It sure sounds like a circulation issue, but once you hit the street...... Sorry to break this to ya but that non-vacuum distributor is gonna harm performance and may lead to running hot in use (even with a good thermostat). Non vacuum distributors are for supercharged and racing apps only. Street engines, especially mild ones, need vacuum advance. This is not a situation where "racing" parts are better. How much mechanical advance is contained in the distributor??? It should say somewhere in the literature. Small chevys like yours end up wanting around 36-40 degrees total timing. If you're set at 4, then you're gonna need at least 32 in the distributor. You get major points for using a shroud. Equal points are deducted for the fan choice however Again, not the cause of this specific issue but may lead to issues depending on useage. Good luck with the project!
It's screwed into aluminum so it's probabley just stuck from the water and corrosion. I'd put a six point socket on it with a long extension so you can get up where you have room. You could put some penetrating oil on it if you want, and or try removing it with the enging hot. A half inch drive ratchet should do it... turning counterclockwise. The new one needs to ground...so if you put teflon tape on it ? leave some threads exposed so it will ground. Check to see if the engine has a good ground also, as this will effect an electric gauge....mine would pulse with the blinkers before I put a ground to the frame. I'd also take care of your timing and vacuum issues. And put some coolant in it.
id like to ask something without anyone gettin pissy here. everyone says this, about the vac advance, but cant a non vac be set up right? what did they do before vac advance? i always hear how great and reliable a magneto is, but they have no vac advance, so how are they a good choice but not a nonvac distributor? just some point of confusion.... thanx
I think I have the answer to your intriguing question. Those old Chevy trucks used the heater as a bypass for the cooling system. If there is no means of bypassing the cooling system while it warms up, it will climb to over 210 FAST. I noticed that there are no heater hoses on the engine. An easy fix is to loop a short piece of heater hose from the water outlet/thermostat housing heater fitting to the heater water inlet fitting on the water pump. Had this happen on my 51 with a 235, completely plugged, after clearing the rust, no more overheating.
Non vacuum distributors are strickly for racing applications where the engine is going to be run wide open like in drag racing. While running wide open there is no manifold vacuum to operate a vacuum advance anyway. The vacuum advance adds idle quality and economy into the equation.
I have to agree. I have rarely ever used vacuum advance on any car I have ever owned (mild to wild V8's) and they all ran fine, although they will get a little better gas mileage and idle smoother when utilized. It does help to use lighter springs on the advance weights (which is usually the case in an aftermarket performance distributor) and make sure your timing is set accordingly. Also, if we were talking about a completely stock driver car I wouldn't advise ditching the vacuum advance.
The reason the bottom hose is not hot is the engine is not running long enough. Anyway you WANT the lower hose to be cooler, this tells me the radiator is fine. The thermostat also appears to be working because the upper hose gets hot. The fan/shroud maybe the area to look at. The radiator should be sealed in such a way as to NOT allow air to pass around it. The shroud should be against the radiator and the fan should have 1/2 to 1/4 of the blade width protruding from the shrould. The fan must also be facing the correct direction. If the fan will hold a piece of paper against the radiator, you should have enough air flow. The reason you cannot see the coolant move in the radiator is it's baffeled. If the upper radiator hose is getting hot, then the coolant is moving. Water is the best coolant for heat transfer, but be sure that your additive has rust inhibitors and will also work with aluminum. Aluminum will oxidize in pure water, just as bad as rust. Get yourself a GOOD thermometer or a buddy with a thermal sensor (gun) and verify the tempreture that way. Gauges and sending units may or may not be accurate, but a good old thermometer should tell you wants going on.
a small hi-jack here, how fast would the temp climb if it was running lean, I mean it wouldn't jump as fast as his is right ?
Just one more thing, when setting your timing, it is much simpler to go by total timing. Your Pertronix distributor should have advance springs light enough to allow this and it would just require installing the correct timing tape on your balancer. I haven't had much luck keeping them from eventually falling off though and usually just use them for reference and stamp marks directly on the balancer at 32,36 & 40 deg. On a SBC, 36 deg. is usually a good starting point. Just make sure you are at least a couple of degrees below where it starts to ping which may be 40 deg.+ on your 283. You can also get close (assuming your distributor isn't advancing any at idle) by setting your initial timing at what the difference would be by subtracting your known mechanical advance limit from the desired total, i.e., 36-20?=16 deg. I'm also leaning towards your temp issues being a faulty gauge or incorrect sender and a cooking thermometer would determine that. Another thing, I'd only use distilled water and antifreeze with an aluminum radiator.
