Cooling Issue
- Thread starter mopowers
- Start date
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Mopowers, looks like you have a very clean setup, and I hope you find your problem quickly and cheaply. I have pretty much the same pain in the a$$ problem. I had to check my pulleys are the same dia. as yours. I am pretty much sure I have my problem licked, my fan still spins nicely after I shut off my engine hot. So I will try to find a good unit to install on the car. Not to change the subject, but liking your fuel pump, Holley- Carter looks to be clock-able? Need one over the stock unit I have, and like the fuel pressure gauge setup.
And yet, that horse has been beat SLAP to DEATH in this thread and he still talks about removing the thermostat, and questions your fan clutch test method. Makes you just want to cut the computer off.
yellow rose
Overnight Sensation
If the water pump isn't at LEAST 1:1 with the crank it's turing TOO slow. And so it the FAN.
Speed up the water pump.
Speed up the water pump.
mopowers
Well-Known Member
I did test the clutch. It works fine. Even called Hayden since it was a prototype of the new HD shorty clutch. I thought maybe something was off with it. But it works as designed.
And wouldn't the fact that the temp cycles between 190-220 at a constant cruise mean the thermostat is acting strange, regardless of the minor idle cooling issue?
How many different diameter w/p and crank pulleys did Dodge make? The pulleys on it now are stock. Why wouldn't the stock fans spin the fan fast enough? I'm not trying to be a smartass, just asking cause I don't know. I'll look for a smaller water pump pulley or larger crank pulley.
And wouldn't the fact that the temp cycles between 190-220 at a constant cruise mean the thermostat is acting strange, regardless of the minor idle cooling issue?
How many different diameter w/p and crank pulleys did Dodge make? The pulleys on it now are stock. Why wouldn't the stock fans spin the fan fast enough? I'm not trying to be a smartass, just asking cause I don't know. I'll look for a smaller water pump pulley or larger crank pulley.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Do the gutted stat test.Yours is sticking. Might as well gut that one.
In my stash,I have about 4 different fan pulleys and at least 2 different crank size pulleys,and a big box of spacers.
I have under drive on my 360 too, same size pulleys as you, and it's fine.
Stock stuff works perfect on stock powertrains for it's intended stock-type useage.
When we hotrod stuff, we have to be prepared to un-stock it. We mod the heads, the valve timing, the CRs, the ignition timing, and the fuel system. And we put hi-stalls,and performance rear gears in it. Sometimes we add 125 or more horsepower to it, and ask it to rev 1000 rpm higher.Making power adds heat. It is the heat that makes the power, the heat of altering the engine to burn more gas. More gas equals more heat. More heat equals more power. Mostly when you are in deep, but the inefficiency at low rpm of this now H.O. engine, means it is making heat there too.
Why would we expect the stock cooling system to work.
I can't remember if you stated your cam specs of CR yet, but the stock 340 cooling system is just enough for it's 268* cam, Cr, and TC. I think it can handle 1 or maybe 2 cam sizes and a 2800TC. After that, it needs upgrades. That system is basically a 318 A/C system. When the factory installed A/C in an A-body, they upgraded the rad size, the fan, and the pump.And that was just to handle the compressor and the condenser. So that gives you an idea of the thinking involved.
If you have a 230@050 and a 3000TC, The stock system is long ago inadequate. You are on the right track with the rad, and the 6-blade, and the shroud. You already stated that you have the anti-collapse spring in the lower hose, and plenty of timing. There are only three variables left; the stat, the pump, and the fan-clutch or fan.
The thermostat is by far the cheapest to replace, the easiest to test, and the most likely culprit.
In my stash,I have about 4 different fan pulleys and at least 2 different crank size pulleys,and a big box of spacers.
I have under drive on my 360 too, same size pulleys as you, and it's fine.
Stock stuff works perfect on stock powertrains for it's intended stock-type useage.
