j200pruf

Hey all I was just wondering how well a 6 port motor with mild primary ports and a mild exhuast ports would run with the secondary and aux ports shut?



I am trying to find a way to get a bridge or aggressive street port motor through smog testing. I was thinking of ditching the stock aux port sleeves and machining an adapter between the intake manifold and engine that would house some bike carb slides machined into valve things that would shut the secondary and aux ports.



I was also wondering what ppl's thoughts are on running IDA and/or DCOE manifolds on the street( I would be using TB;s with a standalone of course).

White_FC

Well as stock the 6-port engines run entirly on the primary ports up until 15% throttle opening...



So it'll drive just fine, will be slow as all fsck..

mazdaspeed7

It will work, and you could pass smog like that. But youll have to block off the runners as close to the engine as possible.



I do that for break-in on heavily ported motors.

GMON

If your goal is to pass smog you should just drop in an engine that will pass. From what you said it would be less work.



GregW

j200pruf

The aux ports on E Spec cars is right off of the housing so I think my idea should work. Hopefully I can get the carb slide thing to work since there would be nothing in the way when they were open. And GMON, I will be going to this much trouble anyway to keep the aux ports functioning as they do stock.



Now I slowly have to start buying parts for the next motor Cuz I want to have a backup incase my current engine dies.



But what about ppl with really short intake manifolds, like the one that I described?

kahren

on a stock motor the primay ports only seem to peak at about 3k rpm.

it woudl drive normal, prolly even better then stock, but its been alittle while since i drove a stock car so i cant compare too much.

ArmyOfOne

I am working on something like this right now. I will be picking up the rest of my parts by friday. I will be using carburator throttle plates that are actuated buy main throttle position.

kahren

mayeb u can just pick up a euro manifold from one of our euro friends on this forum. they use that style manifold from factory

j200pruf

I was going to jsut use carb butterflys, but then I realized I could use slide out of a bike carb. These will leave the port completly open with nothing blocking flow.



I think I should be able to put them in a adapter plate for the 4 port manifold like this.

ArmyOfOne

The "euro" manifold would restrict flow too much, the RB 6 port manifold is somewhat tuned and flows a lot more. I can see how the euro might work best with the turbo but not N/A.



I looked into the slide thing also but it would add length to the runners and completely throw the initial setup off. The home made butterfly setup is the most cost effective and should yield similar results to the sleeve and slide.