Slow cranking after engine is warm

[disorder_in_dminor]

My 400 small block just recently suffered the misfortune of being caught in a storm. The engine doesnt quite fit under the hood so there is a hole, i usually have the carb and air cleaner covered with a trashbag and all that sits under a car cover. For years this seemed to be all it took to keep my car, car cover ready.


So this storm came and blew the car cover and the plastic bag off, there was so much water in 2 of the pistons it was unreal. I tried to get some oil down the pistons but i cant really vouch that any got in there. i cranked it with the plugs out to get all the water out (of course when i put the plugs back in they wernt dry and wouldnt fire so i had to pull them back out).

So the car is running but after the engine gets warm it gets really hard to start, it slows down to almost not moving, spins over once really fast then starts right up. Im thinking bad times inside this engine.

very bad times.

once it cools back down it cranks normal.

 

[85 Cutlass Brougham]

Well, I wouldn't be so quick to ring the death knell for your beleaguered 400. The fact that it's hard starting is only when warm makes me think the headers have captured the starter, and it is getting heat soaked. So, I think your issue is with the starter and not the engine itself. Heat Soak issues are common on GM engines due to their integral starter solenoid. Add to this the tendency for 400 blocks to run warm, and it only compounds the problem. Some people use remote solenoids from Fords as the cure for this issue. However, it may also be that the starter is getting tired from all that heat over the years, and is getting ready to fail. Check your wiring to the starter first, and make sure the positive cable is still tight and well insulated. Also, check the tightness of the bolts that hold it to the block. Do the basics first before you change anything. Just remember that if the water really hurt anything, it would be running poorly all the time and have low compression, not just having an issue during warm starts.

 

[disorder_in_dminor]

I see!, yes and now that you do mention it i rember reading that the headers warm up the commutator inside the starter and melts all the varnish off the windings. I have a mini race starter thats indexable, do you think that would help? I didnt put it on becasue when i first put it on i didnt know it was indexable and thought it wouldnt fit but then my friend showed me how to rotate it around on the mounting flange.

I think i need to wrap my headers and get that starter insulator shield.

with the infared thermometer i see that most of my header tubes are at 400-500 degrees with cylinder 1 only at 300 something . Its definitly missing but after being outside this long it needs new plugs and wires and cap and rotor.

 

[megaladon6]

if this just started after the storm, pull all of your ground straps and pos cable connections and check them for corrosion also. especially if you are using a side terminal battery.
i'd definately try and index the starter, i actually run mine upside down. header wrap is a questionable practice. it causes the headers to rot like nothing else. first try and index the starter away from the pipes, if you get 1in of clearence you should be perfectly fine. then i'd look at ceramic coating the headers. it's expensive but it really drops the engine bay temps, accelerates the exhaust flow, and looks really nice.

 

[srercrcr]

I tried the starter foil wrap and the only thing it helped was the bank account of the company who sold it to me.

 

[megaladon6]

not too surprised. to insulate the starter (or anything for that matter) you need an air-gap. what you could try is zip-ties to create the gap, and the foil over that.