Moparts
Which is the right water pump for my 383 Roadrunner
Posted By: Imrare
Which is the right water pump for my 383 Roadrunner - 09/10/11 09:16 PM
I have had a problem with my 383 overheating at idle. I pulled the water pump and realized the pump only has 6 blades on the impeller and is only 3.5" in diameter (A/C pump on a non-A/C car). The service manual states that a non-A/C 383 should have an 8 blade impeller that is 4.3 inches in diameter. I oredered a new water pump from Year-One and it has 8 blades and is 4.3 inches in diameter but when the new pump, on the right, is compared to the old 6 blade impeller pump, on the left (attachment), I noticed the new pump has the impeller reveresed from the old pump. I need help. Which way should the impeller face? Since the engine turns clockwise (when facing from the front) it appears the 8 blade impeller is backwards. Can someone help me on this?
Posted By: 6bblgt
Re: Which is the right water pump for my 383 Roadrunner - 09/10/11 10:09 PM
The blades move the water, the support for the blades (which are opposite in your pic) have some effect but basically do not matter.
Posted By: A12
Re: Which is the right water pump for my 383 Roadrunner - 09/10/11 10:32 PM
Are there flow ratings available for the two water pumps? Why does it appear that the A/C pump would flow less than a non-A/C pump, I would think it would be the exact opposite need. I can see that the A/C pump would have less drag or resistance than the non-A/C pump and can understand that would be important because of the increased drag of the A/C system but why such a big difference? What is the flow rate difference between the two??
Posted By: 6bblgt
Re: Which is the right water pump for my 383 Roadrunner - 09/10/11 10:54 PM
It's an engineered system (flow/volume/temperature/pressure/etc.), big radiator, higher temp thermostat, you want the water to have a chance to COOL when it's in the radiator not blast thru uncontrollably.
Posted By: A12
Re: Which is the right water pump for my 383 Roadrunner - 09/10/11 11:17 PM
Quote:
It's an engineered system (flow/volume/temperature/pressure/etc.), big radiator, higher temp thermostat, you want the water to have a chance to COOL when it's in the radiator not blast thru uncontrollably.
I thought the thermostat determined how long the fluid stayed in the radiator and the pump circulated the fluid through the engine until that time?
Posted By: ahy
Re: Which is the right water pump for my 383 Roadrunner - 09/10/11 11:49 PM
Quote:
Are there flow ratings available for the two water pumps? Why does it appear that the A/C pump would flow less than a non-A/C pump, I would think it would be the exact opposite need. I can see that the A/C pump would have less drag or resistance than the non-A/C pump and can understand that would be important because of the increased drag of the A/C system but why such a big difference? What is the flow rate difference between the two??
The AC pump is designed to be overdriven - it spins faster along with the fan. With the higher speed water flow is increased.
Using the AC pump on a non-AC car reduces cooling because the pulley set up does not spin it fast enough.
Posted By: RapidRobert
Re: Which is the right water pump for my 383 Roadrunner - 09/11/11 04:29 AM
Use the 8 blader on the R & tack weld an anticav plate behind it (between vanes/pump) & will need to cut a circular piece into 2 pieces (halves) to slip each half behind the vanes then weld them. I suspect you have more of an airflow prob &
;run the smallest WP pulley you can find/tight fitting shroud/MP thermal clutch fan spaced ~2/3 into the shroud/good aftermarket 180 stat tested in a suspended pot of water ahead of time & a 1/16" hole will help elim air pockets/easier filling/3 core rad/unobstructed air flow 2 it
Posted By: NachoRT74
Re: Which is the right water pump for my 383 Roadrunner - 09/11/11 04:56 AM
Quote:
I have had a problem with my 383 overheating at idle. I pulled the water pump and realized the pump only has 6 blades on the impeller and is only 3.5" in diameter (A/C pump on a non-A/C car). The service manual states that a non-A/C 383 should have an 8 blade impeller that is 4.3 inches in diameter. I oredered a new water pump from Year-One and it has 8 blades and is 4.3 inches in diameter but when the new pump, on the right, is compared to the old 6 blade impeller pump, on the left (attachment), I noticed the new pump has the impeller reveresed from the old pump. I need help. Which way should the impeller face? Since the engine turns clockwise (when facing from the front) it appears the 8 blade impeller is backwards. Can someone help me on this?
