patsmx5

iTrader: (16)

Ok, I'm just thinking out loud again, as usual. I know Loki is building OP gears, and maybe one day they will be available for cheap. However, it doesn't directly SOLVE the problem that causes oil pump failures.

The problem: Crank Flex.

Crank flex is what causes the stock oil pump gears to fail. The forces acting on the crankshaft increase exponentially with RPM. Crank flex is pretty much unavoidable.

Our oil pump is a bad design for those who plan to increase crank flex. It's easy to look at some other more popular, dead reliable designs and learn from them. Take any American small block V8 and you'll find a few interesting similarities. None of them have oil pump gears shattering, they all have sintered gears, they are all dead reliable regardless of HP, and they all have a drive shaft powering them. The later is key.

I'm thinking about adding a different oil pump to the engine to replace our at-the-mercy-of-crank-flex oil pump gears.

The cheapest oil pump to add would be a pump for a chevy 350, or a ford 302, or the likes. Something that's been around forever and is cheap and readily available at any auto parts store.

There of course would be obstacles. For one, how would we spin it? It could be adapted to run off a serpentine belt, but then you could loose a belt and lose oil pressure. Not good. That's more common than shattered oil pump gears.

So my next best idea would be to have it run off the timing belt. Here there's a distinct advantage. If that belt brakes, the engine shuts off anyways. This is how a lot of OEM oil pumps are driven on Toyota's and Honda's.

The said chevy oil pump is designed to spin 1/2 engine speed, as they run off the camshaft that turns 1/2 engine speed on a small block v8. Our cam gears turn 1/2 crank speed too. Perhaps the pump could be driven somehow by the cam gears. Perhaps add a special bolt to the exhaust cam gear that has the correct notch cut out of it's center so that the drive shaft from the oil pump will snap right in. On a ford 302, the drive shaft that spins it is 5/16 hex I think. Not sure on a Chevy though.

There is a good amount of room in front of the valve cover, so this may be the best location for the pump.

Another possibility is to have the new oil pump driven off the rear of the exhaust cam, where a CAS would snap in. My 99 dosn't have anything there, so this too may be a possibility if there's sufficient room to mount an oil pump back there.

There would be other obstacles too. Once it spins, it would need a inlet and outlet. Inlet is easy, tap the bottom of the pan and run a hose off of it. Ideally there would be a 1 way check valve so that when you crank the engine, the pump doesn't have to pick up all the oil that drained out of the inlet hose.

The outlet will need to go wherever the stock oil pumps outlet is. This part I'm 100% unsure of how I'd do it, as I've never had my oil pump out or apart. If there was a way to remove the gears and drill and tap the old oil pump housing to allows a large AN hose to connect, then that would work wonderfully.

Ok, this could be a simple solution or not. I really don't know. I need to do some research on the stock OP, as taping into where it feeds oil into is going to be the biggest obstacle I can see. I'm sure it blows oil into a hole in the cast iron block. if I could just remove the stock oil pump, drill the block, and screw in my pipe to AN fitting, that would be great. However, I'm pretty sure it's not gonna be that easy.

Discuss.

M-Tuned

iTrader: (6)

Can I get pics of the said pump you are thinking about using?

I've been told by a few people that our gear might not be the problem, but infact the cover on the back of the Oil pump flexes and that we should get a billet cover. (Never tried this, but was told by Unorthodox Racing this helped fix some issues with the H series honda engines have Oil Pump gear issues.

patsmx5

iTrader: (16)

http://store.summitracing.com/partde...5&autoview=sku


http://store.summitracing.com/partde...5&autoview=sku

2nd one is 18.95 for a Melling.

jsisco

iTrader: (7)

http://www.drysump.com/index1.htm

Found these guys the other day. They have a dry sump pan for the miata, but they also have an external oil pump for 4-cylinders. I don't know exactly how you would get it mounted on the engine, and the gear doesn't look like it would work with our timing belt.

Pan:
http://www.drysump.com/pan19.htm

Pump:
http://www.drysump.com/3000.htm

Get ready to pay though. Be better off buying some gears from Miata Roadster.

patsmx5

iTrader: (16)

I just got out of bed to type this. I bet I know where the oil pump pushes the oil to... THE OIL FILTER. I could just build or modify a sand which plate for the line that feeds oil from the pump to the engine. Sweet. I think that's right anyways. Perhaps have the filter relocated or something, so oil goes in new pump, out to a filter, then into the a sand which plate thing. More thinking tomorrow, I mainly typed this so I wouldn't forget it overnight.

Ben

iTrader: (33)

Instead of dealing with logistics involved in mounting an external mechanical pump, why not just go electric?

Joe Perez

iTrader: (8)

I'm curious as to how easily the pump is going to prime itself at startup if it's mounted all the way up at the head...

Splitime

iTrader: (24)

Majority of Hondas are Crank driven actually.

Also, it isn't just about crank flex (if at all), its vibrational/harmonic damage to the crappy sintered metal gears (from my understanding)

Arkmage

iTrader: (3)

+1, you can also install a pressure switch on the ground side of an ign relay so that if you lose oil pressure (get's below set point of say 8 psi) it will automatically kill the spark. Electric also gives you the ability to cold start with full oil pressure at the flick of a switch... which would be great for engine life too.

