Shimmed oil pump, why?
 

So why would you want to get different shims on your oil pump?

Is there a reason not to get +35psi all the time?

Under what situations would you want different shims?

How does this work with the high volume pump?

Stock pumps will produce the needed psi with the stock clearances in the crankshaft and connecting rods. Race motors often have much looser clearances, so to get the oil pressure to the correct level, you have to make an adjustment on the pump.

That is why you want to know what kind of clearances you will have in the bottom end before knowing exactly what kind of pump set up you will need. Also, I believe turbo oiling can rob some of that pressure as well, resulting in the need for an adjustment on the oil pump.

I know about loose tolerances needing more flow, but that's why the high volume pump was produced, so that seems pointless to shim instead.

I can understand shimming for oil coolers and turbos, more lines and pressure loss, I'd forgotten about that when I posted, thanks for the reminder. But that wouldn't be more than 7psi, so I don't see the point of more.

So: Loose engine = High flow pump. Turbo/oil cooler = one shim. What's the point of more?

So far as I'm aware, "shimming" in this context is done to the plunger & spring which set the maximum oil pressure.

In the stock design, the bypass is supposed to open at around 60 PSI. So when the oil is very cold, this protects the system by setting a cap on the maximum pressure that will be generated. (Too much oil pressure and your oil filter bursts.)

However, it's important to remember that this mechanism determines the maximum oil pressure. It should have no effect whatsoever on oil pressure below the bypass threshold. In other words, if you have only 10 PSI at idle, then you're going to have 10 PSI at idle no matter how stiffly you've shimmed the bypass spring. (Unless of course the whole reason you only have 10 PSI is because the bypass valve is sticking, though in that case the solution is simply to repair the plunger.)

That's strange, I'd read the bypass was at 90psi when reading the original BE pump thread earlier today.

I assumed the shim set base pressure instead of maximum, that's good to know, thank you. It does seem to make shimming even more silly, though...

(Responded to my post on m.net about the LS1 IAC, Joe.)

I was easily seeing more than 60psi on my VVT motor for quite some time, on a quality solid state sensor.

Joe that may be partially true. I was under the impression that oil is being recirculated all the time, and that it is fully open at 60 psi. From what I understood, shims would get your idle psi to a safe operating pressure when you have a loose motor. That is why there are so many options.

From the '92 FSM:

Attachment 241320


Ditto on my '92. If I really rev it on a cold morning, the stock OPG goes off-scale. I expect that we both have bypass valves which are sticking in their bores and failing to open when they should.


While the operation of the plunger and spring is definitely an analog phenomenon rather than an on-off switch, it's not like an oil thermostat where there's a leak engineered in. If you take apart an oil pump and inspect the bore, it's pretty clear that no oil should be flowing through the bypass when the plunger is extended. If there is, then (IMO) something is very wrong. You'd have to replace the spring with the one from Hustler's novelty dildos-in-a-can product to get it to depress past the bypass hole at only 10 or 20 PSI.

Then why so many options?

I had a verbal conversation with the folks at Boundary, and they wanted to know what my final clearances were before they knew how to shim the pump. I do not recall the exact conversation, but that is how I remembered it.

I don't know.

Maybe if your engine is set up on the tight side, you want to increase the pressure beyond stock in order to achieve enough flow. That's a question for an experienced engine builder, of which I am not one.

Yeah, I posted in this section rather than in a general one in the hope that someone from BE would show up and comment.

Noticed Travis hadn't been on in a few days, shot off an email...

Yes, that is exactly it. So what you need to do this is the Petroff equation and a plane flow equation, and then a reaction force equation to make sure you get the proper bearing support at the lowest friction. What I usually tell people instead is that if your running a tight clearance increase the pressure, if you run a loose clearance get a high flow oil pump and maintain the stock pressure.

So the stock relief valve is basically like a poppet valve. You can only get so much flow through the valve regardless of how far it opens. When the oil is extremely viscous it exceeds the valves ability to relieve more flow. The good thing is that your engine actually needs that extra pressure because of how viscous it is.