I'm EXACTLY wondering the same in another thread LOL.
Need to take in mind AC cars got smaller pulleys at water pump so spins faster.
I have known 8 blades on smaller pulleys can create cavitation at high rpms
Now, the doubt about blades facing opposite its still on the air
Posted By: 6bblgt
Re: Which is the right water pump for my 383 Roadrunner - 09/11/11 08:17 AM
The blades on a big-block water pump run perpendicular to the shaft, there is NO front or back by design.
Here's a picture with the "anti-cavitation" modification, does it appear to function any differently run forward or reverse?
Posted By: NachoRT74
Re: Which is the right water pump for my 383 Roadrunner - 09/11/11 02:36 PM
my initial doubt on the earlier thread I made mention was mainly because water pumps remanufacturers locally says where they are faced is important.
of course I don't trust on that or them, so that's why I wondered here
Posted By: Imrare
Re: Which is the right water pump for my 383 Roadrunner - 09/11/11 05:26 PM
6bblgt: your anti-cavataion modification was done to move more coolant, correct? However, to me it seems it shouldn't be a necessary modification required to have my OE 383 operate as designed. I've had the radator, thermostat, etc, etc, checked out and so far I have been unable to determine why I have an "overheating problem at extended idle" in very hot weather. I think I have found my problem when I discoved an A/C water pump in my non-A/C equiped Roadrunner. In fact, now it all kind of makes sense. I was just concerned when I noticed the impellers between to two pumps are reversed from each other.
Posted By: RapidRobert
Re: Which is the right water pump for my 383 Roadrunner - 09/11/11 05:33 PM
yes the anticav plate makes the impellers more eff (moves more water) but in your case if an 8 blader does not fix things (& measure the pulley dia while you're at it) then consider airflow. Good luck w it & holler (in this thread if you would) how it turns out
Posted By: 6bblgt
Re: Which is the right water pump for my 383 Roadrunner - 09/11/11 05:43 PM
The "anti-cavitation" (not mine) isn't for moving more coolant. At high speed the blades will form a "cavity" in the fluid & cause loss of flow (like a clogged snow-blower or lawnmower, still spinning but not throwing/cutting). The plate is a remedy, how well it works - I don't know.
Is the overheating a recent problem? What are the specs. of your 383 build, .060" over, etc.? Is your gauge accurate?
Posted By: Junky
Re: Which is the right water pump for my 383 Roadrunner - 09/11/11 06:05 PM
Does anyone have diameter sizes for ac and non ac water pump pulleys? That would help me know what combo I have.
Posted By: Imrare
Re: Which is the right water pump for my 383 Roadrunner - 09/12/11 02:47 PM
Junky: Non-A/C Pulleys: Water pump 6 13/16; Crankshaft 6 9/16. The service manual calls for a rotation ratio of .95:1 (Water pump vs Crankshaft). I believe these measurement come out to about .96:1 but I was measuring with a plastic ruler leaning over the grill of my Roadrunner (could have been a little off).
6bblgt: No this is not a recent issue; I've been half-heartedly pursuing this problem for the last 3 years. If you look back in the archives I have had several posts on this forum and I've tried numerous remedies. I have had all components in the cooling system toughly checked and the last thing to check was the water pump. It has not been a huge issue because my car is a show car I have been reluctant to disassemble a pristine engine compartment and unless I get caught is stopped traffic on a hot summer day, I'm fine. One other thing I am going to do is drain the block and look for any debris. If I see any debris, I may focus there to make sure I don't have an obstruction. I doubt I’ll see anything as the engine was “Hot Tanked” when it was rebuilt (bored .30 over). This whole ordeal doesn't seem like it should be that complicated, I have been assured by two different shops that the radiator is good and if the pump is working properly and there is good "flow", the system has to cool.
Posted By: savoy64
Re: Which is the right water pump for my 383 Roadrunner - 09/12/11 02:57 PM
a properly fitted fan shroud will give more cooling than anything else---bob
Posted By: RapidRobert
Re: Which is the right water pump for my 383 Roadrunner - 09/12/11 03:22 PM
8 blader/overdriven WP/more airflow
Posted By: Junky
Re: Which is the right water pump for my 383 Roadrunner - 09/12/11 04:39 PM
Thanks for the measurements.
