I have no idea which carb it has, but it WAS a Colorado Car, and is now in SoCAL, and runs like crap, overheats like crazy (if running on an average warm day, 10-15 miles and she's quit). I just changed the Master Cylinder and Brake lines as they were shot, and need to know how to tune the Carb for A/F flow (never worked on a carb before I'm an EFI guy ) and get her running right. It appears she is running REALLY rich. And that overheating issue is a bear....WHAT TO DO? There isn't ANYONE in HB/GG/Orange area that I trust with a Nailhead. I also need to change out the Wheel Cylinders, but that can wait a few...
Might want to check the timing before getting into the carb, unless there are visible signs that it is running rich. Does it idle ok? Check the mechanical advance mechanism and vacuum advance to make sure they are free and not stuck in the retard position. Mike
I would think lean if it were the carb and came from Colorado and is now in Southern California. If it came from say..... Denver, there could be a mile difference in the elevation and let me tell you from experience, there is a huge difference between the amount of oxygen at sea level and over 5000 feet. Go from sea level to that elevation and start climbing up a mountain and you will know how a car feels with that kind of change. Fuel / oxygen ratio could be way different. It would be more oxygen though so that would be a lean condition and if your car makes you feel like it's rich, you may want to check things like the timing like was already said. Pull the plugs one at a time and pay attention to how they look. You can find pictures on the internet of plugs that have various issues showing up on them to compare. Might not help to do that, but it's a good place to start.
With any water cooled engine there is a cause and effect thing that has to be addressed.... Most of the time the cause of overheating is poor circulation of water or air.... you must have good circulation of both to cool an engine.... With a 425 you need a large 4 core radiator, that is in good shape and not plugged up.... then the lower hose has to have the spring in it or it will suck flat and cause overheating....and of course the water pump has to be in good shape with no leaks any where in the system[ freeze plugs, heater hoses,head gaskets, ect.] the thermostat has to be in good working order and installed correctly,,,,the coolant has to be at least 50/50 mix.... on the air side, the rad. has to be clean on the outside, no bugs/mud/bird nests/ ect . and ,,,,you need a fan shroud, with a fan that is sticking half way of the blade width into the hole and with 3/4'' clearance from the tips of the blades to the shroud all the way around... the fan needs to be at least 7 blades and in good shape...With the car at a hot idle you should be able to place your hand 6 in. or so in front of the grill and feel a good breeze going into the front...if you dont there is something wrong... Run a ''pressure up'' test to see if there is a leak,,,, then observe the amount of circulation with the thermostat open at idle and then slightly run up.... it would not hurt to set the basic ign. timing with a timing light and ck the vac advance out....and the mechanical advance..... BUT.... DONT RUN THE ENGINE HOT VERY MUCH ,,, YOU WILL DESTROY IT.....
Plugs are fouled, bad. AND she STINKS when idling...Know that smell pretty well... I'm just starting to get edumacated on mechanical advances and stuff, as again, I have NO idea what I'm doing with this particular setup...Learning curve is HUGE...Only thing REALLY worked on was a 1.3L Roatary Turbo, and yeah, that's a little different.
Sounds like a carb issue, maybe a float sinking or just in need of serious overhaul. You will find the mechanical advance under the rotor. Pull the rotor and see if you can move the weights outward by twisting the the points plate. If you have a vacuum source you might want to hook it to the vacuum advance while you have the rotor off and check for actuation when you apply vacuum. Mike
I think straight water is the best coolant, and 66 425's don't have shrouds or fan clutches. I don't think they do even with AC; my Cadillac doesn't. Mine ran cool here in 100+* temps. If it's overheating, first make sure you have a good strong flow through the block and water pump and radiator and thermostat. Let the car idle until it reaches operating temp with the radiator cap off and observe the flow. It should really pour through there. Next check the timing and the vacuum advance. After that is correct adjust the idle mixture and then recheck the timing. If it still overheats that quickly, in your cool climate, I would suspect a blockage somewhere. This engine is stock and not bored I presume.