----
The only downside of running more pressure is that there is more power needed to drive the pump. There is a bit of an over limit situation where you can get bearing erosion by having too much pressure, but I wouldn't necessarily worry about it unless you are over 100 PSI all the time.

If the shimming is for a tight engine, doesn't that make the high flow pump a bit useless?

I'm just not seeing the difference between a high flow pump and shims in that case, unless high flows are only for loose engines... but then why couldn't you just shim more for that?

Oh no, there are actually physical limitations to the stock oils pumps. Some of the people on the boards here have used pre-VVT oil pumps with VVT engines and experienced no more then 40 PSI. Mazda sized the pumps extremely marginally for best fuel mileage and power. So if you change anything at all in the dynamics, raise the rev limit, or increase the boost pressure then you have changed the design operating condition of the bearing.

The main reason that we sell our assembled pumps in only high flow varieties is because we machine all the areas where the pump actually sits. This gets the most amount of flatness and concentric measurement out of the bore we can reasonably get. We want to produce the best product possible, and the as cast and machined surfaces aren't that great. This is especially true in used pumps were we've ween wear over .005 inches from the inside to the outside edge of the housing.

my daddy was tellin me a story about his race cars one day.

and he told his friends he was putting motor X into his race car and they all said "those are oil starved with two pumps!" and he did some testing and determined that he was not having a pressure issue but he was having a flow issue so he ran four pumps and his motor did not starve and die.

or something like that.

Soooo... How much oil pressure do your VVT pumps generate when oil is hot? At idle? Max psi?

55-65 should be typical at high rpm. 15-20 typical at idle with stock shimming. I've seen as high as 85PSI on the street/strip pumps. The problem is there are ALOT of variables that move that number up or down. The high flow pumps are capable of over 90PSI at high RPM, and some tests have indicated over 150 PSI.

Jason was the guy on here who was having problems with pressure and his VVT motor. He made a post about it some months back. There was another instance posted before that, but I forgot the originators name. It is important to size the pump with the amount of oil flow that you need. Generally the street strip pump does it for everyone. If you're deleting oil squirters you can definitely use stock sizes. If you are going with a larger then normal clearances, have VVT, and keep the oil squirters you might want to consider a high flow.

Best,
Travis

Random question:

I've already got a new set of your gears sitting on the shelf, and when I tore down the pump that came on my donor '99 engine, it seemed a bit worn. Not horrible, just "a bit."

So I surf over to Rosenthal looking for new pump housings. They list two parts for 1999-2005 Miata. One is BP4W-14-100A "Through 2/28/1999 production" and the other is BP6D-14-100 "From 3/01/199 production." No mention is made of a change occurring in '01, which would have been VVT time. Moreover, the "old production" pump is $130, the "new production" pump is $250.

The parts catalogs confirm this. A change happened in mid '99 (at VIN -9301) and this pump was used at least through the end of '02 production, which is the last catalog I have.


Whiskey Tango Foxtrot?

99 year is when they changed the casting to a softer alloy I do know that. Wear in the 99+ housings is REALLY bad. We tested the housings and they were so soft we couldn't get a good reading with our equipment.

The gear thickness change has always been reported in 01. The complete pumps we sell fit on any block with a long nose crank though. We don't worry about it too much because most everyone who has a new housing and wants a billet set of gears has so much housing wear it won't work anyways. Thats not to say we don't exchange gear sets if they need the upgrade size. We have both in stock, we just have them send it back and then we exchange it.

As far as why the catalog doesn't match that?? I don't know. The oil pump lineage I know about is as follows.

So our motor line came from the protege, and the 1.6L used the original non-turbo protege pump and block. The upgrade to the 1.6L long nose crank also switched to the oil pump that the turbo protege (GTR or whatever) had. The pre 1.6L long nose blocks had a pump that was both smaller radially and axially.

