Welcome to our resource for MG Car Information.
|
MG Midget and Sprite Technical - Dual Facet pumps. How?
Probably one for the 'racing' fraternity. I've a need for 2 pumps to run at the same time, both feeding from the same tank, both independent of each other apart from the switch and main fuse, both feeding to one carb. It is not a Spridget, just my homebuilt aeroplane. The problem is that I can't get anyone to tell me whether I can run them in parallel without NRVs or whether I must put somthing in the line of the 'failed' pump to keep the pressure of the good pump up to spec. I have 1psi (static) due to gravity feed from a wing tank and it seems that gravity feed still works through a pump with the pump switched off. I haven't yet run it at full power in this config, though. Any thoughts or experience with these pumps? Anyone got a pair of them that they want to rig up? Are the black ones better and are they lighter? Cheers Obligatory midget content in bottom right corner of pic. |
rob thomas |
Rob Is there any reason why you need two pumps running in parallel? It seems to me that there are Facet pumps that could pump the volume you need with one pump. That said, there is no reason that I know of that you can't run two of the pumps in parallel. All of the Facet pumps, like the SU pumps run with check valves (NRV), so you could switch on pump on at a time or both at the same time and they should work fine. Cheers - Dave |
David DuBois |
Rob - Assuming clickety pumps, rotary motor ones could be different: Every fuel pump has two check valves, both of which only allow flow in the usual direction. But I expect even rotary ones have at least one check valve; just try to blow (or pump fuel) backwards through the pump. And make sure you have a shutoff in the line, else your whole tank could wind up in the sump! FRM |
Fletcher R Millmore |
DD. It is a UK requirement to have 2 independent fuel systems that can both flow 125% of the max fuel requirement and I'm not sure that gravity can flow enough fuel through a disabled facet "cube" pump. DD & FRM. Thanks. Sounds like your info suggests I can run them in parallel, or in series if I run one at a time. I've heard of them failing but they seem to fail 'safe' in the open-flow position. Currently it has 2 feeds from the header tank that "Y" into a shutoff tap and then goes to a gascolator filer bowl before reaching the pump and Stromberg carb. I have an old version with the steel casing but it also gives off quite a lot of electrical noise to the intercom/radio. Any ideas? |
rob thomas |
I think you may need check valves i have fitted a few rotax 914 engines and they recommend check valves look here for how rotax recommend http://www.rotax-aircraft-engines.com/pdf/dokus/d04273.pdf hope this helps |
mark (1977 1500 Midget) Preston Lancs |
This thread was discussed between 20/06/2010 and 21/06/2010
MG Midget and Sprite Technical index
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.