heretic

Perhaps then I had the rare 3mm seal FC rotor housings, or the 2mm seal 12A housings. (Not likely!)



It is good to actually measure things and experiment instead of playing librarian and repeating what everyone else says.



For instance, there was a diagram in the late 60's put out by Ford detailing the upgrades made to their small block when they bumped the displacement up from 289ci to 302ci. (1/8" more stroke, biiig deal) On the graph was a notation that the cylinders were made deeper to accomodate the stroke. This may have been something the engineers intended to do, but somewhere in the lead time between making the graph and actual production of engines, that dimension ended up NOT changing. So you get a lot of people regurgitating that the 302 has a longer cylinder wall, you can't put 302 cranks in 289 blocks or all manner of bad things will result, and so on. And the people who bother to sit two blocks next to each other and measure find out that it's been the same thing all along, and the diagram was in error...





Do not also forget that for the FC engines, the turbo rotor housings are drilled for coolant flow to the intake manifold and the non turbo engines are not. This needs to be dealt with if cross-pollinating.

bumpstart

LOL

is black blue?



i can aslo recall seeing the mazda article showing the changes to the trochoid

so your calling mazda and cerment liars??? could it be that your wrong??



have you seen the very slight housing contact that 13B 3mm rotors make near the combustion zone under boost in 13Bt housings ?



i have

i have also lay-ed the two different housings on same dowels and i could see the difference with naked eye



the rotors will swap, and run OK, but not optimum OEM sealing pressures or angles





thanks for your misinformation



take it or leave it,, at least i provided some backup for my statements

( thanks cerment , though apparently you don't know how to measure a housing, and should get out your straight edge ????!! )

i have done the swaps, and noted the results

i failed to take photos of this sort of crap because--

gee- pre digital camera days , and mazda state it plainly