identifying rotary (year, type, na-turbo)
 

Hi everyone,

I'm quite new to this place, so my apologies if this is an often asked question. In 2 weeks time I will be visiting someone who has a 13B for sale. He claims it is an S5, but reading the emails he sent he does not come across as someone with a lot of technical knowledge. The 13b he is selling is supposed to be a 13B-Tii, from an S5 series, which had a rebuild not to long before he got it (he claims he has it for 2 years now, never installed). My question is; How can I identify the engine as such being a 13B-Tii S5? I do not want to make the mistake of buying maybe a S4 or S6 block. The engine itself is bare, no exhaust, no turbo, no intake. Also, any tips to check if the rebuild was done correctly without tearing it apart in the guy's driveway? It would be great to get some advice from you all.
Thanks!

Look in the exhaust holes, turbo engines are wide open, n/a's have a diffuser (kinda looks like a crappy paper airplane)

Also the s5 t2 rotor housings will have a threaded hole above the spark plugs for a knock sensor, s4's do not

Look at the the front and rear irons also, n/a's have 2 holes stacked for the intake, t2's are single oval shaped

Those are the biggest differences, now if internals were swapped, theres no way of knowing unless you open the engine up

Great advice! Thanks :). Do you happen to have a photo of the diffuser you're talking about? I can't quite make out with what you mean by that.

Let's just hope the internals are from the same engine as the external parts...

welcome to the board. :)

S4 to S5: the only things i can think of would be knock sensor bosses, spark plug location and the MOP.

S4s don't have a boss for knock sensors, S5s do.

spark plug location is sort of meaningless without an actual measurement or an S4 housing to physically compare it to. that said, the difference between Leading and Trailing are different between S4 and S5. however, the knock sensor would let you know to begin with.

with the MOP, you're basically looking for electric versus mechanical.

the rotors may also help if you are able to get a halfway decent look at the recesses through the exhaust ports. S4 is cast, S5 is machined and if the engine was rebuilt as you were told, then the recesses should be clean enough to tell, if you are able to see them in the first place.

S5 to S6: secondary port runners, past EGR area, front cover

the S6+ engines have comparatively huge secondary port runners compared to an S5 (which pretty much is the same as the S4)

the EGR area is a little hard to explain, but i will try. here goes, if you are familiar with the EGR port on some past engines, where it incorporated a port in the top of the intermediate housing, then you'll see that the T2 engines maintain a flat area with the same general shape/outline. the S6+ engines do not have that flat area. i hope that makes sense. chances are an identification won't come down to that, but if for some improbable reason, it does, i can take photos and post them for you.

the front cover is fairly simple. the S5 used the CAS based on a distributor, so there will be the hole for it on the right (facing the front of the engine). the REW will have the two CAS sensors on the right, but around the periphery of the hole that the eccentric shaft passes through.

i hope this helps. also, keep in mind that some people mix and match parts in rebuilds, so it will then be a question of where you think an S5 block begins and ends (rotor housings, front cover, rotating assembly, etc).

as for your question about checking the quality of the build, that can't be done without pulling apart. however, if the seller really never used the engine since it was built, then you should be able to pull it apart, check everything and theoretically re-use the soft seals when you re-assemble it.

Wow, quite a comprehensive description, I think it will help me a lot to identify the engine in question:). If the rebuild is done good, I will re-use the apex-seals, oil rings and bearings, but not the water seals etc. A new kit for those isn't that expensive, better safe then sorry. The plan is to pull the engine apart if it checks out, port it to a race-port (pineapple racing template), if needed relapping the plates, and give it some more side-seal clearance. I want to put the engine in my rally-x car, but still keeping it somewhat 'normal' in terms of driving characteristics.

there are also casting letters on the irons.

the FD uses N3A1/N3F1/N3G1 castings.

the cosmo uses NF01 castings.

the Rx8 is N3H something

unfortunately i haven't made the full list of casting numbers yet, so except for the S4 T2, i don't know which letter goes with which engine.

the JDM S4 T2 uses G/G/G irons, the US spec has a different center. there are D and E, and maybe F castings too, one of these is S5 T2 (i wanna say D) and the others are S4/S5 NA

if you see something like a Y or an R5, its an older engine

the S5 and later engines have a boss above the spark plugs for a knock sensor, the S4 and earlier engines do not.

also, if you goto Banzai Racing Home Page and go under their FAQs, they have picture differences, I would've copied and pasted the link, but the URL doesn't change when you goto the page, I'm guessing its flashed based

Thanks for the advice, and the website :). I printed out the photo's off of Banzai's website to take with when I pick up the engine:). I think all my questions on this topic are answered:). Thanks guys for the help and the quick replies!