Pace belt warning system?

[k80rum]

I'm about to fit a Pace pump to my K series. Looking at how it works, I'm guessing there's no mileage in trying to rig up some belt faliure alert, as the pressure line runs straight to the oil filter and pressure sender, so I'd get a big red light on the Stack pretty much straight away anyway if the pressure plummeted.

 

I remember reading some people had made microswitch-alarms for the CC dry sump system, but nodody's bothered with their Pace setup have they?

 

Cheers,

Darren

 

 

Darren E

 

With an all-new website

K80RUM Superlight R #54

 

 

[Bob Simon]

Unless I'm missing something, I can't see why one would need to know if the belt was intact on a three stage dry sump pump. If the belt parts ways the result is instant zero oil pressure. A standard OP switch and warning light is going to tell you all you need to know. (or wish you didn't know)

 

If the pressure pump is internal and the external pump is only scavenging the sump (CC type system), then a belt switch will give you some advance warning that the oil tank is going to run dry.

 

 

 

-Bob

94 HPC VX Evo III

 

[k80rum]

Hi Bob - Thanks for that. Yep, that's my understanding. Just wanted a sanity check. I couldn't see a reason for doing it on a 3-stage pump setup either.

 

All the best,

 

 

Darren E

 

With an all-new website

K80RUM Superlight R #54

 

 

[Unclefester]

The Pace system recommends use of a pressure switch set so that if pressure drops below 30psi, "something is told about it" this something usually being a light.

 

The "something" could be a switch that cuts the ignition, so saving the motor if the belt breaks, but there'd need to be a subsystem so the thing didn't cut in traffic at tickover when the pressure probably does drop below 30 psi, or a way of keeping it over 30psi at tickover, or a switch that cuts the ignition at a lower preset pressure to avoid this problem.

 

Embarrassing if it cuts out while in the middle of a hairy uphill overtake of two HGVs, with oncoming traffic, but hey, that's racing! 😬

 

Just as embarrassing, but much more expensive if it didn't cut out and the engine blows instead in the same circs.....

 

Lucy in the Sky with Diamonds..ooooh hooo hooo!!...

😬 😬Abbey Road Time-Machine *eek*

 

[NigelJ]

Hi there

 

I too have the Pace system and after some consideration I used a VDO gauge with the 2 pole sender. One is for pressure and the other grounds when the pressure is below about 7psi. I have this linked into a lamp on the dash with a permanent 12V + feed. If the belt breaks I guess it gives me a slight edge! Not perfect but........

 

Cheers

 

NigelJ

[Unclefester]

So....what about an 'intelligent' system that simply cuts the ignition if the belt breaks?

 

Better, no?

 

Or am I a monkey?

 

Lucy in the Sky with Diamonds..ooooh hooo hooo!!...

😬 😬Abbey Road Time-Machine *eek*

 

[Unclefester]

Could be done with a movement sensor reading off the sprocket. That way it's instant and doesn't get confused by low tickover pressure, plus no chance of any false-alarm ignition cuts.

 

If the sprockets stop, your engine dies if the ignition isn't cut instantly, so that's what would happen.

 

 

Lucy in the Sky with Diamonds..ooooh hooo hooo!!...

😬 😬Abbey Road Time-Machine *eek*

 

 

Edited by - Unclefester on 10 May 2007 08:23:18

[k80rum]

I think I'm pretty much covered with the Stack - It's taking a pressure sender reading (rather than a pressure switch reading)from what's effectively the outlet port of the pump. I've configured the Stack with a low pressure setting of 30PSI and a gate RPM of 1200, so it'll give me a pressure reading as normal and light the dash up like a christmas tree if that reading drops below 30PSI when the engine's doing more than 1200rpm.

 

Like you UncleF, I toyed with the idea of using an alarm of some sort to cut the ignition, but I just wouldn't be happy with what that could result in on the road- That experience you get if the the rear wheels lock when braking and downshifting hard is plain unsettling. I think I'd rather shaft the engine through oil starvation than have to deal with the car if it instantly shut off at speed. (of course, It'd give me a better reason to move to a bike engine, should the worst happen to the engine, too 😬 )

 

Darren E

 

With an all-new website

K80RUM Superlight R #54

 

 

 

Edited by - k80rum on 9 May 2007 22:59:52

[SLR No.77]

I've thought some about this recently - I run a Caterham d/s setup and already have a microswitch fitted to a warning light on the dash, positioned in the lowest hole of the 3 between the tachometer and speedo. The light's not as big as the center dash low-pressure light on my old Seven, but it's better than a standard warning light because I'm using a brighter LED. BUT, I'm not convinced I'd immediately see it when on track on a really bright day!

