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Need 6 port bridging advice

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Old 10-09-14, 12:23 PM
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Need 6 port bridging advice

I know that many of you may see the title and think "oh boy another one of these" but I've looked around and can't seem to find an answer on my specific question.

I have an SE 13b with a weber 48 (bored to a 50) DCO/SP carb with 44mm chokes and racing beat upper intake on it, and currently it is stock port with no sleeves. This will be going into my next FB, and I've been thinking about bridging it to make full use of the big 'ol carb (it seems a little excessive for a stock port doesn't it?)

However, my plan gives respect to the fact that the aux ports do not need any more opening time or increased volume, so I plan to get the atkins ramp sleeves, and somehow affix them in the open position, but as far as porting, I won't touch the aux ports at all (my actuator rods are cut and the holes in the LIM for the rods are plugged). Any tips on how to freeze them in there? I thought about green loctite but I'm not sure if that would stand up to the heat, and I'd hate to have a sleeve rotate closed on me at a random point in time.

Anyways, back on topic, I plan to do a small full-bridgeport to the center primaries and secondaries only (with no rotor housing relief, just up to the edge of the housing) to advance the intake timing but retard it no further. So this will be a relatively small bridgeport, concentrating mainly on flow improvement (NASTY casting **** left over in the stock runners) and advancing timing slightly, since the 6 port already has plenty of port area. The exhaust will be widened and cosing time retarded just a touch.

Now, my question is, I realize there are no bridge templates for a 6 port, however since all rotors follow the same path in every rotary, theoretically I should be able to use any old 12a bridge/13bt bridge template for the secondaries, but cutting only up the the point of the aux port and stopping. I can go all the way down on the template and the bridge timing will be correct there. The main problem I see is on bridging the primary center ports, as they are much smaller in this engine, so I'm not sure just overlaying another template to the primary would give me the right amount of material I need to remove without breaking into the water jacket. How does one sync the timing of both primary and secondary bridges on one of these? Is there enough material behind the primary to do a regular-sized bridge? Anyone that's done a 6pbp (i know there are a few of you) got any tips/advice? I feel like this set up I have in mind has potential for good all round power with not-too-terrible driveablity (I'd rather it be fast than pleasant to drive).

Thanks,

Jon
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