Hi I am from Poland and I have 72Duster with slant six. We try with two engines (clifford intake, 600 Edelbrock carburetor, custom exhaust and cam probably perf) with both of this engines I have problem with overheathing. Is cool up to 40mph but if drive more is booiling. In town the same up to 40 -50 mph is not bed but if more very quickly water is boolied I change block radiator fans. I instal electric normal I install new water pump and always the same. I try with or without termostat. I check the rubber against collapsing. One time more even without termostat engine is warm after very short time. And second when is idle and cap on radiator is open i hav feeiling that is air in water but is impossible that this is from engine. Cavitation from water pomp? I dont know. Have you any idea? I don't know anybody in Poland who have knowledge about this engines.
Sorry for my english I hope you understand me.
Regards

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so far so difficult. 72 DUSTER

could be a clog someplace, have you tried flushing the system? is the antifreeze dirty when you look at it?

could be a bad\clogged heater core

-dave

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what part of "illegal" is so confusing???

Yes system was flushed on both of engines. Last weeks was in poland hot but i try day and night and was not difference. I think that this simpkle stupid thing but... I have experience since two three years and never have this kind of problems with US engines. I work with Mopar V6 3,9l, 440cui, Ford 289-302, GM 5,7, 2,8 and 3,8. This is my first time with slant six was not bad when i try i have 110mph in duster with no problem. Overything is good exempt temp.

Thanx[/img]

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so far so difficult. 72 DUSTER

It might be the gauge, and you aren't overheating.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

too much timing will cause over heating at higher speeds.

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not enough timing will also cause overheating. i had the vacuum advance hose fall off and the engine would overheat like crazy. put the hose back on and no more overheating. also if the secondaries are open at all it will cause overheating at speed. the engine will run lean. had that problem, too. sec. were open slighty and the engine overheat on the freeway. closed the sec. and no more overheating.

zedpapa

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1970 dodge dart w/225 /6 bored .040" over, holley 390cfm w/vac. sec., compcams 252s, clifford shorty headers w/2.5" exhaust w/flowmaster, f-body 11" front discs, aluminum A-833OD, 8 1/4 w/3.21 SG
soon to have 5 gears!!!

This can happen if the heater core is plugged...I have replaced these in Dusters and you could back flow the core with a hose and it still doesn't clear it 100%...replace the core. (it will become evident if you place the heater on "hot" and are over heating and the air out of the vents isn't "hot")...

You have replaced the water pump, sometimes when the cooling system is drained for that replacement a bubble can develop in the system, I just run the engine until the thermostat opens, without the radiator cap installed, the system usually "burps" then I just refill, cap and go...

Another thing to watch for is your car may not have come stock with a "catch bottle" for the coolant, so if you drive it like mad then park it...chances are after a few runs you are low a few quarts of coolant and need to top up...you can relieve this a bit, by plumbing a pipe and a hose into the radiator neck and into a plastic bottle (pick one out of a later car) so it'll drain and get sucked back up next time the engine is warmed up and started (if you can get a 1973+ mopar radiator it should have the little spout). My '67 used to leave a nice "trail" of coolant when it got hot after pulling into a parking lot...got a catch bottle and now no problem there.

What radiator cap are you using (how many pounds?)

Your timing can be off, another thing to check is the color of your spark plug electrodes (if the carburator is running lean you will have lots of heat, and soon a bad engine). When you do run it are there bubbles in the coolant in the radiator? (if so the head gasket is bad)

Hmmmm....

-D.Idiot

Thanx I assembly back engine and try all what you write. I hope something will change.
Its really nice place for those which spend free time with dirty hands.

I will post what is with this engine and which was mistake if find it.

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so far so difficult. 72 DUSTER

I had exactly the same problem and this is how I fixed it.
Number one; NEVER RUN WITHOUT THE thermostate! Yes it heats the car quicker in the winter, BUT, it slows down the coolant flow, so it stays in the radiator long enough to pull enough heat from the coolant so the car does not over heat at high RPMs.
Number two; Run a High Temperature thermostate. I run a 190 degree thermostate all the time and it does not overheat even when the summer temp hits 100 degrees here in California.
Number three; Make sure the Mechanical Advance is not FROZEN INSIDE the distributor. When you remove the cap and twist the Rotor, it should turn about twenty degrees and then spring back. If it does not turn, it is frozen and needs to be repaired or BETTER replaced with a fresh distributor. ALSO! If you can turn the distributor and there IS movement, but it is not spingey, then the springs are worn out and the distributor AGAIN, should be replaced.
When this happened to me the car ran fine around town and just as soon as you got on the freeway (Over 40 MPH!) it would shoot up HOT and boil over.
When the engine is running correctly it should run, plus or minus 15 degrees and not fluctuate any more than that. You can tell when the engine is happy by how it responds from a short stop. You are running around town and making stops. After being stopped, with the engine off, for about fifteen minutes. When you climb back in and turn the key the temp gauge reads real hot, thirty seconds after you start the engine it returns to a more normal range. That is a happy engine. A hot engine gets better fuel economy. The engine that runs 190 to 210 degrees will get better fuel economy than the engine that runs 160 to 180. Not to mention it keeps you comfortable, in the winter, a lot better!