Lucas Pump Cooling Coil Pipework

[Peter Cobbold]

PRV overflow> pump cooling coil > underbody cooling coil exposed to air flow > tank

Use a power steering cooler?

 

I never had pump heating issues but had removed the rear panel in the boot to make more space.

[Schnippel]

 

......................

 

If I had to modify the PI I would pump the fuel with a BOSCH pump to the MU

have the PRV there and guide the backstream through a cooler in front of the

radiator and than back to the trunk. Thats much work but perfect result!

 

 

And in an accident everything is in flames . Wonderful.

Edited May 10, 2016 by Schnippel

[RogerH]

....cooling the Peltier device would be easy enough......

 

Roger

[GT6M]

And in an accident everything is in flames . Wonderful.

 

Its no very often a petrol leak ina crash causes a fire

its moer like brake fluid.

 

go try and set a dish of petrol alight in the open air, wid a slight breeze up

yer box of matches wil soon run oot,!!!

Its no the petrol, but the fumes thats the problem

 

M

[astontr6]

The Lucas/CAV Service Centres Mod. of the early 70's was to increase the bore size of the pipework on the input side from tank to pump to 3/8" bore (9.5mm). Go to the next size of filter head to accommodate the increase in pipe work and delete the banjo fitting/bolt from the inside of the filter head as this was a major obstruction to the flow rate. ( Many JRT Garages cross drilled this fitting and opened up the bore in an attempt to increase flow rate) The input side to the filter head was now from the front using a formed piece of pipe. It is normal engineering practice when pumping liquids in many industries to have the input pipework larger that the out put as a protection against cavitation.

 

Bruce.

[GT6M]

For what the OP is wanting, then the standard set up,

wid maybe a coil will suffice for short trips,short time oot.

 

Butt, I would try and get that pump onits side,

this way the bottom thrust , which is not a spinning bearing, but justa flat wsher

will no be tek,n the load, so so causing friction an heating up.

 

And, as other have said, bung a better wire in, say 2 MM,or 3 MM thin wall

same to for earth, earth it as near to pump as poss, then a short direct run.

 

Lucas should only be drawing aboot 5-6 ish amps {Bosches upto 17 }

so owt above this fig wil mean ye may have connection probs,

 

Some times the probs for a bad connection are in the cut oot, as the wee ball rusts

so stops a good contact, and the thing gets hot to touch.

 

M

[TriumphV8]

And in an accident everything is in flames . Wonderful.

 

My suggestion has nothing to do with the prevention to switch the pump off

in case of accident. That can be left unattended as it is.

 

The modified line from the rear to the PRV is locked by the valve when pump is switched off.

The line back to the tank is already there, too if its a original PI.

It is mounted that there will be no dripping of fuel when damaged.

So we deal with 100 cc of fuel in the cooler and the additional piping that might catch fire.

Not good from that view but I think that is acceptable especially as its rubber that can be bended

and the fuel has no pressure. It must be cut from some braking steel or glass. That is much unlikely.

 

The only additional thing is the one metre of rubber hose and the cooler.

As that is the same like used in BMW ot VW I do not see a bigger problem.

Anyway its right, with every routing to the cooler the risk of damage is rising.

I would take a look at the injector hoses, they are made from hard plastic and

break if bended. From that it might be a good idea to swap to steel braided lines.

 

All changes in fuel routing should be taken with some view on acciddents

but as 90% of the PIs I watched had the anti collosion switch removed

I would start there with that problem first if safety is in the view.

Also it might be a good idea to add a switch that cuts pump off when motor stops

like MegaSquirt does. If the impact is too small to cut pump off the stopped engine

will do that quickly.

 

There are long articles in the MegaSquirt manual that fuel and engine is not a game

and all connections must be made carefully and especially the PI on the high pressure

side needs more attention because modern cars employ only 3 bars instead of 8 in the PIs.

All the fuel hoses availiable today are much thinner than the ruber parts in the PI.

I would look for the systems like EARLS which are made for pressure beyond 20 bars.

ISA Racing and SANDTLER in Germany has suitable hoses and connectors.

[TriumphV8]

The Lucas/CAV Service Centres Mod. of the early 70's was to increase the bore size of the pipework on the input side from tank to pump to 3/8" bore (9.5mm). Go to the next size of filter head to accommodate the increase in pipe work and delete the banjo fitting/bolt from the inside of the filter head as this was a major obstruction to the flow rate.

 

 

I can report that in the V8 I still have the stock 8mm pipings.

The trick is to feed the pump with cool fuel and a little bit of pressure.

 

With that the tank and CAV fuel filter and banjos can handle beyond 300 BHP

(That was the power of my 5 litre TVR engine before the tuning started)

 

The whole change in fuel feeding must be seen as a complete system, not as a single part.

