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SU fuel pump question

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nevets

nevets

Jedi Knight
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The picture shows the pump that is in the car, BN6, and a replacementon the left. There are significant differences, including the distance between the threaded mounting holes and the fuel line connections. I can't seem to identify one that matches the current pump on the Moss site.The closest one that appears similar is an electrionic (point-less) unit. Any ideas on how /where to obtain a suitable replacement? Is the electronic unit a good alternative?
Thanks!
 

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Nevets,

I have bought a couple of pumps out of the U.K. Burlen has a very helpful site.

https://sucarb.co.uk/su-fuel-pumps-spares.html

The site has a considerable amount of information which is well organized.

You need to be patient as it takes a few weeks to get the pump but it is a good product.

I would go with the electronic vs the points,

Jeff
 
Thanks for the info Jeff, I will check put that site...I think I may have partially figured out my situation. The pump that's currently in the car (one on the right) appears to be a BJ8 pump. Although my car is a BN6 I believe that when the engine was rebuilt it was fitted with a BJ8 head and cam, while retaining the original BN6 carbs. Perhaps that is the reason for the BJ8 fuel pump? I'm just guesing here. These cars test your forensic investigation skills.
 
nevets said:
The picture shows the pump that is in the car, BN6, and a replacementon the left. There are significant differences, including the distance between the threaded mounting holes and the fuel line connections. I can't seem to identify one that matches the current pump on the Moss site.The closest one that appears similar is an electrionic (point-less) unit. Any ideas on how /where to obtain a suitable replacement? Is the electronic unit a good alternative?
Thanks!
Click to expand...

The correct pump for a BN6--called a 'square body'--is item# 20 on this page: https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=28868&SortOrder=150

Looks like someone installed a (relatively) less expensive BJ8 pump (output, PSI, etc. are the same AFAIK, and it looks like the same plumbing would work for either). The other pump in your photo is for a 100 or 100-6.

Electronic pumps are theoretically better--and, in general, they are--but they aren't perfect. Points pumps work but should be serviced regularly, and the quality of the points sets I've seen lately is pathetic.
 
Although I usually appreciate and agree with Bob, Iquestion whether he is correct in stating the superiority of the electronicpump over a points-triggered unit. In the past, the SU Electronic fuelpump was plagued with burnouts that left the user calling for a flatbed. On the other hand, I have also experienced points failure that has also left meon the side of the road. However, with the points, I was able to cleanand adjust the points and be on my way with the original pump and no flatbed. Better yet, by adding a TSV diode, the lifeof the points would be extended indefinitely without any maintenance. I personally like and have come to favor thepoints-triggered pump with TSV over the Electronic SU because of its long lifeand probability of being resurrected at the side of the road if it does fail…somethingthe Electronic unit can’t do.
Ray (64BJ8P1)
 
Yes I believe the BJ8 pump was installed because it is considerably less expensive than the square body pump. I'm torn between staying with a points unit or going with an electronic version. What, if any, are the issues with the electronic unit? And where can I find out more about servicing a regular points unit? Ha...love the remote hammer...looks like a very nice Moris Minor. Great cars, if you aren't in a hurry.
 
RAC68 said:
Although I usually appreciate and agree with Bob, Iquestion whether he is correct in stating the superiority of the electronicpump over a points-triggered unit. In the past, the SU Electronic fuelpump was plagued with burnouts that left the user calling for a flatbed. On the other hand, I have also experienced points failure that has also left meon the side of the road. However, with the points, I was able to cleanand adjust the points and be on my way with the original pump and no flatbed. Better yet, by adding a TSV diode, the lifeof the points would be extended indefinitely without any maintenance. I personally like and have come to favor thepoints-triggered pump with TSV over the Electronic SU because of its long lifeand probability of being resurrected at the side of the road if it does fail…somethingthe Electronic unit can’t do.
Ray (64BJ8P1)
Click to expand...

No issue, Ray. I've put almost 130K miles on my BJ8 in the 32 years I've owned it, much of it driving through some of the most remote areas in the US and Canada so having reliable kit is important to me. Fuel pumps have been the major bugaboo over the years; I've tried points with capacitor, points with diode--SU and home-made--Dave DuBois' points-switched power transistor mod, TSV diode-equipped, SU electronic kit, SU factory-installed electronic, and Dave's LED-triggered. Yes, the early SU electronic pumps--esp. the kits--were problematic. I believe SU has improved their design; I recall there are visible differences between the older and newer versions (I own both).

The issues with points-triggered is that the points will eventually erode (yes, the TSV-damped units are probably the best solution). Also, the points are--or should be--tungsten plated, tungsten will oxidize just sitting in the car or on the bench, and points pumps can be DOA if they've sat on the shelf too long. I'm not sure if it's because of the tendency to erode or oxidize, but the points sets are designed to 'sweep' the points so as to wipe corrosion and/or erosion off the points while running. Norman Nock once said filing and cleaning points was part of 'routine service' every 15K miles or so. I bought some point sets from Moss and the points surfaces were too shiny to be tungsten; they looked like they were silver and started eroding after just a few miles. I doubt SU Burlen would sell such junk; these appeared to be Chinese crap. Dave DuBois told me he had encountered same.

