hey guys, i just picked up a set of 12a irons to convert my 6 port 13b to a 4 port when i get it rebuilt and i have a few questions.

1. i plan to do a weber downdraft setup, would the racing beat 4 port manifold for any 13b work? or do i have to get a custom one?

2. do i need any extra parts other than the 12a irons to complete the conversion? it came with the 12a water pump. could i use my 13b water pump? oil pump? etc?

basically my main question is what do i need other than the 12a irons to complete the conversion?

 

Everything will be a direct swap except for, obviously, the intake manifold. Make sure you get one for a 4-port 13B and not a Turbo II, they are much different.

You *may* need to plug a tension bolt hole in the rear housing. Maybe.

When 4-port 13Bs were made, they used the same side housings as contemporary 12As.

 

thanks alot pj i really appreciate the help.

 

1. like peejay said, make sure it's for the old-school 13Bs. the newer 4-port manifolds are much different.

2. use the 13B oil pump because it moves more volume. get an REW regulator and shim the front. other than that, everything is pretty straight forward.

 

REW regulator and shim the front? any suggestions where i can find the shims? im assuming u mean shim the front iron... if so, where? could i just simply stack metal gaskets, lol? (are there even any gaskets between the iron and the housings?) and what kind of regulator? this sounds kinda broad... i apologize for being a noob, i work on aircraft more than i do cars, this is my first rotary as well. hope u guys dont mind clarifying all this for me, i wanna build this motor for reliability so i plan to do it right.

 

 

I wouldn't worry at all about the oil pressure on an engine with 3mm seals, stock oil pressure will be just fine. You won't be able to rev it high enough to hurt things with only 70psi. That's the nice (?) thing about 3mm seals, they force you to keep the revs low, so there's no point in doing all sorts of oil system mods or clearancing - just slap the parts together and go.

BTW - I use 12A oil pumps on early style engines because they're smaller. Less power loss to the oil pump. They still make 70psi by 3000 or so.

 

ah ic, 13b oil pump and rew regulator with a shim to change the pressure... i had to re-read that one, i didnt realize. once again, sorry for being a noob. thanks again pj and diabolical, appreciate the input... and thanks to the smart guy up there for making me feel real welcome lol.