essex engine problems

[landkeeper]

lads there is a lad who posted on our club website in ireland with an essex engine in a speedboat , it's giving him problems heres a link to the thread

http://www.clri.net/smf/index.php?topic=6073.0;topicseen

if anyone can offer any help it'd be great

[task]

lads there is a lad who posted on our club website in ireland with an essex engine in a speedboat , it's giving him problems heres a link to the thread

http://www.clri.net/smf/index.php?topic=6073.0;topicseen

if anyone can offer any help it'd be great

I had one of these in a series 3. Sounds like he could need a heat isolator plate between the manifold and the carb. We made one from tuffnol. It was many years ago but I seem to remember this giving the same problem and this being the solution.

[TSD]

I had one of these in a series 3. Sounds like he could need a heat isolator plate between the manifold and the carb. We made one from tuffnol. It was many years ago but I seem to remember this giving the same problem and this being the solution.

The standard Ford isolator was a 1/2" thick plastic plate, with a baffle plate to stop all the fuel dropping straight onto the manifold and running straight down the middle cylinder ports.

Actually it sounds to me more like the opposite problem, carb icing. Running at partial throttle in a wet environment can do that. I'd try drawing the inlet air over one of the manifolds and see if it improves matters.

[task]

The standard Ford isolator was a 1/2" thick plastic plate, with a baffle plate to stop all the fuel dropping straight onto the manifold and running straight down the middle cylinder ports.

Actually it sounds to me more like the opposite problem, carb icing. Running at partial throttle in a wet environment can do that. I'd try drawing the inlet air over one of the manifolds and see if it improves matters.

That's pretty much what we made. I used to get problems with icing untill the engine had warmed up but it was never a problem 20 mins into running. I would have thought any problems with icing would manifest fairly quickly and not once the engine had reached a higher temp?

[TSD]

That's pretty much what we made. I used to get problems with icing untill the engine had warmed up but it was never a problem 20 mins into running. I would have thought any problems with icing would manifest fairly quickly and not once the engine had reached a higher temp?

You may be right, the only time I've experienced carb icing it took about 5 mins to become a problem. On a boat though, who knows? There's likely to be a lot of moisture in the intake air, and the cooling setup may be very different - total loss cooling/heat exchanger/radiator? I don't know whats usually done when fitting but the engine temperatures could be a lot different to a typical car setup.

[task]

You may be right, the only time I've experienced carb icing it took about 5 mins to become a problem. On a boat though, who knows? There's likely to be a lot of moisture in the intake air, and the cooling setup may be very different - total loss cooling/heat exchanger/radiator? I don't know whats usually done when fitting but the engine temperatures could be a lot different to a typical car setup.

Ahh, that's true. I hadn't taken the different cooling method into account. Perhaps it's an issue with the cooling system itself, I would have thought there would be some way of keeping the engine at an optimum temp, perhaps it could also be a fault with that?

[steve_d]

Ahh, that's true. I hadn't taken the different cooling method into account. Perhaps it's an issue with the cooling system itself, I would have thought there would be some way of keeping the engine at an optimum temp, perhaps it could also be a fault with that?

If the engine has no thermostat or it is jammed open then the cooling system would perhaps be too efficient.

Steve

[TSD]

If the engine has no thermostat or it is jammed open then the cooling system would perhaps be too efficient.

Steve

The 38DGAS on that engine was a pig of a thing at the best of times, and the isolator pad was so thick I don't think the carb itself got much heating directly by the manifold, even though the manifold has a big heating pad at the base and carries all the coolant from the heads. If the autochoke has been removed (so no water heating by that) and the engine compartment temperatures are low...

(Megasquirt transforms that lump totally!)

In a car with that engine the underbonnet temps often get quite high, and the standard Ford setup took a warm air feed off one exhaust manifold into the airbox.

I guess in a boat there's no radiator and fan blowing hot air around.

The other thing that can throw the cooling off in the Essex is the that coolant flow rates around each cylinder are controlled by the size of holes in the inlet manifold gasket. Sometime people open up the holes thinking they will get better cooling, but all that happens is some cylinder get more cooling and others get less. Alternatively, sometimes the copper shims (attached to the gasket) slip during assembly and block one coolant port.

I don't think that the block cooling as such is the problem though.

Dave

[SteveRK]

Before getting too deep into the technical possibilities I would urge you to establish whether it is fuel related or not with a very basic teat. Take the boat out at full power and after 20 minutes when it starts to cut out squirt fuel down the carb from a washing up bottle or similar and see what happens. That will tell you whether you need to look elsewhere.

My gut feel is that it will be the coil breaking down. either due to a 6 volt coil getting 12volts (no ballast resistor) or other reason.

[TSD]

Before getting too deep into the technical possibilities I would urge you to establish whether it is fuel related or not with a very basic teat. Take the boat out at full power and after 20 minutes when it starts to cut out squirt fuel down the carb from a washing up bottle or similar and see what happens. That will tell you whether you need to look elsewhere.

