Mixing N/A and TII engine housings/rotors
 

As the title says, I am inquiring about the mixing of N/A and TII housings/rotors and the like. I have searched tirelessly and have found little info. Are there benefits to using N/A housings with TII rotors or the other way around? I have a few S4 and S5 N/A and TII engines and am about to tear them all apart and see what I have that can be used. I apologize in advance if this thread is pointless to some, but I would like to gather as much info as possible. Maybe I'm missing something somewhere. Any info or links would be greatly appreciated.

It depends on what you want to build.

If you want a strong N/A, use 6 port irons and t2 housings, even better if you use s5 rotors and s4 housings IIRC.

If you want to build a turbo motor, keep all turbo parts together, but you can use N/A rotors in a turbo build, but you gotta have deeper pockets for all the equipment you need to buy

Either way works. It all depends on your budget and goals. Either engine is good. But, I prefer all turbo parts together. Or Turbo everything w/ NA rotors.

Any links? I am interested in N/A and TII variants. I may build both. But right now I just want to gather my info to see where I go and/or start from.

I'm not the best person to answer, but I believe people like the turbo housings because they don't have that metal thing in the way. Or they new port sleeves if you have a na housings. If I were you, I would build a high comp turbo

thanks for all the input guys. Maybe some of you can point me to someones build thread or any thread that has more information on this particular topic. I do plan to build both an N/A and TII engines, just wanted to see if there is any documentation of this and the pros and cons of doing this.

S4 NA rotors in S5 TII keg

I am pretty certain that the spark plug placement is in a slightly different position when you compare a turbo housing and a NA housing.

Thanks for all input. Every bit helps.

Rotating Assemblies have to stay together for obvious reasons.
No mix and matching rotors.
Difference in Housings
X You can interchange between NA and Turbo Housings. The exhaust sleeve is different between NA and Turbo. You can pop the roller pins out of your Turbo housings if you so desire to use the NA housing if they are better condition....or cut the NA diffusers and go deaf in the process. lol
X Turbo housings have water feeds drilled into them.
X S4 Spark locations are DIFFERENT from S5 (mix at your own risk)

Difference in Irons
X Obviously NA and Turbo are different.
X "yes you can mix and match S4 and S5 turbo irons, the S5 irons port runners are about 1-2mm larger than the S4 but it isn't enough of a difference to the engine. if running S4 irons on a S5 though you should port the runners to match the LIM ports as they are smaller." - RotaryEvolution
X Late S5 rear irons have the nice fancy bridge on the oil pedestal. (Have cracked on S4's)

That is everything I can think of off the top my head.


I apologize for my Signature.....changing it when I get home.

I'm glad 2 posts were made about the spark plug placement. I have yet to research the timing placement of breathing ports and spark plugs. But spark plug placement should not be a huge issue. Maybe the spark being in the right position of the compression stroke?

I've actually asked this question before and never got a real answer, but at the same time, a search would have me hashing out 50 pages before I got the right answer. I've heard from some gurus that the old fb gslse irons are good for na because you can port a lot. Timing? I don't know. 4 port 13bt housings being portable for na use, I don't know.

After a while I just figured you might get 200ish whp na without major porting. Less than 250?

With that many options why not build a low compression monster boost high speed, or high compression, low boost response

I guess it depends what you want, street, drag, drift, track, auto x.
Turbo size has a lot to do also, but budget limitations rule over all.