The V8 Owners Forum -

I have a 1998 Westfield SEight with Rover 3.5 V8 on Edelbrock 500 and inlet.
The problem i have is that when the engine is fully up to temprature the WOT position feels like it has major fuel starvation.
If the engine has only just reached temprature everything is perfect but after about 5-10 minutes it is really bad.
I have a Facet red top pump and i have just fitted a filter king pressure regulator but it has made no difference. About 2 months ago i fitted a new distributor, distributor cap, rotor arm and leads.

Can anyone help?

As you guessed it most likely will be fuel starvation if it goes lean and horrible after a few seconds of WOT, you really need to get a fuel pressure gauge in line right before the carb, if you can plumb it so you can see it when driving (temporary fitment is fine) then you can see when the pressure goes to zero at full throttle. Mine is out the bonnet right infront of me so I can see it all the time. An AFR gauge would help too and will let you tune the carb perfectly (again is how I did mine) but they aren't cheap at around £180>.

Hi
Having fitted the regulator, what do you have it set to? is the pressure maintained when the car revs under load? you will obviously need a gauge fitted to the carb fuel inlet port to check this.
If the pressure stays up under full load then it is probably sthe carb, so:-
Have you set the float bowl levels correctly? the carb is very sensitive to wrong fuel levels
Have you had the carb set up on a RR? As it comes out the box the jetting is a mile out
Is it a new carb? If not has it been cleaned before installation?
Has it had a back fire? A back fire will kill the power valve.
have a go at these and come back with some results
Best regards
Mike

kiwicar wrote:Hi
Having fitted the regulator, what do you have it set to? is the pressure maintained when the car revs under load? you will obviously need a gauge fitted to the carb fuel inlet port to check this.
If the pressure stays up under full load then it is probably sthe carb, so:-
Have you set the float bowl levels correctly? the carb is very sensitive to wrong fuel levels
Have you had the carb set up on a RR? As it comes out the box the jetting is a mile out
Is it a new carb? If not has it been cleaned before installation?
Has it had a back fire? A back fire will kill the power valve.
have a go at these and come back with some results
Best regards
Mike

Please don't take this the wrong way but the eddy 500 does not have a power valve.

sidecar wrote:

kiwicar wrote:Hi
Having fitted the regulator, what do you have it set to? is the pressure maintained when the car revs under load? you will obviously need a gauge fitted to the carb fuel inlet port to check this.
If the pressure stays up under full load then it is probably sthe carb, so:-
Have you set the float bowl levels correctly? the carb is very sensitive to wrong fuel levels
Have you had the carb set up on a RR? As it comes out the box the jetting is a mile out
Is it a new carb? If not has it been cleaned before installation?
Has it had a back fire? A back fire will kill the power valve.
have a go at these and come back with some results
Best regards
Mike

Please don't take this the wrong way but the eddy 500 does not have a power valve.

I won't "take it the wrong way" as I can't see how I might be offended by your reply.
My reply was generic in that I was trying to get the chap started on some methodical fault finding and I was trying to recall everything I could about 4 barrel carbs that made their metering go even further out than just normal use. A carb is a carb to me, they all have similar faults even when they come with 4 holes in them.
Best regards
Mike

The Eddy 500 is a good carb but out of the box they are setup pretty crap, the floats are always miles out for starters. The jetting ain't that great for a 3.5 lump either.

In my humble I reckon that your regulator is not only controlling the pressure but also the volume of fuel which is no good. I run a low pressure pump which means that I don't need a regulator. If your pump is less than 7 PSI ditch the regulator. A bloke on the Cobra forum had all sorts of issues and it was the regulator.

A simple test is to disconnect the fuel feed to the carb, and bung it into a 2 litre container (Cleaned out milk containers are good for this). Run the pump for exactly one minute then mark the fuel level on the container. If you have a good way of measuring the volume then measure it. If you won't then do the following.

Drain the fuel out of the container and re-fill it with water up to the mark. weigh the water on some good kitchen scales, every gram of weight will be 1cc of water and hence fuel. (Roughly!)

The formula below will tell you whether the fuel system is up to the job:-


BHP= (Vol of fuel per min)/4.7

Or (Vol of fuel per min) = BHP x 4.7

A hot 3.5 might make around 230 BHP, it would need 1081cc's of fuel per minute to make this BHP. Really in this case you would want the system to deliver at least 1300cc to give some safety margin.

You can try the same test without the regulator fitted.

The bloke on with the Cobra quickly sussed out his problem using the gumph above.

If you think that the fuel pump is somehow slowing down when it gets hot you could run the pump for 5-10 minutes into a large container then run it for 1 minute into the milk container.

