2nd Generation Specific 1986-1992 Discussion

13b compatibility questions...

Old 03-09-2011, 11:57 AM
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Join Date: Jan 2010
Location: nor-cal
Posts: 8

So my '76 cosmo engine needs a rebuild, but due to smog requirements and parts availability, I'm exploring the possibility of swapping in a good used 13b from an ,85 gsl-se 6 port. I only have the complete block, no accessories, flywheel, etc.

My question is what year engine's accessories will swap on to this block... and will everything from a bad turbo II swap over (turbo included!)???

Also, will the stock ECU from a later car operate with my instrument cluster, or will I need an aftermarket engine mgmt system?

Any help is appreciated... hate to blow money on stuff that won't work.

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Old 03-09-2011, 09:38 PM
Join Date: Aug 2007
Location: uranus WA australia
Posts: 59

rx4/5 13b flywheel will suit these rotors ( same with auto counterweight if selecting a light flywheel )

the later s4/s5 engines share the inlet bolt pattern,, though only 6 port ones match the engine runners

( you can weld up and port the t2 LIM to suit )

the s4/5 manifolds will allow you to use 4 injectors for sequential operation ,, and allow you to chose aftermarket ECU to do so

( earlier GSL-SE is only two primary plate injectors )

you will also need the s4/5 CAS to utelize a modern ECU ,, and no these do not talk to the dash cluster

the dash on the rx5/cosmo is all mechanical,, you only need to fit the temp sender and oil pressure switch that suits the dash to the new block

in an rx5 engine bay on a right hand drive vehicle

you will need aftermarket turbo manifold to hold the s4 turbo

( and that may require further mods if you chose to use the NA inlet manifolds )

however,, if using modded t2 LIM ,, you can flip a s5 turbo manifold upside-down, oval two holes, add a spacer, bend the water pipes ,, and it fits and works

( this mod moves the turbo forward to adjacent the front rotor )

i am not so sure the turbo manifold mods apply directly to left hand drive vehicles ,, as you have much more room

alternatively,, there is manifold adapter avail for these to fit the 12a or 13b manifolds and carbs ,, though the EGR and ACV will amount to being deleted
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Old 03-09-2011, 11:20 PM
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Join Date: Jan 2010
Location: nor-cal
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Wow... great info!

I understand that going to t2 stuff on a n/a engine will a create problem with too high compression? I should probably stay n/a just to get my feet wet and keep things simple.

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Old 03-10-2011, 07:10 PM
Join Date: Aug 2007
Location: uranus WA australia
Posts: 59

i have run 9.4:1 under boost AOK

you need to be conservative with ignition timing at boost to make them live

the GSL-SE though is 9.2:1 ( same as rx4 13b ) and this is not all that far from the 9.0 of the later FC and FD turbo engines

if done well with sequential injection

( which brings economy and drivability gains down low to the batch fire 2 injector motors )

it will work well if timing is revised,, and the fuel system upgraded to cope

it s quite OK to set the motor up NA now with intention of evolving it later to be a turbo-- much of the support hardware is the same beyond the turbo and maybe the injector sizing

if you set this NA engine up as 4 x 550 injectors ,, you will be covered for just over 250 rwhp later if adding a stockish turbo

my main concern is that you set it up now with the right selection of ECU

,, one that has user adjust for the map definition and plots

,, or can use a combination of TPS input and map sensor for load input

( so they can be skewed to have more plots in the NA ranges )

one that also works in closed loop will be very beneficial in helping pass local emissions

cheapest, best rep, best support with best fit for all these qualities is almost certainly the haltech sprint RE range
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