Re: [DML] Re: She starts (painfully), she runs (mostly), she doesn't go
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [DML] Re: She starts (painfully), she runs (mostly), she doesn't go anywhere...



Tom
I just picked up an Eagle Premier 3.0 l PRV engine that I want to build up. Do you have a source for forged pistons over there?  I'm looking at $1,000 for a set here in the states. 

Ian Yanagisawa

On Jun 20, 2013, at 1:42 PM, "Tom" <dmctom@xxxxxxxxx> wrote:

> Elvis is right. A simple calculation of the voltage, current and resistance 
> can easily prove this.
> The resistance of the fuel pump stays the same and voltage will change. 
> Let's see what happens with the current.
> This is just an example as I don't know the actual resistance of the pump.
> 
> Let's assume that ideally the pump runs at 12.5V and its resistance is 1.5 
> ohm. A simple formula of I=U/R (current = voltage divided by resistance) 
> will help determine the current. Thank you Mr. Ohm ;)
> I = 12.5 / 1.5
> I = 8.33
> So, under ideal conditions our example pump will use 8.33 amps.
> To calculate power use we can multiply voltage by current. Thank you Mr. 
> Watt ;)
> P = 12.5 * 8.33
> P = 104.125 Watts
> 
> Now, if the voltage drops due to bad connections, weak battery, failed 
> alternator the result will change. So, lets assume that the voltage at our 
> example pump drops to 10.5 volts.
> I = 10.5 / 1.5
> I = 7
> The current drops to 7 amps.
> And the total power....
> P = 10.5 * 7
> P = 73.5 Watts
> 
> You can check my math to make sure I got it right.
> As you can see from these calculations if the resistance stays the same and 
> the voltage drops the current will drop with it. As a result the power use 
> will drop and the power OUTPUT will drop as well. This means lower fuel 
> pressure and lower fuel volume. As some point the engine will simply stall 
> because of lack of fuel.
> 
> Greetings from Poland!
> Tom Niemczewski
> Vin 6149 plus 2418, 3633, 5030, 16473, 17086
> Google earth: 52°25'17.66"N, 21° 1'58.40"E
> 
> --------------------------------------------------
> From: "Elvis" <elvisnocita@xxxxxx>
> Sent: Thursday, June 20, 2013 4:38 PM
> To: <dmcnews@xxxxxxxxxxxxxxx>
> Subject: [DML] Re: She starts (painfully), she runs (mostly), she doesn't go 
> anywhere...
> 
> >
> > Gentlemen,
> >
> > there is nothing inside the pumpt that controls the output power of it !
> > This is a stupid brushed motor that spins depending of the counterpressur 
> > that it sees.
> >
> > The unused pressure is transformed into fluid flow by the pressure 
> > regulator.
> >
> > And - a higher resistance (bad connector, thin wire, oxydized fuse, melted 
> > fuse holder) reduces the current.
> >
> >
> > NO need to believe me, I just make my money with fans - which is nothing 
> > else but an air-pump.
> > BTW - powerfull fans do have electronics inside to limit the max speed by 
> > PWM - therefore they can keep the power constant. When the voltage goes 
> > down - in certain limits - it draws more current.
> > Again - nothing like this in a fuel pump.
> > Yes, I even cut an old pump open to see how it works.
> >
> > Oh another example - the interior fan - it uses resistors to reduce the 
> > power, position 1 and 2 don't even require an extra relay...strang if - 
> > according to you - the current goes up ?!?!?!? :-P
> >
> > Have fun ;-)
> > Elvis & 6548
> >
> >
> >
> > --- In dmcnews@xxxxxxxxxxxxxxx, Ian <texas.twister@...> wrote:
> >>
> >> Ditto!
> >>
> >> Ian Yanagisawa
> >>
> >> On Jun 18, 2013, at 12:53 PM, JP Hindin <jplist2008@...> wrote:
> >>
> >> >
> >> >
> >> > On Tue, 18 Jun 2013, Elvis wrote:
> >> > > This is a very strange theory, that a lower voltages kill something 
> >> > > and draws more current.
> >> >
> >> > This one I /can/ answer - the work of the pump doesn't change, so it's
> >> > fixed - the laws of physics state that by lowering the voltage, the
> >> > amperage must go up (Volts x Amps = Watts). This damages the pump 
> >> > because
> >> > it's not designed to run at higher amperages, which would require it to 
> >> > be
> >> > more sturdy with heavier duty wiring and stators, thus it burns out.
> >> >
> >> > > Anyhow - is the piston in the fuel distributor stuck ?
> >> > >
> >> > > Push the air metering plate down and you 'll see.
> >> >
> >> > I'll check this also, thank you.
> >> >
> >> > I've never actually dug into the engine bay - I only redid the tank - 
> >> > so
> >> > I'm a little gunshy of tearing off covers and digging into it. I guess 
> >> > I'd
> >> > best get over it and get cracking.
> >> >
> >> > - JP
> >> >
> >> > > --- In dmcnews@xxxxxxxxxxxxxxx, Ian <texas.twister@> wrote:
> >> > > >
> >> > > >...
> >> > > > The low voltage ends up requiring more amperage to run the pump. 
> >> > > > This will eventually burn out the pump. There have been several 
> >> > > > threads on this issue. ...
> >> > >
> >> > > >
> 
> 
> 


[Non-text portions of this message have been removed]



------------------------------------

To address comments privately to the moderating team, please address:
moderators@xxxxxxxxxxx

For more info on the list, tech articles, cars for sale see www.dmcnews.com

To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnewsYahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/dmcnews/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/dmcnews/join
    (Yahoo! ID required)

<*> To change settings via email:
    dmcnews-digest@xxxxxxxxxxxxxxx 
    dmcnews-fullfeatured@xxxxxxxxxxxxxxx

<*> To unsubscribe from this group, send an email to:
    dmcnews-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/



Home Back to the Home of PROJECT VIXEN


Copyright 2006 ProjectVixen.com.  All rights reserved.

Opinions expressed in posts reflect the views of their respective authors.
DMCForum Mailing List Archive  DMCNews Mailing List Archive  DMC-UK Mailing List Archive