Electric motor for starter

[Christ]

Anyone ever tried this or have a clue where to start? I figured on using a 24 or 48V motor since the truck already has 2 batteries and will likely end up with 4 anyway.. Not particularly difficult to make a 24/48VDC circuit and still have 12VDC from all 2/4 batteries and the OE starter doesn't spin the engine fast enough to start it without help anymore.

I'm not fixing it, I just wondered about putting an electric motor in place of the Vac pump [since I don't need it anymore] and using it as a starter to spin the motor faster so it'll start up without getting out of the truck anymore.

[Cobb]

You want to use the same electric motor to start the engine and to run a vacuum pump?

How about buy a vacuum pump for vacuum and use a belt drive motor for the engine to start it. Use to starter were series wound motors, but many have converted to permanent magnet motors as they are more efficient.

[Christ]

I want to replace the vacuum pump's position with an electric motor for starting the engine. I no longer need the vacuum pump.

[dirtydave]

Why wouldn't you need a vacuum pump?

[Christ]

Swapping over to hydroboost braking system, and the Vac pump only works for brake booster and HVAC. I never change the HVAC settings so I can just plug the lines and the PS pump will be running the brake booster once the changeover is done.

Wonder how many HP motor I'll need for a 7.3 liter diesel...

[Cobb]

If the stock starter isnt spinning the engine fast enough to start it Id get a new starter or at least a rebuild one. Many of those suffer from a short to ground causing it to suck your batteries dry and not deliver enough rpms due to voltage drop below 9 volts when you start cranking.

[Christ]

It's not the starter that's causing the problem... that's actually new and spins the engine plenty fast under normal conditions - It's the engine itself, or the injectors, more appropriately.

They bleed off pressure while it's sitting, introducing air into the fuel lines, which causes a no-start issue on the International 6.9/7.3 family of engines. Spinning the engine faster always gets it to start [like using a boost charge from another car to increase the system voltage], or spraying ether in it.

Since I now have to drive the truck full time again, I'm gonna try to pull the injectors from my old 7.3 that ran well and see if those clear up the problem til I can find another motor to toss in the old beast [this one needs more work than just injectors].

[Cobb]

I think my father had an issue like this with his old golf 85 vw diesel. He added a fuel transfer pump he turned on before cranking and it fixed the issue.

You could try running more voltage through the starter, get like 3 6 volt batteries, but I wouldnt double it. You may spin it too fast throwing the windings off the coil.

[2000mc]

Load tested each battery individually? Checked voltage drops on both sides? I'm just thinking I would want to be sure the standard starting system was working at 100% before tring to add another.