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Best Fuel Filter for Bosch Pump


Guest GeoffWalker

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Hi Geoff,

 

Sorry to hear that your mod didn't work :( - but you appear to have had a great time in France! :D

 

Perhaps the Bosch filter was a bit too efficient for its own good, especially if the fuel flow began to slow down as the filter began to pick up debris. I haven't installed my set-up yet because other jobs have taken precedence. I have removed the boot lid and driver's door for spraying. At the same time I am fitting a Surrey top.

 

I had planned to go to Malvern in the Stag (with the TR being off the road) but it sprang a leak from the fuel tank at weekend! I think I've fixed that, so I'll probably do the fuel modification to the TR in August - there's amazing access with the boot lid off! I'll keep you posted.

 

regards

Ray

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Guest GeoffWalker
Hi Geoff,

 

Sorry to hear that your mod didn't work :( - but you appear to have had a great time in France! :D

 

Perhaps the Bosch filter was a bit too efficient for its own good, especially if the fuel flow began to slow down as the filter began to pick up debris. I haven't installed my set-up yet because other jobs have taken precedence. I have removed the boot lid and driver's door for spraying. At the same time I am fitting a Surrey top.

 

I had planned to go to Malvern in the Stag (with the TR being off the road) but it sprang a leak from the fuel tank at weekend! I think I've fixed that, so I'll probably do the fuel modification to the TR in August - there's amazing access with the boot lid off! I'll keep you posted.

 

regards

Ray

 

 

Talking to a mate/Mechanic over in France and he said the best fix for surge problems in a Petrol tank is a special honey comb Sponge which you push into the tank and it expands. This creates a perfect baffle, but doesn't affect capacity too much as the Petrol flows through it at less of a pace. All teh Rally boys use it.

He didn't mention a supplier but DemonTweeks might have it.

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  • 1 month later...

I hope the following is an interesting update to all who have the glass pre-filter in their Bosch set-up.

 

I installed my upturned Lucas filter bowl as an anti-surge tank and the car went all of 400 yds before stopping. I decided it was fuel starvation and disconnected my mod at the side of the road. Back to its original configuration it then went all of 50 yds. :huh:

 

To cut a long story short, yesterday, on my way to the TR meeting, it stopped again so I removed the nylon filter from the glass Pro Flow filter which is fitted before the Bosch pump, in the standard Revington set-up and the problem vanished. It was obviously too choked to cope with the fuel demands of the pump although I had previously cleaned it using clean fuel and an air line. So I must have been running the car for 12 months on the edge of this starvation problem all along. The question is, who else is, unknowingly?

 

A search of the archives shows Rob Wilsher and Victor discussing this very issue in July 2005 whereupon it was stated thet Malcolm at Prestige had dumped the glass filter in favour of an aluminium cannister with a paper filter. A photo of that set-up can be seen on the Prestige website. Further inspection of that photo showed me that this is a Bullet filter available from Fuel Systems, who also sell the Pro Flow filter, but who state on their product leaflet that the Pro Flow should not be used in an injection system.

 

I called Fuel Systems today and spoke to one of their techie guys who was horrified that the Pro Flow filter is being sold as a pre-filter to the Bosch pump. He told me that it is far too restrictive and I would get fuel starvation (I am, believe me!) and that the pump would eventually burn out. I made the point that this filter is on the gravity feed side and not the pressure side so should be OK - he put me right, stating that the pump needs to pump far more fuel than the engine needs, that is why there is a recirculatory system, so this filter, whilst in some cases might allow sufficient fuel for the engine to run, it will starve the pump of fuel causing premature failure.

 

Needless to say, I was a pushover for the purchase of a Bullet filter, even though it is 5 times the price, but this guy even made sure I bought the right one. If it's good enough for Prestige, it's good enough for me.

 

I know from the postings that there are many out there who are running the Pro Flow successfully, but so was I until last week. It didn't take much crud to stop it functioning.

 

Geoff, Andy, I put my mod back in yesterday and it ran well with low fuel in the tank, but this is with no filter in the Pro Flow glass housing, so I will reserve judgement on whether it works until after I have taken delivery and fitted the Bullet filter.

 

I don't mean to be alarmist but this little glass filter thingy could be the source of a number of poor-running issues, maybe even the ones I have had over the last 6 months. Fingers crossed.

 

Ray

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Needless to say, I was a pushover for the purchase of a Bullet filter, even though it is 5 times the price, but this guy even made sure I bought the right one. If it's good enough for Prestige, it's good enough for me.

 

 

Ray

Interesting.... what's the "right one" - paper or metal filter and what size unions?

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The unions should be 12mm for the Bosch side of the set up (that's the inlet of most Bosch filters) & the other side depends on your outlet.

