March performance vs cvf pulleys on 340

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71DodgeDemon340

71DodgeDemon340

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Hey everyone, i guess im on a aluminum kick now lol. When i first built my demon we used factory pulleys as i was on a budget, i used factory water pump, crank and alternator pulleys to free up some cash for other parts that were more beneficial to the extra green backs. I had to install i believe a march performance power steering pulley on my federal pump because i could not get the pulley to budge off of the old one, so i already have my power steering pulley in aluminum but was thinking of swapping my crank, water pump and alternator pulley to the aluminum so they will all match. Any pros and cons of the march vs cvf? I still need to measure my pulleys to make sure but i believe my crank is 5-1/4, the water pump pulley is 6-1/2 and the alternator pulley is 2-3/4. I know the cvf will probably be cheaper but i have the march power steering pulley and would like them to match. Also i know the crank and water pump pulleys are just a matter of unbolting and bolting but the alternator is a factory replacement one with the pulley that came with it, whats the easiest way to swap the alternator pulley? Thank you for any guidance
 
Ok so i just went and measured, right now my alternator pulley is 2-3/4”, my march power steering pulley is 7”, water pump pulley is 6-1/2”. My crank pulley has two different diameters, the outer groove for the power steering is 7” same as the power steering pulley, my best guess the inner crank pulley groove is 6-1/2”. So my power steering and water pump is driven 1:1. According to march their water flow setup the crank and water pump pulley are both 6-1/2” and the performance setup the crank is 5-1/4” and the water pump is 6-1/2”. So on the performance setup the water pump And fan spins slower which may affect cooling correct? No issues with overheating and i just installed a milodon high flow water pump and high flow t stat last year. Temps reach maybe 190 in the summer and stay at 180-185 in the cooler weather, also have a fan clutch as well.
 
Walllace racing blower ratio calculator shows you are going to be running the water pump and fan 19.23 percent under-driven. I recommend a good aftermarket waterpump, either a flow cooler or one th eductile iron impeller one and to macke sure the rest of the cooling system is up to snuff.
 
Garrett Ellison said:
Walllace racing blower ratio calculator shows you are going to be running the water pump and fan 19.23 percent under-driven. I recommend a good aftermarket waterpump, either a flow cooler or one th eductile iron impeller one and to macke sure the rest of the cooling system is up to snuff.
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I filled in some more info and my actual pulley specs in post 4. Thank you for taking the time to calculate it.
 
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Garrett Ellison said:
Walllace racing blower ratio calculator shows you are going to be running the water pump and fan 19.23 percent under-driven. I recommend a good aftermarket waterpump, either a flow cooler or one th eductile iron impeller one and to macke sure the rest of the cooling system is up to snuff.
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the power steering would be under driven as well. 5-1/4” to 7”
 
Unless yall can convince me the aluminum pulleys are a good idea i may just swap the alternator pulley and maybe the water pump pulley and leave the crank pulley alone. It is painted black which looks pretty good as is and blends in with the dampener. If i did just the alternator pulley and water pump pulley it would give it a nice balance since the power steering pulley is already aluminum.
 
25 percent underdrive power steering, which is doable. But I generally don't like under driven water pump pulleys and will be the last person to try to convince you that it's a good idea. The 19.23 percent was for the an using 5-1/4 crank, 6-1/2 water pump pulleys.
 
Garrett Ellison said:
25 percent underdrive power steering, which is doable. But I generally don't like under driven water pump pulleys and will be the last person to try to convince you that it's a good idea.
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thank you for your honesty, so my crank needs to be at least a 6-1/2 to match the water pump pulley at a 6-1/2 as well to keep it 1:1 which i agree makes a lot more sense not to stress the cooling system.
 
So where does the aligning issue come from? Are they not made exactly to match the factory spec or is it just variance from engine to engine that makes it a issue for some but not for all?
 
Water pump standard vbelt alum pulley from March needs needs to come out another 1/16 to line up with March crank pulley...had shim outwards...kinda thought since it was sold to me by them as a matching set it would line up...Nope!!!
 