It's a 283 in a truck with a grille area the size of a barn door. The radiator that's there is completely sufficient if the rest of the system works. Regarding the vacuum advance mentioned above. There's always people that run without them. Always. And usually, if you read deep into their responses they admit they're leaving 2 mpg and 30 ft-lbs on the table during street driving conditions. The only engines that don't need vacuum advance are supercharged or RACE engines. And I don't mean a cammed 327 in a street car that's called a race engine at cruise night. I mean a full on stock car or drag engine that lives it's live at 7000 rpm. The bottom line is if your engine operates at part throttle you need vacuum advance. good luck
^oh sh*t my bad, I was thinking he put a stock type radiator in, that sucker is aluminum. Jeez there's major circulation or timing issues if a 283 is overheating with that. An aluminum heater core should keep that motor cool Yeah good advice on the coolant too.
If it is an aluninum radiator you had better have it grounded. If not electrolis could be your problem.
Change your timing to something like 16-18 degrees btdc at idle and 34-38 btdc at 3000 or so. That's what small blocks like. I'm betting it's just a timing issue. Does the truck run like crap too?
ck w/p for impeller shaft spinning but impeller isnt, happened to me with a 305 chev showing no water flow at top of rad it aint pumping,mine worked till operating temp then shaft spun inside impeller
Electrolysis is a process by which the movement or flowing of coolant systematically removes the aluminum from inside the radiator, YET it really only happens when there is improper grounding and can cause damage to the cooling system and the spread of corrosion. An aluminum radiator MUST be grounded if mounted using rubber insulators. Most aluminum radiators SHOULD be mounted with rubber insulators due to the fact that vibration can work AGAINST the rigidity of the aluminum radiator and cause small fissures/cracks in the outer housing. Bottom line, ground your properly mounted aluminum radiator or you're asking for future problems.
I think he's just implying that he hadn't read the title of this thread. The comments about corrosion were only additional pointers and not a solution to his main dilemma.
My guess is the water pump. Also... the 235 in my truck ran at 180 all day long for many years. Recently it started getting hot and I couldn't get it below 210 - 220. Turns out that my freeze plugs were corroded and leaking. Knocked them out and and dropped in the new types with the rubber and the bolt tightner ... and no more problems. 20 minute fix for under $10.
The bypass is built into the pump. One side of the sbc pump has 3 holes, and the 3rd hole is a bypass. Now if that for some reason was plugged it wouldn't circulate. Jeff
Ok you say without the thermo it is circulating, well that tells me that you problem is the thermo, not a sending unit, not a guage, not a air pocket, and it damn sure ain't the timing. I had almost the same problem on my '60 Bel Air, a new rebuilt 4 core radiator on a a small block 327, the gauge would say it was running hot. I changed the thermo to a 160 to make it open sooner which get the water flowing and cooling sooner, and it still showed hot, new wire to the sending unit, new sending unit, and still showing hot. Then I saw one of them little shinny things we can't do without, ie...a radiator cap with a gauge built into it, guess what.......the hottest I ever got was 220 in parade traffic, but usually between 180-200 and once I added water wetter to it I started running down in the 160-180 range, and that is with a 50/50 mix. The old factory gauge was bad. Replacing the sending unit will not make it run cooler, it will only tell you what temp it is running (if your gauge is good).
Good to know that, I guess this is at the block mounting for the pump? U R right about it being plugged up. If it were my problem, I would start with removing the pump and inspecting the bypass passages, along with the pump impeller. Some people are just plain set in their ways, (vacuum advance, radiator, mixture).
Not a good idea except for maybe some of the core (not freeze) plugs not too accessible. They are there for a two reasons, one to keep coolant in engine, two to pop under extreme expansion in cooling system whether hot or cold. I would put the metal plugs back in where it is easily accomplished. BTW: I used one of the rubber plugs for a 54 Cad, only at the Power steering box area where I would've had to remove the steering box, which is a mess on the early 54's. The rest were brass plugs.
Actually, the "freeze plugs" aren't there to protect the block in case of freezing or expansion. (they're also sometimes called "expansion plugs.") The holes in the block is how the foundry removed the casting sand cores from inside the water jackets. That's why they're there. All also chime in with the sludge in the bottom of the block. the 283 that was in my '62 Suburban had been rebuilt at least once in its life, with new pistons, so it had been hot tanked. When I pulled the engine out and moth-balled it, I pulled the plugs along the pan rail to drain the coolant out of all the internal passages. Except when I removed the plugs, nothing happened, not even a drip. I had to pound (yes pound) an ice pick into the hole to break through the sediment in the bottom of the block. I don't know how much was in there, but it was considerable. -Brad
TRy pulling the lower radiator hose off and see if the water emptys from the rad. That should tell you if the rad is plugged. It sure sounds like the water is not circulating. Can you see the water flowing with the cap off? This should tell you if the thermostat is opening and pump pumping.
I had this happen to me. One of my new hoses had a paper sticky lable on the inside that came loose and blocked the radiator inlet. Gotta love Auto Zone parts....
Hey guys, it's been a hectic week at work so I haven't spent any evenings working on my truck. I've got today off so I'll be back to troubleshooting the issue today and through the weekend if need be. I appreciate everyones input and will provide an update when I have one!!
The Jalopy Journal
