323f block swap with mx-5

shanebrk · 04-07-2010, 02:36 AM

I have a 1992 323f(astina) with a 1.6 sohc 16 valve carbed engine. I was having cooling problems and i found a crack in the wall of cylinder 2 which means i need a new block. Now I know a guy near me who has a mk1 MX-5 breaker with a 1.6 engine. I know the bore stroke and capacity of both these engines is the same but will the block from the mx-5 (miata) work with the cylinder head i have?

project.r.racing · 04-07-2010, 08:16 AM

Yes if from a 89-97 NA6 MX5/Miata/Roadster.

Clean_Cookie · 04-07-2010, 08:32 AM

off topic but random question sort of related: does that mean the engines are pretty much inteirely swappable i.e buying an mx5 with no engine would mine fit/work...

project.r.racing · 04-07-2010, 08:58 AM

yes, the NA8 MX5 (1.8/BP) have the extact same engine has 323/Astinas.

block, crank, pistons, head, cams, valves, water pump and timing gear are all the same.

the sump oil reservior and pickup is under cylinder no.4, not no.1 like 323/Astinas.
timing belt covers and cam covers are different, but bolt to everything the same.
and an MX5 has a CAS instead if a dissy, but again bolts up the same and the butterfly attaches to the end of the exhaust cam the same.

both intake and exhaust manifolds bolt up the same. the exhaust manifold is a different shape as it does not have to curve under the engine cos it sits in the engine bay rotated90 degrees. the intake manifold also intake come from the opposite side.

series 1 and 2 323/Astina throttle bodies are the same as NA8 throttle bodies. they bolt to the different intake manifolds the same.

the injectors are difference but interchangable as they are both bosch downfeed types. 94-98 323/Astina's are 233cc and 94-97 NA8 MX5s are 250 or 252cc. Cosmo has these injectors fitted to his hardtop.

the injector rail is the same shape but the vaccuum and fuel feed pipes are different due to the different shape intake manifold.

04-07-2010, 02:36 AM	#1
shanebrk Junior Member Join Date: Nov 2009 Location: Ireland Car: 1992 323f Posts: 4	323f block swap with mx-5 I have a 1992 323f(astina) with a 1.6 sohc 16 valve carbed engine. I was having cooling problems and i found a crack in the wall of cylinder 2 which means i need a new block. Now I know a guy near me who has a mk1 MX-5 breaker with a 1.6 engine. I know the bore stroke and capacity of both these engines is the same but will the block from the mx-5 (miata) work with the cylinder head i have?

04-07-2010, 08:32 AM	#3
Clean_Cookie obsessed-incomplete-broke Join Date: Oct 2008 Location: Brisbane Car: BA Hardtop/Hatch Posts: 5,441	off topic but random question sort of related: does that mean the engines are pretty much inteirely swappable i.e buying an mx5 with no engine would mine fit/work... __________________ Worklog

04-07-2010, 08:16 AM	#2
project.r.racing Senior Member Join Date: Sep 2004 Location: n/a Car: n/a Posts: 10,929	Yes if from a 89-97 NA6 MX5/Miata/Roadster.

04-07-2010, 08:58 AM	#4
project.r.racing Senior Member Join Date: Sep 2004 Location: n/a Car: n/a Posts: 10,929	yes, the NA8 MX5 (1.8/BP) have the extact same engine has 323/Astinas. block, crank, pistons, head, cams, valves, water pump and timing gear are all the same. the sump oil reservior and pickup is under cylinder no.4, not no.1 like 323/Astinas. timing belt covers and cam covers are different, but bolt to everything the same. and an MX5 has a CAS instead if a dissy, but again bolts up the same and the butterfly attaches to the end of the exhaust cam the same. both intake and exhaust manifolds bolt up the same. the exhaust manifold is a different shape as it does not have to curve under the engine cos it sits in the engine bay rotated90 degrees. the intake manifold also intake come from the opposite side. series 1 and 2 323/Astina throttle bodies are the same as NA8 throttle bodies. they bolt to the different intake manifolds the same. the injectors are difference but interchangable as they are both bosch downfeed types. 94-98 323/Astina's are 233cc and 94-97 NA8 MX5s are 250 or 252cc. Cosmo has these injectors fitted to his hardtop. the injector rail is the same shape but the vaccuum and fuel feed pipes are different due to the different shape intake manifold.