WTF...Water Pumps!
05-29-2009, 01:45 PM
#46
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Well, I just had the very first Lasco pump I installed seize on a stroker motor, while on the dyno. The car has a few hundred miles on it...no signs of problems. Huge squeal from the belt area. Temperature went nuts, instantly! Got it shut down and the belt took a beating, but hung in there. ...
Well, I just had the very first Lasco pump I installed seize on a stroker motor, while on the dyno. The car has a few hundred miles on it...no signs of problems. Huge squeal from the belt area. Temperature went nuts, instantly! Got it shut down and the belt took a beating, but hung in there. ...
05-29-2009, 01:50 PM
#47
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Randy I had a car I bought with a "blown engine" that had been driven across a bridge, in heavy traffic, probably the equivalent of a mile ... the belt was shredded, half the belt was missing all along its length, only teeth remained on the other half ... but it did not break. Pump was totally seized. Not one vlave bent, and didn't skip a tooth. What happened there, was a seized pump. WHere the belt tension system gives in, THERE is your real danger. So as long as tension is maintained, the seized pump won't kill the motor.
05-29-2009, 01:52 PM
#48
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05-29-2009, 01:58 PM
#49
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I'm thinking about putting in an air cooled 2-stroke engine. That way I won't have to worry about the water pump or the 2/6 rod bearings anymore.
The more power the engine makes, the faster it and the water pump are accelerated through the RPM range at full throttle. Accelerating cams that have more lift, and stiffer valve springs, at a faster than stock rate, is harder to do, and puts more strain on the timing belt. It also puts more sideways force on the water pump pulley.
The more power the engine makes, the faster it and the water pump are accelerated through the RPM range at full throttle. Accelerating cams that have more lift, and stiffer valve springs, at a faster than stock rate, is harder to do, and puts more strain on the timing belt. It also puts more sideways force on the water pump pulley.
05-29-2009, 02:00 PM
#50
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05-29-2009, 02:09 PM
#51
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Here is a crazy idea for those of you which are ok with changing the original components.
Pull the guts out of the water pump completely and shorten the timing belt to work without it. Remove the air pump and replace it with a water pump driven off of the auxiliary belts. Plumb the new pump to the engine as needed.
I'm sure pumps can be purchased which offer similar flow and pressure capabilities. Someone can fabricate a new bracket for the pump. This would also make it easier to offer a pump with higher capacity to handle the higher loads generated by the turbo's, superchargers and strokers.
Pull the guts out of the water pump completely and shorten the timing belt to work without it. Remove the air pump and replace it with a water pump driven off of the auxiliary belts. Plumb the new pump to the engine as needed.
I'm sure pumps can be purchased which offer similar flow and pressure capabilities. Someone can fabricate a new bracket for the pump. This would also make it easier to offer a pump with higher capacity to handle the higher loads generated by the turbo's, superchargers and strokers.
05-29-2009, 02:36 PM
#52
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What is most interesting about this is that the pump seized. Ceramic face seals do sometimes leak in short order -- I found this to be the case using this type seal in an industrial application in the past. For anything that is manufactured there will be some(hopefully small) failure rate of new parts. Seizure is completely unacceptable though. IMHO this is most likely either a grenaded bearing or hard debris in the coolant path. If I were a betting man I'd put odds at 100:1 in favor of the former.
05-29-2009, 03:09 PM
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05-29-2009, 03:40 PM
#55
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ugggg. I've got a rebuilt porsche pump ready to go in... Now I'm contemplating swapping my old pump in too. Seems if there was a way (there's always a way) to drill (or mill) and cross pin the impeller shaft to the impeller, it would eliminate the impeller coming off the shaft at the very least.... I sure as hell don't want to grenade an engine which I am putting so much time into...
05-29-2009, 04:09 PM
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05-29-2009, 04:40 PM
#57
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So, here's an update. The water pump started turning normally, once the engine cooled down. Perhaps I should just pretend that this never happened and just reuse the pump? Not!
We had been running it, but not super hard....never above 6,500. Oil temp and water temp low/normal. Big fans blow lots of air, on the dyno. Trying to do a bit of airflow research. The engine had been turned off for about 10 minutes, while we changed the air flow meter. The noise occurred on restart....but only above 2500 rpms...I think the belt just slipped without making noise, below this.
This might suggest that the water pump could have heat soaked and perhaps allowed the bearing to migrate in the housing? There is one thing that you can be sure of....I'll find out.
We had been running it, but not super hard....never above 6,500. Oil temp and water temp low/normal. Big fans blow lots of air, on the dyno. Trying to do a bit of airflow research. The engine had been turned off for about 10 minutes, while we changed the air flow meter. The noise occurred on restart....but only above 2500 rpms...I think the belt just slipped without making noise, below this.
This might suggest that the water pump could have heat soaked and perhaps allowed the bearing to migrate in the housing? There is one thing that you can be sure of....I'll find out.
I helped someone replace a WP on a 944 that had apparently siezed. I removed the WP and found a piece of some kind of spring wedged between the impeller and WP housing. Once freed, the pulley turned just fine, like nothing had ever happened. Your situation made me think of this.
BTW, I installed one of 928 Int'ls "new" Laso's and have put several hundred miles on it so far without issue.
05-29-2009, 04:46 PM
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Leslie, what happened to the billet pump project your guys were working on? I never saw the conclusion to that thread...was the idea scrapped? Just asking, not criticizing...
Steve
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05-29-2009, 05:18 PM
#59
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Damm that sucks.....the good news is Doc shut it down in time to save the $troker!!!
So it appears the best solution is a new design pump....either something custom billet with a larger-stronger bearing....or remove the belt driven waterpump altogether and fabricate a electric pump.....the electric pump does have many advantages....mostly being able to control the flow amount based on heat...vs flow determined solely by engine RPM.......so you could get max flow at idle if needed?
So it appears the best solution is a new design pump....either something custom billet with a larger-stronger bearing....or remove the belt driven waterpump altogether and fabricate a electric pump.....the electric pump does have many advantages....mostly being able to control the flow amount based on heat...vs flow determined solely by engine RPM.......so you could get max flow at idle if needed?