Mtrhead said:
Water pump standard vbelt alum pulley from March needs needs to come out another 1/16 to line up with March crank pulley...had shim outwards...kinda thought since it was sold to me by them as a matching set it would line up...Nope!!!
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i agree! Is it possible that the variance could be in the water pump shaft between different brands?
 
If I were going after market, the CFV wraptor eight rib serpentine set up is the best set up I have seen, as it uses a heavy duty eight rib belt and runs a 22-1/2% overdrive ratio to the water pump pulley (IIRC, I had to call tech support after noticing the pulleys were differently sized and get the measurements and that was a while back.).
 
Thanks for the recommendation, im fine with the v belt setup just would like to add to the appearance. Car runs perfect and no issues with current setup. How much of a pain is it to swap the alternator pulley?
 
71DodgeDemon340 said:
Thanks for the recommendation, im fine with the v belt setup just would like to add to the appearance. Car runs perfect and no issues with current setup. How much of a pain is it to swap the alternator pulley?
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Not a pain at all other than driving up to the store.
Autozone should have the loaner pulley pullers in one hardcase, check the parts counter sheet they have with all the various tools they loan out. Thread the tool into the shaft end and draw the pulley off, then the reverse- draw the new pulley on. It’s easy with the correct tool. Once you have it and follow the steps you’ll see.
 
12many said:
Not a pain at all other than driving up to the store.
Autozone should have the loaner pulley pullers in one hardcase, check the parts counter sheet they have with all the various tools they loan out. Thread the tool into the shaft end and draw the pulley off, then the reverse- draw the new pulley on. It’s easy with the correct tool. Once you have it and follow the steps you’ll see.
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thats what i was thinking but figured it wouldnt hurt to ask, i looked it the alternator shaft and couldnt see a threaded hole in the shaft, ill take another look. Is there a certain point i have to stop or does the pulley go on until it stops?
 
If you have March pieces it makes sense to keep it all matching. Otherwise, the CVF has the bigger crank pulley option which is how the water pump and alt is spun faster. Their standard setup is using a smaller crank pulley, thus underdriven water pump and alt
 
71DodgeDemon340 said:
thats what i was thinking but figured it wouldnt hurt to ask, i looked it the alternator shaft and couldnt see a threaded hole in the shaft, ill take another look. Is there a certain point i have to stop or does the pulley go on until it stops?
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Best way is you have to measure things with a straight edge and draw it on till it is in line with the other pulleys you use. That’s the ideal way considering all the variation with brackets etc Trial fit and get it exact.
 
no threads in the alternator shaft

DD9E5EFA-CD47-4343-AC8D-E95772724CE7.jpeg
 
71DodgeDemon340 said:
no threads in the alternator shaft

View attachment 1715467002
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I’m going off cloudy memory :(yes no threaded shaft. But the tool they have clamps on a certain way and you draw it off and reverse the procedure. Been a couple years. I used the Autozone tool and it does the job just wish I could recall, but it was no problem. May have confused pulling a power steering pulley...I think it clamps onto the face shoulder of the alt pulley and you screw in the threaded shaft and the pulley comes off. That’s the easy. Then you take the back off of the alternator, support the other end of the alt shaft and carefully press the new pulley on.
 
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12many said:
I’m going off cloudy memory :(yes no threaded shaft. But the tool they have clamps on a certain way and you draw it off and reverse the procedure. Been a couple years. I used the Autozone tool and it does the job just wish I could recall, but it was no problem. I think it clamps from behind the pulley and you screw in a threaded bolt which contacts the shaft end.
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ahh ok that makes sense, been awhile since i pulled and pressed a pulley
 
71DodgeDemon340 said:
so you have to split the case to install the new pulley? How does the old pulley come out without separating the case?
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I'd personally use a press and a couple of plates, but you can use a split bearing puller to take one off.

I'd also heat the pulley to reinstall instead of pressing it on. Take some measurements and see how much I needed to heat it for a slip fit.
 
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