Posted By: 6bblgt
Re: Which is the right water pump for my 383 Roadrunner - 09/12/11 05:01 PM
Quote:
This whole ordeal doesn't seem like it should be that complicated, I have been assured by two different shops that the radiator is good and if the pump is working properly and there is good "flow", the system has to cool.
Timing (too advanced at idle?) & carb (too lean at idle?) can also affect running temps. What is telling you it is too HOT?
Posted By: Imrare
Re: Which is the right water pump for my 383 Roadrunner - 09/12/11 07:49 PM
The engine is definetly overheating. The engine has been so hot in the past (from idling) that it has melted the foam steering column gasket that goes between the firewall and the base mount of the steering column, plus, like I've mentioned previously the engine begins to spark-knock and the amount of heat coming off of the engine is dramatic. It gets so hot that even with leather "Mechanix" gloves on the carb throttle is too hot to touch for very long. I haven't put a laser temp gage on the block to see what the degrees are, but belive me, it is very hot.
Posted By: JohnRR
Re: Which is the right water pump for my 383 Roadrunner - 09/12/11 07:59 PM
Quote:
The engine is definetly overheating. The engine has been so hot in the past (from idling) that it has melted the foam steering column gasket that goes between the firewall and the base mount of the steering column, plus, like I've mentioned previously the engine begins to spark-knock and the amount of heat coming off of the engine is dramatic. It gets so hot that even with leather "Mechanix" gloves on the carb throttle is too hot to touch for very long. I haven't put a laser temp gage on the block to see what the degrees are, but belive me, it is very hot.
I have seen these off and on , do you have an ACTUAL TEMP READING ??? till then you could be chasing the wrong problem.
also how long are you leaving it sitting "idling" ??? The steering column foam is being melted by the heat off the EXHAUST MANIFOLDS , not the engine itself ...
Posted By: mikemee1331
Re: Which is the right water pump for my 383 Roadrunner - 09/12/11 11:20 PM
Quote:
Quote:
The engine is definetly overheating. The engine has been so hot in the past (from idling) that it has melted the foam steering column gasket that goes between the firewall and the base mount of the steering column, plus, like I've mentioned previously the engine begins to spark-knock and the amount of heat coming off of the engine is dramatic. It gets so hot that even with leather "Mechanix" gloves on the carb throttle is too hot to touch for very long. I haven't put a laser temp gage on the block to see what the degrees are, but belive me, it is very hot.
I have seen these off and on , do you have an ACTUAL TEMP READING ??? till then you could be chasing the wrong problem.
also how long are you leaving it sitting "idling" ??? The steering column foam is being melted by the heat off the EXHAUST MANIFOLDS , not the engine itself ...
are you actually over-heating or is the 'reflected' heat of the engine your concern?
Posted By: Imrare
Re: Which is the right water pump for my 383 Roadrunner - 09/13/11 11:05 PM
My engine is overheating no ifs, ands, or buts. It's not radiant heat etc. It just slowly gets hotter and hotter if left at idle on a hot day. It doesn’t overheat if the temp is 80 degrees or less. One year at the Nationals I got caught in traffic and about burned up the engine before I could get it shut down (spark knocking, coolant overflowing, etc).
However, I am confident the incorrect water pump has been my problem all along (6 vane impeller for A/C application on a non-A/C engine). I believe when I install the correct 8 vane pump it will cool properly. It only makes sense that the engine would overheat slowly at idle with the lower volume 6 blade pump. I bought two pumps, one from NAPA and one from Year One. The year one looks to have the impeller set up for counter clock-wise rotation while the NAPA pump is set up for clock-wise rotation (they also sell the same pump for counter clock-wise rotation with an impeller that looks like the Year-One pump. For my application, I need clock-wise rotation. However, Year-One only lists this pump for the "383 - 440" application? I'm going with the NAPA pump.
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Posted By: ahy
Re: Which is the right water pump for my 383 Roadrunner - 09/14/11 12:06 AM
It sounds like a solid diagnosis and the right place to start.
If it cools ok when moving (sounds like it does) that usually means the radiator is OK. Get the right water pump and check again. Next up, if it still runs a bit warm is airflow - fan & shroud.
