Hot Rods 383 Stroker - Overheating - Water Pump?

I've got a '64 C20 that I've put a 383 Stroker in. The block is a '89, but I've got a belt system of ~'77 vintage. There is a serpentine belt for the alt and water pump (CW rotation) and a V-belt for the pwr steering. This is the setup that came with the truck...and worked.

I've been battling an overheating problem for over a week now. I have a new radiator and cap (16lb). I've taken the thermostat out. I most recently put on a new water pump (NAPA 58-147). I took the old one (which was working when I dismantled the motor) in and matched it to this new pump for the alt/pwr bracket mounting points

The antifreeze is not circulating - that's the problem. It's the cause that's proving tough to diagnose. With the new pump I thought it would be a slam dunk for a fix, but antifreeze is still not circulating. To check the pump I disconnected the heater hose going to the heater directly from the pump and stuck it in a container - so this hose comes directly off of the pump. I used an old hose and attached it to the heater connection and put it in the container as well just in case I got back pressure through the heater core. Started the engine and nothing was pumped into the container - bone dry.

So, my questions are: this is a good test to see if a water pump is pumping...right...I should see a steady stream of water through the hose coming directly from the pump? If so, I'm suspecting that this water pump rotates CCW 'cause there is not a drip coming out of the hose. Anyone know if this water pump has two version (CW and CCW) 'cause it has all the mounting point on it for the alt and pwr steering brackets that are needed for this belt setup? The NAPA folks can't tell me for sure what the rotation on the pump is or if there's another rotation version. I know this particular pump was used up into the mid-late 80s which is after the full serpentine belt system that use CCW rotating water pumps became popular...I think.

Thx,
-mark

 

If the water pump pulley is smooth ( no grooves ) then you need the reverse rotation water pump.
Easy to have this issue, both pumps look the same...
Dave

 

I agree with Dave, Check to see if you have the correct rotation pump for your set up. Most serpentine are reverse rotation.

 

Re: hose from heater. Did you use the hose on the pressure side or the vacuum side? If you used the vacuum side it would pull air and the pump will cavitate. Hence no flow from the hose into the jug.

 

Dave,
There are grooves on the pulley. The belt is flat and was referred to as a serpentine system...I guess for that reason. This flat belt goes to the Alt and water pump - and of course the crank. The pwr steering belt is a V-belt - it also goes to the water pump and crank.

This is part of my question - I don't know what year of pump to get for this setup. NAPA can't tell me if this pump is CW or CCW nor can they tell me if there are even 2 versions of this pump. They want me to tell them what year of truck it's for and I don't know 'cause this belt system didn't come on the truck in '64. All I know is that I need a CW rotation on a pump that look exactly like the one I've got. That's the dilemma. I'm hopin' someone out there knows if there two version of this pump and what year of truck I can use to get the right one. The one I've got was spec'd from a '77 Chev 350 2wd truck. Did they use CCW water pumps in '77?

 

Actually post a pic would be the best thing, for safety when ordering a pump say a 95 chevy truck w 350 for counter rotation and a 75 chevy truck w 350 for standard rotation. but if you post a pic of belt routing I as alot here can tell you right off what rotation pump you need.

 

handyandy289,
There is only one heater hose port on the pump other than the main radiator inlet and return. The heater return line goes to the intake manifold. My massive powers of deduction lead me to believe that one port is the pressure side and that it ought to be kicking out a steady stream of water any time the pump is turning as long as there's a supply of water on the inlet side (the radiator is new and full of water).
Given the clarification to the situation, would you agree with me that water should be flowing into the container or am I still missing something?
Is there a better way to test a water pump? I thought about taking the back of the pump off and looking at the impellers and I may still do that. The NAPA guy wasn't to keen on that idea...given that I'll probably be bringing it back in for exchange.

 

Sorry you got it backwards ! The heater hose port on the pump is suction, the one on the intake is pressure .

 

If it was me, I'd swap the alternator and put conventional pully on everthing, seeing how you have a new pump. Also make sure the lower radiator hose in not colapsing. They must be fairly rigid with a wire spring like insert inside them, or else they pinch off the flow.

 

I think intake gasket water jacket ports have to match direction of water pump flow.

 

Is the water pump pulley turning in the same direction as the crank pulley?
If it is you need a standard rotation pump.

If the pump is turning in the opposite direction from the crank you need a reverse rotation pump.

 

The belt system you describe is probably 86 or 87 which is std rotation. What happened to the original water pump? Which head are you using? Intake? Vortec intakes had coolant restrictors on the gaskets. peace

 

You guys are great, thanks for your help.

I thought I had narrowed the overheating problem down to the pump, but that's not a sure thing at this point and I don't think it's likely, but my little pump test wasn't effective. I've learned that the heater core feed-hose is out of the intake not directly from the pump, which make sense given that you want send the warmest water to the heater.

I have RHS heads on the motor and a Weiland Action+ intake. I've talked to the motor builder yesterday. He's sure there's no blockage in the heads. Specifically, he said it would be hard to f**k that up on Chev small block.

I know I need a water pump that rotates in the std direction, the same direction as the motor. I'm just not 100% sure the of the rotation of the pump I've got. I left the original pump as a core for the new pump, they were identical casing.