My gut feel is that it will be the coil breaking down. either due to a 6 volt coil getting 12volts (no ballast resistor) or other reason.

I agree with you Steve, but I wouldn't try squirting petrol into a hot Essex lump, they can be a real pig to start when warm if the fueling isn't just right, and lead to a wrong conclusion.

Easistart will do the job just lovely though!

[stifz]

Hi Lads,

Landkeeper posted this on my behalf. Thanks for the input so far. To answer some of the above questions its easier to say whats new and has been replaced already / possible problems elimated. New coil & resistor, dizzie cap , rotar arm and leads. Points & condenser. All piping for cooling all gaskets etc. recon starter motor, alternator , new battery, new fuel tank, fuel line and breather on tank is open..

After advice from the irish landy guys they spotted the carb was'nt being cooled and possible causing a vapour lock or fuel being vapourized. After looking at the carb its missing the water cooled choke. So i think i have it sorted. Gonna replace out choke fit cooling to carb and heat resistant spacer plate between manifold and carb.

Failing that i think i'll sink it if it does'nt fix it!!

[task]

Hi Lads,

Landkeeper posted this on my behalf. Thanks for the input so far. To answer some of the above questions its easier to say whats new and has been replaced already / possible problems elimated. New coil & resistor, dizzie cap , rotar arm and leads. Points & condenser. All piping for cooling all gaskets etc. recon starter motor, alternator , new battery, new fuel tank, fuel line and breather on tank is open..

After advice from the irish landy guys they spotted the carb was'nt being cooled and possible causing a vapour lock or fuel being vapourized. After looking at the carb its missing the water cooled choke. So i think i have it sorted. Gonna replace out choke fit cooling to carb and heat resistant spacer plate between manifold and carb.

Failing that i think i'll sink it if it does'nt fix it!!

"water cooled choke" is the automatic choke. This was also removed on the engine I had and the Scimitar my dad used to have when I was a kid.

[SacredDog]

That's pretty much what we made. I used to get problems with icing until the engine had warmed up but it was never a problem 20 mins into running. I would have thought any problems with icing would manifest fairly quickly and not once the engine had reached a higher temp?

I used to get Carb icing problems on my old highly tuned crosssflow Fiesta, on a cold damp day travelling at continuous Motorway speeds it would start coughing after 20-30 mins and die altogether after about 40 mins unless I slowed down considerably or pulled over for 5-10 mins.

After 5-10 mins (ideally with the Filter off) it would fire up & run fine for another 30 mins or so.

Of course this was many years ago when you could run at high speeds for over half an hour without hitting a traffic jam .

I did improve matter by fitting a heat deflector above the exhaust that pushed some hot air towards the Carb.

Colin.

[TheRecklessEngineer]

Sounds very very similar to a problem I had on a rover V8 -

I was using (unknowlingly) a 6v coil without a ballast resistor on points. After a few mins of running, it would cough, miss and die. Tried new coil, new points, nothing.

After a while though, it was noticed that the points were getting very hot. What was happening was without the ballast resistor, the points were getting hot enough to soften the plastic cam follower - this then prevented the points from opening/altered the timing, engine died. After a few mins to cool down, all was well and good.

Fitted ballast resistor, problem solved!

(Then I fitted electronic...)

[SteveRK]

If its above 0C then carb icing is a physical impossibility.

I would also forget about vapourising of the fuel - at full power the fuel will be dribbling through at a fair old lick so the flow rate will elliminate this also.

We are talking about a very significant event happening for the engine to suddenly die like this so i'm sticking with coil/ignition related problems for now.

[TheRecklessEngineer]

If its above 0C then carb icing is a physical impossibility.

The pressure drop in the venturi of the carburettor will also cause a temperature drop (can't remember the name of the law!)

Under humid conditions, carb icing is possible regardless of temperature - within reason. Certainly you won't get it in 30 degrees of Med sunshine, but 6-7 degrees in the UK, in moist sea air...perfectly possible.

However, my gut also points to ignition...

[TSD]

If its above 0C then carb icing is a physical impossibility.

Where do you think it's above 0C ?

[SacredDog]

The pressure drop in the venturi of the carburettor will also cause a temperature drop (can't remember the name of the law!)

Under humid conditions, carb icing is possible regardless of temperature - within reason. Certainly you won't get it in 30 degrees of Med sunshine, but 6-7 degrees in the UK, in moist sea air...perfectly possible.

However, my gut also points to ignition...

I can confirm the icing with my Fiesta was at it's worst when the temperature was above 0 degrees. Below 0 and I think the air tends to be dry enough for it not to be a problem.

I had a quick release Air Filter (Pipercross I think). If I whipped the Filter off just after it had totally died the main venturi would be almost totally blocked with ice, until the first time I saw that ice I didn't have a clue what the problem was.

