I am in the process of preventative maintenance on my 84 qv Mon. I am now looking at the water pump and thinking a change may be a good idea, although I have not experienced any problems so far. I am considering changing to an electrical pump, the costs are similar and I am being convinced by the sales pitch, they are a better bet. Has anybody had any experience good or bad with these things?
Good day Philip, Ensure that your electric pump can meet the necessary coolant flow rates. I seem to remember a thread not too long ago where someone had determined that the electric pumps were not up to the task... Cheers, Sam
the EWP's with an issue on flow are those rated with a 'free flow' rate and are the ones that replace the factory unit with an electric one in it's place. in the case of our Ferrari's no body makes a bolt on pump like that. you have to use an in-line pump and those are rated at very high flow rates. i'm currently designing a plate to bypass flow on the stock water pump and use the meziere pump. it's flow rate is 55gpm with a 3k hour life span. the cost of converting to the electric would be in-line with a new stock pump or one of nicks rebuilt beefier units. for stock motors the EWP isn't going to really gain you anything, better fans and a new rad would be better spent money. for those going down the SC install and motor modifications than the EWP becomes a worthwhile project. I'll keep the group updated on the progress.
A few Lotus guys went to an electric pump. A few thoughts: You'll be drawing more amps. Be sure this is okay on the alt. as well as the rest of the wiring. You don't have a dedicated belt so you'll have to keep the pully. What internal parts you keep and lose will need to be worked out. Flow rate, as mentioned, needs to be adequate and you'll have to fabricate a mount and the plumbing. This could get complicated. Won't be cheap, or original. On the plus side, you can get a thermostatically controlled pump and dial in the engine temp. which is neat, but you'll have a non original dial in the cockpit. And they are more reliable than a belt driven mechanical pump. In the end, I doubt it will be worth the expense but you'll never have a WP worry if go this route. Ken
Ken's right there are pluses and minuses to the swap. for the 'kit' i'm developing it would retain a idler pulley so that you can retain the original belt. for the purist this is probably not the route to go. the pump would be located at the radiator and would need some welding or drilling to mount the brackets. another thing to consider. for track cars and those modifying without concern to originality than this probably isn't an issue. a temp switch can be added quite easily as well and due to it's location it would have it's own harness. the stock 65amp alt would need to be upgraded to at least 90amp I went to 110amp. ideally it would have a variable flow rate, slower when cold and faster when hot. a programed temp curve would handle that nicely with at least a failsafe. this of course adds cost to the final price. I figure you're looking at around $750 for a correctly done conversion. the upshot is the life expectancy would be a min of 5yrs and replacement pumps are around the $300~$350 mark. for track guys I'd suspect they'd want a programmable temp curve to match conditions. yet another option. mods that bring the future to the past. we'll cal it a 'resto-mod'
this is why an electric pump can very beneficial. the flow should be dependent upon the temp not engine speed, that way it can be more efficiently controlled.