, you need an intake/throttle system that does not feed the secondary housings at part throttle / low rpm situations; it must only feed the primary center housing primary port during low speed situations.

 

gunna jump in here while we're on the subject... how does the half bridge port compare to a street port and full bridge port on reliability? Is it right in the middle of the two as well? I know the street port stays on the more conservative end and is more reliable and gas friendly, and i know the full BP is more hectic... so how much of a compramise is the half-BP?

Thanks,
Mike

 

Reliability isn't a question if the cut isn't too big with a thick bridge remaining. I've got about 35 half-bridgeport engines out there right now and not a single one has had an issue w/ reliability due to a bridge breaking. I think the reliability comes into question when the bridge is uber-thin and/or there's a breaking into the water jacket purposefully.

B

 

Great info! Thanks fellas.

 

Thanks BDC.

 

sorry but i kinda got thrown off with how a half bridge works when you mentioned something about throttle/ inatke and primary and secondary stuff. i plan on having a TII ported and want to go as extreme as i possibly can for the road and was looking into this

 

If I understand it right, since the secondary rotors are the ones getting the bridge port on a half bridge, and the bridge port is what causes the rough idle and poor low-end power, then you want an intake/throttle system that will only feed air/fuel to the secondary rotors at higher RPMs and high throttle situations.

 

In other words primary ports are used at idle and for low-end power. The secondary ports are in use when the engine is normally being pushed for power. Dont know if that made sense? lol

 

Great info!!!

 

if half bridge for 20b @ 25psi roughly can b achieve how much whp?

 

depends on your turbo. on stock twins you'll probably make about the same power as you would at 13PSI. maybe less. with a large single turbo, you'd probably make a **** ton of power...and yes, **** ton is a technical term.

 

Well, I'll swap in large intercooler, xtreme 10mm stud kit, Garrett TA45 turbocharger and Microtech LT12s for this half bridge setup. Cause i'm new to rotary. Can u figure out the whp (roughly)? Thanks