 

If you go like Bruce said you have to look after the filter in the suction side that itself

robs pressure and so very carefully every additional loss in pressure from tank outlet,

piping, banjos and feed to the pump must be avoided.

 

[StuartG]

Never tempt fate ......................speaking to a guy at the Wallingford classic car show on Sunday and I made the fatal error of saying "it has a lucas pump and has never given any trouble in the 5 years I have owned the car" ...........broke down with VERY hot lucas pump 1 mile from home on the way back from the show. Administered ice block from the cool bag for 20mins and then got home.

 

Decided to investigate this morning and found that within 5 mins of starting the car and running it on the drive the earth connection to the pump was very hot. So remade the connections and heat has now gone away. Had only 11.5 volts at the pump before remaking connections, now have 12.5 volts (at tickover) Going to Chiltern Hills rally this coming Sunday, so hopefully .......................

[astontr6]

Andreas,

 

I do not understand your response as the filter assembly that you show is not a CAV as fitted to PIs? Please can you explain again!

 

Bruce.

[TriumphV8]

Its the replacement for the CAV type.

Has the same two in- and oulets and

the air outlet at the top like original.

 

This is the same, found when searching for "CAV"

http://www.ebay.com/itm/DIESEL-FUEL-INJECTION-CAV-FILTER-ASSEMBLY-MASSEY-FERGUSON-FORD-TRACTOR-NEW-/162025700910

 

I simply added the pickup from the bottom

that the pump will not run short of fuel under

hard cornering. So this acts both as a filter

and as a catch tank in one piece.

[astontr6]

Andres,

 

Re-looking at your set-up, you are not using the original BL fittings? I cannot see how big the banjo bolt bore is or the size of the hole drilling at right angles to the bore. I assume that the banjo on the R/H/S is the fuel supply inlet from the tank?

 

Bruce.

[Denis]

I thought the picture in Andrew Smiths post looked familiar...it's my pump! And just out of interest the Coil was fitted by CAV LUCAS Service Centre in Acton in 1973 so one would assume that they did it correctly...And I reiterate that it has worked perfectly ever since to this day! Nuff said eh!

[Stag powered]

When I had my 6 and was running into hot pump problems I fitted a cooling coil plumbed in to the return from the PRV as was suggested at the time.

 

It made a marginal difference, but that was all. Not enough fuel was returning to do much good.

 

I then decided to plumb the coil so it was on the supply side of the pump so all the fuel went through it. This worked brilliantly, the quantity of fuel flowing through the cooling coil meant that the pump stayed cool (coating the coil with grease helped the heat transfer), but the fuel never picked up enough heat to cause boiling problems.

 

As Andreas mentioned,I too have experienced problems with hot fuel leaning the mixture, not on the TR, but on my Stag where the exhaust runs rather too close to the feed and return lines.

 

It was only the fitting of the megasquirt and the digital wideband display that alerted me to this. At first I thought it was the rather too small feed pipes to the Bosch pump causing trouble as the fuel level got low as the situation always improved after filling the tank.

However, after one long journey where the tank was down to the last couple of gallons and the mixture was going very weak, I parked up for a few hours while attending an event, and the mixture had returned to normal as the fuel had cooled down.

I am going to add some heat shields between the exhaust and fuel pipes before going to the South of France again this Summer.

Neil

[TriumphV8]

Re-looking at your set-up, you are not using the original BL fittings? I cannot see how big the banjo bolt bore is or the size of the hole drilling at right angles to the bore. I assume that the banjo on the R/H/S is the fuel supply inlet from the tank?

 

 

Hi Bruce, the upper four connections are 1/2" Banjo or this connection

with the olive on the tube or a plug all from the original PI equipment..

 

On the bottom is M10 x 1 and banjo for 8mm hose and that is the pump feed.

This works only because there is a little pressure in the filter but it worked for

years on the V8 with proper fuel supply even on high revs/full load what was

controlled by a log of the air/fuel ratio by the MegaSquirt.

 

The actual modification is a new pump body at the bottom.

It is made from a round aluminium piece on a lathe.

Connection is now M16 x 1,5 and a 12mm hose that directly bolts

on the 12mm tube on the BOSCH pump.

 

[Gary Flinn]

A bit of a thread resurrection here, so bear with me.

 

I've decided to stick with the standard Lucas Pump in the spirit of trying to keep my TR5 original and have just purchased a fully reconditioned Pump with a cooling coil fitted by the specialist who refurbished the Pump (The late Mike Pumford).

 

I know Mike had a good reputation for servicing and reconditioning of the Lucas PI System, after reading some of the old copies of the TRaction magazine I got on CD when I joined a couple of years ago.

 

I've read all the comments above and on other posts, there seems to be a roughly 70/30 split in favour of the Cooling Coil.

 

I was thinking of using the cooling coil but not using fuel to cool the pump, I was thinking of using water and connecting up to a small radiator (Heater Matrix or small Oil Cooler possibly) fitted some where under the car local to the pump and using a small 12V Pump and some sort of thermostatic switch to circulate the water when the pump gets hot.

