Okay so I finally found a motor for my rx-7. A member on the forum here has S5 block that I am planning on getting. ( I have a S4 1987) I am taking all the accessories , intakes and manifolds and putting them onto the S5 block. I am trying to make a check list and making sure that this swap will indeed work.
As far as I know from what I have found searching I need these items.
1. Flywheel for an S5 motor ( Im assuming this bolts straight up to the stock tranny)
2. S5 Temperature probe for the rear iron.
3. Front Covers must be swapped to accomodate the different OMPs?

Are there any big no no's that I dont know about?
Any potential trouble spots when swapping everything over to the S5 block?

 

Watching....

I am going through this same process. I'm getting my S5 engine prepped to go into my '86 GXL.

 

This is an NA, right?

1)The flywheel does need to match the rotors, so an S5 is correct. NA flywheels are the same size regardless of series, but the integrated counterweights are different.

2)S5 temperature probe? Not sure what you would want/need this for, since you'll be using all S4 electronics.

3)The front cover does need to be swapped to S4, along with the OMP, OMP linkage and water pump housing. The S5 water pump housing is slightly different.

Other things: The emissions ports on an S4 LIM won't line up properly with those on an S5 block, so hopefully you don't need to smog the car. I would suggest keeping the S5 manifolds and fuel rails, then rigging 2 rpm switches\ 2 solenoids & the air pump to operate the 6PI and VDI systems. By doing this, you'll gain some top end power, and also be able to pump air to the exhaust ports to pass smog.

 

Is this still required if your OMP is blocked off and you run premix?

 

Nope. But you would still need to use the S4 TB, since the S5 TB can't use the S4 TPS without modification.