By the way a good starting point for the jetting would be 86 primaries, 67-55 rods, silver springs, and maybe 83 secondaries. (I'm a bit reluctant to recommend secondaries because if they are miles out then you could blow the motor)

My mates fairly standard 3.5 needs 83 seconardaries as does Muscle Manta's stage III 4.6. My stage III 4.6 needs 66 secondaries. (Which I had to make! ) Both the 4.6 lumps run 86 primaries and at the moment 69-52 rods, we are going to try 69-55 rods. You can not buy these rods, they are home made. 69 is right on the limit for the cruise on our engines, they are fine with 69's but 'un-drivable' with a 70!...only 1 thou difference!

kiwicar wrote:

sidecar wrote:

kiwicar wrote:Hi
Having fitted the regulator, what do you have it set to? is the pressure maintained when the car revs under load? you will obviously need a gauge fitted to the carb fuel inlet port to check this.
If the pressure stays up under full load then it is probably sthe carb, so:-
Have you set the float bowl levels correctly? the carb is very sensitive to wrong fuel levels
Have you had the carb set up on a RR? As it comes out the box the jetting is a mile out
Is it a new carb? If not has it been cleaned before installation?
Has it had a back fire? A back fire will kill the power valve.
have a go at these and come back with some results
Best regards
Mike

Please don't take this the wrong way but the eddy 500 does not have a power valve.

I won't "take it the wrong way" as I can't see how I might be offended by your reply.
My reply was generic in that I was trying to get the chap started on some methodical fault finding and I was trying to recall everything I could about 4 barrel carbs that made their metering go even further out than just normal use. A carb is a carb to me, they all have similar faults even when they come with 4 holes in them.
Best regards
Mike

Fair enough!

Thanks for all that info. I will give some of it a try and see how i get on

The carb is about 12 years old and i am sure it was fitted when the car was built. Could the jets and rods be worn?

I was speaking to a guy who reckons it could be fuel vapourisation as it sometimes happens on part throttle. If you dip the clutch and give it a good few revs then it is better but still not perfect. All the fuel pipes and regulator are as far away from the block as possible.
Could it be this?

S8Westie wrote:Thanks for all that info. I will give some of it a try and see how i get on

The carb is about 12 years old and i am sure it was fitted when the car was built. Could the jets and rods be worn?

I was speaking to a guy who reckons it could be fuel vapourisation as it sometimes happens on part throttle. If you dip the clutch and give it a good few revs then it is better but still not perfect. All the fuel pipes and regulator are as far away from the block as possible.
Could it be this?

I guess it is possible for the jets and rods to be worn but the mixture would actually go richer! (I'd be surprised if they are worn)

The rods are really well made, if you get a decent quality micrometer you should find that the rod diameters are exactly what is stated on them. E.g. a 65-52 is 65 thou thick on the cruise and 52 thou thick on the power step.

The digital verniers that you can get off ebay for 5 quid whilst being OK are not good enough to measure the rods! Mine reads about 2 thou out from the stated rod size but the rods do tally up with my 25 year old micrometer.

Some of the jet and rod combo's that the professionals recommend are not that good either! (RPI)

I run a thermo plate to help with hot starts, I don't think that it makes much difference when the engine is running, it does cause the carb to ice up in winter about 2 minutes after it has started, after 3 minutes its then OK again.

Do you know what is in the carb now? It's not just full of dirt is it?

I have had the carb in bits and it was immaculate inside with not a trace of dirt to be found.
The Jets that are in it just now are.086 primary but the main ones are not easy to read. I think they have 120 and 380 stamped on them.
The rods are 65 52
The spring on the primary doesnt have any colour

S8Westie wrote:I have had the carb in bits and it was immaculate inside with not a trace of dirt to be found.
The Jets that are in it just now are.086 primary but the main ones are not easy to read. I think they have 120 and 380 stamped on them.
The rods are 65 52
The spring on the primary doesnt have any colour

The primaries and the rods are standard, the standard secondaries are 95, if yours are 80's then someone has changed them. I have found that the 65 rod is usually too rich. Going to 67 leans the mixture off on cruise by 10%

BTW the Edelbrock chart has several errors in it!

The springs may well have been orange at some point in time, the problem is that the paint falls off them! If you can get hold of a set of silver springs you would be able to see if yours are the same.

sidecar wrote:

S8Westie wrote:I have had the carb in bits and it was immaculate inside with not a trace of dirt to be found.
The Jets that are in it just now are.086 primary but the main ones are not easy to read. I think they have 120 and 380 stamped on them.
The rods are 65 52
The spring on the primary doesnt have any colour

The primaries and the rods are standard, the standard secondaries are 95, if yours are 80's then someone has changed them. I have found that the 65 rod is usually too rich. Going to 67 leans the mixture off on cruise by 10%

BTW the Edelbrock chart has several errors in it!

The springs may well have been orange at some point in time, the problem is that the paint falls off them! If you can get hold of a set of silver springs you would be able to see if yours are the same.

Thankyou for your help. I will let you know how i get on once the weather is a bit drier in Scotland and i can get out