Oil filter question
 

Hello everyone!
I have a 2005 year car with recently replaced engine, which was supposed to be new. I saw some members of this forum who doubt that new engines may be found theese days. But I've paid over 5K bucks for this one, the seller sweared it was brand new, from the warehouse, and it had proud N3H3-02-200 title on box with no any "R" suffixes and with no blue tags on engine itself. Though I never saw any documents on it. The engine came to me in a box with mazda stickers but without a single paper.
Now the question is: if this was really a new engine, should I maintain it with parts for series 2 cars, despite my car being 2005? I mean - parts, relevant to engine, particulary - oil filter. I've read here on forum, that one should use only original mazda oil filter with series 2 engines since it's connected to oil pressure being different on theese engines. Oil pump, being a part of engine, was obviously replaced.
On the other hand, engine may be series 1 even if seller did not intentionally fool me. Manufacturer must supply customers with maintenance parts many years since car production ending.
Is there any way to finally establish what engine have I got, for example from it's appearence? All I can see on the engine is number "561414".
I understand, the question is difficult, but I could make some photo if someone would tell me what to shoot. After all, now I'm just intrested in one simple thing: what oil filter to install. Much thanks for any tips and your attention!

Alright, looks like the question is solved. More thorough searching revealed that:
1) Series 2 engine cannot be labeled n3h3, because their labels start with n3r
2) Looks like theese engines have only 4 fuel injectors, while s1 have 6. Therefore installing s2 engine to s1 car by difficulty is something sitting close to installing 2jz-gte there. Obviously not what was my case :)

Well good research
(wiserhood clap)

I'm pretty darn sure 99.9999% sure they didn't put an SII engine in your SI
The reason is this thread.
https://www.rx8club.com/series-ii-te...n-done-222458/

That said it's not impossible just highly improbable
And I've not really paid any attention to such things other than that thread.

I suppose it could possibly be a brand new Series I engine, but I doubt that as well, however its more possible than a series II engine being replaced in your 2005.

Yes the SII engines only have 4 injectors.
The SI originally had 2 versions the low power engine had 4 injectors the high power had 6 ... later at some points they went to just making the high power version.
(at least for NA models)

So after all that, yes like close to installing a 2jz-gte

I'm new to the rx8 thing and I just purchased a 2004 4 speed automatic. I've run into a problem recently. I'll get on the interstate and go about 75-80 for about and hour and my car runs very smooth, but when I get off the interstate and come to a stop light or stop sign, my car while idling drops under 1000 rpms and most of the time dies. Once I get it started back up, which takes awhile, I have no power until I've reached 3000 rpms in 2nd gear. I have no idea what's going on. I saw that it might be a fuel pump, but I'm not for sure.

Hi! Probly not a best necrothread for this question) But as I'm an OP, i'll try to answer)
First (and simplest): do you have any idea about what is your engine's compression? At least, what is its mileage? If it's anywhere above 60k miles, and the engine was never overhauled, it's probably rather near to death from apex seal failure. The car is old enough, and if previous owners did nothing to engine yet (rebuild, replacement), you should get ready to serious problems. In fact, such cars are most frequently sold with engines almost raped to death. Trust me)
But if you're very lucky, and you've got car with great, recently rebuilt engine then the area of search widens: vacuum leaks, MAF or O2 sensor failure, dusty throttle, etc. But nonetheless, the problem is MUCH less then.

Common causes:
- low compression (hard to start warm, stalls when coming to a stop are classic signs)
- ignition failure (leading to low compression)
- fuel pump overheat (though that would manifest while running at speed, not just stop signs)

Next steps:
- compression test to determine the health of the engine (best done before purchase). You need Mazda for this, regular non-rotary specialist shops don't have the equipment to do it properly. The output should be 6 numbers @ rpm, which will determine whether you need a new engine or not.