340 Duster running hot

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Skeven33 said:
Destroy my engine? it runs just fine. no pinging. but it could be bad for the engine with no noticable effects while running low octane?
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Are you sure you would be able to hear it if it did? Headers... loud exhaust... You may never know you have a detonation problem until it's to late... I learned this the hard way.
 
very true it is quite loud with the headers and exhaust. Im going to fill the rest of my tank with super and see if it helps. is there anyway i can tell whether i have detonation or not?
 
9.5 to1, .508 cam, headers, A/C, stock cooling sytem, 180 stat, ThermoPuke, nice converter, 13.8@105 and it never overheats.

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Skeven33 said:
very true it is quite loud with the headers and exhaust. Im going to fill the rest of my tank with super and see if it helps. is there anyway i can tell whether i have detonation or not?
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Well... If you weren't at least running super with 11.5 compression I guarantee you have detonation.
 
when they are fresh alot of times they will run warm and yes go with an aluminum radiator i am assuming the "jegs water pump" is an electric? if so what kind of thermostat are you running? what sise and kind of carb? and lastly what elevation do you live i noticed its colorado high compression and high elevation are a pretty much done deal as far as needing high octane fuel
 
its a mechanical water pump. 180 stat. 750 holley carb. I live real close to denver so elevation is 5280 and ill be running it at bandimere speedway which is known for altitude
 
Skeven 33, I have not had any problems with my edelbrock heads. My valve covers weeped a tad when first got it together but after slighty snugging them down more it has stopped. Also, if your headers are leaking, It is probably the flange or gasket, or both, as I have found that the cheaper headers have pretty crappy flange thickness and surface. I have TTI s and they have a nice thick flange.

Now, as far as your car goes, you said you took it around the block a couple times, I am assuming you didnt drive that fast. If your car is running hot at idle or low speeds but cools down at highway speeds, then you most likely have an air flow issue through the radiator, which in your case is being hurt more by a lack of a shroud. I agree, put a shroud on it. You can make one out of aluminum and cut a hole so the fan OD fits snug in it and bolt your electric fan directly to the front of it, thats what I have. Also, I do not believe in the idea that you can move the water too fast to cool it. It goes against everything they taught is in thermodynamics. I think this idea got started with people putting high flow pumps on cars with plugged radiators or passageways and/or lower radiator hoses that were collapsing and the pumps actually cavitated, which made the engine run hotter, because they could not suck the coolant fast enough.

I actually confirmed this the other night. Have a steep hill on a state highway, probably a 1/2 mile from top to bottom. Took the car down the hill twice at my operating temp of 210 degrees. I put the car in neutral when i crested the hill so the car would coast down at 60 mph or so. Now, this kept my airflow across the radiator the same as in gear, but dropped my rpm and WATERPUMP SPEED from 3000 rpm to 800 rpm. Both times down the 1/2 mile stretch the car did not cool down 1 degree. The next two times I went down in gear, at 3000 rpm, at 60 mph and 210 degrees just like before, and both times the temp dropped to around 200 degrees at the bottom of the hill.

Hope this helps
 
1wildandcrazyguy, 38* is actually where the dyno made the most power and lowest temps. I've actually played with it a little in the car but it runs the coolest at 38. I do not have vacuum advance, have msd distributor. Also, I am switching to straight distilled water and water wetter to see if that will get me around 195-200. If so I will be happy. Speaking of which, anyone have a good idea for removing all of the old coolant out of a small block mopar so that I get all of the glycol out so I can fill with 100% distilled? I thought about continuing to fill the engine down the thermostat neck while I let it drain out the lower radiator hose until I just see clean water come out.

And as for the converter, it is a PTC converter built for my engine/car.
9.5" converter 3500 flash stall. I LOVE this converter, would recommend them to anyone. It flashes nice and high but it is very efficient while driving down the road. Like I said, the temperature is never over 170 degrees on the hot days in the transmission, and most days runs around 160
 
moparmade43 said:
1wildandcrazyguy, 38* is actually where the dyno made the most power and lowest temps. I've actually played with it a little in the car but it runs the coolest at 38. I do not have vacuum advance, have msd distributor. Also, I am switching to straight distilled water and water wetter to see if that will get me around 195-200. If so I will be happy. Speaking of which, anyone have a good idea for removing all of the old coolant out of a small block mopar so that I get all of the glycol out so I can fill with 100% distilled? I thought about continuing to fill the engine down the thermostat neck while I let it drain out the lower radiator hose until I just see clean water come out.

And as for the converter, it is a PTC converter built for my engine/car.
9.5" converter 3500 flash stall. I LOVE this converter, would recommend them to anyone. It flashes nice and high but it is very efficient while driving down the road. Like I said, the temperature is never over 170 degrees on the hot days in the transmission, and most days runs around 160
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agreed i run mine at 36*
 
moparmade43 said:
1wildandcrazyguy, 38* is actually where the dyno made the most power and lowest temps. I've actually played with it a little in the car but it runs the coolest at 38. I do not have vacuum advance, have msd distributor. Also, I am switching to straight distilled water and water wetter to see if that will get me around 195-200. If so I will be happy. Speaking of which, anyone have a good idea for removing all of the old coolant out of a small block mopar so that I get all of the glycol out so I can fill with 100% distilled? I thought about continuing to fill the engine down the thermostat neck while I let it drain out the lower radiator hose until I just see clean water come out.

And as for the converter, it is a PTC converter built for my engine/car.
9.5" converter 3500 flash stall. I LOVE this converter, would recommend them to anyone. It flashes nice and high but it is very efficient while driving down the road. Like I said, the temperature is never over 170 degrees on the hot days in the transmission, and most days runs around 160
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It is my opinion that you may have too lil comp for your cam to get the timing that high.jmo

a closed chamber head should need less timing than open if all's matched cam/comp.jmo
according to chrysler and my own experience, 30* timing if all's matched. Amongst other things like compression, the chamber shape plays in dictating when spark should happen.jmo
 
Check your timing. My total was @40 and came in @2100 rpm, and the temp would creep up close to 210 on the highway. I backed it off to 34 deg w/10 deg initial and disconnected the vacuum adv. 2 hour trip from Carlisle in the heat, it was stuck at 195. Problem solved.
 
Skeven33 said:
What kind of fuel should i be running with that kind of compression? i also have the six pack fiberglass hood. what kind of radiator were you running to keep your 340 cool?
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Just one thought on your overheating. First is it overheating in traffic or when you are driving down the road? I have a 69 Swinger 340 and no matter WHAT I tried I just couldn't get it to run cool in traffic. After trying every cooling trick in the book I stumbled on the cause. If you have a fiberglass six pack hood like mine and it does not have a rubber seal (like the factory hoods) on the underside of the hood that mates with the rad support, hot under hood air will come out from under the hood and will be sucked back through the rad and will be heated up more and then back out and back through the rad and eventually the car will overheat. I temporarily used foam pipe insulation held onto the rad support with zip ties. What a drastic improvement. Give it a try it's a cheap test. Good Luck
 
Do NOT RUN A 160 stat....put a fan shroud on... And I have some of that water Wetter stuff..I dont think it works...mine has run 210 while driving and at idle...But i had a lil too much of timing for mag heads...and I have a UDP.. Try a stock Crank pulley on the street then the UDP on the track
 
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