Posted October 6, 20213 yr comment_629593 Does anyone know the actual flow rate of the mechanical pump? I am tempted to support mine with an electric pump. - a facet silver top as it’s not too juicy on pressure for my SUs (with a regulator of course) but their literature says it’s good for up to 200bhp - mine makes anywhere from 230-245 depending on whose dyno it’s on! ;) But the difference between a silver top and a red top is only 10% more flow for the red top. Yet the red top is quoted as 200+ applications. But what does the “+” mean if it’s only 10% more flow? 10% more power or infinity!? ;) But foremost I’m interested to know the flow of the mech pump - can’t seem to find it in the FSM I have. Link to comment https://www.classiczcars.com/forums/topic/65898-mechanical-fuel-pump-flow-rate/ Share on other sites More sharing options...
October 6, 20213 yr comment_629601 Might be able to calculate it based on the FSM test Link to comment https://www.classiczcars.com/forums/topic/65898-mechanical-fuel-pump-flow-rate/#findComment-629601 Share on other sites More sharing options...
October 6, 20213 yr Author comment_629639 Might be able to calculate it based on the FSM testThanks sir, I will look into it! [emoji106]Interestingly, the online fuel flow calculators all converge on around 18-20 gph (imperial) for 240bhp, so the silver top at 30 should be OK I think. [emoji848] Link to comment https://www.classiczcars.com/forums/topic/65898-mechanical-fuel-pump-flow-rate/#findComment-629639 Share on other sites More sharing options...
October 6, 20213 yr comment_629641 I would think in a support role the electric pump would flow even more because the mechanical is helping pull somewhat Link to comment https://www.classiczcars.com/forums/topic/65898-mechanical-fuel-pump-flow-rate/#findComment-629641 Share on other sites More sharing options...
October 7, 20213 yr Author comment_629672 I would think in a support role the electric pump would flow even more because the mechanical is helping pull somewhatI have to agree with you there! [emoji106]I like keeping the mech pump - i may also look into a bypass set up on the elec pump in case it ever fails. The problem is never fitting these things, it’s the stuff we put around them like not using the wiring loom supply and adding inertia cut off relays etc ;) Link to comment https://www.classiczcars.com/forums/topic/65898-mechanical-fuel-pump-flow-rate/#findComment-629672 Share on other sites More sharing options...
October 7, 20213 yr comment_629681 On 10/6/2021 at 12:15 AM, AK260 said: Does anyone know the actual flow rate of the mechanical pump? Doesn't it depend on engine RPM? It's eccentric actuated. Link to comment https://www.classiczcars.com/forums/topic/65898-mechanical-fuel-pump-flow-rate/#findComment-629681 Share on other sites More sharing options...
October 7, 20213 yr Author comment_629683 22 minutes ago, Zed Head said: Doesn't it depend on engine RPM? It's eccentric actuated. Fair point, I guess I was looking for max flow at 6K RPM where the engine "should" be thirstiest. Link to comment https://www.classiczcars.com/forums/topic/65898-mechanical-fuel-pump-flow-rate/#findComment-629683 Share on other sites More sharing options...
October 7, 20213 yr comment_629684 I can't think of a single time where I've read about the need for a higher capacity mechanical pump. Never read of any engine running lean because the mechanical pump couldn't keep the float bowls full. It might be a thing but I've never heard of it happening. A mechanical pump delivers a certain volume of fuel with each pump, and the pumps are tied to each engine revolution which also pumps about the same amount of air. Doesn't really help your quest but I don't think that you can make a direct comparison between the two types of pump. One's capacity increases automatically, the other's is constant. Link to comment https://www.classiczcars.com/forums/topic/65898-mechanical-fuel-pump-flow-rate/#findComment-629684 Share on other sites More sharing options...
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