LS7 Starter motor question

[San Diego GTR]

I know these have a lot of cubes with high compression and so it doesn't surprise me, but sometimes my starter has a tough time turning the motor over. Today I was out driving and stalled it at a street light and you guessed it...it wouldn't turn over. My Alt seems to be working great and the battery runs at about 13.5-14v during operation so I don't think it is the lack of amps to turn it over. I'm starting to think its the starter motor rather than the battery. The G50 used such a small flywheel that there isn't much mechanical advantage as compared to the Corvette setup that uses a much larger diameter flywheel. FWIW I am using a G50/52 with an upgraded starter motor from CMS.

Does anyone else have this issue or is there something I'm missing?
Paul

Edited by San Diego GTR on Monday 16th February 19:11

[ezakimak]

Mark Koch - USA site admin and Turbo canam owner had some heat sheilds on his, shown on his web site.

[San Diego GTR]

I'll go look but are you suggesting that heat would be the culprit? I'm not sure that can be the case because I'm not running anything hot near the starter like an exhaust tube but maybe I'm wrong. It happened once, when I thought I made a mistake but didn't really :-)
Paul

[Steve_D]

San Diego GTR said:

.........Does anyone else have this issue or is there something I'm missing?
Paul..

Have always had this problem. I believe the starter just gets too hot. All I get is a machine gun type rattle of the solenoid trying to engage. It will work again after 5 minutes.
Keep meaning to get in there and fit a heat shield but never seem to get around to it.

Steve

[Boosted LS1]

^ Why won't the selonoid engage, is this a tooth problem? I'm wondering if there's a mismatch given the respective sizes of a porker ring gear and a chevy one and just maybe it causes an issue? Maybe once things are a bit worn they work better?

[CanAm Dave]

In my experience it's usually the starter that is at fault, but like Mike says it could be mechanical? The meshing of the two gears needs to be correct. It may be that it is too tight and when the engine is hot it gets even tighter, hence the slow turning.

Regards Dave

The starter on my setup is the best I've used to date.
http://www.powerlite-units.com/

[spatz]

it is maybe worth checking the voltage at the starter directly, with these high currents there might be
a significant voltage drop on the battery cable.
to check this you will have to run the starter and measure the voltage directly at the battery and
at the starter itself, it will sure be less than open voltage but the interesting part is the voltage drop.
Pls somebody check this with a LS7 it really might be the problem.

Maybe I will install 2 cables in paralled to avoid this problem.

[ROWDYRENAULT]

Certainly everything has to be correct with gear engagement ect for the starter to work over the long haul. But if the starter at one point turned the motor over at a good rate and the starter is still engaging correctly then the problem is in the Batteray or the wiring. I think the first place you should look for trouble is ground. If you have a weak ground the starter will burn up over a period of time and fail. Put in a new starter the same thing happens 3 months later. Once you know that you have a good ground I would connect a good batteray straight to the power side of the starter and see what the starter does if it then works correctly the trouble is either your car batteray or the powerline to the starter. I have seen several people suggest that heat might be the problem because thier exhaust system comes near the starter. Thats one of the reasons that unless you need cats in the system I would keep the exhaust system up at the same level as the heads all the way back to the mufflers. That said remember that lots of v8s in front engine applications have their exhaust system very close to their starters and use a simple shield between the two and run for years as a daily driver that way. just some thoughts. Lee

[rduart]

To echo Lee. Sometime ago I had a very similar issue on my FFR (Cobra) Roadster. The starter would not turn the engine over when it was hot. When the engine was cold it worked just fine. My engine builder suggested that I had a weak or bad ground. I reworked the ground and the problem went away. Later on I wrapped the starter in heat shielding, and added a aluminum plate between the header and the starter. I have not had any problems sense.

Randy

[San Diego GTR]

rduart said:

To echo Lee. Sometime ago I had a very similar issue on my FFR (Cobra) Roadster. The starter would not turn the engine over when it was hot. When the engine was cold it worked just fine. My engine builder suggested that I had a weak or bad ground. I reworked the ground and the problem went away. Later on I wrapped the starter in heat shielding, and added a aluminum plate between the header and the starter. I have not had any problems sense.

Randy

Guess what I'm doing this weekend?

Thanks Lee and Randy!