Bosch 044 pumps how noisey should they be

[wildo105e]

Just a quicky, I have just replaced my really cheap copy bosch 044 pump with a slightly more expensive sytec one as it was really noisey. The new one is slightly better but still unbearable. I have it fitted the the underside of the boot floor and i have no rear seats fitted etc that's something i can remedy with rubber mounts or something but how noisey are they generally ?


Thanks

[Graham]

in my experience they are not noisy unless they are sucking air

[wildo105e]

Thanks Graham, I have been doing a bit of searching and a lot points to that or them not getting enough feed causing cavitation. I am running it on gravity feed from my mk1 tank through a sytec fuel filter on -6 an hose and 8mm copper tube. The tank isn't that full to be fair and I know the obvious thing would be a swirl pot and low pressure pump but i am trying to avoid that at the moment, it maybe worth trying a full tank ? or an in line low pressure pump ( i have one i can use) ?

[Graham]

it wont like gravity feed if its above the tank outlet, if its only a little above a full tank may help

[Forest_rallying]

Is your sytec filter an inline prefilter? Your 8mm feed pipe might not be quite large enough for gravity feed, you might be better off with a low pressure pump and swirl pot before your HP pump to eliminate problems. I had similar problems with a Cosworth Rally car until it dawned on me what the problem was. On corners with half or less of a tank of fuel the engine would start to die due to fuel starvation.

The early Sierrra Cosworths and some Escort Turbos had their fuel pumps mounted under the spare wheel well and gravity fed, from memory the pump inlet was over 3/4 inch diameter.

[Graham]

The early Sierrra Cosworths and some Escort Turbos had their fuel pumps mounted under the spare wheel well and gravity fed, from memory the pump inlet was over 3/4 inch diameter.

i dont know about the size, but your correct most cars from that age had huge feed pipes if they were gravity feed.

the pump on my race car is gravity feed from the swirl pot using -8 pipe, rest of system is -6

[katana]

Aren't the 044 inlets around 12mm? See specs attached - https://www.bosch-motorsport-shop.co...line-fuel-pump - bigger fitting than I thought. You may get away with 8mm feed on the pressure side but not from tank to pump - cavitation can kill pumps if its long term!

[wildo105e]

Thanks guys, i think we are on the right track here. When i had running issue with the ECU i swapped the standard sierra pump out as a suspect (it didn't fix the issue) the sierra pump has a huge inlet (probably gravity feed) as does the 044. In my make it better approach i used an- fittings etc but that has sized down everything as that is what everybody sells. I think basically the 044 pump is drawing just too much fuel for my line from the tank to the pump just to send it back to the tank in a big circle. What makes me laugh is the sytec pre filter i supposed to be good for 350bhp on the the fittings.

I might be better going back to the old sierra pump for now or fitting what i should have done from the start and fitted a swirl pot and lift pump etc

If the group buy of tank adapters to an -10 comes off that could help me get a big enough feed.

I love and hate these cars.

[wildo105e]

So i have had a good think today, My short term will be the sierra pump which i think is just a lot less greedy and will work better with the 8mm pipe coming from the tank and is designed to supply enough fuel for the engine anyway currently 2 litre injection pinto.

I put the 044 on as i had it and thought it would be straight forward (as usual how wrong was I). The pump came with a cheap swirl pot off ebay which drops the 044 pump into the tank so it can suck all the fuel it wants from it's inlet without restriction.
I suppose the next step would be to install the swirl tank etc. That i have.

What i don't get is the tank has a vent and a feed (from lift pump) and return. Where do you run the vent to to stop fuel gushing out under pressure

this is the one got a few years ago

https://www.ebay.co.uk/itm/Bosch-044...MAAOSwRFNcz1hD

[wildo105e]

I think i have just answered my own question, they call it a vent but it looks like it is an overflow which could feed back to the return i currently have in my escort tank.

[katana]

The swirl pot overflow / vent usually goes back to the main tank otherwise the fuel just goes round and round in circles getting hotter as pressurising the fuel through the pump heats it a bit each time. The main tank acts as a reservoir & is a lot cooler.

[wildo105e]

Ok so i have put back the sierra pump and this is much quieter. I think the issue is basically an 8mm pipe on gravity feed to a bosch o44 is not sufficient coupled with the outlet position in a mk1 escort. When you mount the pump to the boot floor it actually sits higher than the outlet. Although the head of petrol should still feed it (which it does) it is still too greedy for the 8mm pipe.

I suspect a an -8 pipe might do it which i think is an 11mm pipe but the affort of gambling whether it would or not i might as well fit the swirl port and lift pump which i have already in stock from various years of collecting. It seems to work for most people.

The issue with gravity setup it needs to keep up with the demand of the 044 pump with a swirl pot the lift pump theoretically only has to keep up with demand or the engine becaus most of the fuel comes back directly to the pump with no restrictions

Currently the engine doesn't warrant such a high capacity setup. If i keep the tank pretty full i think it will be alright for testing purposes.

[katana]

Personally I might favour waiting on the 'group buy' tank adapter - it measures minimum 12mm bore so correct for the 044 inlet and as long as the pump is below the fuel level it will fill by gravity. An Escort tank is pretty good for anti surge - the main reason for a swirl pot. If you had a 'rally' style tank over the axle then swirl pots make sense - it doesn't make sense to pump from below the floor up to a pot in the boot only for it to gravity flow down below the floor to the HP pump - just a lot of superfluous plumbing and electrics IMHO!
Even if you fit a smaller inlet pump it won't suffer by having an oversized supply pipe!

[wildo105e]

Thanks katana, I am still thinking about the no swirl pot system as i had gone this route for the very reasons you mention. If the group buy comes off i will probably give it a go. The only thing that niggles me i could do it be in the same situation just with bigger more expensive fittings and the AN fittings soon mount up in cost. Conversely doing the swirl pot i would no doubt swallow up the same in fittings if i do it right.

My pre-filter is 1/4npt and i can only find fittings to go to an-8 max so that would be the limit on pipe size although to go larger i may consider moving the filter after the injection pump (save the injectors) so i could go to an -10 (gasp) if i was to get debris in the pump it is probably cheaper these days for a new pump. The outlet of the pump i could use my existing an -6 stuff.

Tbh it gets quite interesting this. Any thoughts welcome

[Graham]

having had pumps fail, i now always pre filter them, it only takes the smallest spec of foreign matter to stop a pump, but gravity feed and pre filtering dont go together so for that reason i would go with a swirl pot feed by a facet

[katana]

I'm guessing external electric pumps are the actual problem - especially the like of 044's that have inlets / flow requirements larger than even the biggest pre filters! I suppose an alternative is cut a big hole in the bottom of the escort tank, weld in a mounting ring and throw a modern in-tank pump with integrated pre and outlet filters in there ? Another bonus is inbuilt pressure regulation so you only need a single fuel pipe to the injectors.

[wildo105e]

So, I had another night of internet joy. Most bosch 044 pump suppliers and swirl pots suppliers seem to put an -8 on which i think equates to about 12.7mm dia pipe. I tried to work out how much that could flow with gravity but the internet maths geeks made a simple job difficult. So i gave up.

My pre filter can flow 300 litres/hour and the 044 pump 330 litres/hour or less 285 l/hr at 3 bar, that may indicate that the filter and an-8 could do it ????

you can get filters with an -10 fittings but tis seem to come from the JDM ricer world were everything is just bigger (so they can brag) but we are looking at £120.

Hopefully when i drive the car the current pump won't run out of fuel when demand rises. Time to watch the AFR