Possible 4-Port N/A Start?

[infernosg]

EDIT: nvm...

Why can't I delete my own posts?

[vex]

Originally Posted by infernosg

So for the longest time I've wanted to do a 4-port N/A build on my '89 GXL. I've found an engine locally for a good price that may be a good candidate, but I'm not sure. It's a '88 TII engine w/ 100k miles on it. I'm told it holds compression but the coolant seals are gone. I'm really only interested in the housings as my plan consists of swapping in a S5 front cover, RX-8 e-shaft and some S5 N/A rotors (RX-8 rotors would be nice, but I've heard there are timing issues?). Ultimate plan would be a streetported or bridgeported motor with ITB's and being controlled by a PS1000 or Sprint RE.

I don't believe there are any timing issues with the RX8 rotors. Same physical dimensions--just higher compression ratio and that comes in the tub.

I'm just curious if I should be weary of the coolant seal failure even though I will be rebuilding the engine from the ground up. Also, are there other incompatabilities between S4 motors and the S5 chassis I should be aware of?

Coolant seal failure motors are a crap shoot. It could just be a simple seal gave out and it hasn't done any damage to the housing. However, when my coolant seal crapped itself, the actual housing that held the groove for the seal had been removed/fell out/eroded away. Depending on how the seal went bust the engine may have been over heated.

There is minimal incompatibilities between the S4 and S5 motors (I'm currently running an S5 rear plate since my S4 took a crap)

Originally Posted by infernosg

So I'll want to hold onto the S4 front cover, water pump, water pump cover and OMP it seems. Either that or swap everything over from a S5, but I didn't want to have two engines pulled apart at the same time so I could actually still drive the car

You can swap what ever you want from any gen 13B except the renesis. The trouble comes when you want to use alternate versions of the same engine. IE you can't go between an S4 and S5 front cover and oil pump/distribution block. A little research could help you out with the details.

Seller mentioned one or more of the coolant o-rings have failed, but that the engine still ran. Waiting to hear back from him so I can go check it out.

Has anyone else gone retro-active with a S4 motor in a S5?

It should be fine. It's the same basic engine, it's just the OMP is mechanical instead of run via a stepper motor (and a few other odds and ends).

Originally Posted by infernosg

EDIT: nvm...

Why can't I delete my own posts?

because you're not 1337! You has no powA' here!

[infernosg]

^^^ Figured as much. I know I could easily just swap the front and rear covers from the current engine in and call it a day. Only reason for considering the S4 front was because of the mechanical OMP, which I'm on the fence about keeping and I don't really want to have to pull the current engine and have the car down for the entire duration of the build.

The RX-8 rotating assembly is tempting - I just thought I read somewhere (probably RX7C) that the RX-8 rotors weren't necessary a good change, despite the increased compression, which is something I'd like to have.

Hopefully will be checking out engine today. May also be picking up the transmission as well (don't know if I'm going to use it or not though).

EDIT: Still debating between a small bridgeport (not cutting into water jacket) or large streetport for the motor. I've read a lot on both and am still not decided. Can anyone make a case for either?

[SLIDN2]

Originally Posted by infernosg

^^^ Figured as much. I know I could easily just swap the front and rear covers from the current engine in and call it a day. Only reason for considering the S4 front was because of the mechanical OMP, which I'm on the fence about keeping and I don't really want to have to pull the current engine and have the car down for the entire duration of the build.

The RX-8 rotating assembly is tempting - I just thought I read somewhere (probably RX7C) that the RX-8 rotors weren't necessary a good change, despite the increased compression, which is something I'd like to have.

Hopefully will be checking out engine today. May also be picking up the transmission as well (don't know if I'm going to use it or not though).

EDIT: Still debating between a small bridgeport (not cutting into water jacket) or large streetport for the motor. I've read a lot on both and am still not decided. Can anyone make a case for either?

Half Bridgeport TII engine NA (loving it).