dgbcharger

Hey gearheads, Got a new, probably self- inflicted problem. My 72 Charger engine is running hot. Very high on the temp gauge after 50 to 60 minutes of running at about 55mph at 2600rpm. The rear end now has a 3.55 posi in it. It used to be 2.45. The engine of course runs 700 rpm higher than it use to at 55mph. I expected that. The temp gauge very slowly rises to 3/4 of the gauge and stays their unless I slow down 300 rpms, then it moves back a bit. Engine has been rebuilt, and everything about the cooling system has been changed to new except the rad which was flushed out.(also a AC rad is in front of the main rad). I believe my engine compartment is too hot w/the headers. The rad so far hasn't puked out any coolant. Now for the real problem: I recently found out I have a lean 4 barrel carb on a large intake. According to the manufacturer these to components are not recommended to be mated. I believe the engine is running too lean although the spark plugs are a nice tan. Need advice on how to cool the engine compartment and or the engine. Do I need a different carb?, header sleeves?, different coolant(purple)? or thermostat. I really don't want to remove the AC system even though I do not use it. This is what's new: pump, hoses, rad cap, thermostat, fan clutch, temp sender,belts. Drove in Memorial Day parade with it running real slow, basically at idle and the temp gauge was slightly past the middle and held there. One guy told me to put in an aluminum rad, another said an electric fan in front of the AC rad. The thermostat is 195 degree. Gotta do something. Come on gearheads give me your best answers pleeease!

RacerHog

I would start by installing a 180* thermostat..... Fan Shroud is a must !!!!!
Check the engine timing... If it's retarded that will also cause it to run hot.
The headers are going to radiate heat... No issues there... Also check and make sure you have the rite spark plugs in the motor... You can also try jetting the carb up at a later time if you feel that might be a problem... But if there tan... Thats not the first place I would go just yet.... Check the stuff above... Oh... And did it always have this problem?

peter123wallace

What brand do you propose?

Archer

d -

Bob gave you some good advice, and I would try to get a factory shroud.
I hesitate making any suggestions, since your description goes against an air flow issue, since you said it get hotter while driving at speed. That would indicate a root level cooling problem, like an inadequate radiator or water flow obstruction.

Archer

dgbcharger

No this problem is new since the gear change in the rear end.

dgbcharger

The car has a fan shroud around the fan. When the engine was rebuilt I flushed the rad with water pressure. Not much rust came out.

dgbcharger

Thanks guys, I'll go with header wraps first, a 180 thermostat second, carb jets third and spark plugs fourth. I really want this carb richer though, can always change the jets back I suppose.

RacerHog

Keep up posted.....

dgbcharger

The engine rebuilder forgot to put a thermostat back in my engine. I ran the car for 3 months with no thermostat.(the MORON), Now it has an 180 thermostat. The car runs cooler on the gauge but still hotter than I like. The engine is running lean due to the carb & intake combination per the manufacturer. Two spark plugs are white the rest somewhat tan. I will change the main & secondary jets to richer ones and wrap the headers. Hopefully these changes will cool the engine further.

Iowan

You can see the thermostat when you hook up the upper hose. It's not necessarily up to the engine builder to put a thermostat in it, in fact I never have gotten one back with one in.

RacerHog

I agree....

What 2 plugs are white? Sounds like you have a vacuum leak. Not a lean carb. issue....


What was the timing at?

dgbcharger

number 5 and number 8 are white the rest slightly tan. Timing don't know yet my timing light as I just found out is broke. Will get new one soon and let you all know. As for the engine rebuilder I gave him a new thermostat with the new water pump. At least he could have told me he did not put it back in!!! Got an idea I need a new rad.

RacerHog

Check the vacuum fitting on the back of your intake manifold... The fitting is the vacuum source for the power booster, and Vacuum Accessories inside the car. Check the following...
Cracked hoses
Loose Hoses
Fitting just loose
Vacuum booster leaking
and so on....
Or just plug them all off to test the system.... But be warned,,, You will have no power brake assist at this point of testing....

Also... You might just need to have the radiator cleaned and rottered out.
Check the fan clutch.... if its bad or you think its bad.... Just install a direct drive 18" Hayden Flex Fan and space it just past the inside edge of the shroud.

Keep us posted

dgbcharger

Timing is 10 before, at750 rpm (warmed up)
Vacuum is 11 while the needle vibrates a half, at 750 rpm, used to be 14 before rebuild
Vacuum is 19, holds steady at 2000 rpm Are these readings low???
Checked all fittings and hose to booster can not find any leaks
tightened down on intake bolts, no difference made
next to try is the head bolts, won't be till this weekend though
fan clutch was new with the pump - should be ok
already pricing rads should I go aluminum?
spark plugs autolite 85 - middle of the road heat range.

Special thanks to racerhog, your the guru on top of the automotive mountain! all you need is long white hair

RacerHog

Looking for about 18" of vacuum at Idle.... 750 RPM is a great number...
Might try to bump it up just a tad 12-16* on the timing... As long as its not hard to start or running on or pinging... those numbers should be good... let see if you can get it up in the vacuum to 18"....
It might not it the cam has a long duration cam... But I would try... Your rite in kind of thinking the vacuum is low... It would appear to seem retarded...

