View Full Version : Electric water pump setup on late c20xe, advice needed
t45_ste
17-10-09, 05:21 PM
Afternoon all
Im thinking about doing away with the belt driven water pump on my late c20xe and opting for an electric pump.
The reason for this is that the engine will be revving to 9.1k and ive heard the standard water pump can start to cavitate at higher revs, also i hope to gain a litlle bit more power due to not having to drive the pump. I know lee303 has had success on his 1600 and 1800 engines.
Ive noticed on SBD's website that their 290bhp engine isnt running a water pump, seee pic below. Obviousley their using a shorter belt but other than that i cant see any differance on the engine i.e an added idler.
http://www.sbdev.co.uk/Taper%20Kits/New%202.0L%20Taper%20Kits/2.0L%20TP%20kits%206th%20upgrade/Peter%20Hayter%27s%202.0L%20VX%20engine%20March%20 2007%20(9).gif
Ive tried re-creating this and the belt misses the top left idle due to it being taught around the bottom idler.
Can anybody suggest a way i can get round this?
Ive also thought about machining all the inners out of the pump and just keeping the pulley, would this work or would it still be sapping a bit of power?
Thanks for any input http://www.migweb.co.uk/forums/images/smilies/beer.gif
if you machine the innards out of the pump, where are you going to fit the electric one?????
getting a shorter belt is actually fairly easy, you need to run a piece of string round the pulleys & measure the length, then go & ask a nice motor factors man to let you loose with his stock of gm belts.. if this fails, find a decent engineering supplies firm & see if they can get you a belt, you might be surprised....
or ring sbd.........
Jon_nova1
17-10-09, 07:52 PM
Doesn't the pump get mounted on the bottom radiator hose anywy? also don't forget to take the termostat out
I believe he has a belt, but it's missing one of the idlers. It's possible SBD moved one on their engine? or used a smaller lower idler.
Rick Draper
17-10-09, 08:54 PM
Call SBD Ste?
electric water pumps dont have much "life" in them.... so a rather expensive mod for little gain imho
750mc hot hatch racing boys were using them...
trouble is that the QH (also gm genuine) water pumps have crappy impellors and cause cavitation.
for power gains, turning off the alternator on full throttle will do more, but i'm not sure about the necessary coolant flow/pump requirements/placement for an elec one...
the flow abilities are fine, its just they are ****ing unreliable :(
stu, there are loads of really good dc pumps available, but the car tuning ones seem crap... there was a company doing australian ones a few years back.. are they the crap ones????
ive seen a central heating pump adapted to fit ;)
the craig david ones are cak (Think its dawes craig or what ever tweeks sell)
Some yank stuff listed in the GM sport compact build book are worth a punt
ive seen a central heating pump adapted to fit ;)
they weigh a fooking ton!
yes but they are reliable lmao
t45_ste
17-10-09, 10:49 PM
Ive looked into the davies craig setup, think thats what lee303 is using. Dont think he's got any complaints?
Machining the inards out isnt a problem, will this still sap a litlle power?
I have been given the belt number for the belt required, just cant think of a way in making it fit (ie without leaving out the top left pulley) and looking at that photo i cant see whats changed, may have to give SBD a ring.
As for cutting the alt, done and done:)
t45_ste
17-10-09, 10:50 PM
I believe he has a belt, but it's missing one of the idlers. It's possible SBD moved one on their engine? or used a smaller lower idler.
Sorry missed this post, smaller idler may work. Thanks :)
Sorry missed this post, smaller idler may work. Thanks :)
No worries, is just a pure guess looking at the problem though lol Can you tension the belt somewhere other than the water pump? Just thinking it might cause problems with the belt tension effectively shortening the route it takes? And obviously you're removing the normal tensioning point.
Might be possible to remove that idler entirely and run an even shorter belt though, as it's probably there to make sure the belt wraps around the cam pulley well enough, after going round the water pump which is a little further out than the crank pulley.
@ mk999 - Dont it tention by a tensioner? I dont know bigblocks so im just looking.
@ mk999 - Dont it tention by a tensioner? I dont know bigblocks so im just looking.
Maybe but they do have an 'optimum' point which is normally marked, they hold a decent amount of tension as the belt goes round, but they need to be sat on that midpoint to stop it 'bottoming out' somewhere. If you've ever looked at one while it runs it flickers about.
t45_ste
17-10-09, 11:05 PM
The belt is normally tensioned by the water pump yes. Lee303 has suggested making the bottom idler eccentric to get the tension.
The belt is normally tensioned by the water pump yes. Lee303 has suggested making the bottom idler eccentric to get the tension.could you not get and already eccentric tensionor off another engine
t45_ste
17-10-09, 11:14 PM
could you not get and already eccentric tensionor off another engine
Elaborate................... lol do you know of an engine that already uses an eccentric pulley?
Elaborate................... lol do you know of an engine that already uses an eccentric pulley?
IIRC my 1.6 8v ones are but have a locating plate in them which slots into the block? Could probably be fiddled with?
vaux v6 ones are. theres sheet loads. id do a scrappy run and rob a load of eccentric ones and find one that works for you, then buy a new one
t45_ste
17-10-09, 11:38 PM
thank yaw :thumb:
just dont use the 8v small block one as its utter turd, even when new lol
just dont use the 8v small block one as its utter turd, even when new lol
Never noticed a problem with mine? Whats up with them exactly?
Never noticed a problem with mine? Whats up with them exactly?
Ever had an engine on the dyno with the cambelt cover off?
even with a brand spanking new auto tensioner the belt danced all over the place and you could see the tension going mad
Ever had an engine on the dyno with the cambelt cover off?
even with a brand spanking new auto tensioner the belt danced all over the place and you could see the tension going mad
stu, surely a fibre reinforced rubber belt would jump about under normal circumstances, let alone on a dyno
Ever had an engine on the dyno with the cambelt cover off?
even with a brand spanking new auto tensioner the belt danced all over the place and you could see the tension going mad
Have noticed that yeah, but didn't think much of it tbh, can make the tension go up/down by spinning the cambelt by hand, would have thought it would dance around a bit when it's putting x Nm of torque through it every other millisecond.
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