The long nose 1.6L pump was carried over to the 1.8L pump all the way up to 99 when they retooled the castings to a softer alloy. For what reason? I have no idea! In 01 when the VVT mechanism was added they also increased the oil pump size about 10% to accommodate for the increased volume demand. I also theorize that they increased the volume because of the high wear the pumps naturally went through due to the softer alloy. If my thinking is right we should see pumps wearing to the point where oil pressure is a problem in the next 2-3 years. This increase in pump size could delay the housing wear problem.

Meh, the one thing I've learned about doing ignition systems in Miatas is that the progression is in no way linear. Quite frankly its pretty hackneyed! There is no telling what the actual reasons and when the actual changes occurred.

Hmm thanks for the info. I currently see about 38 tops at high RPM. In general, when the oil is hot, from 3000-7000 RPM I only see 40. It flatlines at 38psi. My oil pump is the part number mz-bp4w-14-100a. I think that is the pre-99 pump? Anyways, this pressure seems a bit low. I have no oil cooler. What are your thoughts?

I think its probably ok, but its not optimal.

Did you do anything different with engine clearances/ relief valve or anything you can imagine to change oil pressure?

The simple things that change oil pressure the most have been viscosity, oil filter brand, and outside temperature(viscosity again basically). You could try upping the viscosity for one oil change to see if your oil pressure goes up with it. If it doesn't then its the relief valve. If it does go up then it could be a flow limitation(leakage or pump is too small).

The catalog is still bugging me.

Looking over the history of the oil pump, I'm seeing a lot of different part numbers over the years. It's not uncommon for mazda to change P/Ns on something fit-form-function compatible, though they usually denote this with a suffix letter change, rather than a number change.


There's at least one functional difference I can think of between the longnose 1.6 / early 1.8 NA and the '99: the mounting point for the crank sensor. I don't know whether the '96-'97 crank sensor were mounted in the same way as the NB ones, but from '99 onward, they screwed into a threaded fitting on the oil pump that the 1.6 oil pumps don't have.

I realize that it's not the most accurate dataset, however when I do a search on aftermarket oil pumps for various years in the RockAuto catalog, I see one set of pumps listed as compatible with '94-'97, and a second pump listed for '99-'00. (They have no pumps listed for any of the 1.6 engines, or for '01 and later.)


Going to the Mazda catalog gives me a slightly different dataset. I'll focus on comparing three different parts here.

For '91-'92, the oil pump as an assembly went through a major revision at VIN -0910. After that, the whole assembly is B6S8-14-100C, the inner gear is B6S7-14-132, and the outer gear is B6S7-14-141.

For '94, the assembly went through a major revision at VIN -4301. The major change was the oil control plunger. Prior to this change, the assembly was B6S8-14-100F, and afterwards it was B6BF-14-100A. The fact that the prefix changed (B6BF to B6S8) suggests that Mazda considered this a major revision. The gears remain at B6S7-14-132 and B6S7-14-141, unchanged from '92.

For '95, the assembly undergoes only minor revisions (-100G and -100H), again reflecting changes to the plunger. (Boy, Mazda sure did a lot of work on that plunger.) Gears remain unchanged, still at B6S7-14-132 and B6S7-14-141.

'97 is completely unchanged.

In '99, everything changed. The assembly went through three major revisions, starting at BP4W-14-100 (through VIN-9301), moving through BP5A-14-100 (VIN 9301-0701), and ending at BP6D-14-100. None of these are similar to any NA, and I wouldn't expect them to be. Crank sensor, remember? (Distressingly, I can't find any part numbers for the actual cast housing.) The internal changes for the first rev change (at 9301) were fairly trivial. At the 0701 change, however, they changed the internal gears. Prior to that, they were the same as the NA. Afterwards, they went to inner = BP6D-14-132 and outer = BP6D-14-141. These pumps are all noted as applying to engines with a casting mark of "BP4W", which is definitely the '99-'00 engine.