When we hotrod stuff, we have to be prepared to un-stock it. We mod the heads, the valve timing, the CRs, the ignition timing, and the fuel system. And we put hi-stalls,and performance rear gears in it. Sometimes we add 125 or more horsepower to it, and ask it to rev 1000 rpm higher.Making power adds heat. It is the heat that makes the power, the heat of altering the engine to burn more gas. More gas equals more heat. More heat equals more power. Mostly when you are in deep, but the inefficiency at low rpm of this now H.O. engine, means it is making heat there too.
Why would we expect the stock cooling system to work.
I can't remember if you stated your cam specs of CR yet, but the stock 340 cooling system is just enough for it's 268* cam, Cr, and TC. I think it can handle 1 or maybe 2 cam sizes and a 2800TC. After that, it needs upgrades. That system is basically a 318 A/C system. When the factory installed A/C in an A-body, they upgraded the rad size, the fan, and the pump.And that was just to handle the compressor and the condenser. So that gives you an idea of the thinking involved.
If you have a 230@050 and a 3000TC, The stock system is long ago inadequate. You are on the right track with the rad, and the 6-blade, and the shroud. You already stated that you have the anti-collapse spring in the lower hose, and plenty of timing. There are only three variables left; the stat, the pump, and the fan-clutch or fan.
The thermostat is by far the cheapest to replace, the easiest to test, and the most likely culprit.
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mopowers
Well-Known Member
Do you have a picture? Where did you get your pulley set? Thanks!
I found them on ebay that had been blasted and painted. The crank is a 3 groove mopar #3614377 and water pump is single groove mopar #3462825. I have Vintage air and power steering. Hope this helps, Joe
yellow rose
Overnight Sensation
Perfect. About 16-17% over drive on the water pump.
You may have issues at engine speeds over 7000 RPM but you can use a narrower belt to keep it in the pulley.
I had this problem with a set of March pulleys on my 499" in the GTS. Crank pulley was smaller that water pump making it an underdrive. I put steel pulleys back on it. The contour fans solved my heating problems on it. These other pulleys that I gave the part numbers for are on the small block in my GT "decoy".
famous bob
mopar misfit
sucking air the wrong way can happen underneath the rad. too. look at the new cars, all of them have something underneath to stop this. I really like the front "spoilers by randy", but don`t think I could tow the car, if I needed to, w/ one on it.
mopowers
Well-Known Member
Thanks guys. I think I've got it figured out. I appreciate it.
mopowers
Well-Known Member
The thermostat solved one issue. Now I just need to find the right combination of pulleys. The problem I'm encountering is, the smaller diameter w/p pulleys I'm finding on ebay are shorter than the one I've got now. I guess I can go that route, then simply install a spacer behind the crank pulley and alternator mount. A fixed fan would solve it as well.
Anyone know a good source for a single groove pulley set?
Anyone know a good source for a single groove pulley set?
famous bob
mopar misfit
440 source ??
mopowers
Well-Known Member
Unfortunately, all they've got is the same as what I have now.
yellow rose
Overnight Sensation
If you don't want to spend the money on aluminum pulleys ( I wouldn't if you don't have to) just use a spacer behind the WP pulley. I do it all the time to get all the belts to line up.
mopowers
Well-Known Member
For the smaller waterpump pulleys out there I've seen, I'd have to use a spacer behind the crank pulley, since the smaller water pump pulleys are shorter the the one I've got. This is likely the route I'll go if I can't find a longer crank pulley.
mopowers
Well-Known Member
Post #47 Went out and took some measurements yesterday. My WP pulley is about 6-7/8 OD and my cranks pulley is 6-1/2" OD, so obviously my WP pulley is larger than my crank pulley. I am done here..........
mopowers
Well-Known Member
Yeah, I saw that. They're different than one the ones they have pictured. Go figure... You'd think they have a bit more information about their products available. I'm on the look out for one of those 3614377 w/p pulleys. I'll be able to use it with the front groove of the pulley I currently have. Thank you.
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