i have an 83 12a rx7 that im turboing, blow through. Its time to address my oil issues. What oil pump do i have in the car? is it the 15mm or the smaller 12mm and which part number do I need to buy/where to find it. I check autozone and napa for a 1985 gsl-se oil pump and it doesnt look like they carry it. thank you

 

will one work out of an s5 turboII?

 

get the SE pump (17mm, if i recall). there's an option to get a hardened one. i bought mine from Mazdatrix a few years ago. you can check for other sources as well though.

 

https://www.rx7club.com/showthread.p...light=oil+pump i found this, can anyone confirm? i can get a TII pump for freeish

 

T2 pump won't fit... I've got a couple good used SE pumps I picked up for my blowthrough build. I decided to go the hardened route, since I decided I'm going to run higher boost levels (15+psi). Hardened gears are not really required, but cheap insurance I guess. For a normal turbo build an SE pump will work fine. You can have both of the SE pumps I have for $50 shipped, and pick the one you want to use.

 

how much just for one shipped? why wont the t2 pump work? it seems like in that link i posted it should.

 

Run the newer 17.5mm pump,

 

I just stripped my kid brother's S4 T2 and I can tell you it will not "bolt on" to a 12a front iron. The bolt pattern is different/wider. Maybe people are making them work, but there's really no need. An SE pump's rotors are nearly the same size.

If you want just one I can do $25 shipped.

 

going to autozone for rotary parts is like trying to order pizza at mcdonalds....

either buy a gsl-se pump or there is the competition pump, which is the same except the guts are hardened.

 

getting ready to pull the front cover soon, i read on mazda trix how to do it, and got their parts list. where can i order the parts? i already have the pan gasket, and i can get the front seal from black dragon, do they sell the other parts? It doesnt look like they sell just the front cover gasket, and im not sure what front cover "O" ring their talking about. also, is it necessary to replace the first torington bearing?

 

i found all the parts from atkins rotary that i need. but do i need to replace the torington bearings or not? if mine never dropped and arent smashed i shouldnt need them right?

 

Probably not, but I always replace them. Mazdatrix has the front engine parts also. http://www.mazdatrix.com/b5.htm

 

83-85 12As already have the 17.5mm pump. I just blew your mind.

 

Are you sure all the 83 12a's have the bigger pump?

 

if you don't believe.get some dial caliper...the se pump is the same one on 12a's...83 to 85...like jeff sed

 

All my 12a blowthrough readings this is the first I've noticed anyone addressing the oil pump. Is this just for more volume to feed the turbo?

 

All beehive 12As and all late model R5 12As and R5 13Bs have the big oil pump. Believe it. If you only read Racing Beat, you're lead to believe only the GSL-SEs got the big pump, so you end up buying a new big pump from RB that may not have been necessary.

One bit of trivia that I'll be able to answer shortly is did the 6 port 12A get the big oil pump? It has the N255 rotating assembly, exact same as all 83-85 12As, and use the same counterweights. There is even a notch on the front counterweight to clear the aux port casting that all 83-85 12As got even though it they didn't need it.

 

Jeff, what's your source? are there any exceptions? i ask because the last 12A i pulled apart (about 6 years ago or so) was an '84 and i put a hardened SE pump in it. anyway, the point is, before assembly, i laid both the 12A and 13B pumps side by side and the 13B was definitely larger.

 

I tore down about 20 12As last year and every beehive engine that had been factory assembled, meaning no dumb ham-fisted mechanics messed with it, had the larger 17.5mm oil pump. This included modern R5 12As that came stock with cat convertors but yet also had the early rotating assembly with 30 pound flywheel like an SA. Every engine had the large oil pump except for all non-nitrided (early) R5 engines and all US-spec 79-80 and 81-82 12As which only got the 12mm pump. Maybe your engine had been messed with by someone who didn't know what he was doing?

There were three oil pump sizes as you know. 74-75 got a 15mm oil pump. Kinda rare but I have like two I think. Then all 76-82 US-spec 12As AND 13Bs got the smaller 12mm pump. These small pump engines suffered lots of oil related problems like high amounts of wear in the thrust assemblies, usually more step wear on side plates, more copper showing in the bearings etc. The 83-85 12As and all GSL-SE and RE-SI engines, well you know the rest of story. This includes the 12A turbo and I'm 99% sure the 6 port 12A also got the larger pump even though its run began in '81 I think. The point is that it got the N rotors (same as our 83-85 assemblies) and so should also have gotten the large pump. Anyway this proves the large pumps were being made as far back as 81, so the "modern" R5 engines (both 12A and 13B) also got them.

I'll be checking the oil pumps of two engines here pretty soon (probably not today but maybe tomorrow). One is from an R5 12A and the other is from a 6 port 12A. I bet both are 17.5mm.

 

it's a distinct possibility. it was definitely an '83+ case/block, but i certainly wouldn't swear to the engine's history since i bought it from a guy in Connecticut (circa 1998).

 

Yeah, your engine was messed with.

I checked the oil pump from the R5 12A. It does indeed have the 17.5mm oil pump.

It's really easy to tell which oil pump you have just by looking at the housing thickness. Thick housing = 17.5mm. Thin housing = 12mm or possibly 15mm.

 

Is this a common upgrade for 12a turbo guys?

 

how many good rotor housings did you get from that? two?

 

Yep.

 

I checked the oil pump from the 6 port 12A. It's a 12mm. I've got a nice 83-85 17.5mm to throw in.