Electic Fuel pumps
Discussion
Hi I have a couple of questions I'm currently researching but figured I might miss something...
The engine is a Morris Marina 1800TC in the kit-car, escort mrk2 petrol tank and Fiesta Diesel sender (don't ask
).
* I'm reading that a fuel pump for SU Carbs can't create pressure over 3psi without flooding the carbs, is this right?
* Does the fuel pump flood the engine if I switch it on before the key?
* What can I connect the pump (electrical) to so that I don't have a manual switch and so that it will be killed should the engine stall/car crash?
* Are there any makes which are much better than others in reliability stakes, where abouts to get them?
* I'm assuming I can just leave the mechanical pump in the engine attached to nothing?
* Will this solve the Vapour Lock problem I'm told I will have or will more heat sheilding / header manifold blankets be needed?
Thanks for any advice
The engine is a Morris Marina 1800TC in the kit-car, escort mrk2 petrol tank and Fiesta Diesel sender (don't ask
). * I'm reading that a fuel pump for SU Carbs can't create pressure over 3psi without flooding the carbs, is this right?
* Does the fuel pump flood the engine if I switch it on before the key?
* What can I connect the pump (electrical) to so that I don't have a manual switch and so that it will be killed should the engine stall/car crash?
* Are there any makes which are much better than others in reliability stakes, where abouts to get them?
* I'm assuming I can just leave the mechanical pump in the engine attached to nothing?
* Will this solve the Vapour Lock problem I'm told I will have or will more heat sheilding / header manifold blankets be needed?
Thanks for any advice
* I'm reading that a fuel pump for SU Carbs can't create pressure over 3psi without flooding the carbs, is this right?
No. When the SU fuel reservoir fills a float should shut the flow of fuel off. It is not unusual to have these be partially ineffective but you can get a valve called a Grose Jet which is sold by Moss and works very well indeed. www.moss-europe.co.uk/
* Does the fuel pump flood the engine if I switch it on before the key?
No, because the float chamber should shut off fuel when the level in the reservoir is correct.
* What can I connect the pump (electrical) to so that I don't have a manual switch and so that it will be killed should the engine stall/car crash?
You could take an inertia switch from a scrapped car and simply wire it in series to the fuel pump relay. You would therefore need ignition switch on and a switch working to get fuel pump power.
* Are there any makes which are much better than others in reliability stakes, where abouts to get them?
Facet are very good. Get a pump at Think Automotive:- www.thinkauto.com/
* I'm assuming I can just leave the mechanical pump in the engine attached to nothing?
You could do but you could also get a blanking plate for a couple of quid and save the engine from having to drive it.
* Will this solve the Vapour Lock problem I'm told I will have or will more heat sheilding / header manifold blankets be needed?
It will help. I'd speak to moss for advice though before spending money.
No. When the SU fuel reservoir fills a float should shut the flow of fuel off. It is not unusual to have these be partially ineffective but you can get a valve called a Grose Jet which is sold by Moss and works very well indeed. www.moss-europe.co.uk/
* Does the fuel pump flood the engine if I switch it on before the key?
No, because the float chamber should shut off fuel when the level in the reservoir is correct.
* What can I connect the pump (electrical) to so that I don't have a manual switch and so that it will be killed should the engine stall/car crash?
You could take an inertia switch from a scrapped car and simply wire it in series to the fuel pump relay. You would therefore need ignition switch on and a switch working to get fuel pump power.
* Are there any makes which are much better than others in reliability stakes, where abouts to get them?
Facet are very good. Get a pump at Think Automotive:- www.thinkauto.com/
* I'm assuming I can just leave the mechanical pump in the engine attached to nothing?
You could do but you could also get a blanking plate for a couple of quid and save the engine from having to drive it.
* Will this solve the Vapour Lock problem I'm told I will have or will more heat sheilding / header manifold blankets be needed?
It will help. I'd speak to moss for advice though before spending money.
excellent, thank you
incidently, one presumes that the pump has a back-flow / pressure valve so that it's not constantly pumping fuel into the line. Does this have to be implemented or is it natural thing of the pump?
If the engine is running faster (therefore needing more fuel) does the pump increase it's pressure?
The interia swith mentioned, does that not cut the power to the pump when the car idles?
Are electric fuel pumps really > £100, I didn't expect that one!
So many questions, sorry!
>> Edited by docevi1 on Saturday 8th May 15:58
incidently, one presumes that the pump has a back-flow / pressure valve so that it's not constantly pumping fuel into the line. Does this have to be implemented or is it natural thing of the pump?
If the engine is running faster (therefore needing more fuel) does the pump increase it's pressure?
The interia swith mentioned, does that not cut the power to the pump when the car idles?
Are electric fuel pumps really > £100, I didn't expect that one!
So many questions, sorry!
>> Edited by docevi1 on Saturday 8th May 15:58
Don't know about the Facet, but the original BL electric fuel pump, as on Minis, Morris Minors etc, only pumps when the carb downstream of it requires fuel.
If the engine runs faster the pump does not increase its pressure, but the flow rate does increase.
An inertia switch cuts power if the car crashes, and also sometimes if you go over a nasty bump. It doesn't cut power at idle.
If the engine runs faster the pump does not increase its pressure, but the flow rate does increase.
An inertia switch cuts power if the car crashes, and also sometimes if you go over a nasty bump. It doesn't cut power at idle.
Didn't the later old style minis/metros use an electric lift pump with the SU carb?
As long as the float chamber remains full, engine speed won't be an issue for you.
an inertia switch will break the electrical circuit to the pump in the event of a shunt/bang/crash/wallop etc.
All injected cars have inertia switches to prevent the pump emptying the tank in the event of a crash.
As long as the float chamber remains full, engine speed won't be an issue for you.
an inertia switch will break the electrical circuit to the pump in the event of a shunt/bang/crash/wallop etc.
All injected cars have inertia switches to prevent the pump emptying the tank in the event of a crash.
docevi1 said:
Are electric fuel pumps really > £100, I didn't expect that one!
>> Edited by docevi1 on Saturday 8th May 15:58
Not always, try looking here:
www.trackstore.co.uk/shop%20frame.html
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