[Mr Nerv]

Ok, quick story, buying an Astra GSI this weekend, with 204 mini horses underneath its bonnet i.e. C20LET from a Cally Turbo. But it needs a new waterpump, so looking for info/prices. Is there such a thing as an uprated waterpump?

Cheerz!

 

[xx 5id xx]

dont think so. They all do the same thing!
Around £40 innit?

 

[green manalishi]

ohh, there was a waterpump thread a bit back.... all water pumps are not the same!

hold on...

 

[green manalishi]

bah, can't find it

the upshot was that there are 3(?) types, one is metal and pretty rough, another is metal and well made (the vx stock item iirc) and a third is made of resin(??)

the problem with the metallic ones is corrosion due to cavitation.

but i really can't remember the detail - although there is a difference

 

[JohnA]

see my website under 'cooling' :beer:

 

[green manalishi]

yeah, that was about the long and the short of it... avoid the folded metal ones

btw - good site that

 

[ChrisB]

£28.21 for a late type QH one (plastic impeller) from local motor factors at the weekend.

 

[green manalishi]

and no cavitation corrosion

 

[Dave Hay]

you really get cavitation on LET's cause of a water pump????

rather strange if you do!

 

[Mr Nerv]

Thanx everyone, glad I got more than 1 post! Am now looking forward to handing over my bank balance, in exchange for something that's a bit better than my crappy 306.

 

[green manalishi]

you really get cavitation on LET's cause of a water pump????

rather strange if you do!

no, you get cavitation on the vanes of the pump

 

[ChrisB]

no, you get cavitation on the vanes of the pump

I guess he meant RPM. I doubt the LET would have any major problems, but i'd go for the cast metal or plastic impeller over the folded metal anyway.

I would think/hope that idle/low rpm water flow would be better, which is the the bigger issue with a LET.

 

[Dave Hay]

cavitation is a result of a drop in pressure though??

does the water flow that quick/change temp enough??

 

[ChrisB]

cavitation is a result of a drop in pressure though??

does the water flow that quick/change temp enough??

Cavitation is caused by too high RPM of the impeller, cavities emerge (air bubbles) and essential it stops pumping and just makes a lot of turbulence.

More of an issue on high RPM (TB'ed) NA engines rather than the LET which being turbo'ed isn't really subjected to high RPM.

 

[Mr Nerv]

Went out and got a QH type today, cost just under £30! Happy with that...
(just hope it lasts for a while!)

Thanx again for all the info, another question to be addressed is in styling!

Cheerz