I installed a 289 in a 63 fairlane. Engine is basicly a stock rebuild by a local builder with a mild cam. New edlebrock 1403 carb, performer intake. It will idle perfect cold to 210. Runs great but idle is horrible. I've tuned the carb repeatedly and get the same results. Moved the timing around and its about 8 before TDC. There in no pinging or predetination. It is a bit hard to restart when hot but not bad. If I move the timing back 2 or 3 degrees the hot restart is better but still bad idle. There are no vac leaks. All hoses have either been replace or capped to elimniate this. Replaced intake gasket and carb gaskets just to make sure. Sprayed starting fluid everywhere and no change in engine idle so the a vac leak (at least external is not the cause.) What would change to make the idle so poor when warm but so good at 210?? I also don't think it is vapor lock. Installed a new fuel pump and fuel lines away from heat sources. If I drive it around once it I get it up to speed (15mph plus) it runs great and makes good power it just will not idle. I've tried a second carb as well and it still does the same thing.
Maybe two things are working against you. One would be that your temp is way above 210 and you temp gauge doesn;t know it and the other is that maybe your oil is thinning out on you and you are not getting proper oiling because of it. Just thoughts off the top of my head, maybe someone else has a better idea.
Why would you want to run a carburated car at 210? something isn't right here. And just saying USA doesn't tell me if you are in a state like CA or AZ where ALL that youcan purchase is "Oxygenated" fuel, in other words 15% alchy. That stuff boils at about 185-190, so it leans things up a bunch right there. Get it running at about 180, then tune from there.
I agree the 210 is problematic. Going for a larger radiator anyway and also going to check eveything with a laser temp gauge. I've had a few vehicles that were happy at or around 210 but this one don't like it. Keep the ideas coming I'm all out.
Are you using a thick isolator gasket under the carb? I had similar problems with my 500 edelbrock on an aluminum intake (off topic car) until i used the thick gasket. We believe it was fuel percolation.
That was the first thing that jumped out at me, why is this car running at 210 at all ??? It was designed to run at 180. My daily runs at 210, but it is injected and computerized and was designed to run at that temperature, yours was not. What is probably happening is that your fuel is boiling in the carb. My Son has two fours on his T and on a very hot day here in Florida one time it started idling rough. We couldn't touch the carbs as they were really hot. We are going to add insulated spacers under them to cure that problem before Summer comes again. You can do the same, but I would get that temperature down. There is something wrong with your cooling system that needs addressed. Don
fuel perculation--add a phenolic resin spacer or make one--had this issue a few times--this seems to fix it
Throw a readily available 1" spacer under the carb. Definitely install a 180 thermostat. The combination should eliminate your described issue. The Edelbrock carbs are very susceptible to heat soak.
My edelbrock intake and a single water jacket. Front only. I replaced it with a dual water jacket intake. Front and back. Temperature went from 210 to 175 all day long.
Thanks guys, Going to order spacer now and I have new radiator (bigger core) on the way. PO had installed an aluminum radiator but it is obviously too small. The radiator that is in it doesn't quite fill the core support opening. Thanks again
Also check the fuel pressure Carter AFB's and Edelbrocks do best at 4 1/2-5 1/2 psi, over that plus the heat and you will have problems that heat insulator is a must.
210 Is too hot for a carbed engine as stated...... check your tail pipes [while running]when it reaches the high side of temperature range that you describe...... I have seen heads with very minute cracks that open only at higher temps and seep coolant even tho very minimal it will do what you describe.
210 that fuel is most likely boiling in the carb... get it cooled down and put that spacer on there and everything should be gravy from there. Edelbrocks dont like to be hot!
Hmmm...sounds familiar. My '65 mustang's 289 had similar problems when it got hot. First the idle goes, then acceleration goes, then it dies and won't restart. Sounds like you haven't gotten to #2 and #3 yet. The carb spacer should help, but I really felt that heat soak in the mechanical fuel pump was as big of a problem (or bigger) than the carburetor running hot. If the fuel pump gets too hot (and with today's "gasoline" this is a bigger issue than it used to be) the fuel will start to vaporize in the pump. Worse yet, it can start to vaporize in the fuel filter or the fuel line feeding the pump. This is exacerbated by the fact the pump is sucking on (pulling down the pressure of) the fuel in the fuel line. Long story short, you end up with yourself, 3 kids and your wife waiting for a rollback on I65 in 98 degree heat. The spacer will help, but my ultimate, can't miss, fix was to put in an electric fuel pump at the tank. I started with an extremely cheap pump wired to a switch under my dash. The pump was located on the fuel line at the tank that would just assist in feeding the old mechanical pump. If the car started to stumble, or if it was hot out, I could turn on that pump and that took care of it. Eventually I went to a tank's inc intank setup (for fuel injection) with a return style FPR under the hood, that would deliver about 5psi to the carb (eliminating the mechanical pump all together). Finally, I just switched to fuel injection and that was the end of ever worrying about vapor lock. And yes...210 is too hot. You might consider looking at an aluminum radiator and an electric fan (spal works pretty good). Phil
Just a note on 289s, I've had a couple, both with low to mid-rise aluminum intakes on them, which ran at 180 or less all day, but I still had problems with them, and hard starting too. The cast iron intakes usually have a splash pan on the bottom which deflects some of the hot oil and helps dissipate heat. I couldn't run the spacer as it meant I couldn't fit an air filter under the hood, so to remedy this I used a readily available "heat dissipator" which is just a flat metal plate which goes between your carb and intake. It requires two gaskets, one on either side, but it works like a charm. Just my experiences. Mike
Agree about the spash shield on the intake. I had 2 SBF's get hot and shitty like that, both times the balancer had slipped and my timing was way off. Respectfully suggest you double check that THC on the balancer is really TDC on the crank. Maybe rig a dial indicator in the plug hole. Good luck on sorting out the motor.
Double and triple checked TDC and remarked the balancer. The more I read on this forum and others I'm pretty convinced it is fuel boiling in the carb. We'll see if the spacer and bigger raddy cures it.
I dont know if 210 is horrible. My 289's have always run cool. Is the radiator plugged. 289's used to have an alluminum spacer under the carb, and often had an egr valve in the spacer as well. Modern day engines run hotter because of emissions. Heat is very hard on the valve seats, and a stuck EGR will run and engine hotter and if open will run like hell as well. My 68 has one. If your ignition has issue's heat will mess with that. Even the condensor.... I would talk to the engine builder. Ignition timing isnt going to drasticaly change the engine temp, but a lean condition ight play in as well.
I don't know where in the USA you live, have you considered blocking the exhaust cross over in the intake that runs between the heads and under the carb? Not a good idea in cold climates, but something to consider in a place like TX.
Two thoughts. Radiator doesn't fill the core. Is air going by the radiator through the gaps? Does the 289 have a heat riser valve on the exhaust manifold? If it's stuck closed, you could be getting way too much heat in the intake. RB
if the fuel is boiling, you will be able to see it. Take the air cleaner off, shut it down, and wait to see if fuel starts to bubble out of the squirters. What are you using for an ignition system? improper dwell on points can cause some of your rough running problems, and mounting the coil too close to exhaust can cause the coil to get too hot.
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