Posted By: NachoRT74
Re: Which is the right water pump for my 383 Roadrunner - 09/14/11 04:24 AM
Quote:
It only makes sense that the engine would overheat slowly at idle with the lower volume 6 blade pump.
as far I can tell is not about low or high volume, is related about the size of the pulley. A/C cars got smaller pulleys on Water pump, so at same RPMs will spin faster being 6 vanes
Quote:
I bought two pumps, one from NAPA and one from Year One. The year one looks to have the impeller set up for counter clock-wise rotation while the NAPA pump is set up for clock-wise rotation (they also sell the same pump for counter clock-wise rotation with an impeller that looks like the Year-One pump. For my application, I need clock-wise rotation. However, Year-One only lists this pump for the "383 - 440" application? I'm going with the NAPA pump.
This is very interesting... CW against CCW talking about same 8 vanes pump... aren't all engines with regular belts the same rotation no matter the belt setup with or without A/C ?
now there is something said by 6bblgt what is true... blades are 90 degrees, and if you install an "anti-cavitation" plate it will make work the impellers the same no matter how are cut the vanes if faced CW or CCW
Posted By: JohnRR
Re: Which is the right water pump for my 383 Roadrunner - 09/14/11 01:51 PM
Quote:
Quote:
It only makes sense that the engine would overheat slowly at idle with the lower volume 6 blade pump.
as far I can tell is not about low or high volume, is related about the size of the pulley. A/C cars got smaller pulleys on Water pump, so at same RPMs will spin faster being 6 vanes
Quote:
I bought two pumps, one from NAPA and one from Year One. The year one looks to have the impeller set up for counter clock-wise rotation while the NAPA pump is set up for clock-wise rotation (they also sell the same pump for counter clock-wise rotation with an impeller that looks like the Year-One pump. For my application, I need clock-wise rotation. However, Year-One only lists this pump for the "383 - 440" application? I'm going with the NAPA pump.
This is very interesting... CW against CCW talking about same 8 vanes pump... aren't all engines with regular belts the same rotation no matter the belt setup with or without A/C ?
now there is something said by 6bblgt what is true... blades are 90 degrees, and if you install an "anti-cavitation" plate it will make work the impellers the same no matter how are cut the vanes if faced CW or CCW
There is no factory serpentine setup for a big block mopar so I can't see the aftermarket making a CW and CCW pump , those pumps will push water no matter what direction they spin .
Posted By: RapidRobert
Re: Which is the right water pump for my 383 Roadrunner - 09/14/11 02:03 PM
Quote:
There is no factory serpentine setup for a big block mopar so I can't see the aftermarket making a CW and CCW pump , those pumps will push water no matter what direction they spin .
it's the 90 deg "paddle" that does the work & adding the anticav plate makes it a bit more efficient & is easy 2 do & reduces what the engineers call "parasitic recirculation" at all speeds and helps w cav at high speeds. It helps a little bit & is easy/cheap 2 do but mainly the others needs 2 b right (overdriven WP pulley imo) & enough airflow, adequate radiator
Posted By: RoadRunnerJD
Re: Which is the right water pump for my 383 Roadrunner - 09/14/11 02:36 PM
Hemi's came with 6 blade impellers. I would venture a guess that you have something else causing your overheating. I don't know about the orientation of the blades where one seems to be backwards? That could be a problem but it's not because you only had a 6 blade impeller. There is something more serious going on for your engine to overheat that badly.
Posted By: RoadRunnerJD
Re: Which is the right water pump for my 383 Roadrunner - 09/14/11 03:02 PM
Quote:
Are there flow ratings available for the two water pumps? Why does it appear that the A/C pump would flow less than a non-A/C pump, I would think it would be the exact opposite need. I can see that the A/C pump would have less drag or resistance than the non-A/C pump and can understand that would be important because of the increased drag of the A/C system but why such a big difference? What is the flow rate difference between the two??
I read up on this a long time ago. If you move the coolant through the motor too fast, it does not allow the
water/coolant adequate time to transfer the heat. Hemi's put
out more heat and only have a 6 blade impeller just for that
reason...to slow the flow down a little. I think Chrysler
engineers also increased the diameter of the Hemi crank pulley and reduced the diameter of the water pump pulley from 68- 69 to try to get the optimum rpm's for the water pump? I believe 383/440 HP's and A/C equipped cars had 8 blade impellers. It's a little hard to understand. On the otherhand, I would be concerned about the backwards configuration of the impeller too? It just does not look right.