I'm going to test the coolant flow at the upper radiator hose, which was suggested. If there's no flow (which is likely) I'll take the intake off and see what I can learn from that.

I've put a lot of time and money into this truck with a new motor, trany, front Xmember, rear end, disk brake upgrade & new brake lines and booster. I thought I had all the tough stuff done. It's frustrating to hit a wall with this overheating problem when it's so close to being on the road.

Thx.

 

Maybe mark the pulley on the pump with an arrow, then pull the pump off and see if the fins on the propeller are angled in the correct direction.

 

From what I can figure a NAPA 58-147 is a reverse rotation pump.
It is the same pump listed for my '86 4.3 V6 engine and that was reverse rotation.

The same style casting for standard rotation was used on '76 and prior sbc trucks.
Napa number would be 58361.

 

Obviously your engine builder has not dealt with any 400 smallblock Chevy engines if he told you it would be hard to screw the coolant flow up in a sb .Use the wrong gaskets is all it takes to do this so I would be questioning his building skills on the whole dang job.

 

if you want to you can take off the lower radiator hose at the rad.and stick it in a bucket of water,take off upper hose and aim it away from anything you dont want to get soaked ,remove thermostat if you havent already and start the engine.if pump is working youll know.fastest way to be sure is remove the rear cover on the pump and check the impeller direction.also never run a sbc without a thermostat,the engine needs to get to 190 degrees to make power,also with no therm,which is a restriction the coolant cant spend enough time in the heads and block to absorb the heat.if the engine didnt require one g.m. would have saved millions of dollars by not installing them.

 

Dumb question,,,Is the radiator clogged,maybe a rag stuffed into the lower opening and forgot about ? Worth a check

 

I experienced this same problem a few years ago on my son's camaro, first check and make rotation is correct.. if so the problem I found after beating my brains out and going crazy I had a flash back to my high school auto shop days when we actually rebuilt a water pumps, I noticed the gap between the impellor (sp) and the pump body looked too wide out of a hunch I looked up the gap in an old 55 chevy chiltons manuel and it said it was to be .010-.015 thousands I had damn near .060. So I got 2 feeler gauges .010 each and pressed the shaft thru to bottom out the impellor on the feelers and presto ...problem solved. The pump was cavitating and not moving any water, and this was a brand new pump? Lunch whistle must have blew I guess

 

It can be stupid stuff: Case in point , I had just freshened up a nasty SBC for my '61 Impala and put it in with fresh 4spd etc etc. Ran super, hauled ass, but every now and then it would just overheat out of the blue, sometimes every time you drove, sometimes not...so after starting diagnosis by pulling hoses to check for flow(all new parts everywhere and no reverse shit to worry about) it ended up being when NAPA had delivered my new radiator hoses someone elses small bottle of Grape air freshener spray slipped into my lower hose...the hose was put on without checking for said Grape bottle( I check every time now) and it was acting like a check valve...sometimes it would just be in the hose somewhere allowing enough water to pass to cool just enough, then sometimes I guess it would get cockeyed or pushed up against the inlet of the waterpump stopping flow and overheating.....pulled it out and all was good...But missed driving to The Roundup in Austin due to that little piece of shit....

 

Alright, just as a sanity check ('cause my fluid dynamics aren't so good), what direction does this pump rotate?

 

Looks like a counter rotation, wrong unit for your application. but I can be bass akwards at times...

 

Needs to turn CCW when viewed from the front(CW from the back).

Normal direction with V-belts is CW from the front.

 

Yup, wrong pump!
Use NAPA 58-361.

 

Model A Vette,
Hey, I noted your original post and went and picked up a 58-361. It's a rev rotation as well. It's a different casting #, but essentially the same pump. Heres a pick - the 58-361 is on the left.
Do you have any other clues for the std rotation version of either of these pumps? The one I had mounted is a 58-147.
Is there a web site listing these, I've been out to Cardone, but the number I'm not sure all the numbers cross to Napa's.

On Monday I'll be down at NAPA trying to find one, so any clues would help.

 

Just get a pump for a 75 chevy truck w 350 it will be standard rotation.

 

58-134 is for a 69 Camaro - definitely NOT reverse rotation!

The www.napaonline.com pictures show similar photos for both pumps.

I did some more research and I think I misled you on the 58-361. It is indeed a reverse rotation pump. Sorry.

The 58-134 should get you what you need.

 

The prob w/ getting any water pump is that the belt system I've got uses bosses on the water pump for the alt and pwrstr brackets. Not all the pumps I've looked at have them. 58-134 doesn't, the pumps called out for the 75 chev truck doesn't either.

I made it into Napa before they closed and got with a knowledgeable parts guy - at least experienced with finding parts. He thinks he's found one that matches the water pump casting I've got, a new one: 43-099. It says in the description that it's a std rot pump. The image looks like it will work (if it was the right picture). This pump was used on 77-86 C20's and a bunch of other GM vehicles in and around those years. I hope it's the right one.

Of course, it won't be here 'till next Tuesday.

 

Forgot to add my thanks for your help and to wish you all a Happy New Year!

 

It is the same pump(1986 Blazer 5.7) I am using on my 82 Corvette motor in my 47 COE Chevy. Here is a pic of mine with the alt/ps brackets installed.