Afternoon all.

I've spent a fair bit of time Googling of late, but I can't seem to find the info I need about spec'ing an external oil pump for an engine, in my case Mazda's KL V6. Nearly all of the info and products I can find are engine specific and as such of no real use.

The problem I have is that the V6's oil pump can't handle sustained revs of 7,500 RPM +, and if I manage to build my engine that way I hope to, that will causes me potential problems. Or least make me worry about blowing it every time I go for a hoon and thus take some of the edge of the fun.

The ideal set up would be a dry sump. But one isn't available and even if I manage to make a suitable sump the pump, pipes and so are aren't cheap. I also know of a few guys running the KL up to a supposed 10,000RPM on external pumps and the normal wet sump, which seems a much cheaper/easier way of doing things.

But I know very little about such set ups or how to spec the pump so I can begin looking for suitable parts. So can anyone fill me in on some more details of such set ups, or point to somewhere so I can read up on it myself? The plumbing side of it I get, it's just the pump and pressure regulation side of things I need to know more about....

Motor racing is expensive, how fast do you want to go?

A proper dry sump system is very expensive.

It requires a cog belt driven external pump with three chambers, two for scavenge and one for pressure, plus lots of expensive AN pipework, and an oil tank.

The scavenge pipes are placed at the front and rear of a special dry sump oil pan, the oil is pumped back to the tank, from there it gets pumped through filters an oil cooler then to the engine.

As I said expensive, or you could limit the RPM to 7000 with a rev limiter and save a lot of money and trouble.

Having worked with these systems on Can Am and Formula A cars there are many ways for them to go wrong as well.

The dry sump option would be nice, but as said above unnecessarily expensive as an external wet sump pump will do the trick.

Yes, I could limit the revs, but I don't want to. It's more info on spec'ing the pump and any pressure reg stuff that I need.

you need to take the old pump apart measure the surface area of the vanes from that you can calculate the theoretical amount of oil one revolution can move from that you then times it by the rpm and from that you can get to lpm at a specific rpm.

there will be different calculations depending on the type of pump you already have as standard but the info for working it all out is there if you look. try searching for dry sump pump calculations as the data for working out the efficiency of the standard pump will be the same

once you have that info you can work out what pump you need for the replacement. the important bit is getting the oil pressure relief valve setting correct. too much and you will over oil the engine and too little you will kill it.

You seem to be doing a lot of worrying for nothing. Formula Junior engines are revving well beyond what you are intending using a simple side or front mounted pump with 3/4" pressure rotor, BDAs will use the same size rotors with 3/4" pipe work with a belt driven or a side mounted pump and these, as you know are seriously expensive engines. I run my Zetec with a full dry sump system using a belt driven CD 2000 pump without any problems. This delivers, for me, 85psi on start up and falls off to about 50 on tick over, more than enough. I produce dry sump pans for, mainly Ford engines but have done some for the Toyota 4 age motors and they are happy with a 3 stage belt driven pump.....The pump will be the dearest item, about £400 new, you can acquire a second hand tank and piping is cheap. You would need a belt of course and I have just replaced mine for the grand sum of £4. The difficult bit will be fabricating a mounting bracket, depending on your skills.......

It may be nothing to worry about to you, but you clearly know much more about this stuff than I do. Hence why I'm asking questions trying to gain that knowledge from those that do.

Since you're someone who seems to know this stuff inside out, is there a best type of pump to use or a best manufacturer? I don't even know who makes suitable pumps in the UK, or if such things are all built to suit. Any additional info on where to look is appreciated.

Pace Products (East Anglia) supply great dry sump equipment as do Titan. All available through Burton Power. Have a look at their website for full information. I would suggest that a 3 stage belt driven pump running at 2:1 will be ideal for what you want for your engine. Try to find some race engines for sale on various sales sites and see how they are set up. You will feel a bit more at ease then. If you are in Nottingham area I have a couple of dry sumprd engines you are welcome to have a look at.

The dry sump route isn't really where I want to head though, as no-one makes a dry sump itself for my engine. That and I know of people spinning the same engine to 10KRPM on just an external pump which will save me a fair bit of hassle. Space is also very limited and I'm not sure I'd have room for an oil tank in the engine bay.

Unless you think I may as well go the hole hog? But I assume that will be quite a bit more expensive?

But if Pace and Titan make dry sump pumps, I'm sure they'll be able to sell me just the pressure stage. I'll give them a call and see what they can do for me, as I can only find Ford kits on Burton's site.

Is the KL mazda related to the Ford duratec V6 or have i imagined that? Theres a drysump pan made for the ford dura v6 as used in the Ginettas G50 & 55

Unfortunately they're not related at all. The both have 2.5L versions, and both were used in Fords, but that's about it.

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Originally posted by DIY Si
The dry sump route isn't really where I want to head though, as no-one makes a dry sump itself for my engine..

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Given that the sump on my engine is just for holding oil and not for clearances for anything, is a dry sump version basically just a shallow V that bolts to the bottom of the block with appropriate drain plugs on it? It's just a shame I won't be able to lower the engine in my shell any further if I do go the dry sump route.....

Exactly that, though bear in mind that the main idea of the dry sump system is to ensure that you don't get oil swilling from side to side when cornering hard and causing the pick up pipe to be dry and sucking air...............

So a shallow V with a trap in it? Should be simple enough to make out of sheet steel I hope......

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Originally posted by DIY Si
So a shallow V with a trap in it? Should be simple enough to make out of sheet steel I hope......

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I meant something like this, more of a non-return plate or shallow tray than a trap. I suspect trap was maybe not the best word to use!





The bottom of my block looks like this:



And has this tray below it. I assume that is Mazda's version of a windage tray. Would I be better off trying to make something else or something better?



For the scavenge ports and so on I was intending to weld bungs onto the outside of the pan as in the top picture, and have fine mesh filters covering the ports. Unless there's an easier way? Sorry for all the questions, but since we've got someone who knows what he's on about, I may as well ask you! Feel free to PM me if it's easier for you. I'd ask people that know these engines, but there aren't really any that I know of in the UK!