I lose track of what I've got now, but IIRC all the BJ8 pumps--I have five 'working' ones, I think--have been gone through by Dave. One of his modded pumps failed on me; Dave thinks it got water inside--we did drive through a couple deluges--which caused one of the IC traces to fry, so that's one potential downside of the electronics (note the pump caps should have an air check valve to allow points-generated ozone out and keep water out; make sure your pump has it--I don't think it comes with the pumps). And yes, I've spent hours in motel rooms dis/assembling pumps and filing points. Also, the procedure in the shop manual for adjusting tension on the diaphragm may not be correct; I THINK Dave told me they should be one 'hole' looser in case the electromagnet in the solenoid is on the weak side. I now carry two spare pumps, but the one I have in there has been solid for 15K miles or so; don't know what it is--I lose track. I can change out a pump in 20min on the side of the road blindfolded (but I'd rather not). For our BN2/100M I have both an SU electronic and a points pump; I think the points pump is in there now and it's been solid for the few hundred miles I've put on that car. If you carry a spare pre-install the studs. You'll save 5min.

Note electric fuel pumps can also be problematic in modern fuel-injected cars, and you have to drop the tank to replace them. And, we just put another mechanical pump in Dad's '55 T-Bird, and he has 3 or 4 old ones sitting on the shelf.

No question--the points pumps sound 'better.'
 
I would buy a Facet pump and install it in the wing well on the left side of the trunk where it is out of trouble and away from road dirt etc. Use flexible fuel lines. Its much simpler than the original set up.
 
DerekJ said:
I would buy a Facet pump and install it in the wing well on the left side of the trunk where it is out of trouble and away from road dirt etc. Use flexible fuel lines. Its much simpler than the original set up.
Click to expand...

Argument for using the Facet:
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DerekJ said:
I would buy a Facet pump and install it in the wing well on the left side of the trunk where it is out of trouble and away from road dirt etc. Use flexible fuel lines. Its much simpler than the original set up.
Click to expand...

And a Chevy or Ford small block is lighter and more powerful than a Healey engine and Mini-Lites are lighter and stronger than wire wheels and require little to no maintenance and a Toyota 5-speed is superior to a MOWOG gearbox and Laycock de Normanville overdrive and rack-and-pinion steering is better than worm-and-peg and fuel-injection is vastly superior to a couple--or three--SU carburettors and IRS blows solid axle away and AWD beats rear-drive hands down and ...

The sound of an SU fuel pump filling the float bowls on the first run of the day is part of the ritual, for better or worse (come to think of it, owning a Healey is a bit like a marriage, though I have more experience and better luck with Healeys).
 
Nope. But radials don't sound different; Facet pumps are fine but the constant rapid ticking don't sound right in a Healey (IMO, of course). I do understand why a racer would want the reliability of a Facet; we ran a Facet in our BN2/100M until we were able to completely re-plumb the fuel system. And, if I'm not mistaken, Healeys did come with radials as an option towards the end of their production run, which would make them 'period correct' for our cars.

It's a fine line and a matter of opinion or preference to be sure, but some mods do change the essential nature of the car and some don't (certainly an engine or gearbox change does). I run Pertronix in both my Healeys; the sound of the engine is not changed but it does start and idle better and I don't have to change points, which gives me more time to contemplate fuel pumps. When I want reliability, a V8, SPFI and rack-and-pinion I drive my Mustang.
 
All part of the eternal debate of originality vs reliability, for which there is no definitive answer, only personal choice...
I just wanna get the right fuel pump in my car before the snow flies...leaning towards the clicky sticky one.
And if anyone can suggest a resource and/or video that covers refreshing the points on an SU fuel pump I would be grateful.
 
Nevets,

Realize that the original points were made of tungsten to handle the flash created by the increased voltage as a result of the pump coil's influence and voltage was raised from the original 12 volts to more then 200 volts. This high voltage proved have some benefit as it was sufficient to clean points oxidation that would form when the pump remained inactive over a period (i.e. winter storage, etc.).

As Bob previously mentioned, a long while back, Dave DuBois offered a schematic and directions for installing a power transistor to lower voltage and extend points life. However, as one who followed Dave's direction, this proved to succeed in lowering operational voltage across the points but now, with the lower voltage, the tungsten point oxidation was no longer burned off and pump maintenance or pump failures increased as a result of oxidation on points.

In 2011, I was introduced to the TSV diode during a discussion on this forum. This diode, differing from the many approaches implemented by Lucas, would allow up to a specific voltage and gate to ground any voltage over the selected maximum. Since the TSV is manufactured at a broad range of specifications, I selected a TSV with an upper limit of 23 volts (close to my 20 volt target I believed would be sufficient to de-oxidize the points). For the past 3 years since implementation, I have inspected the points each year without finding any reason for any maintenance or re-adjustments. I plan to do the same points examination next spring, after a short run to clean the points, and if I find all well as I expect, that will be my last scheduled inspection.

I see and expect the TSV installation to eliminate routine points maintenance and, so far, have been proven correct. If you do select a points pump, I suggest you install the $0.10 addition and don't expect you will need to be concerned further.

All the best,
Ray (64BJ8P1)
 
Nevets,

I have found that the easiest way to address the trigger head of the SU pump is extract it from the car by removing the multiple screws around the coil and diaphragm and separating from the body (leaving the body and fuel lines in place). This will eliminate the risk of cross threading the fuel lines when reinstalling the pump and provide all you need. Also, it allows easy installation and adjustment.

Ray (64BJ8P1)
 
Ray

Thank you for the detailed information. I am intrigued by the TSV diode option (what does TSV stand for?), though I must admit I have no idea of where to obtain one (Radio Shack?) or how to integrate one into the fuel pump circuitry? I must admit that whenever I consider making a Healey deviation from standard, I’m always concerned about unintended consequences, especially with electrical adventures.

As for cleaning the points in situ, not my issue…I’m thinking about servicing the pump that’s already out of the car. Would still recommend the same approach?
 
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