Maybe I have a solution? Can an interim circuit be designed/used that cuts the engine speed in a similar way that an Emerald rev limiter does? eg. a soft cut initially, maybe for a couple/few seconds, followed by a full hard-cut/no-ignition. Obviously once the system is triggered it is time based unlike rev-limitting which is rev triggered therefore returns to normal as the revs fall.

The soft cut (with warning light) would safely alert the driver that there was a problem and be controllable in a full-on cornering situation, the hard cut would then protect the engine. The hard cut would only be the same as killing the ignition anyway which I'm sure is done more safely using an automatic system than trying to get to the keys (a minority of cars are fitted with an aircraft style ignition kill switch).

This kind of setup could probably be easily designed into a programmable management such as the Emerald, but for o/e ecu setups a separate box would be better. Where's Chris Wyles when you need him 😬

 

Stu.

 

www.superse7ens.co.uk..........the rebuild 😬

 

 

[Unclefester]

I'd rather have a noticeable light come on if the belt breaks, with an instant ignition cut at the same time.

 

After all, if the ignition doesn't cut when the belt breaks, how much time do you have before the engine scatters anyway, which would have as unsettling an effect as would the engine simply stopping, but not trashing itself.

 

If the engine seizes or throws a rod halfway through a corner, is that better than it simply cutting power to protect itself?

 

I suppose it depends if you are looking for an excuse to change to a bike engine......like K80RUM

 

Lucy in the Sky with Diamonds..ooooh hooo hooo!!...

😬 😬Abbey Road Time-Machine *eek*

 

 

Edited by - Unclefester on 10 May 2007 08:30:42

[Paul Deslandes]

I fitted a 30psi switch and a huge bright red LED cluster from Maplin, but I'm not convinced I'd see even that with it right in my field of vision when the red mist is down on a sprint or hillclimb.

 

Remember you also have to dump the clutch to stop the engine turning, even though you've cut the ignition. The best you can really hope for is that you'll prevent the engine grenading and have a chance of recovering the block, pistons and crank from the bottom end. I'm told that the rods shouldn't be relied upon, even if you change the shells, as the heat can affect their strength and they could let go eventually.

 

Never carry a spare oil pump belt as you'll be tempted to replace it after its broken, with potentially disastrous consequences.

 

 

[SLR No.77]

UF - my setup is the Caterham d/s not the Pace system therefore I have a little extra time before the oil feed is lost, but I still need to know early. A unit that can be set for either a short time delay or no delay at all would be ideal - it's one less thing to do if the belt goes. A trigger to the ecu would be good.

 

If power is lost I'm pretty sure I'm going to have a damn good look at the gauges and lights, then all I'd need to do is dump the clutch whilst still having both hands steering. More likely to be a quick response than realising a bright light has come on. An example - Anglesey in bright sunshine is particularly bad for seeing warning lights.

 

Stu.

 

 

www.superse7ens.co.uk..........the rebuild 😬

 

 

[MartinWoodham]

I have to question the sanity of having a falied belt automatically cut the engine, whether soft or hard cut.

If this happens whilst exiting a corner/ overtaking you're trading off possible (likely) engine damage ☹️against possible car and driver damage... 😳 😳 😳

 

That said, the soft cut option is fairly easy to implement, either with an ECU that supports full-throttle gearchanges or a standalone rev limiter.

In full-throttle shift mode, these work by having a soft-cut (ie drop one spark in every 3 (on a 4 cylinder engine)) at a lowish rpm point eg 3500, that's initiated by a pin switch on the clutch.

Fit a suitable switch in place of the clutch pin switch, that operates when the belt fails eg porsche 993 fan belt sensor, and the revs will be then held at the revlimiter/ ecu's set point.

Any old suitable revlimiter can be used for this if your ecu doesn't support a secondary rev limit.

 

Martin

Aero'd supersported ex-Roadsports B...anyone got a cheap LSD?

[SLR No.77]

The problem is, if your overtaking or in a corner and that bright light comes on, what's going to happen next? Kill it manually, drive to safety first, lose concentration on what was actually gouing on at the time? It's difficult to know really? And when you do spot the light, how long has it been on?

 

I'd certainly like to investigate the soft cut option, maybe as you suggest Martin, wired in conjunction with a clutch switch that'll kill the engine by dropping the clutch when the system is activated (I think that's your comment?).

 

Stu.

 

www.superse7ens.co.uk..........the rebuild 😬

 

 

[MartinWoodham]

Stu, I was suggesting using a switch driven from a belt sensor, to soft-cut automatically if the belt goes.

ie use a standard flat-shift setup using a revlimiter and clutch switch, but wire the switch to the belt sensor instead of to the clutch.

 

The prob really is the design problem that you lose oil pressure the moment the belt fails. the only way around that is to use the existing pressure pump which is spinning whenever the crank is spinning, then make sure that it's always supplied with oil. ie the CC setup.