Posted By: ZIPPY
Re: Which is the right water pump for my 383 Roadrunner - 09/14/11 04:00 PM
I ran a 6 blade AC water pump on the 440 that used to be in my GTX for about 14 years. The first one had 93,000 miles on it when I installed it, it started leaking about 10 years later. I replaced it with another 6 blade from the parts store.
I always used non/ac pulleys.
In 14 years, many of which were daily driven (for a few years the GTX was my only transportation) the only heating problems I ever had were due to either me not using the fan shroud, or the radiator being clogged. Even when the first water pump leaked, it did not overheat.
So I guess I don't agree with the whole diagnosis, but good luck with it nonetheless.
Posted By: Imrare
Re: Which is the right water pump for my 383 Roadrunner - 09/15/11 10:46 PM
Thanks for the encouragement Zippy I hope the correct pump solves the problem. I have heard your story before, using the wrong pump application and not having a problem. I wish that was the case with me, I hate this problem. But, if it really didn't make any difference which pump should be used, why would Chrysler go to the expense of installing two different pumps and state "boldly" in their service manual on page 7-4 "do not use a non-A/C pump on an A/C engine and visa versa"? It must make a difference or they would not go to the trouble and expense of training personnel and noting that in their manaual. We'll find out soon, I received my radiator back from Glen Ray Radiator today and they said it solid and flowing fine. So I should have it together pretty soon but if the wather turns cool I won't know if it over heats until we have a 90+ day.
Posted By: RapidRobert
Re: Which is the right water pump for my 383 Roadrunner - 09/15/11 10:57 PM
Holler (in this thread) how it turns out. Yes Ma had their recommendations on that & I'm certainly not an engineer (or even close 2 it) but I haven't seen a prob w cavitation & I gotta go w an 8 blader/smallest WP pulley I can find/fit
but I always use an added anticav plate esp on a SB
Posted By: Imrare
Re: Which is the right water pump for my 383 Roadrunner - 09/29/11 11:04 PM
RR, got the engine together last Monday afternoon. Before replacing the coolant with fresh anti-freeze, I drained the block on both sides, left the drain plugs out and ran water through it for about 15 min to be sure no obstructions existed. After filling with anti-freeze let the engine idle for about 30 minutes or so, no over heating or close to over heating issues, however, the temp in Missouri was 67 degrees...so I might have to wait until next summer to determine if changing to the correct water pump will fix my over heating problem. Good news is no leaks...I need to take her out for a drive now.
Posted By: RapidRobert
Re: Which is the right water pump for my 383 Roadrunner - 09/30/11 01:11 AM
Quote:
let the engine idle for about 30 minutes or so, no over heating or close to over heating issues,
Sounds promising Even at 67 deg I'd think after 30 minutes it'd be acting up if we were not good now
Posted By: Imrare
Re: Which is the right water pump for my 383 Roadrunner - 08/17/12 03:43 PM
Well, summer has almost come and gone. The Mopar Nationals are over and I can again turn my attention to unbolting parts off of my engine and try to fix the overheating problem. All the fixes I did last fall have had no change, the engine is still over heating at idle. The change in water pumps did not solve the issue. The only thing I can think of is that there MUST be a blockage in the coolant jackets in the block. To test this I am planning on installing a specialized part the custom rodders use called "Cool View. See it at "http://www.youtube.com/watch?v=hW7PyU-kPtU&feature=related. It is like a glass thermostat housing that will let you veiw the termostat in operation and the coolant running through it. If I don't have coolant flowing after all that I've done, the coolant blockage has to be in the block. The only other thing I can think of is if the coolant isn't flowing, maybe it could be a defective water pump housing (I've checked everything else) and maybe the coolant is just cavatating in the housing because the clearance is too great between the housing walls and pump impeller (checked the impeller blade diameter to the service manual before installing and it was correct)? I don't know, I'm trying to think outside the box here? Has anyone ever had a defective waterpump housing casting where it wouldn't let the water pump do its job? Still looking for a solution.
