Weird heat soak problem

[TitanTn]

New: battery cables and connectors, alternator, 10 month old starter, coil, plugs, 2 year old plug wires, newly rebuilt 7.4L.

I rebuilt my 454 over the winter. Bored .30 over, new pistons, lifters, head job, oil pump, cam, etc. I did nothing to the transmission other than paint it. I went through the break-in for the cam and then the rings. Timing is set to 10 degrees. It seems to be running great.

I've never been excited about how fast (it's slow) the engine turns over. But the batteries are both 1000 CCA and both have been tested to be within expected performance. My issue is that after running for 15 - 20 minutes - on the lake - it will not restart. It won't turn over. It tries to crank, but won't. The starter is very hot to the touch, and the transmission bell housing is also very hot. On several different lake tests I have cooled the starter with cold lake water and within a few minutes it will turn over again - albeit slowly. I've bench tested the starter and it seems to work as it should. I really think the bell housing is getting hot for some reason and the starter is getting heat soak. I don't know. Could I have installed something weird with the damper plate?

Now for the strange part. When I get the engine started after one of these non-crank situations, it is a pill to keep idling. It just stumbles all over itself. Anything over 1,200 rpms runs great. I can seemingly go as long as I want until I slow down and try to idle (sucks because at this point I'm trying to load on the trailer).

I can confirm that the starter is letting go of the flywheel after starting the engine. I'm confused about why things are heating up. I can't reproduce the issue on the trailer. It seems that I have to be in gear and running on the lake. Transmission oil is fresh, smells fine, and shows no sign of water.

[Zim]

Are you SURE the timing is set correctly?

That's a big motor...

[TitanTn]

Specs call for the initial timing to between 5-9 degrees. I'm right in-between 9 and 10 right now.

[2500HD]

is there a possibility that something isn't aligned correctly between the engine and tranny? This could create a drag and heat.

[CJD]

What temp thermostat are you running?

Also, when trying to start are you getting the solenoid click, or nothing at all?

[TitanTn]

is there a possibility that something isn't aligned correctly between the engine and tranny? This could create a drag and heat.

I'm wondering that too, but I'm not really sure what would be out of alignment. I don't know that there's any adjustment.

What temp thermostat are you running?

Also, when trying to start are you getting the solenoid click, or nothing at all?

I'm running the stock 145 degree stat. When the overheat happens the engine will make an attempt to turn over, but it never actually completes a full revolution and then it's silent.

[michael hunter]

Are there any heat shields around the starter?

[TitanTn]

Are there any heat shields around the starter?

No, there's not. Never have been that I know.

[chris young]

Can you locate the hottest item? ie is the starter gettting hot and heating the rest of the bell housing area or the other way around? I'm wondering if your tranny cooler is plugged. What you might do, is borrow or buy an IR thermometer, take the boat out for a run an keep measuring temperatures in the area and pinpoint the heat source.

I've never heard of this, but I have experienced some pretty funky solenoid and relay issues in my former employ as an avionics technician, so anything is possible. I'm wondering if your starter solenoid might be hanging up just enough to pull current though the starter circuit without actually turning the starter, so over time it slowly heats up. The problem with this is it doesn't explain the shitty idle. Unless you have a ballast resistor bypass on your solenoid. Then you could be overheating the ignition coil as well and it might exhibit all the symptoms you describe. Good news is this is all easy to check. Even without the IR thermometer, you could just go for a cruise and keep checking by hand the starter, bell housing, transmission, solenoid, and ignition coil. Probably with it heating up so much the starter won't turn, you'll locate your heat source pretty fast.

Good luck, let's hope the engine build is not the issue, that would truly suck.

[michael hunter]

Rob I bounced this off my brother in law he was a truck mechanic for rider . He said they had the same problem with the trucks the fix was a heat shield on the starter. If I remember correctly GM used a heat shield on their starters so it shouldn't be hard to find. Also check the battery cables hots and especially grounds if you are having connection issues when hot low voltage can effect the ignition.Check voltage at all the components at the time of fail. Are the cables getting hot?