 

(or my b4stardised MGF solution - twin scavenge and use the internal pressure pump. I'll get around to fitting it at some point...)

 

 

 

Martin

Aero'd supersported ex-Roadsports B...anyone got a cheap LSD?

[SLR No.77]

Now I understand Mines the CC system so worth looking into.

 

Stu.

 

www.superse7ens.co.uk..........the rebuild 😬

 

 

[Unclefester]

>

 

I repeat my question.....how much difference would this make?

 

If belt goes, a light comes on and the ignition goes to soft cut mode, how long wil the engine actually give useful powere without scattering?

 

I personally would rather be able to give full concentration to the job in hand, controlling the car in or exiting a corner, without worrying about the engine, knowing that I don't need to flounder around trying to turn it off manually.

 

I'm SURE I wouldn't react to a light anyway. At least not in time.

 

If the engine simply loses powere because the belt's bust, you clutch down automatically (well I do) and find a way out of whatever dynamic mess you are in....

 

Lucy in the Sky with Diamonds..ooooh hooo hooo!!...

😬 😬Abbey Road Time-Machine *eek*

 

[Paul McKenzie]

Can't remember who, but some-one was looking at a 'belt failure indicator' for those of us with a DS system using a scav pump and the internal oil pump..obviously well worthwhile as you would have the time before the tank empties and the LP warning comes on to do something constructive .

 

I would imagine it only needs some sort of 'light source thingy' directed at the scav pump pulley..should be easy really . Does anybody know if there is any progress on this?

 

Paul

[SLR No.77]

Paul, mine has a simple microswitch rigged to the belt auto-tensioner pulley (K-Series). If the belt isn't there the tensioner swings out and releases the microswitch causing illumination of an LED on the dash. Very simple, but whether I can react fast enough to the LED is anyones guess!

 

Stu.

 

 

www.superse7ens.co.uk..........the rebuild 😬

 

 

[k.russell]

Paul was going to post exacly the same thing, would have to be on the pulley though as you suggest as the VX titan set up doesnt have a tensioner. anyone any ideas, a level indicator on the tank seems floored as it would have perhaps filled up the engine with oil and done damage prior to the warning.

 

kevin R

black-ali HPC

[Beelzebub]

This thread has got me thinking about a belt failure detection device. I've taken some inspiration from this webby here

[Bob Simon]

No need to hire Wallace and Gromit to create something that's already available. The DC version of this gadget would work nicely.

 

clickity click here

 

We use these on packaging and assembly machinery. A magnetic prox sensor or even a VR sensor could pick up ferric bolt heads or dowels pressed into the pump pulley. The relay is fully programmable for different pulse rates. When the pulse drops below the programmed rate, the alarm output is triggered. A startup feature keeps the alarm output normal until operating speed is reached (something less than cranking speed).

 

What you want to do with the alarm signal is up to you.

 

Pdf data sheet here.

 

A small enclosure would probably be a good idea as these types of devices are not rated for water spray and such.

 

about 150USD (75 quid?)

 

-Bob

94 HPC VX Evo III

 

 

Edited by - Bob Simon on 11 May 2007 03:38:21

[SLR No.77]

Bob, it sounds like such a sytem could work for both the Pace and Caterham VX installs.

 

Stu.

 

 

www.superse7ens.co.uk..........the rebuild 😬

 

 

[Jason Plato]

It should be remembered that the main difference between the Pace set up and the Caterham K series setup is that the Caterham / Titan pump is only the scavenge .The pressure pump is still the original rover one inside the engine. So if the belt fails on this setup then the engine will fill with oil and the pressure pump will still pump and the engine will eventually spurt the oil out of the breathers all over your face so a warning system would be useful to allow you to shut the engine down .

 

with the pace pump you loose all pressure immediately ☹️. so you might just as well wire in a bright lowe pressure lamp or use the 12v signal to the lamp to action an ignition cut off - but the engine will still be buggared

 

before all the pace users jump down my throat in defence of their systems - BOTH systems have their limitaions and drawbacks

 

 

 

Edited by - Dave J on 11 May 2007 09:54:11

[MartinWoodham]

ref my earlier post, Porsche fitted a fan belt failure switch to 993 (& some 964) models, a little wheel that runs on the belt itself. Sounded dodgy to me too, if anyone other than Porsche designed it I wouldn't suggest it.

you can buy them here part no 993.106.035.00, £42.24 inc vat.

 

I should say that I've not used this myself (since my DS system is still sitting on the bench waiting for a few final problems to be solved, like engine mount fouling the pump outlets...!) but I'll be fitting one in due course.

 

 

 

 

Martin

Aero'd supersported ex-Roadsports B...anyone got a cheap LSD?