 

What do you guys think, is it a crazy idea?

[cp7535he]

pic as requested , send pm if more wanted, close ups etc etc robin goodwood tr group

[astontr6]

 

Hi,

Has anyone got a picture of the pipework setup/connections for the cooling coil please?

Regards

Roger

 

There are a number of problems on the Lucas system.

!) modern fuel: it boils at a lower temp and generates bigger vapour bubles.

2) S/S exhaust manifolds.

3) OEM Bore size of pipe work from tank to pump too small. The Lucas-Cav mod used 3/8" bore pipe and a larger CAV filter head. UK !976 summer with temps at well over 30C my TR had no problems. I had no cooling coil!!!!!!.

4) S/S braided ejector hoses.

 

Bruce.

[Peter Cobbold]

Gary,

I'd measure the temperature of the pump gear housing and compare with graph in TRA 298. Are the gears getting that hot, or just the motor ? The fuel flow through the gears will cool them. It must be around 1litre per minute.

Peter

[Ragtag]

I was thinking of using the cooling coil but not using fuel to cool the pump, I was thinking of using water and connecting up to a small radiator (Heater Matrix or small Oil Cooler possibly) fitted some where under the car local to the pump and using a small 12V Pump and some sort of thermostatic switch to circulate the water when the pump gets hot.

 

What do you guys think, is it a crazy idea?

Gary,

 

Many years ago when I bought my TR6 and was still 'green' about the workings of the PI system, I noticed that the previous owner had fitted a cooling coil. However, he had just fitted it in the line between the filter and the pump so it wasn't really doing anything at all.

 

So having read on the Forum about people's problems with cavitation and heated fuel, I decided that I would conduct an experiment. I simply profiled the coil so that it would snugly accept a plastic fizzy pop bottle, filled with fresh water, down the middle.

 

I can't say categorically that my primitive heat exchanger worked as I never really had experienced any problems before but the water in the bottle did warm up so it must have been extracting heat from the fuel.

 

Your suggestion seems to be a more complex version of what I did. It will definitely do something to cool the fuel but whether it is worth the effort is another matter.

Edited June 20, 2017 by Ragtag

[Gary Flinn]

Gary,

I'd measure the temperature of the pump gear housing and compare with graph in TRA 298. Are the gears getting that hot, or just the motor ? The fuel flow through the gears will cool them. It must be around 1litre per minute.

Peter

 

Peter

 

I went out in the Car on Sunday to Santa Pod, a round trip of near on 200 miles, the car ran well with no Fuel vaporization problems even in 30 degree plus heat coming home.

 

What I did notice when I dropped my mate off at home, which was worrying was the Motor part of the pump was Very Hot to touch, I mean I couldn't hold my hand on it for more than a second or so

 

The Pump part was only warmish, due to the cooling effect of the Fuel no doubt.

 

I have fitted a circular profile Aluminium heat sink to the pump, not sure if this is helping or hindering to be honest but it was only warm so I would guess its helping transfer heat away?

 

I've read the pump motors do run hot but it seem to hot

[astontr6]

 

Peter

 

I went out in the Car on Sunday to Santa Pod, a round trip of near on 200 miles, the car ran well with no Fuel vaporization problems even in 30 degree plus heat coming home.

 

What I did notice when I dropped my mate off at home, which was worrying was the Motor part of the pump was Very Hot to touch, I mean I couldn't hold my hand on it for more than a second or so

 

The Pump part was only warmish, due to the cooling effect of the Fuel no doubt.

 

I have fitted a circular profile Aluminium heat sink to the pump, not sure if this is helping or hindering to be honest but it was only warm so I would guess its helping transfer heat away?

 

I've read the pump motors do run hot but it seem to hot

Hi Gary!

 

Your heat sink is that made out of ali, round and finned and clamped to the motor cover of the pump?

 

Bruce.

[Gary Flinn]

 

Bruce

 

Yes, here's a photo of it hopefully?

 

Gary

[Bill944T]

Being a "magpie", I've salvaged the cooling module from the lid one of the portable coolboxes (along with so much other stuff as we all do). Not sure of the principle of operation but it draws around 4 A at 12 V and itself is a cooling fin that provides a good frosting after a while. Apart from thinking about needing a dedicated feed to avoid further dropping of pump voltage, I haven't got any further with the mad professor bit

 

Regards

 

Bill

[astontr6]

Heat Sink Cooling Fins.jpg

 

Bruce

 

Yes, here's a photo of it hopefully?

 

Gary

Gary , Thanks for the picture! Is this an adapted par,t as I see it is black anodised? and I assume the cable tie clamps it to the motor cover. Also it looks to be quite a big chunk of metal which must have an effect to take heat away.

 

Bruce.