My new tank's got a 12mm outlet. At the moment without a pre filter although the bullet seems to be the one to go for as protection against crappy petrol. I ditched the the glass prefilter simply because internally the size of the internal hole is less than 1/4 of an inch so has to be restrictive.

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Bill,

 

As Andy says, the Bosch pump should have a 12mm inlet, and if your tank has a 12mm outlet, then the Bullet A6 is the one to go for. It has 12mm in and out. This is the one I ordered.

 

I also asked about which filter material - paper or metal - and the guy at Fuel Systems said that the metal one is only sold to the likes of Lotus to enable them to do calibration testing on their rigs. It is not for road use. The mesh is too coarse (45 microns versus 8 microns) and would let too much crud through from the tank.

 

regards

Ray

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45 microns is still smaller than the glass crud filter particle size.

 

I guess that's another reason to ditch the Pro-Flow.

 

I didn't ask specifically if the Bullet could be used on its own, as I have the Bosch post-pump filter and see no reason to remove it. Prestige's configuration shows the Bullet pre-filter and the Bosch post-filter both in place.

 

Ray

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Ray

 

I'd be really interested to know how you get on with the bullet filter. Funnilly enough, I just changed the element in my glass pro-flow filter (Revington set-up) at the weekend, because I too was starting to get just the first signs that all was not well. I'd put it down to not having fuel delivered up to pressure via an out of adjustment PRV, and of course it might be, but as you say, if you look at the Fuel Systems website it does say that these pro flows should not be used on injection systems.

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Hi Ray,

I also have a Bosch set up with pro flow and new tank outlet pipe all supplied and fitted by Malcolm at Prestige. I have had a lot of trouble with the pro flow clogging and causing the pump to whine. It seems to get blocked by a sandy coloured dust that is only visible when you take the filter apart. I have stopped using an additive (Castrol valvemaster plus) which seems to have reduced the incidence of clogging. However, I am keen to change to the Bullet but can anyone tell me if the A6 is a direct replacement for the pro flow i.e. will the pipes connected to the pro flow be the right size for the A6. Also, is there physically enough room between the tyre and wheel well for it to fit exactly where the pro flow is at the moment? This has been a really interesting topic.

Thanks everyone.

Regards

Les

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That's why I wondered if the mesh filter for the Bullet was a better option. The fine filter would appear to be similar to the bosch post-filter & fitting it as a prefilter might not be ideal wheas the mesh filter would allow high flow & not restrict the flow to the Bosch pump. (The little glass filters serve a good role in stopping the larger debris from damaging the pump but have a limited filter area so block relatively quickly with debris and only have small bore entry which may well cause fuel starvation)

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Les,

 

Re the Bullet being a direct replacement............

 

It arrived yesterday but I haven't got round to fitting it but I too am going to have to look closely at where I fit it, re the spare wheel etc. The braided hoses I have from my tank to the Pro Flow filter and from the filter to the pump I assume are 12mm as they push on easily to the 12mm inlet on the pump - I am assuming it is the original hose supplied by Revington to the previous owner of the car in the 90's.

 

On the end cap of my Pro Flow is stamped 3/8" but I notice the ones on sale now from Fuel Systems are metric. 3/8" is 10mm so the 12mm hoses are squeezed to fit. So logic says they will fit the Bullet A6. I hope logic is on my side! If not, I'll just get new 12mm hose.

 

I am going to disconnect my home-made swirl pot whilst I test the Bullet, and then modify the pot completely because it will then become the bottleneck in respect of fuel flow to the pump. Good fun eh? Never mind, this type of activity fits in whist I'm waiting for the primer to dry on my Stag project. Is that high-build primer mucky stuff or what? It gets everywhere.

 

Ray

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Hi Ray,

Just had a look in my boot to refresh my memory. I have a 10mm pipe from the tank to the pro flow. The outlet of the pro flow has a short piece of thin 10mm pipe as a thickening collar to bring the outside diameter up to 12mmm and then there is a 12mm pipe to the pump.

Easiest replacement for me would be the Bullet A3 with 10mm in and 10mm out. If I use an A6 will the 10mm pipe stretch to fit over the 12mm inlet? If not, I could change the pipe from the tank to 12mm but don't really want the bother of draining the tank.

Does it really make any difference if I use the A6 or A3 as surely the 10mm o/d brass tank outlet is the limiting factor.

It looks as though there will be just enough room down behind the spare wheel to fit the Bullet but it will be tight.

Grateful for anyone else's thoughts or experiences.

Regards

Les

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Hi Les, Guy and all,

 

Les, I'm sure you noticed that I am on a learning curve, maybe slightly ahead of you, but please don't think I am the expert!!