The last catalog I have is for '01, and it's where things get weird. I downloaded this catalog directly from Mazdaspeed Motorsports' website (link) and it's marked "Mazda MX-5 Miata, USA & Canada ('01 > )"

That catalog lists exactly the same oil pump and internals as the '99 catalog. It also says that the casting mark should say "BP4W".

Trivia time for owners of VVT engines: Does the casting mark on your engine still say BP4W, or did they update it to read BP-Z3?

I know the back of my VVT block still says BP4W.

Casting mark on the head? BP4W

Clearances are factory spec. I have been running rotella 5w-40 synthetic.

If the relief valve is stuck, can I just whack the pan with a hammer to fix it?

You can whack the pan with a hammer as much as you want, but it will not fix the problem, if that even is your issue. I will take a picture of my old oil pump and where the relief valve is located for you tonight when I get home.

Don't listen to that noob. A hammer will fix it. If your oil pressure doesn't rise, that just means you're not using a big enough hammer/hitting hard enough. Try a 10lb sledge and wind up. Alternatively, you could sawzall the opening larger, which would be the best fix.

Stop spouting nonsense, I think he should start with a 15lb hammer and then move onto the sawzall.

I'm stuck.

On the one hand, I don't think there's any question that Travis' practical, hands-on experience with Mazda B-series oil pumps (and with Miata engines in general) probably outstrips mine by at least an order of magnitude. And as a rule, I find that people in that position are more often right than wrong if I find myself in the position of debating something like this with them. So I really, really want everyone (including Travis) to understand that I'm not calling him a liar here.

I just can't get over this contradiction with the Mazda catalogs. They say that the oil pump gears changed in '99, and then remained unchanged throughout at least '01. Rozenthal Mazda's website corroborates this, listing BP4W-14-100A as "Through 02/28/1999 production" and then giving BP6D-14-100 as "From 03/01/1999 production," and listing this part as valid all the way through 2005.

All I can really say is... I've had four Miatas, and found that Mazda likes to change things without any record. Frankensteining different years of Miata parts in my cars, I've run into this more than once. The dealer won't have any record of a change, but it can be obvious with the parts in your hand.

Are you guys trying to get me to fuck up my car?

I went to home depot and picked up some awls. I tried to hammer the awl into where I think the pump is on the block but it just bent :facepalm: So I guess the right thing to do is to go through the oil pan? But what point on the oilpan should I aim at and what angle should the awl face in order to hit the relief valve? /And once I get it in there, should I wiggle it clock wise or counter clockwise?

It could be very well that thats not actually when the gear change occurred. We need y8s back in here. Didn't you have the first mis-matched oil pump? **Pinging y8s

Don't listen to these guys! If its a stuck open relief valve (which is pretty unlikely actually) then the only remedy is a new housing.

Travis, remember that oil pump I sent you? I remember the gears were thicker and the housing was worn out well beyond the 30,000 miles on the motor. But I do not remember the measurements. Maybe they are in a thread somewhere...

I asked you before but I can't find the thread :( -- What's the max hot oil pressure you see, and what oil do you run?

So, Travis, to enhance my knowledge: Do you make these gears in two different thicknesses?

Yea i remember it, I just don't have the data. :X Was that a 99 housing? Although if I remember right the housing was like +.070 tapered. :bowrofl:

Actually 3: .37x .39x .43x

The increases in size are all in the width direction from factory and in the different assemblies I make. Apart from that the teeth/root dimensions are all the same on the different gears. The only root/tooth dimension changes are in the 89-91.5 years.

Interesting.

I just mic'ed the stock gears that came out of the oil pump on my '99 engine. Both gears came in at between .3722" and .3724". I remember measuring the new gears when I got them and finding that they were just a tiny bit thinner than the ones I took out, though the logbook with those measurements is buried away somewhere. I'd guess they were probably closer to the .37" spec you gave.