Posted By: 05dakota
Re: Which is the right water pump for my 383 Roadrunner - 08/17/12 04:02 PM
do you have fan shroud?
Posted By: Sinitro
Re: Which is the right water pump for my 383 Roadrunner - 08/17/12 04:04 PM
What about the distributor and timing curve...
A close friend and his 383 was overheating badly up to 225, he changed water pumps, added a shroud...
Still a problem...
I checked his Mopar performance distributor, he had
14 degrees mechanical advance...
I reset it to 10 degrees mechanical advance, set initial @ 15 degrees and fired it up..
It ran @ 190 degrees and is doing very well in our 105 degree SoCal heat wave..
Check the basics...
Mopar built a pretty robust engine and cooling system..
Just my $0.02...
Posted By: Imrare
Re: Which is the right water pump for my 383 Roadrunner - 08/17/12 04:12 PM
Quote:
do you have fan shroud?
Yes
Posted By: Imrare
Re: Which is the right water pump for my 383 Roadrunner - 08/17/12 04:15 PM
Quote:
What about the distributor and timing curve...
A close friend and his 383 was overheating badly up to 225, he changed water pumps, added a shroud...
Still a problem...
I checked his Mopar performance distributor, he had 14 degrees mechanical advance...
I reset it to 10 degrees mechanical advance, set initial @ 15 degrees and fired it up..
It ran @ 190 degrees and is doing very well in our 105 degree SoCal heat wave..
Check the basics...
Mopar built a pretty robust engine and cooling system..
Just my $0.02...
Good point and easy to check, I will definitely check that out, thank you.
Posted By: JohnRR
Re: Which is the right water pump for my 383 Roadrunner - 08/17/12 05:10 PM
Quote:
What about the distributor and timing curve...
A close friend and his 383 was overheating badly up to 225, he changed water pumps, added a shroud...
Still a problem...
I checked his Mopar performance distributor, he had 14 degrees mechanical advance...
I reset it to 10 degrees mechanical advance, set initial @ 15 degrees and fired it up..
It ran @ 190 degrees and is doing very well in our 105 degree SoCal heat wave..
Check the basics...
Mopar built a pretty robust engine and cooling system..
Just my $0.02...
Is this correct ? That would only be 25 TOTAL, I can see it running even hotter ?????
Posted By: Sinitro
Re: Which is the right water pump for my 383 Roadrunner - 08/17/12 07:24 PM
Quote:
Quote:
What about the distributor and timing curve...
A close friend and his 383 was overheating badly up to 225, he changed water pumps, added a shroud...
Still a problem...
I checked his Mopar performance distributor, he had 14 degrees mechanical advance...
I reset it to 10 degrees mechanical advance, set initial @ 15 degrees and fired it up..
It ran @ 190 degrees and is doing very well in our 105 degree SoCal heat wave..
Check the basics...
Mopar built a pretty robust engine and cooling system..
Just my $0.02...
Is this correct ? That would only be 25 TOTAL, I can see it running even hotter ?????
10 degrees in the distributor is x2 @ the crank + 15 degrees (initial)..
20 + 15=35 degrees total @ the crank.
IMHO...
One can run a little more total advance but the BB wedges don't really run that much better with more advance.
Just my $0.02...
Posted By: JohnRR
Re: Which is the right water pump for my 383 Roadrunner - 08/17/12 09:04 PM
Quote:
Quote:
Quote:
What about the distributor and timing curve...
A close friend and his 383 was overheating badly up to 225, he changed water pumps, added a shroud...
Still a problem...
I checked his Mopar performance distributor, he had 14 degrees mechanical advance...
I reset it to 10 degrees mechanical advance, set initial @ 15 degrees and fired it up..
It ran @ 190 degrees and is doing very well in our 105 degree SoCal heat wave..
Check the basics...
Mopar built a pretty robust engine and cooling system..
Just my $0.02...
Is this correct ? That would only be 25 TOTAL, I can see it running even hotter ?????
10 degrees in the distributor is x2 @ the crank + 15 degrees (initial)..
20 + 15=35 degrees total @ the crank.
IMHO...
One can run a little more total advance but the BB wedges don't really run that much better with more advance.
Just my $0.02...
Thanks for finishing that and some people in Michigan would beg to differ on the total timing for big block wedges ...