 

However, I can confirm that I fitted the Bullet this afternoon and started the engine. The pump is noticeably quieter. What I also found out was that my hoses are similar to yours, and are configured the same as Guy's photo. You can see in his photo that the hose from the tank to the filter is 10mm and the hose from the filter to the pump is 12mm - so were mine - so one of my assumptions in my last missive was wrong.

 

I have managed to use some 10mm (3/8") hose that I had lying around to stretch over the 12mm fitment on the A6, but this is unbraided. I don't think you'd get braided 10mm to stretch. I will try and source the correct stuff at a later date. For the purposes of testing, this is fine - and if the outlet from the tank is only 10mm and not the 12mm that I assumed, then I may stick with 10mm.

 

As to whether the A3 is the correct one to buy I think you should consult Fuel Systems. Don't forget that 12mm connectors are for hose with 12mm inside diameter, which means that the connector is less than 12mm inside diameter - possibly nearer 10mm. So 10mm inside diameter hose isn't too restrictive when compared to the connector. Does that make sense?

 

I'm happy to help anyone as best I can and I'll report on the set-up when I've actually driven it.

 

By the way Les, if you haven't got a tap on the outlet then fit one - draining the tank is not a place I would like to go, especially the number of times I've been playing around with the system whilst designing and installing my swirl pot - and then having to take it out and.......and......it doesn't bear thinking about.

 

I've just added some photos here http://www.triumphowners.com/registry.cgi?...p;vehicleID=827

 

Ray

Edited by raydrink
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Hi Ray,

Thanks for the info especially that you are able to stretch a 10mm rubber hose out to 12mm. You are right, a tap would be a good idea althogh the pipe clamp I use seems to work well for most jobs but of course it wouldn't be any good if I want to change the pipe from the tank as this is the one I clamp. One last thought, when I was at this year's International I had a chat with Malcolm and noticed that his Bullet comes with a right angle connector on the output side. This would allow me to fit the Bullet vertically and use a very short pipe to the tank. This may ease the tight fit between the tyre and the wheel well.

Thanks again

Les

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I've just been out for my first drive with the Bullet filter fitted and it seems to be spot on. 15miles of differing road conditions giving open road, town (including queueing) and motorway driving. AND I saw a TR4 coming in the opposite direction, both of us acknowledging each other with the ear to ear grin that shows what a joy it is to be out and about on a sunny day. :D

 

The pump is most definitely quieter being just the quiet purr of a motor instead of the whine of a dry bearing. Talking of wine........maybe I had too much last night but the temperature gauge seems to be reading lower too. Maybe it's cooler out there than the sunshine indicates but maybe I've been running weak. I can't believe that as the plugs are always sooty, even after a short journey. Ah well, another TR conundrum........

 

The project that kicked all of this off, my addition of a swirl pot, will have to be resurrected because when I went round a sharp bend at speed, the hiccup was still there (fuel gauge reading between 1/2 and 1/4).

 

Ray

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Hi All

Just to say that I spoke to Terry at Fuel Sytem Enterprises today and ordered a Bullet A6 with 10mm inlet and 12mm outlet together with 0.5m of 12mm fuel pipe just in case I can't fit the Bullet between the tyre and the front of the wheel well. I recently fitted a relay and 50A cable as recommended on another thread so I am hoping to have a quiet pump from now on.

Regards

Les

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  • 1 year later...

Hi,

 

I just wanted to make a note of the latest success I've had with the Bosch fuel system and I think this thread is the best place to put it - for the archives' sake if nothing else.

 

After doing all the changes mentioned previously in the thread I eventually purchased a professionally-made fuel swirl tank and positioned it above the pump and below the tank. This was to be my attempt to get rid of the dreaded fuel starvation on left-hand bends.

 

This yielded an improvement but did not fix it, though the car was eminently drivable and took me on the Register Highlands trip this year. However, whenever the fuel got below half way the pump would start making grinding noises as if it was short of fuel, but it never faltered or missed a beat, save for LH bends.

 

I couldn't believe that the swirl tank had not fixed the problem but it was clear that even a full swirl tank, higher than the pump was not sufficient 'head' for the pump.

 

Having replaced or cleaned or tested every other component over the preceding 12 months I bit the bullet and bought a brand new Bosch pump off eBay (for £50 :rolleyes: ) and fitted it. Today I went out for my first run and I seem to have some improvement. Going round LH bends produces no hesitation but the fuel is only between halfway and quarter. I'd like to test it further when it is nearly empty. The pump is quieter and the biggest surprise.............I've no smell of fuel in the boot any more.

 

I've kept the old pump as a spare but clearly it had some limitations, including leaking petrol vapour into the boot (it never showed signs of leaking fuel) and these SEEM to have been overcome by a new pump.

 

Thanks to all for ongoing help

 

Ray

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