???....SLOW DOWN ON THE CAFFINE!  

NaughtyDodge04:
build for torque peak at rpm ya gonna cruise it at speed,is that a decent idea???

Actually it is a excellent idea. When a engine is running at its torque peak, it is at it peak VE (Volumetric Efficiency) and it will use the least amount of fuel per HP/hr under a moderate to heavy load.  What happens is things like warm cams and dual exhaust reduce lower RPM efficiency. If you want to get max MPG you should have you torque peak at say 2400 RPM and have a at least a 9 to 1 CR too. This way if you want you 2200 RPM cruise your engine will being making its best "effort" when doing it. Long ago truck motors had low RPM torque peaks and pulled well. Modern trucks are in HP wars and in order to get more HP out of any SB, you have to move torque peak to a higher RPM (HP = RPM x Torque /5252) but then you reduce lower RPM efficiency. Most diesels reach torque peak by or before 2000 RPM and HP peak by or around 3000 RPM so they do best at lower RPM MPG wise (cruise one at 3000 and watch MPG dump). Now when you take a gas motor with a 5000 RPM HP peak and a 3500 RPM (or more)torque peak, it is not going to do well lugging at 2000 or 2200.  

before you go changing all this expensive stuff, try doing small things to increase your mileage like checking your air pressure in the tires, alignment, and use good high octane gas. also, make sure the under carriage is clean of mud, it adds a lot more weight than u might think. check your carb to make sure you are not running too rich and wasting fuel. also check your timing with a timing light and set it to specs if it is not correct. these are all things that take time and not money to see an improvement. if it's an 84, look for vacuum line leaks by spraying starting fluid around the vacuum lines while idling. if the idle changes, you have a vacuum leak. also, check for good plug wires at night  by using a spray bottle with water. if your plug wires are bad, they will arc to the metal in your truck through the water spray. its like a big spark show if they're really bad. if you're truck needs a tune up, cap/rotor, etc. it will also help. check all of your ignition components for excessive wear. most of this stuff can be done at no cost. then you will have an idea of what to replace or repair to get maximum mpg's.  

wax that g-narley rascal,put the front factory air dam back on,maybe build a bed cover from plywood,ime fat so mine was a 3/4" party patio from the tool box back. run a new air filter,i put 5/30 weight in my 86 k'truckster.i was a commuter type driver so i could run a light viscosity oil,washed out the radiator fins so i got good air flow from cooling system,hence less work from engine.it would run faster than i wanted to push it,yea ime kinda nervous round 115-120 on non speed rated tires.355ci and spun 6800rpm.t 350/208 and 32.11.50s,and bodywise it was a beaten nag.Happy wheelin!  

thats funny ( im fat) how bout putting on an electric fan...  

keithpapa:
thats funny ( im fat) how bout putting on an electric fan...

Any gain from this over a good clutch fan would be marginal and at the expense of the loss of cooling capacity (a electric fan cannot even begin to move the air that a engine driven one can, to do so would take a few hundred amps at peak draw and overload electrical system.  

WOULDNT PUTTING ON SMALLER PULLIES LIKE MARCH PULLY SYSTEM PUT LESS STRAIN ON ENGINE AND SPEED UP WTR PUMP TO KEEP COOLING EFFICIANCY FASTER?  

keithpapa:
WOULDNT PUTTING ON SMALLER PULLIES LIKE MARCH PULLY SYSTEM PUT LESS STRAIN ON ENGINE AND SPEED UP WTR PUMP TO KEEP COOLING EFFICIANCY FASTER?



A smaller drive pulley on engine is going to reduce water pump flow and alternator output too at lower RPM's and engine drive fan too. As far as "strain", it is far less strain than lifts and big tires  and you need to increase cooling not decrease it.  

think about it for a sec... if putting smaller than stock tires speeds up engine rpm,right...then why would the impeller on the wtr pump slow down if you put smaller pullies on? and you have less rotating mass too and you get rid of fan clutch and install dual electric fan asm.  

Generally when you change a pulley, you change one and crankshaft not water pump ans speeding it up is not the problem and as far a dual fans, they cannot begin to move the volume of air than a engine driven one can. A engine driven ones can consume 5 to 10 HP and more at speed and while doing so move 20,000 to 30,000 CFM and more even through a radiator stack with a lot of "drag" to it as high air flow rates. It takes HP to do that and no electric fan is going to do that that draws only 20 or 30 amps. It is going to need to draw 200 to 300 amps to be able to compete with the air that a engine driven one can move. Consider this a engine making 300 HP is going to dump about 400 to 500,000 BTU thru radiator. WHen you consider the mass of air needed, this equals about 1000 to 2000 lbs of air a minute or 14,000 to 28,000 CFM. (the range is for a 67 to 35 degree rise on air temp as it flows to core). At a idle and low power a electric can keep up but WOT it cannot begin to especailly at low vehicle speeds.  

march pullies are billet machined smaller units that replace every pully even wtr pump,they speed up wtr flow and airflow of the fan at low rpms when overheating is more apt to happen.
they claim 12-15 hp gain cause of the less rotating mass and less strain would mean more mpg...
they have them for pretty much all applications (tall wtr pumps and short pmps too)  

This 12 to 15 HP gain is BS. While it takes a little more power to get a larger mass up to speed, it take not more power to keep at there once at speed. Plus this extra mass as stored energy that is transfer to crankshaft (or fan) when engine is suddenly slowed down so it is not lost. Same with flywheel, a 20 lb one will make as much HP on a dyno as a 50 lb one. People like them because it makes engine a bit quicker to rev up but it places more shock on crank shaft when you dump the clutch hard because there is less stored energy in flywheel so engine itself takes a bigger shock load.