Disconnect the booster hose and plug it for the moment.... let see if that helps... booster could be leaking inside??? Big Maybe... Could be the vacuum controller under the dash also... or even the vacuum pots to control the blend doors... Got to check it all buddy....

85 Auto lights are the OEM replacement plug for the 400 Ci... Your safe on that one....

Whatever you choose for a radiator.... You must have a fan shroud... But thats just my preference....

keep us posted..... Will stay tuned......

dgbcharger

Found two rubber vacuum plugs cracked open, after replacing them my vacuum gauge read 3 more pounds to 14 at idle which is what the number was before the engine rebuild. This was without the brake booster hooked up. I do suspect the booster has a leak in it. On another front I changed out the primary and secondary jets making them richer. The engine seemed to respond positively to the extra fuel. It ran stronger and slightly cooler on the temp gauge while driving to and from a recent car show. Can not find any other vac leaks at this time. Tried to wrap my headers with 2 inch wrap. Hasn't worked out well. I quit on this early. I might have to go to 1 inch wraps because the headers are buried and they have too many bends. Timing is still at ten before and compression test shows 130 lbs per cylinder while the engine was still hot. Spark plugs all slightly tan except # 5 plug which was white. This is still a mystery to me. The intake paint is discolored from overheat at the # 5 cylinder port, this is also a mystery to me. Anybody know why this is? But the engine now idles good, accelerates good even when cold. I think I can live with the higher than normal temp gauge reading. Perhaps a new rad is the final solution. It will have to wait until the end of car show season.

RacerHog

Glad to see your finding the little problems....

dgbcharger

Bought a infared thermometer, checked engine when temp gauge at 3/4
and read 208 degrees at idle near the temp sender, 212 degrees at rad hose intake and 195 degrees at output hose. I now believe the engine is not overheating, just runs hot on 85 degree or higher days. Found out I might have the wrong fan clutch . I will update you readers on this in the near future. Also looking at installing electric fan. New rad out for now. Haven't found any more vacuum problems, still looking.

RacerHog

Still seems a little warm.... Keep us posted....

moparted

hi don, ted sweet from the fulton co car club

63 savoy wagon

63 savoy wagon

Look into using an Edelbrock water pump, or even better use a Meizier, have used both with GREAT results, the Meizier is the best if you are going electric.

RacerHog

Love seeing your car Run....

63 savoy wagon

Thanks, It has a best of 6.10 @112 mph @ Irwindale. It has a 383, .060 over, iron heads, flat tappet cam, 1.6 Harlan Sharp rockers. Single 750 Holley with 125HP nitrous.

dgbcharger

The latest is I have a new different fan clutch installed but it did not help. Now I installed a new overflow tank for the rad even though it never had one. The rad now has been puking a little and maybe sucking air back in. I'm making sure the system doesn't get air an bubble. Someone mentioned to me to remove the fan clutch and replace it with a spacer to push the fan farther in the shroud, saying a performance engine really shouldn't have a clutch. Any thoughts from anyone on this idea??
I will also check for a cold spot on my rad using my infared thermometer, I have been given the idea that maybe there is a blockage in the rad and this maybe the way to find it. I'll keep updating about this temp drama!!!


Changing water pumps and rads are for the offseason.


Hey moparted I finally realized who you are. Good luck at Carisle PA

RacerHog

Well...
3 row radiator
Fan shroud
6 blade fan and new fan clutch
Guessing it has the rite pulleys on the engine
Good water pump

Hummmmm other than a good flush... I dont know what else to help you with other than a tear down might be in order, must be something blocking or restricting the cooling system inside.
Steer Clear of Ted !!!!!!! He is a hand full around here....lol

63 savoy wagon

I have had troubles like you are having, I found the stock water pump does not do a good job of moving the water, way too much clearance between the vanes on the pump and the stock water pump housing, like i mentioned earlier a Edelbrock or Meziere pump do a MUCH better job of moving the water, thus allowing the radiator to do is job. The best radiator and cooling systems are not very effective if the water is not movig thus transfering the heat.

66coronet440

Hey, did you check to see if the spring in the lower rad hose is in there? Helped a couple people on this forum and it worked on a few cars couple buddies had it missing, was running fine while idling but ran hot when driving. The lower rad hose collapses and restricts flow with increasing rpm because the waterpump is doing the same speed as the engine rpm. Anyway check for that spring and if its missing that should be your issue.

dgbcharger

Found cold spots in rad, power flushed rad by itself with electric pump and rad cleaner, some rust did come out and the cold spots were essentially gone, also found spring missing in lower rad hose, installed spring. The engine ran cooler but still alittle warm but a definite improvement. Thanks Coronet 66 I forgot about the spring. This is my last entry on this problem until I decide to either go with a new aluminum rad or just an electric fan. Thanks to all who responded and read all the entries. dgbcharger

66coronet440

Glad it helped you!