One quick & easy way I used to get it defrosted (for when I didn't want to wait 5-10 mins) was to squirt some alcohol (the type you degrease with, not drink) into the venturi, that dissolved the ice and allowed the water to mix with the petrol a bit easier. It would then fire up almost instantly.

Colin.

[Roverdrive]

The water connection to the choke was indeed just for engine temperature sensing, and not for cooling.

Might be as well to have a look in to the carb just after it stops to see if there is any icing, or if the auto choke has opened up again. If you don't have a water line connected it might be staying on full choke?

IIRC to "set" the choke from a cold engine, you pressed the throttle to the floor once and let go.

Then crank the engine, and it would start.

Choke would then come off as the engine warmed up.

Had a 3.0 Essex V6 in a lightweight many moons ago. Was really p****d off to see it last year with a 2.25 diseasel in it :-(

[stifz]

Great to get the feedback lads. Keep it coming. Okay the coil is new with ballast resistor also. And all new wiring to engine done. Ran ALOT better.. but same issue 15mins and it winds itself down. after new coil dizzie cap rotar and leads points and condenser i think ive covered the iginition issue. So back to the carb.

Defo not icing.

Roverdrive: You mention the choke water connection just for temp sensing? Not for cooling? Having talked to the new Zealand group of jet boaters ( the boat is originally from there) they say i need to cool the carb as the engine is running flat out. I'm learning as i go i'm not mechanically trained at all. i'm trying to understand how the carb cooling works? Is it not a case of hucking up a water pipe to the inlet that circulates the carb cooling it? Im not sure how a water cooled choke works either!!

My plan so far is to get a secondhand carb with water choke and make a good carb from the two. Also fitting a cooling plate between the manifold and carb.

I have more detailed images on my website under ford essex section www.gavin-casey.com

Keep the advice coming folks. thanks gavin

[TheRecklessEngineer]

stifz - where in the world are you? You may find someone on here who is local and willing to take a peek....

[ian_s]

is the engine exposed to a descent airflow like it would be in a car?

i've had a lot of contact with boats over the years, and i know that boat engines are prone to getting too hot, especially engines that have been transplanted from cars.

to give you an idea, my dad has a boat with twin 6 litre 6 cylinder turbo diesels. these engines were built with the sole intended purpose of going in a boat, and as such they have at least 3 oil coolers, a huge water heat exchanger, all cooled by salt water drawn in from the river. the salt water is then injected into the exhausts after the turbo, and a massive sump is fitted to help cool the oil even more. these can still overheat when pushed hard!

if this engine has been fitted in such a way that no cold air is getting into the engine compartment, then its going to get rather warm in there, and then you run the risk of the fuel vapourising the lines and carb.

[TSD]

I notice you have the mechanical fuel pump... is it possible that there is sediment collected in the pump body?

Do you have a decent filter before the pump? Have you checked it recently?

Have you checked for water in the fuel?

Why do you say it's defo not icing?

Have you checked the floats aren't sticking in the carb?

Do the easi-start thing.

The vacuum bulb on the dizzy is open to the atmosphere on the Essex. I had some very odd symptoms once when some mud got in there - the timing got shifted randomly as the mud jammed the diaphragm in different positions. You won't have mud, but you could have sticking timing?

Dave

[stifz]

Im based in north Kildare Close to Enfield (meath).

The engine is covered over with an engine box thats vented with 4 1ftx1ft vents. I've ran it with it off and makes no difference.

[Roverdrive]

Stifz

By temp sensing, I am referring to the need to operate the automatic choke, The operating element needs to know how hot the engine is, so that it can open the choke flaps.

Might be worth having a look to see if these are operating correctly if they haven't been converted to manual choke already.

Bear in mind that the vehicle I had was about 20 years ago so details are a bit fuzzy!

IIRC the water line to the choke operating unit was plumbed in to the heater circuit, so water was continually flowing through it, not just when the thermostat opens.

You may not see carb icing, as it forms below the venturi usually, and will block the jets.

Not sure if Weber carbs are particularly prone to the icing problem, but I remember my Dad's Cortinas all had an elbow at the end of the filter that was turned to point at the exhaust manifold in the " winter" position.

What is the length of fuel pipe from the suction side of the pump to the tank?

Is this line in the engine bay near to the exhaust? Heating the fuel which is at less than atmosphetic pressure makes it more prone to vapourising. Not such an issue on the pressure side of the pump, and only tends to happen after stopping the engine, and the heat soak from the engine bay boils off the fuel left in the carb. Symptoms would be a prolonged cranking time without firing as the pump fills the float bowls again.

I have never come across a water cooled carb.

The only comparable thing is a water heated inlet manifold, to aid vaporisation. Don't forget the "water cooling" will be at 80 degrees anyway!

Keep at it, you will get there in the end!