The starter is 1000watts and at 12V that is 83amps + some loss. Let's call it 90 amps of current. A 240MCA battery can sustain 240amps for 30 seconds before becoming TOTALLY dead. I think you will be cutting it very close with that battery especially since 3GM's have a rep for being difficult to start. Does yours take a while to get it to turn over?
If you want to try this....Sears has a Gold diehard garden tractor U1 size with 340CCA's (more stringent than MCA's) that may give you a bit more margin for error.
Okay, I sort of knew this answer was coming. Thanks for the feedback. I guess I won't share my idea to wire together 8 AAA Energizers!
No, our engine starts fairly easily (except in sub 40 F -- no glow plugs), but I still would not want to cut it that close.
Paul, thanks for that link, I wasn't aware of that particular Lifeline starting battery. Dimensionally it's fairly close to the standard U1 form factor, but with a lot more output. Anyone tried this battery? Cam, thoughts? Our current Lifeline AGMs have given us great service.
Rockter, I'm at 55 amps (nominally) alt output with a 220-230 ah house bank already. But you're probably right, I normally won't be drawing this starting battery down like the house bank. Hopefully the larger size won't over tax the charging capability of the alternator..