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OK to run the engine without flywheel attached?

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Old Jun 18, 2014 | 08:44 AM
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Default OK to run the engine without flywheel attached?

While the transmission and clutch are out of my LS1 TA, I will be replacing the rear cover gasket and main seal. Everything is still attached at the front of the engine. Posts about botched installs and subsequent leaks are on my mind. After installation of the new gasket and seal, would there be any problems running the engine without the flywheel attached? Should I lightly support the rear of the engine from the oil pan? If this is not a problem, I will do that and probably let it sit for a while to make certain nothing leaks.

Thanks.

ETA
Should I replace the oil galley plug (barbell) while the cover it off? My engine does not leak oil anywhere, AFAIK. This is just preventative maintenance.
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Old Jun 18, 2014 | 08:51 AM
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I ran my car with just the flexplate on there (which is like 7lbs) and it ran like ****. As soon as I put the converter on there, it ran perfect.

I don't think it will hurt anything because the engine is internally balanced and you have the damper installed, but it may not run very well without any rotational weight on the crank.
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Old Jun 18, 2014 | 12:35 PM
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I have one question, how will you start the engine to run it without the flywheel being on?
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Old Jun 18, 2014 | 01:16 PM
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Ok. If I was unaccustomed to humiliation, I would probably edit the title and original post.

So, new question: ok to run with only flywheel attached?

And what about the oil galley plug?
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Old Jun 18, 2014 | 01:53 PM
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Lol,

I was wondering to myself how in the heck someone can safely start the engine with out the fly wheel....
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Old Jun 18, 2014 | 03:01 PM
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Haha, good point. I wasn't even thinking about that.
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Old Jun 18, 2014 | 03:22 PM
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Wrap a rope around the crank pulley and pull! Like an old lawn mower!

If you had misfire detection turned off, it would likely run fine. And snappy too.
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Old Jun 18, 2014 | 04:11 PM
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Originally Posted by bsf
Should I lightly support the rear of the engine from the oil pan?
I'm not sure if this means running the engine without any stabilization or support?
I couldn't tell you for sure, but an engine stand might be beneficial, otherwise that darn thing might wanna bounce off, somewhere!
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Old Jun 18, 2014 | 07:37 PM
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Originally Posted by 2000formulaluvr
I have one question, how will you start the engine to run it without the flywheel being on?
'zackly.
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Old Jun 18, 2014 | 08:08 PM
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Originally Posted by gMAG
I'm not sure if this means running the engine without any stabilization or support?
I couldn't tell you for sure, but an engine stand might be beneficial, otherwise that darn thing might wanna bounce off, somewhere!
Still bolted in to the motor mounts. Just not sure if that is enough.
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Old Jul 7, 2014 | 07:11 PM
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Yes OP it is safe to run with just the flywheel. I test run all my engines on a stand I have. Don't sit under there while its running and don't be revving it to the moon. Don't wanna see the flywheel turn into a saw blade. I've read horror stories of people loosing limbs from doing that kinda thing.
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Old Jul 8, 2014 | 06:48 PM
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Originally Posted by bsf

And what about the oil galley plug?
you definitely want All the oil plugs installed before running the engine.
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Old Jul 8, 2014 | 11:26 PM
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Originally Posted by 2000formulaluvr
I have one question, how will you start the engine to run it without the flywheel being on?
Originally Posted by Paul Bell
'zackly.


Come awn'...don't you guys all have a kick start on yours...???
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Old Jul 9, 2014 | 08:26 AM
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Unless it's a Vette motor.

"Some" of them were "hot balanced" and that means WITH the flywheel and clutch assembly bolted to the motor, and the clutch assembly as a whole being the determining factor for the final balance.

Just food for thought.
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Old Jul 9, 2014 | 04:01 PM
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Looks like I'm late to the "HOW WILL YOU START IT WITH NO FLYWHEEL" party. Damn
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Old Jul 10, 2014 | 07:33 AM
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The idle calcs in the tune are heavily weighted on the fact that the engine is stock. Changing basically any rotational weight causes major idle upset, until the computer relearns. Will it hurt anything? No. Will you have to baby the gas pedal to keep it running? Most likely.
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Old Jul 10, 2014 | 07:51 AM
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I had to replace my rear main, I ran the motor with just a flywheel for about 8 minutes. It was fine, I just let it idle. It idled the exact same as it did when it was put back together.

Make sure you let it idle untill it warms up, with out the trans on, it takes about 4-5 minutes for the oil to actually start dripping down. That way you know if you fixed your leak or not. Also make sure to RTV the corners of the rear cover!
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Old Jul 10, 2014 | 04:13 PM
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Originally Posted by CattleAc
Come awn'...don't you guys all have a kick start on yours...???
I have a "talented" g/f. She starts my Harley by pulling a serious vac on the tail pipe.
Don't know why she couldn't do the same w/ the LS.
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Old Jul 10, 2014 | 04:32 PM
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Originally Posted by Old Geezer
I have a "talented" g/f. She starts my Harley by pulling a serious vac on the tail pipe.
Don't know why she couldn't do the same w/ the LS.
Displacement, looks like you're gonna need two "talented" GF's
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Old Jul 10, 2014 | 08:57 PM
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Originally Posted by Old Geezer
I have a "talented" g/f. She starts my Harley by pulling a serious vac on the tail pipe.
Don't know why she couldn't do the same w/ the LS.


Oh yeah...it's all about the "ring seal"...
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