1.8 NB Oil Pumps?
 

I'm putting my 1.8 back together and MMD lists two Oil pumps for NB 1.8s:
Pump, Eng Oil
99-03 BP4W-14-100A
04 BP6D-14-100

The '99 to '03 pump is less than half the cost of the '04 pump. Did Mazda increase pressure or flow in '04 for the oil supply to the MSM turbo? Any ideas what the difference is? I did some searching and found this thread https://www.miataturbo.net/showthrea...t=56016&page=2from 3/11 where Joe presented this question:

I don't know that I need to go crazy on this build but is it safe to say I want the more expensive pump listed for '04? Did the newer pumps get beefier for VVT in '01 or for the turbo in '04? The MSM doesn't have VVT but I can't imagine they would have gone backwards to an inferior pump - especially with the added demands of turbo oiling. The shortblock I'm building is from an '04 MSM and will be basically stock with China rods. Thoughts? :hustler:

I just ordered one for my 94/01 hybrid motor. I ordered the 01 pump, BP6D-14-100, and that is what was shipped.

When you installed it, did you use the o-ring and paper gasket?

Sounds like you've researched most of what I know:

Mazda continued to use the same oil pump in '99 and '00

In 2001, with the addition of VVT, mazda changed to an oil pump with a slightly higher volume.

At some point in time after changing to the higher volume oil pump, mazda then superceded the '99-00 oil pump part number with the newer high volume part number. NA cars retained the smaller pump part number.

The difference in the oil pump is the thickness of the oil pump gears which also means the housing was machined larger in order to match. The actual dimensional difference between the two oil pumps is 19 thousandths of an inch. The gears are indistinguishable when not next to one another, but if you lay the two on a flat surface and run your fingernail across them, you'll notice that one is indeed thicker than the other. The only circumstance where this could be a problem is if you tried to put aftermarket gears of one vintage into a housing of the other vintage. The smaller gears wont prime in the larger housing, and the larger gears wont fit into the smaller one.

With regard to a change in '04, this is news to me. I would have expected mazda to use the same VVT pump in the turbo model, but I have no evidence to support my theory. If you are using a water cooled turbo, your engine wont see a substantial increase in oil use from the turbo feed, each individual piston squirter probably uses more oil than the turbo.

You could call the mazdaspeed guys if you like, they've got a solid knowledge of anything you'll find in a spec series, and I expect that they've been asked before "wtf" with regard to the pump pricing.

I have not installed it yet. But, the outlet has a o-ring, but there are two possible inlet gaskets, I ordered both and will figure it out later. This is going on the '94 bottom end, maybe your inlet tube/screen is different.

Thanks. I'm one of the mazdaspeed guys who is supposed to know and we don't usually do a lot of cross vintage builds. Everything I have read supports what you are saying with the puzzling exception of MMDs part number break between '03 and '04 instead of '00 and '01 like it should be. I guess this isn't the first time a parts list is off by a few years. I'll buy the bigger pump and be done with it ;). Thanks!

When I took off my 99, there was the o-ring and a paper gasket. Funny thing was, the o-ring was stuck to the block and the paper gasket was stuck on the pump side. Since the pump has a relief in it for the o-ring, I put that in first and then using a small amount of sealant I stuck the paper gasket on top of the pump surface, added some sealant to the other side and then installed it on to the block. I'm having my doubts about this?

The paper gasket covered up the o-ring so basically it's block, paper gasket, oring, pump. I am hoping that the ring still seals with paper inbetween the ring/block surface.

I do not use the paper gasket. I can't actually remember the last time I saw one on a disassembly. The pumps have a sealant groove so that's what I use. The o-ring is required, though.

I also remember the pumps all being the same price once you get through the supercession part numbers.

This is consistent with my recollection of what Travis (of Boundary Engineering) found while designing the billet gears, and I believe (but have never been explicitly told) that this is essentially the basis for their "Racer High Flow Oil Pump Assembly."

So an 01+ oil pump is essentially a high flow pump? MSM even more or the same?

For purposes of ordering a new pump, 99+ part numbers are relatively "high flow". If savington is correct, then it sounds like the 04+ is the same.

The difference as compared to an NA pump is apparently quite small, but essesntially, yes.

As Jeff and Sav have noted, this all applied only to original manufacture; these days, the later-style pump is spec'd as the replacement part for all.

I can't imagine that the MSM would have received a unique pump. Its oiling requirement is less than a non-MSM engine of the same year, as the MSMs didn't get VVT.

So another question - I was planning on using a Boundry pump with my 94 block and VVT head. When HOT, will there be enough flow pressure to operate the VVT without issues - using Rotella 1040? I'm assuming it won't be a problem if I shim the pump - but we all know how that goes.

I chose the 2001 pump because Mazda made it for the VVT application. Other wise I could have just reused my 94 pump. Because of the additional demands of the VVT, the larger volume is welcomed. Now if I was going to boost it, there would be a Boundry Engineering pump being installed, but with my "girly" N/A build, it is not needed.

Yes there will be enough flow pressure. I use Rotella synthetic. Hot oil pressure at idle is very low- like 7psi but is around 40-45psi above 4000rpm. Yes the cam advances properly. I have watched the live data readout.

Boundary makes gears for both pump specs, just ask travis for the VVT spec when you're ordering gears - I would order by phone instead of via website so that you can talk to him.

Actually, you should be able to get the 99-00 thin pump from comp still. I know I have gotten at least one thin pump in the past.

MMD had two distinct 1.8 pumps available last week. I'm just going to run the big one and an ATI. I can't afford Travis' gears with everything else needed at this point. Hopefully nothing blows up. :crx:

So I've got a 99 OEM pump. I'm going to get something from boundary engineering. I'm leaning towards the 01-05 gears since they're billit and flow more than the 99-00 gears would but will they fit in the 99-00 housing correctly? Should I just bump it up to the street/strip setup with 2 or 3 shims? Racer assembly worth another $100 over the street/strip setup? FYI running a 1.9 up to possibily 500 but probably around 300 most of the time.

What's the best course of action here? What's overkill? What's not enough?

The answer to at least one of your questions is literally answered within this thread. Did you bother to actually read it?