Conversion: s4 T2 to s4 NA Bridge Port
 

This thread kinda inspired me: https://www.rx7club.com/naturally-as...d-t2-n-951173/

I want to do something similar. Is it possible to simply swap the s4 T2 irons onto s4 everything else? I was thinking the s4 T2 intake mani would also be needed... do s4 NA injectors fit T2 fuel rails?

Or just go carby... does anyone know if the old school, pre-Rx-7 13B 4 port carb intake mani will fit on a s4 T2 13B block?

the housings all bolt up, no problem. the injectors interchange as well.

for the manifold, you can go with the stock T2 parts, but depending on what you're trying to accomplish (and who you ask) it's probably not optimal. going aftermarket would be better, but again, OEM stuff will work.

no. it will not bolt on without some sort of adapter. again, aftermarket is probably the ticket.

you are a good bit better off with n/a OEM lower/upper intake, and some would say 6 port irons as well, but i wouldn't go out buying 6 port irons as much as i would definitely use the oem N/a lower/upper intake manifold. you'll just have to fill in the extra port, and match them to the turbo block.

the bend into the engine is better on the NA intake. i would like to someday try that combo, NA intakes/turbo irons.

I bought a set of TII housings and a N/A engine with blown water seal lands and put them together to make one good engine. Everything works just fine.

Turbo II have the 6-port intake manifold bolt pattern, not the old 4-port bolt pattern, so you can't use an old style manifold. The ports in a TII engine are also much bigger, you would hit water all around in a 4 port if you tried to open it up to TII size.

For some reason, Holley manifolds for a TII block are a lot more expensive than for a 6 port or a 4 port.

what do you mean by that, Peejay? they're the same price on the RB site.

Huh. Used to be the manifold were $250 for everything except TII which was $350.

hey there i just stumbled onto to your thread im doing excatly the same exscept im using a 48 mm Ida weber and i wil either convert my old 4 port rx4 manifold ore i will convert the lower manifold from the Tii engine. Im also using my old front cover and dizzy, the engine will be with the pineapple rally port. the engine will arrive on the 25 so im looking forward to get on with the project.

Best regards Rasmus in Denmark

i remember there was some Tom-foolery going on with the Weber manifolds a while back to that effect. granted, that was Mazdatrix's site though.

Wait, so just use the 6 port IM, fill where needed, then port match to block?! Its really that easy?! That's good news! What would be the recommended filler? JB Industro Weld? Or...?

well. i weld aluminum so that would be my route, but jb weld will work. just get that bitch clean... like sand blasted clean.

I've been doing a lot of looking at my spare S5 NA LIM and thinking a little welding around the primaries, or complete removal and replacement in that area, would really give some room to enlarge the ports. My thoughts being, four close to equal diameters to make my upper to MC throttle bodies that much easier.

Attachment 625372

Attachment 625373

JB Weld worked just fine. I wouldn't sandblast. I just used a lot of carb clean and toothbrush to get the carbon residue off, then non-chlorinated brake clean to get the carb cleaner residue off.

I think I also drilled small holes and put a couple self-tapping screws in there for mechanical locking, before I puddled in the JB Weld. Have tape ready to tape off the port and be prepared to hold it at funky angles while it dries.

BTW - This was for a half bridge engine. When it was a street port the T2 intake manifold worked okay, but the bridge port didn't like it as much. So I modded the S4 N/A manifold to see if that would make a difference. Boy howdy it did. Best thing I ever did to the engine, even better than the half bridge.