start up current?

[deaf_rattle]

What sort of current is drawn whilst starting up a car?

The reason i ask, is while i was starting my car today (coil packs unplugged to get oil circulating) my circuit breaker would trip after about 40 secs of trying.

Its 140amp, and i dont think i had troubles with it before, but then again i never had the starter going for as long.

Will i need to upgrade my circuit breaker?

Cheers

[ee904age]

On a fresh engine without anything being bedded in there is alot of strain on the starter, if you have no luck try bypassing your circuit breaker for the first few startups until everything is nice and slippery. Depending on your battery you may even need to jump start it the first time.

[evil_si]

40seconds is a fair bit of continuous cranking, which repeated enough will burn out the starter,

140amps is pretty average, i checked a 4agze the other day and it was something like 130a

[TotemoAW11]

my 4ag has a 100A breaker on the batt, never tripped it ever (then again ive never cranked it for 40sec continuously ....but like 10sec maybe once)
what ee904age makes alot of sense, just by-pass it for now. mean.

[deaf_rattle]

sweet as, might leave it as is.

It was just to get oil and shit moving, before i started the car for the first time.


Thanks for the advice

[evil_si]

fair enough, but if you dont have oil flow with in 20 seconds something is wrong,

with the engines i build, i lube everything with a special paste, or just 85w 140 diff oil, as i assemble it, so when it comes to starting, i just plug in a pressure guage and start it. i monitor the oil pressure on cranking, usually within 5 -10 seconds of cranking ill have full oil pressure,

be very careful with cranking engines that long, as you can imagine the heat generated with 40seconds of cranking at 140amps is a fair bit,
you wouldnt have been able to touch the starter or battery lead after that,
and jappers built the way they are, dont handle that for too long

[Lloyd]

As said above, thats a long time to be cranking and a fair while for oil pressure to build up. Most starters on a small-medium car should draw between about 80-150 amps. Try laking the spark plugs out next time, then you've got no real stress on the starter having to compress anything

[dotdog]

I put a clip on ammeter on my starlet at work to check it, it was peaking just shy of 200Amps and when it got cranking it droped off to bout 170ish

[Lloyd]

Starter motor produces its maximum torque and draws it maximum current when its stalled. Faster its turning the less it would draw. Hate to think what come of the high comp V8 would draw

[matt dunn]

Starter motor produces its maximum torque and draws it maximum current when its stalled. Faster its turning the less it would draw. Hate to think what come of the high comp V8 would draw

When a starter motor is stationary and you first turn the key,
it is capable of drawing up to300a or more for a split second.
This usually is so fast the most meters and current clamps wont pick it up.

If you want to test it put you car in 4th gear hold the brake hard on .
crank it and measure the current. Only advisable for a sec though as it is not good on a starters or battery's.
This will actually test the limits of your battery's and cables too.

Best to use a meter than can measure at least the CCA of your battery.

Matt