According to the VIN on the oil pan, and the potentially dubious list of all 10AEs, this car has a "born on" date of March 25, 1999. The complete VIN (from the oil pan) is JM1NB353XX0136036. Does that mean that this engine falls into the "After March 1, 1999" production class?

Dammit, I hate inconslusivity...

Crap. I need to measure my gears.

Got yourself a fancy sec of mics with 4 digit places :)

Yea, the ones we sell are a little looser on the width spec that fit into the stock housing. They are about .002 less then the stock gears. That puts their theoretical clearance at .0035-.0055 which is what we were aiming for.

That goes along with the scheme that the 99-00 gears are equal to the 91.5-97 gears. We need an 00 gear set and 01 gear set for final confirmation.

As Scotty said, "The right tool for the right job."

I think they cost me all of about $20 each. They're cheap Chinese-made mics, but they work ok.



Well, .002 would be almost exactly the difference between my old stock gearset and a theoretical spec of "0.3700". I'm glad to know that this was by design- it worried me slightly.

It also bothers the hell out of me that the Mazda catalog is looking increasingly wrong in this regard. I really wish they'd give the complete VIN suffix, and not just the last four digits.


Wait.


Holy hell, I'm retarded. Literally, as in "My mother smoked meth during the second trimester." Those numbers AREN'T VIN suffixes, they're datecodes! How the hell did I never realize this before?!

9301 means "year 1999, month 3, day 01."

It is there, in small, smudged print at the bottom of the catalog page. As Willy Wonka said, it's right here, in black and white, clear as crystal:

Attachment 241307

136036 definitely puts my engine in the "middle" production class, between 9301 and 0701.


Hmmm. So going back to the '99-'00 catalog:

Attachment 241308


Wait a minute... ZL01? What the hell is a ZL01?

(google google.)

1.6l Mazda3? Was THIS the engine that went into the Euro-spec 1.6l NBs?

If so, then "the change" didn't happen in March of '99 as Rosenthal claims, it happened in July of 2000, which would be about the time that the factory would have started producing VVT engines for model year 2001. And THAT would be consistent with what Travis has been saying all along, and the catalog is not wrong.

So what the hell is up with Rosenthal's website?

Tommy is not perfect?

Quick question as I currently have my oil pan off because of some slow leakage: how many shims do stock VVT oil pumps come with? Reason being: I bought a Boundary Engineering Stage 2 VVT oil pump for my rebuilt VVT engine (no oil squirters). I'm running a turbo, too. I ordered my pump from Fab9, with 1 additional shim.

after the rebuild cold oil pressure was immense. Like rev a little higher and it would hit right the end of the scale. I then went with 0W-40 oil, but pressure still seemed excessively high. The engine would also leak oil, which I suppose is a result from high oil pressure pushing oil beyond the seals.

today I took the engine out and remove the oil pan. When I inspected the bypass valve I discovered FOUR shims! The first one was a special shim with a hat. It goes into the spring and I suppose it's always there. Then came a shim with letters on it, followed by two other blank shims.

so how many shims are standard? Just the hat? Hat + letter shim? I would like to go back to normal max oil pressure.

https://cimg9.ibsrv.net/gimg/www.mia...c0d9640456.jpg

Stock is hat only on a VVT motor, I checked two stock oil pumps and both were hat only.

Yep, stock is hat only.

Thanks guys. So that means I was running 3 spacers instead of 1 as per my order. Great...

Fail9 Strikes again

go figure :(

Question... did it come in a sealed plastic bag with the Boundary documentation? Looks like someone used plain old Home Depot washers for the additional ones.

All roads lead there.

Now you got me wanting to check my oil pump as it came with 2 shims. I will have to look back at my pictures to see if the box was sealed or not. Definitely not buying from Fab9 again.

They are supposed to come in a sealed plastic bag from Boundary.

i can't remember, but I think it did come in a plastic bag. Even if it didn't it still has all the machined and engraved surfaces that the original BE pumps have. I suppose he'd order BE pumps and add shims as requested by his customers?!

