15 replies to this topic

[charliefarlie37]

been doing more work on my the pick up i inherited from my dad and trying to address the running issues.
its a 1967 pickup which at some point has had a 998 engine fitted, its been fitted with a 1 3/4 hif44 carb and electric pump but is always dodgy to start and you have to be delicate with the throttle or it just bogs.

would it originally had a electric or mechanical fuel pump?

ive three carbs in hand and dont know which would be the best to use. ive the choice of a 1 1/2 hs4, a 1 1/2 hif38 or the 1 3/4 hif 44 mentioned above.
which would be best suited to a 998 and easiest to set up?

thanks in advance

[panky]

The 1 3/4" is a bit big for a 998. The HS4 would look a bit more 'period' but the HIF38 would be a simple swap for the 44.

[charliefarlie37]

i was thinking that the 1 3/4 was abit overkill, prob why its always run like crap

[slidehammer]

I agree with Panky HS4 (1 1/2 inch) if you can get a idea of what the engine is out of (or what year it is) you trace a standard needle as a start point. It would originally had an SU electric pump mounted to the rear subframe. 

[Retroman]

If you are after a more standard look then the HS4

Using an alloy manifold I would go with the HIF 38

As others have said a 44 is overkill on a standard 998

A HIF44 should only be used when a 998 is highly tuned

 

Which ever you fit they need to be good...many have very worn throttle spindles and bushes

If you can feel movement its time for new, as it is also the throttle plate which moves and the play allows air to be drawn in.

The needle and jet also wear which can cause mixture / emission / tickover / adjustment issues

[Wim Fournier]

And. When you use an elctric pump you should use a fuel pressure regulator as well.

Electric pumps are so strong that they press the needle in the fuel bowl lid out off its sitting.

[Retroman]

And. When you use an elctric pump you should use a fuel pressure regulator as well.

Electric pumps are so strong that they press the needle in the fuel bowl lid out off its sitting.

Don't think so, I have used many electric SU, Facet and various others, push type & pull type mounted in the boot, underneath or on the bulkhead.....and never used a FPR

A standard fitment AUF214 SU  electric pump only makes low pressure and a FPR is only something else to go wrong

The only time you need a FPR is for a turbo or novelty value

[cal844]

And. When you use an elctric pump you should use a fuel pressure regulator as well.
Electric pumps are so strong that they press the needle in the fuel bowl lid out off its sitting.

Don't think so, I have used many electric SU, Facet and various others, push type & pull type mounted in the boot, underneath or on the bulkhead.....and never used a FPR
A standard fitment AUF214 SU  electric pump only makes low pressure and a FPR is only something else to go wrong
The only time you need a FPR is for a turbo or novelty value

I agree

[nicklouse]

 

 

And. When you use an elctric pump you should use a fuel pressure regulator as well.
Electric pumps are so strong that they press the needle in the fuel bowl lid out off its sitting.

Don't think so, I have used many electric SU, Facet and various others, push type & pull type mounted in the boot, underneath or on the bulkhead.....and never used a FPR
A standard fitment AUF214 SU  electric pump only makes low pressure and a FPR is only something else to go wrong
The only time you need a FPR is for a turbo or novelty value

I agree

 

loads of sweeping statements here.

 

you NEED to use a regulator if the PUMP produces more pressure than the float chamber needle can manage it does not matter  what the pump is.

 

you can get electric pumps that are perfect for the SUs with the old needle valve. but you can also get new needles which are stated to be good to 10PSI (never used or  tested them so cant comment).

[carbon]

Agree there are situations where a fuel pressure regulator is required.

 

But there are many situations where they are not essential, and there can be quite significant downsides. I used to run a FPR (Filter King) mounted on the bulkhead but found this resulted in fuel vapour lock - typically on hot day when used hard or for long distance. Took it out and problem solved.

 

And this was before they put ethanol into fuel. As the % ethanol in petrol continues to increase this will aggravate any fuel vapour lock issues.

[Retroman]

 

 

 

And. When you use an elctric pump you should use a fuel pressure regulator as well.
Electric pumps are so strong that they press the needle in the fuel bowl lid out off its sitting.

Don't think so, I have used many electric SU, Facet and various others, push type & pull type mounted in the boot, underneath or on the bulkhead.....and never used a FPR
A standard fitment AUF214 SU  electric pump only makes low pressure and a FPR is only something else to go wrong
The only time you need a FPR is for a turbo or novelty value

I agree

 

loads of sweeping statements here.

