Got the templates for an agressive street port, but since emmisions dont really matter now can I use the template and turn it into a half bridge???

Looking at photos i cant seeing it being that hard???

Help.

 

Come on lads I need a bit of BRAP in my life

 

I take it most of you's can't then??

 

if you have room for the corner seal to ride the bridge then, yes.

 

I'm no expert, but the RB street port template I have is also for a bridge port. That said, I hear RB templates are "mild". As stated above. Make sure you have enough metal left to leave a bridge. To keep the leading edge of the side seal safe, the eye-brow port can really only extend about 4.5mm out from the rotor housing. Maybe 5mm. No more.

 

This is about as big a streetport you can go and bridgeport it. If you look closely at the first picture you can see a scribe line next to the opening edge of the port that is the path of the leading edge of the sideseal and the wall on the coolant seal is a little over 1mm thick that's about the thinnest you want to go or you will be worrying about it cracking and breaking pieces into your engine. Hope these visuals help you out a bit. This is a motor I just recently built this pictures are the beginning of the porting just rough cuts. I'll try to get pictures of the finished product up.

 

when i did my Bridge i left the opening edge of the port just to get as much metal left in the bridge as poss, The Only way you can realy open the port is up (the closing edge) and when you cut the extra Port make sure you relive the Rotor Housings so you don't block them back up with the Housing and most Importantly leave as much as you can around the water seal groove.

Remember its more about the Runner than the Port its self, and not taking to much out of the Bridge as to weaken it.

You can't realy use an Agressive Street port Template as it takes metal out of the opening edge of the Port (which you don't realy want)

 

Couple more shots.

 

The template I have is one of judges.

I have had a look today and seem like it is possible, but I might make the port 1mm shorter so the bridge is slightly bigger. I'll not know till I scribe it out.

13btnos: nice looking engine there

Half bridge means the primary is street ported and the secondary's are bridged??

 

Yes that's exactly what a half bridge is. This motor will be N/A it has 4port turbo plates full bridged and 9.7 high compression rotating assembly. This will go in a little Datsun 1200 which should make for a fun little car. Picture is of a 1200 but not the one it's going into. Same color but different rims my friend's has Weld Draglites on it.

 

Them datsuns are cool as f*ck. My old man used to have one.

I'll have a look at my templates 2morrow and work summit out and post on here for some advice.

Thanks again.

 

What does a half bridge port idle at???

 

bump

 

well mine used to idle at 1100rpm but people have been known to set them to 900 for the real Brap sound and higher to reduce the Bucking at low speed.

But i liked the 1100 as it was a good mix of both worlds.

 

I can live with 1100rpm, just didn't want it at 2000rpm.

As you can see fromt he other thread I have already started doing it.

13BNOS: Can you give me the diamensions of the exhaust port your using??? I dont have a template for the exhaust so it would be a massive help.