39 replies to this topic

[REDA9X]

more than likely a GMC one with pressed metal fins. ask for a pic of the back

[Dr Terry]

Hi Guys.

The pump pictured on ebay is a GMB brand, but with the 2 outlets on the passengers side it is really only correct for ADR27A motors. i.e. LX/HX/HZ/VB 7/76 onwards.

Dr Terry.

[Dangerous]

I wouldn't use anything other than one from a GMH dealer. I think maybe they aren't oem these days, but at least they have some sort of quality control. Most of the aftermarket stuff has too much clearance betweeen the rotor and body, and allows water/coolant to cavitate and blow back.

[makka]

bursons also sell the ones with a cast iron impeller

[REDA9X]

The Holden ones are not the old cast type anymore I'm lead to believe. I was told by someone you can still get cast impellor types from Repco and other places. If I was buying one, I'd be looking for one of those. I'll get a pic tonight to show what I mean.

[makka]

if he replaces the impellors, does that mean that he could reco an original waterpump with the bearings and stuff from a new pump? that could be a solution for people who want to stay original

[REDA9X]

this is the rear of an original Holden V8 pump with the cast impellor

[MustardGTR]

this is the rear of an original Holden V8 pump with the cast impellor

 

I bought a 308 water pump with a cast impeller and noticed the blades had a curve in them like a real process water pump. At first I thought this was a improvement from the flat blades I remembered in the past, but now I have a suspicion it is wrong impeller for the direction of rotation of the crank.

 

Can anyone tell me:-

 

1. the direction or rotation of the 308 crank, and 

2. are curved impeller blades common these days with replacement water pumps?

      

[Shiney005]

When looking from the front of the car it spins clockwise. (Anticlockwise from the drivers seat.) 

I haven't seen curved blades on a cast impeller before.

[MustardGTR]

Okay, I ordered a water pump to suit 253/308 1969-1984 from EBay and being a GMB cast impeller (70 sold to date) it thought I had done the right thing - too easy!

 

Problem is the impeller blades are apparently curved in the wrong direction for normal vee belt arrangement and rotation of the crank. (i.e. Holden 308 - clockwise [CW] from the front of the car or counterclockwise [CCW] from the driver's seat).

 

Below is a photo of the curved blades including my mark-up of blades from the back.

 

In the normal vee belt set-up the impeller will turn CCW as viewed in the photos. This arrangement represents a centrifugal pump with so called "forward curved vanes" and when similar discussion come up on the interweb (viz. SBC, serpentine belts, etc) this scenario gets poo pooed every time. Some even suggest it can even reverse the normal flow of coolant between motor and the radiator.... 

 

Anyhow, there's probably a truck load of these installed in 253/ 308's by now so it would be interesting if anyone has been through this or has experienced some mysterious symptoms since fitting a similar pump. I will be writing to the supplier, but before suggesting someone may have dropped the ball it would be good to get some feedback.

 

Also just wondering if the latter models have serpentine belts with pumps running in the reverse direction? 

 

     

 

    

 

  

 

      

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[Shiney005]

To me it looks right. But I don't know anything about hydrology so I'll keep my head down at this point.

[Cook]

I bought a GMB one for my 253 but can't seem to find the part # at present.  Anyway it's in and only been running for a couple of months but haven't had any noticeable overheating problems.  The one I got does, from memory look a bit different to the one in the photo as the backing plate (or whatever its called) covers virtually the whole of the base of the pump casing and I might be wrong but I don't recall seeing any noticeable curves in the blades. 

[koalasprint]

Yes, looks like the curve on the vanes are backwards. Compare with this pic. Found at this link. https://www.globalsp...pumps/impellers

Rotation from the drivers side is anticlockwise as above.

 

I bought a GMB. I thought it was a Chinese knock off because it has a stainless steel pressed impeller. It had GMB cast into it though and the casting looks good. Anyway I wrote to GMB. Still bloody waiting. Probably work ok on a stock motor. I think they have different levels of pumps, Blue, Gold, etc. But I won't buy GMB again and this pump won't be going on my motor. I'll be on selling it. $35 plus postage if you are interested.

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[oh five]

Hi Steve, I have a GMP cast alloy impellor pump on my 370 cube hyd roller Holden that made 540HP and have never had a problem with it overheating in Sydney traffic. 

Edited by oh five, 16 March 2018 - 04:20 PM.

[Ice]

Great i just bought one havnt even taken it out of box will do tomorrow
i bought the V8 Commodore long snout one

[MustardGTR]

Gene's GMB pump - V8 Commodore long snout with cast impeller - straight vanes.

 

Also interesting to note the backing plate covers the entire back of the pump. 

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