Water Pumps......CW vs CCW

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Doppleganger

Full Access Member
Joined
May 24, 2019
Posts
11,796
Reaction score
54,545
Location
OH-MI: Just like it sounds
First Name
Chris
Truck Year
1985
Truck Model
K20
Engine Size
5.7
IIRC the older drive belt driven motors had a water pump that spun one way, and the serp belt driven pumps spun the opposite? Is there a physical difference (maybe a cast number or design) that differentiates the two?

My truck is an 85, but the motor is a '97. Its going to be serpentine belt driven. The guy who built it put a new pump on it - he's kind of hard to get ahold of and not 100% sure he'd remember anyways - just want to know I have the correct water pump.

THX
 

Vbb199

B-rate Hillbilly Customs
Joined
Jan 12, 2018
Posts
8,875
Reaction score
14,901
Location
Salisbury NC
First Name
Vince
Truck Year
89, 79
Truck Model
89 Suburban R1500, 79 C10
Engine Size
350, 502
Reverse rotation for serpentine

Standard rotation for v belt I believe

At least in most cases.
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,127
Reaction score
24,038
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
The impeller is the biggest difference.

Externally, the standard rotation pump has an accessory mounting lug on the driver's side, for the v-belt style power steering pump. The counterclockwise rotation pump does not have the accessory lug and will interfere with most (or all?) factory serpentine style accessory brackets if it did.
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,127
Reaction score
24,038
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
Shown here is a standard rotation pump, with accessory mounting lug that is interfering with a 'Vortec' style bracket. The picture is kind of crappy.

You must be registered for see images attach
 

Doppleganger

Full Access Member
Joined
May 24, 2019
Posts
11,796
Reaction score
54,545
Location
OH-MI: Just like it sounds
First Name
Chris
Truck Year
1985
Truck Model
K20
Engine Size
5.7
EXACTLY what I needed! Thanks much!

Best pic I could find.....I will arse-ume that since the vortec AC bracket fits fine, I have the serp style pump?

You must be registered for see images attach
 
Last edited:

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,127
Reaction score
24,038
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
EXACTLY what I needed! Thanks much!

Best pic I could find.....I will arse-ume that since the vortec AC bracket fits fine, I have the serp style pump?

You must be registered for see images attach

Yep, that's the correct vortec style pump too. Threaded stub for a cooling fan hub, larger bolt pattern for the pulley, and two formed heater hose outlets. The extra outlet gets plumbed to the front water crossover in the intake, since the water bypass is not made into the block.
 

gmctrucks

Junior Member
Joined
Feb 10, 2011
Posts
1
Reaction score
0
Location
Houston, Texas
First Name
Roland
Truck Year
1993
Truck Model
1500
Engine Size
5.7
Since we’re talking about water pumps I put a high volume pump on my 93 truck it does put out more water and it can be rebuilt but it’s lasted a LONG time.
 

Vbb199

B-rate Hillbilly Customs
Joined
Jan 12, 2018
Posts
8,875
Reaction score
14,901
Location
Salisbury NC
First Name
Vince
Truck Year
89, 79
Truck Model
89 Suburban R1500, 79 C10
Engine Size
350, 502
Since we’re talking about water pumps I put a high volume pump on my 93 truck it does put out more water and it can be rebuilt but it’s lasted a LONG time.
I couldn't help but notice you joined in 2011, and this is your first post lol
 

scrap--metal

Full Access Member
Joined
Sep 15, 2021
Posts
678
Reaction score
1,266
Location
MN
First Name
Calvin
Truck Year
'85, '81
Truck Model
K10, K20
Engine Size
305, 350
I couldn't help but notice you joined in 2011, and this is your first post lol
Lol. Welcome @gmctrucks. Don't be a stranger.

Also, do yourself a favor and get a square body. Or two!
 

Forum statistics

Threads
42,183
Posts
910,811
Members
33,676
Latest member
jodygraham64
Top