 

you NEED to use a regulator if the PUMP produces more pressure than the float chamber needle can manage it does not matter  what the pump is.

 

you can get electric pumps that are perfect for the SUs with the old needle valve. but you can also get new needles which are stated to be good to 10PSI (never used or  tested them so cant comment).

 

My comment was not a general sweeping statement, its my experience, as I said, other than on turbo's I have never used a fuel pressure regulator (FPR) ....that may not be 100% accurate but I have never fitted one, but have worked on an odd car with one already fitted. So here's the long version;

   My engine work started in 1976ish so I have come across plenty since then in all states of tune, off road, road, race, rally, Mini Stox, F2 Stockcar, hillclimb and sprint....A, B, and K series ,Crossflow, Pinto, BDA, Zetec, Rover, VW Jag TVR Lotus TR's Nissan....SU carbs H HS HD HIF and Webers, DCOE IDA and DCO. I don't touch tuned fuel injection or odd production line webers.
None of them rolled of the production line with an FPR either.
Nicklouse I agree as you say   " if the PUMP produces more pressure than the float chamber needle can manage it does not matter  what the pump is."
  But if thats the case you need a new float needle valve (Genuine SU or Weber) first, not a FPR
Then if the float needle won't do the job then consider an SU or Facet pump with less pressure, which would be a better choice.

So I guess I am saying the pump does matter as its supplying too much pressure for a carb which was not designed for more than about 4psi.
Both SU and Weber carbs need no more fuel pressure than about 3 or 4psi, but cope with higher OK and I have never found the need for a regulator, even with 7.5psi Facet pumps.

On bigger more powerful engines (over 150hp) they need the extra volume of fuel ie; more flow in Gallons Per Hour (GPH), not pressure.

The vast majority of 18 GPH size pumps supply less than 8 psi and some 1/2 that, and its perfectly good for any Mini and many other cars without higher pressure or a FPR.

In my opinion a fuel pressure regulator is a pointless un-needed complication, which has both setup and ongoing adjustment issues, with potential leak and unreliability worries, and any fuel pump supplying more than about 7 psi on a normally aspirated engine is also uneeded.

Fast and complicated is never cheap or reliable, and never will be.

[charliefarlie37]

thank you for all your replies and input, it looks like differing opinions of the need for a fpr, as far as im aware as standard no fpr was fitted so i will see how it goes without one.
i basically wanted confirmation about the use of the 1 3/4 carb on my engine.
looks like im going to use the 1 1/2 hif38, is there anything to take notice of when i strip it to give it a clean?

[nicklouse]

thank you for all your replies and input, it looks like differing opinions of the need for a fpr, as far as im aware as standard no fpr was fitted so i will see how it goes without one.
i basically wanted confirmation about the use of the 1 3/4 carb on my engine.
looks like im going to use the 1 1/2 hif38, is there anything to take notice of when i strip it to give it a clean?

they all require the same pressure. and if the pump provides the correct pressure you dont need one.

[Retroman]

thank you for all your replies and input, it looks like differing opinions of the need for a fpr, as far as im aware as standard no fpr was fitted so i will see how it goes without one.
i basically wanted confirmation about the use of the 1 3/4 carb on my engine.
looks like im going to use the 1 1/2 hif38, is there anything to take notice of when i strip it to give it a clean?

As above unless you have some random pump making over 8 psi you should not have float needle issues, or need an FPR they were never fitted as standard to a carb Mini.

   Make sure there is no play to feel in the throttle spindle / bushes as any play allows air in and causes all sorts of emission /  tickover / mixture / adjustment issues, its also worth fitting new main jet and needle unless you know they are good for the same reasons.

[cal844]

thank you for all your replies and input, it looks like differing opinions of the need for a fpr, as far as im aware as standard no fpr was fitted so i will see how it goes without one.
i basically wanted confirmation about the use of the 1 3/4 carb on my engine.
looks like im going to use the 1 1/2 hif38, is there anything to take notice of when i strip it to give it a clean?

As above unless you have some random pump making over 8 psi you should not have float needle issues, or need an FPR they were never fitted as standard to a carb Mini.
   Make sure there is no play to feel in the throttle spindle / bushes as any play allows air in and causes all sorts of emission /  tickover / mixture / adjustment issues, its also worth fitting new main jet and needle unless you know they are good for the same reasons.

As above, if the HiF38 has been on a similar engine id note the settings of the mixture screw