Re: [Chrysler300] 375 Troubled Horses

[Michael Moore <mmoore8425@xxxxxxx>]

Keith,
I had a different make car do that exact same thing. It turned out to have had a really tiny pinhole leak which kept the radiator from pressurizing, but didn't leak enough water from that hole to notice. It would boil over after I shut it down.
Mike Moore
On Aug 16, 2011, at 3:12 PM, Keith Boonstra wrote:

> Several of you suggested that the floats and needle valves were the 
> place to look for the cause. Turns out you were right. One of the 
> float pairs in the primary (rear) carb was incorrectly set by the 
> rebuilder. At least I doubt that shaking in transport could have bent 
> them if they were correctly set to begin with. The bottom line is 
> fixing that float level cured the problem and I thank all of you for 
> your help.
> 
> Here's the next question:
> Why would my radiator boil out the overflow tube after shutting down 
> under certain (not all) conditions? Here's the scenario: Ambient temp 
> about 80 degrees, 20 minute highway ride at 80mph, shut down for 10 
> minutes (no overflow), started and drove low speed for 2 minutes, idled 
> for 5-10 minutes in neutral and shut it down. It boiled out the 
> overflow tube. Registers about 3/4 to the hot mark on the dash gauge
> 
> Everything is fresh - engine, water pump, radiator core, and 14 lb. 
> cap. The thermal fan clutch is not new but worked fine before. 
> Ignition advance is 5 degrees. Is there a way to test the fan clutch 
> for proper performance? Where else could I look for a source of the 
> problem? Radiator cap not actually holding to 14psi? (I will check that).
> 
> Thanks.
> Keith Boonstra
> 
> -
> On 8/11/2011 1:07 PM, loren nelson wrote:
> > It sounds like a leaking float needle valve or incorrect float level. 
> > I just had the same problem on my G. I think the carbs are similar to 
> > the AFB on the G and there are 2 needle valves on each carb. This 
> > doubles your chance of a leak. At high RPM the engine consumes the 
> > fuel faster than the leak, but at idle the leak adds more fuel than 
> > the engine consumes and it floods.
> > There could be gas leakage at the base of the offending carb, but with 
> > all new gaskets there may not be any leakage. You may have to wait 
> > until it stalls and remove the carb tops to see which one has the 
> > highest fuel level. The floats should all fall the same distance from 
> > the top and when lifted should stop at the same distance from the top. 
> > If the floats look good, you have a leaking needle valve. It could 
> > just be a piece of dirt in it but you may need to replace the needle 
> > and seat. I fixed mine by cleaning them up with some very fine emery 
> > cloth but that will not work with the rubber tipped needles.
> > Good luck,
> > Loren in Hotlanta
> >
> > ----- Original Message -----
> > *From:* keboonstra <mailto:kboonstra@xxxxxxxxxxxx>
> > *To:* Chrysler300@xxxxxxxxxxxxxxx
> > <mailto:Chrysler300@xxxxxxxxxxxxxxx>
> > *Sent:* Thursday, August 11, 2011 10:21 AM
> > *Subject:* [Chrysler300] 375 Troubled Horses
> >
> > Would someone who knows a whole lot more than I do about WCFB
> > carburetors try to help me out? The car is a '57 300C.
> >
> > Basically what I've got happening on my freshly rebuilt carbs is
> > that I can't get the engine to idle without flooding out. I've
> > tried to follow the book and set the idle mix and air mix screws
> > on both carbs at 1 turn out. Then I followed another expert's
> > advice to put them all at 1-1/2 turns out, and yet another
> > recommendation I heard which said you should close the idle
> > circuit screws on the forward carb completely and set up the idle
> > on only the rear carb.
> >
> > I've spent hours tinkering, but no matter what I have done the
> > engine always dies when I let off the throttle below something
> > like 700 rpm. The only way I can then restart the warm engine is
> > to hold the throttle wide open while cranking until the manifold
> > clears after about 20 seconds of grinding. The engine then
> > gradually struggles and coughs back to life. There's so much fuel
> > in the manifold when it dies that I have to keep the the air
> > cleaners on during restarting just to keep flames from licking out
> > of the tops of my carbs. I've learned to keep a towel handy to put
> > the fires out.
> >
> > When the above attempts did nothing to help the flooding, I shut
> > down the idle mixture and air mix screws on the front carb, and
> > then tried turning in the rear carb mixture screws until they were
> > all but closed while opening the air mix screw as far as 2-1/2
> > turns. But no matter what I do the engine always quits and the
> > manifold always loads with fuel. And BTW, I can't blame the fuel
> > octane as I'm using 100LL aviation fuel for the setup.
> >
> > I'm pretty green when it comes to carburetor tweaking so I'm
> > really baffled as to where to look next for the solution. Why is
> > it running so rich? The choke plate is wide open with the engine
> > warmed up to operating temp, and yet I have to go wide open on the
> > throttle during the cranking to clear it out before it will run.
> > And even then it doesn't run very well.
> >
> > And here's my rant. I REALLY want to hit the road a bit with this
> > car, but it's fighting me every step of the way. I've only gotten
> > to rack up 10 fitful miles so far since the restoration. I've had
> > to track down and fix leaks of every single fluid the car has,
> > even though everything has been rebuilt - gas, engine oil,
> > coolant, brake fluid, transmission oil, PS fluid - along with any
> > other problem you can imagine. It drove me nuts. The only things
> > that haven't leaked are the tires and the battery. So after
> > getting all these issues fixed, I really didn't need a carburetor
> > problem on top of it all.
> >
> > Well anyway, where do I look next? Float levels or or incorrect
> > jets or something else? Shall I limp it over to my engine builder
> > who does a lot of carbureted engines - including race engines?
> > They claim to have some "tricks" they know how to perform on the
> > WCFBs. What else can I do?
> >
> > HELP !!!!!!!!!!!!!!!!!!!!!!!!
> >
> > Thanks.
> > Keith Boonstra
> >
> > 
> >
> 
> [Non-text portions of this message have been removed]
> 
> 



[Non-text portions of this message have been removed]



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