That's correct, completely stock, no mods at all. AC through that abysmal Buick Automatic CLimate control system. Am getting everything sorted tomorrow. Radiator check and pulling the thermostat. GOing to do stuff I know before tearing into the carb and timing. I am sure the carb needs rebuilt. All original and 58,000 miles total on it, and now in Cal from Colorado, its going to need it for sure. Therm is probably shot too. Gonna do that and then get into full on tuneup procedures. I'll keep you updated as I get in WAY too far...LOL As a note, since you obviously have a nice 425, how do I tell which carb is on there so I can get a rebuild kit?
Here is the location for a Quadrajet, which is correct for your car. If you have another carb, post a pic and I'll try to help.
Of course 66' had fan shroud and 7 blade fan on clutch,its called HD cooling.I´ll post some pics when i get home.And you are 100% right about water beeing best cooler,thats why cars in WRC uses only destilated water to cool their engines. I would go Doc's route.:3gears: Btw great looking Nailhead and engine compartment.
I hate to agitate here,:laugh: :laugh: but,,,,If you run straight water the alluminum parts are going to corrode very fast,,, and 50/50 mix prevents that...the way I know , is from paying to get aluminum parts heli-arc, welded up... the metal worms will eat holes every where...back then the factorys all said make up a mix of at least 50/50 porportions of distilled water and anti- freeze and,,,, if you had to add fluid, add anti-freeze...... Now, I had to learn this lesson the hard way,'' but if you dont believe ole Doc, jus go on and run jus water in there and see what happens''...:laugh: :laugh:
You are right: I just said it cools best. Water Wetter is the best product for a SoCal, but it costs more than a 50 50 mix of coolant.
And,,,, :Smarty: You are right,,,, water does cool best,,,, but it alone will corrode the crap out of the aluminum parts of the engine...... i guess the best set up would be distilled water with some sort of corrosion inhibitor ..... but I dont know what that would be.....except antifreeze....o No: o No:
A product similar to Water Wetter like Frank suggested, I believe, has anti-corrosion properties, and also is said to cool and transfer heat better than water alone. But, I've heard of products like that gelling up and causing all sorts of cooling system problems. Myth o No: ?
Welllll,,,,, :idea2: :idea2: Lets stir the mixture a little more,,,,, Has any body seen any data on the difference in temp drop of 50/50 mix and pure water????? and then with Water wetter,,,, which is what I have in my riv...:Brow: :Brow: o No: o No:
After a little Googling, I found more than one source that claims 46% coolant, 50% water, and 4% Water Wetter/Purple Ice is the ideal combo. However, I also found this interesting bit; From Stewart Components Tech Tips. "UNEQUIVOCALLY WATER IS THE BEST COOLANT! We recommend using a corrosion inhibitor comparable to Prestone Super Anti-Rust when using pure water. If freezing is a concern, use the minimum amount of antifreeze required for your climate. Stewart Components has extensively tested all of the popular "magic" cooling system additives, and found that none work better than water. In fact, some additives have been found to swell the water pumps seals and contribute to pump failures. In static cooling situations, such as quenching metal during heat treating, softening agents (sometimes referred to as water wetting agents) will allow the water to cool the quenched part more evenly and quickly. The part will cool quicker, and the water will heat up faster. However, an automotive cooling system is not static. In fact, the velocities inside a cooling system are comparable to a fire hose forcing coolant against the walls of the engine's water jackets. If the softening agents actually aided in cooling the engine, the temperature of the coolant as it exited the engine would have to be higher because it would have absorbed more heat." Physics, gotta love it :Smarty: .
When I had my Grand National (which is a whole 'nother animal, of course, except that it really wants to run cool) water wetter lowered my coolant temp by 10-15 degrees in the summer. It is a quality product and a nice tool to have if you need it. http://www.redlineoil.com/Products.aspx?pcid=10
