Allright so it has come time i put my rx7 back togeather and drive it, i was looking onlone for a new engine for it.. i found "1975 mazda cosmo 13b with header and other parts, holly carb. Engine is a complete long block that has just been street ported by rotory reliability." (he is only asking $300 he needs it out of his garage) its a non turbo engine and my car is turbo im trying to decide if i should use the engine in my car as a non turbo or just run low boost... i was planing on just fiting my intake and exaust to it and geting rid of the carb set up.. And i was wondering with it bolt up to my trans??
Thanks chris

 

There are many complications with such a swap, but first and foremost the mounts from that Cosmo and an FC are completely different.

 

Bad idea...

Best bet would be to pick up a jspec turbo motor if you can't find one locally. Either may need to be rebuilt.

A cheaper option would be to run a series appropriate n/a engine that would actually bolt up. GringoGrande has a petit s5 n/a for sale in the SE section.

 

is the block the same can i just bolt my stock mounts to it?

 

i have a engine allready it just needs to be rebult it a s5 turboII but i over heated it and the apex seals stuck in but a rebult kit is expensive... i figured if the cosmo engine would work for $300 even if i have to do a little fabrication it would be worth it even if i have to go NA for now..

 

the blocks are not the same.

the cosmo engine has motor mount attachment points on the front cover. s4-s5 has engine mounts on center iron.

listen to these people and dont even bother trying to talk yourself into this deal. it wont work without a lot of time and money/skill. do it right, do it once.

 

The n/a 13b mounts are the same. If you you want to keep it n/a some of the sensors may be in different places, so the harness may need to be modified. It will bolt up to the turbo trans.

 

so custom mounts and wiring up a temp sensor and tach and bolt it in.. as long as i keep it carb and dizzy....?

 

carb means that you are going to have to change your fuel pump to a 4psi unit instead of the stocker thats designed to run something like 40psi. also will have to wire a coil and ditch the stock coils or somehow get the stock cas to run the motor. it sounds like a huge ******* mess to save a measly 300$ (600$ rebuild-300$ for janky motor) up front.. which you will probably easily blow through retrofitting all this hack mess to your car. and still not have power or have it run right. you will spend the difference you saved with the purchase of the now necessary exhaust **** alone.

my opinion says that if you start this, the car will never make it back onto the road

 

That is not what he is saying. He is saying a fuel injected N/A 13B from an FC would bolt up, but the harness may need some modifying.

Forget the Cosmo engine. It will not work. Unless it's a 13B-RE from the later Cosmos, but that's a whole other story.

 

ok...for a second I thought I was unclear.

Which brings us back to my original post.... BAD IDEA!