I hear blocking it with silicone and whatnot... but how is this all done?



Here is a thread started in the other forum, has more information than here.



http://www.rx7club.com/showthread.php?t=781852



Here is a picture, I have a stock 12a Iron on bottom, then a smaller bridge (comes within 1mm of the coolant seal) that is black, and the larger bridge over the top.



The big bridge I know has worked and ran, but the coolant seal is what has me mystified.

 

First, drill a bunch of holes through this area in a junk iron, to get an idea of how deep the port can be without striking water. Near the closing line the port must be very shallow.



The seal groove is blocked with a roll pin or a piece of the drill pit shank used to drill the hole. A shallow hole held back from the port about 3/8". Look at your junk iron and use it as a depth tool to set you drill press stop. Lay in the seal. put a drop of silicone on the end of the seal. From that drop of silicone, seal along the outside of the seal groove on the iron on up to the other roll pin or shank piece.



So now you should have a bead of silicone from seal end to seal end along the outer seal groove wall.



Go easy on the silicone, as 98% of it will squish out when the stack is torqued up. The pins in the groove keep the seal ends from extruding into the port. So choose a pin diameter that fills the groove. Make the pin flush with the surface, and the housing will hold it in place. I can make drawings if you want them.



Turn the assembled engine over backwards a few times and rake the excess silicone out through the exhaust port.



Make the bridge wide enough to support the corner piece of the apex seal, if the center iron is not ported, assemble the engine with the corner pieces against the center iron.



Lynn E. Hanover



Here is your port in a 12A iron. Same thing is done to the rotor housing as far as pinning the groove.

Note the sliver of iron left to seal against the rotor housing to keep water out of the port. But it works just fine.

 

Thanks Lynn, I knew you would be the one to chime in



What kind of powerband do you expect from a motor ported this high? I don't want to do a 10kRPM motor, but I guess when you get going, might as well finish, eh?

 

Port I am using, and then I painted where the port is on the housing. Would that small bit of housing work for the silicone?

 

With 38MM chokes in a 48IDF Weber, we get 250HP. A 13B maybe 265HP. More based on choke size

Or, TB size.



This sheet only goes to 9,000. I cannot find the rest of this one, but peak is 9,400 RPM and shifts are at 9,600 RPM. Note the EGTs to keep carbon apex seals in good shape.



Lynn E. Hanover

 

There is more than enough to get a good seal. If racing rules are not involved, you can fill the water passage in the iron with a metal filled epoxy. You can do this on the rotor housings, alone and no water can get through. This is none when a Pport housing is fabricated. The rotor housing adjacent to the runner in the iron is filled solid with epoxy. No coolant is needed in this area. If there is no water next to the port, nothing can leak.



Lynn E. Hanover



The picture is a fuel cell fitting in the last car.