Ben

iTrader: (33)

I'd feel much better after oil changes if I could build up pressure before the first start.

MX5-4me

if you are going to do through all of this Drysump is the way to go..

the OEM Corvette Drysump tank would be a good source you might find in a junkyard. Since you have a remote tank using an electric pump also remotely would be easier than trying to adapt somethign to the block.




This is off a ZO6 i believe.

patsmx5

iTrader: (16)

http://cgi.ebay.com/ebaymotors/Mazda-RX7-RX8-Miata-3-6-CX7-Oil-Cooler-Sandwich-Plate_W0QQcmdZViewItemQQcategoryZ33613QQihZ012QQit emZ220218470430QQrdZ1QQsspagenameZWDVW

that has an two AN fittings. One is coming from the oil pump, the other is what feeds the engine. Could simply remove the gears from the stock pump and just install a sandwhich plate. Now you have the oil pickup tube on an AN fitting and the oil supply for the engine on an AN fitting.

I thought about an electric oil pump. Of course that would make things a lot simpler. However, they are expensive for one, and I'm unsure how reliable they would be. Also, I'm not sure if they would pump enough oil. Mechanically driven would be fool proof.

I am not sure how well it will or won't prime itself it mounted up high. I was planing to use a 1 way valve in the the oil feed line, close to the oil pan, so that oil stays in the inlet line when the engine is shut off so that it has oil to the pump when starting. This may not be a problem

Splitime- I'm pretty sure it's crank flex too. Agreed that it's harmonics as well though. Overall it's just a bad design.

Links to several diff electric oil pumps. THe last is rated 40PSI, 3gallons per minute continuous.

http://www.rbracing-rsr.com/oilsystems.htm

If anything maybe I can buy a bullit proof 12V electric motor to spin a 18 dollar chevy oil pump?

Zabac

iTrader: (39)

I think we are getting way ahead of ourselves. Is there anyone with a billet gear that ever had a failure? Ever? IMO, the gears are fine where they are, Mazda didn't go billet because a OEM 102rwhp 1.8 Miata does not have enough juice to shatter anything in its Drive train. If you increase power, you increase crank flex, you increase vibration, and you increase stress! Had Mazda made a 300rwhp Miata, they would have gone with billet gears. Billet is far more expensive from a production standpoint than sintered. Look at it this way, not even considering all the other cars the B6/BP motors came in, but there are around 797,000 Miatas produced. Lets say that billet cost about $3 more per unit to produce, even though i think it is even more than that, but at $3 more a pop, in the Miatas alone you are looking at a $2,391,000 over the past 17 odd years. That is 2.4 million dollars more than using sintered. In conclusion, i think it is safe to say that billet gears are sufficient enough and we do not need to add complexity to the system by adding an remote mounted OP.

MX5-4me

you just pissed in the punch bowl.. Thanks.. Thanks a whole ******* lot..




I have to agree with you though. an ATI damper and a billet gear would be way easier and more than likely cheaper.

Zabac

iTrader: (39)

Didn't mean to **** in anything, but we are working on a cheap easy fix that is known to work on our cars, why would you want to change to something far more complex and expensive, it doesn't make $$ sense. You want change? Go vote for Obama or something, I am happy with my hopefully soon to come gears.

Ben

iTrader: (33)

There are ways to reduce crank flex. 01+ MBSP is easy, or you could look into billet bearing caps.

I like the vette oil pump/canister. That's a sexy bitch. And it could literally make things as simple as removing the stock OP gear, adding in a sandwich plate and remote filter, and hanging the can. Done. And it will add a bit of oil capacity too.

MX5-4me

That just the reservoir you would still need a pump a new oil pan and lines but yeah i agree.

Ben

iTrader: (33)

oh I thought it was a tank with internal electric pump.

The_Pipefather

iTrader: (5)

Can't we just use an fuel lift pump from a common-rail diesel engine? I bet it can handle the viscosity and still discharge enough oil at enough pressure.

EDIT: Something like this:

http://cgi.ebay.com/ebaymotors/00-Do...spagenameZWDVW

patsmx5

iTrader: (16)

Zabac, there are two benifits of my original idea, which is to have the chevy oil pump mechanically driven. One is it's cheap, the other is it's bullet proof reliable. I would have to build the right stuff to mount the pump to the cam gear. That would take time, but wouldn't be overly expensive. The sand which plate and 2 AN lines will likely cost more than the oil pump and associated brackets to mount and drive it. Plus this eliminates the problem of crank-anything damaging the oil pump. My idea isn't to make a high dollar solution. Not at all. This would have to be cheap. I really think it can be done. I could likely just make a new bolt that goes into the exhaust cam gear sprocket. The bolt will thread in, you tighten it with a wrench, and it would have a drive shaft sticking out of the head of the bolt to spin the OP. Then build some brackets to hold the pump in place. Drill and tap the ends of the OP for pipe thread, then screw in a pipe to AN fitting and connect them to the sand which plate. Of course have an oil filter too.

The bolt in the cam gear idea is undeveloped. It's just the general idea of adding one piece to drive the pump.