Good question. The bag is too ensure no dirt get's inside the pump during transport/storage. There's been others who haven't got a pump in a bag. I ordered mine through him earlier this year but it shipped from a distributor directly so Fab9 was just a reseller.

If I was Boundary, and a reseller was doing work [adding shims] and representing it as mine I'd be pretty pissed although with distributors in the mix + resellers [Fab9 and others] who knows where the blame lies.

@TravisR any ideas here?

Hello Everyone,

Basically if you order from Fab9Tuning and it is not a dropship, they have our authorization to shim the pumps. Its an easy process, and it does not void customer warranty to shim their own. If you have concerns about getting someone to do it for you, just order the pumps without shims and do it yourself. If you have questions, just call I'm always here. I talked to Fab9 about this, and he is reviewing his records on what happened here. We couldn't figure out Eunis91's name, so we didn't get too far on that! 3 Shims should put you at about 78 PSI, its a little more then we recommend for non-rebuilds without oil coolers, but it should have been safe. We ship 5 shims to Italy all the time, seems to be a thing in that region, and they run stock engines and race engines in that configuration. They see a 100+ down the tach with no issues. So I don't think it would have hurt anything, but we do need to make sure we are getting the customer what they ordered.

Thanks,
Travis

Thanks guys, shots fired of course. Travis just gave me a ring. The photo above shows 3 shims, the spring hat is just to keep the spring centered to avoid plunger alignment issues. I don't know what your order looked like but if you ordered it with an additional shim, it's as it should be.

I'd first like to make this clear, 3 shims is intended to reach 78PSI as stated on our website and the Boundary Engineering site. A perfectly SAFE oil pressure. It sounds like the plunger in this case may have ingested a contaminate and needs to be cleaned up? It's hard to say because problems with these pumps is VERY rare and we ship more of them than anyone.

Pump Shim Configurations:
The Stage 2 (Street/Strip) pumps start their lives as a 2 shim pump. - Shims added beyond this point should increase pressure as advertised.
The Stage1 (Street) pumps begin at a 0 shim configuration - Shims added beyond this point should increase pressure as advertised.

Unless we missed something, it appears we don't have actual data? What was the recorded oil pressure? Is the factory gauge the source of reading here?

@FAB, looking at your web site as I write this...

So, if the Street/Strip VVT Compatible "starts" with 2 shims, it would be 72PSI? So if you ordered that pump with "1 shim" you'd actually get a 3 shim pump? Sorry, but I don't see that as at all clear.


https://cimg3.ibsrv.net/gimg/www.mia...6111e9eb61.png

I understand the confusion there. - this was changed after the initial description of the product because we realized months into it that the Stage 1/Stage 2 pumps were shimmed differently out of the box. I'll clarify the verbiage accordingly.

so Bryan dropped me a PM, props for that. When I ordered in December I was lacking the information that stage 2 pumps already have 2 shims before adding additional ones. This is the only fault I can blame Fab9 for, and I apologize for accusing Bryan of shipping the wrong product.

However the BE oil pump is already under my suspension, since I did have to replace the front main seal shortly after installing the pump (as it turned out the pump came with a non-OEM inferior quality seal). I will hook up a mechanical oil pressure gauge and go from there. Until then, I will reseal the oil pan and pump with a different sealant, and switch to 5W-40 oil (I previously ran 0W-40).

Foxtrot Uniform Charlie Kilo

so my front main seal was partially pushed out, grinding against the timing belt sprocket. I KNOW it was flush because I had to replace the seal two months ago.

https://cimg1.ibsrv.net/gimg/www.mia...84a67ef9c3.jpg
https://cimg9.ibsrv.net/gimg/www.mia...0aec1dc85f.jpg
https://cimg8.ibsrv.net/gimg/www.mia...da64083f3b.jpg
https://cimg7.ibsrv.net/gimg/www.mia...e0002585a8.jpg