Overheating after WP replacement... Place your bets...
10-17-2010, 02:14 AM
#121
Rennlist Member
interesting. I do remember when it was talked about way back, but now we have to see if it all works. there are so many trade offs. I guess as long as the forces are known, then it can be designed to do the job. my only worry would be sheering those teeth off before there was impeller to block contact, but I guess, if the worst that can happen is that you over heat, that is a pretty decent trade off. modes of failure can be pretty bad! valves to block damage. I just pray that my pump that has lasted this long is a good one and it will only go bad by leaking some water to warn me i need a new pump. 
Now, we wait to see!
Mk
Now, we wait to see!
Mk
MK:
The pump has a rubber coupler with teeth internal and teeth external. Lives behind the metal cover that's held on with the four screws. Inside teeth connect to the center shaft and impellor. Outside teeth fit inside the pulley that the belt rides on. There's a second BIG bearing that carries all the belt pulley radial load, similar to the way an AC clutch bearing carries the belt load. Anyway, too much impellor drag will cause the teeth on the rubber coupler to shear, so the belt can coninue to turn (survive) if the impellor hits the block or is otherwise stopped while the belt is moving. The red index marks indicate the original alignment of shaft and pulley; If they don't line up the coupler has uncoupled.
Ed's design is very ingenious and might save someone a slew of engine damage if something stops the impellor. With the spate of impellor-damaed blocks it's a great bit of cheap insurance, IMHO.
The pump has a rubber coupler with teeth internal and teeth external. Lives behind the metal cover that's held on with the four screws. Inside teeth connect to the center shaft and impellor. Outside teeth fit inside the pulley that the belt rides on. There's a second BIG bearing that carries all the belt pulley radial load, similar to the way an AC clutch bearing carries the belt load. Anyway, too much impellor drag will cause the teeth on the rubber coupler to shear, so the belt can coninue to turn (survive) if the impellor hits the block or is otherwise stopped while the belt is moving. The red index marks indicate the original alignment of shaft and pulley; If they don't line up the coupler has uncoupled.
Ed's design is very ingenious and might save someone a slew of engine damage if something stops the impellor. With the spate of impellor-damaed blocks it's a great bit of cheap insurance, IMHO.
10-17-2010, 07:07 PM
#123
Burning Brakes
Thread Starter
Ok. Here we go... Pulled the timing belt, and checked out the front of the pump... Video shows that we've got essentially complete freedom of movement with no real resistance at all.
http://www.youtube.com/watch?v=AW3hgGLBPyU
Pictures of impeller seem to indicate nice fresh sharp edges.
Pictures of block show no impact or signs of foreign objects.
Coolant was clear without evidence of debris.
http://www.youtube.com/watch?v=AW3hgGLBPyU
Pictures of impeller seem to indicate nice fresh sharp edges.
Pictures of block show no impact or signs of foreign objects.
Coolant was clear without evidence of debris.
10-17-2010, 07:48 PM
#126
Former Vendor
If you look at the video it shows the outer pulley and the drive hub are spinning independantly of each othe meaning the coupler sheared.The reason why needs to be determined.
Check for debris between the impeller and the pump housing and in the 2 holes in the impweller.
Check for debris between the impeller and the pump housing and in the 2 holes in the impweller.
Last edited by OBehave; 10-17-2010 at 07:50 PM. Reason: check impeller
10-17-2010, 08:17 PM
#127
Burning Brakes
Thread Starter
If you look at the video it shows the outer pulley and the drive hub are spinning independantly of each othe meaning the coupler sheared.The reason why needs to be determined.
Check for debris between the impeller and the pump housing and in the 2 holes in the impweller.
Check for debris between the impeller and the pump housing and in the 2 holes in the impweller.
I didn't see anything in my casual inspection of the impeller (I have some other "head on" shots of it that I didn't post and they look clear). Admittedly, I didn't do a full rotation of the impeller looking through the inspection holes...
10-17-2010, 08:33 PM
#128
Shameful Thread Killer
Rennlist Member
Rennlist Member
10-18-2010, 01:24 PM
#130
Rennlist Member
Could it be that the coupling "rubber" was not enough to support the hydraulic drag of the water ? that force is pretty significant. rubber, heat, changing forces, might weaken it over time. I dont know, just tossing it out there for the design guys. How does the design differentiate from a pump spinning from 3000rpm to 7000rpm on a quick rev, vs rubbing on the block surface. i would imagine those forces would be very very similar. In fact, the force on the block (if the impleller moves inward) will be related to the force against the pulley and it will be determined by flow and rpm. Im not being critical of the design, as I havent given it much thought, but something seems intuitively very risky that this kind of failure could occur. (i.e. accelerative forces on the pump in very quick revs, with no cavitation, could equal the grinding force of an impeller that was, now lose and now grinding into the block)
10-18-2010, 01:52 PM
#131
Addict
Rennlist Member
Rennlist Member
Could it be that the coupling "rubber" was not enough to support the hydraulic drag of the water ? that force is pretty significant. rubber, heat, changing forces, might weaken it over time. I dont know, just tossing it out there for the design guys. How does the design differentiate from a pump spinning from 3000rpm to 7000rpm on a quick rev, vs rubbing on the block surface. i would imagine those forces would be very very similar. In fact, the force on the block (if the impleller moves inward) will be related to the force against the pulley and it will be determined by flow and rpm. Im not being critical of the design, as I havent given it much thought, but something seems intuitively very risky that this kind of failure could occur. (i.e. accelerative forces on the pump in very quick revs, with no cavitation, could equal the grinding force of an impeller that was, now lose and now grinding into the block)
Either way I think it is extremely important to work with Ed to determine the cause and work toward a solution. Its for the greater good of these cars and we need to support those that support our hobby.
10-18-2010, 05:43 PM
#133
Rennlist Member
No doubt, Ed knows what ihe is doing, thats why I posed the question. I wonder how that part of the pump was designed. certainly it is the only questionable part of the design, because of that element's design.
Having met Ed and knowing his background I can say that he has probably already considered the temperature and force affects on the rubber. That really leaves two options, faulty part or debris in the coolant system.
Either way I think it is extremely important to work with Ed to determine the cause and work toward a solution. Its for the greater good of these cars and we need to support those that support our hobby.
Either way I think it is extremely important to work with Ed to determine the cause and work toward a solution. Its for the greater good of these cars and we need to support those that support our hobby.
10-18-2010, 05:48 PM
#134
Drifting
If the cooling system is good,
then it is either air locking which I have seen some different models do to the degree that the front of the car had to be on a ramp and the throttle had to be WOT blurped on and off, to force the air out.
Another area is a leaking head gasket putting air into the system.
The Stat I am sure you have check 2 or 3 times.
Have you made sure that the direction of this water pump turns the correct direction.
Look at the impeller well it is off and compare it to the old one, and that the belt is routed correctly, sorry had to say it.
then it is either air locking which I have seen some different models do to the degree that the front of the car had to be on a ramp and the throttle had to be WOT blurped on and off, to force the air out.
Another area is a leaking head gasket putting air into the system.
The Stat I am sure you have check 2 or 3 times.
Have you made sure that the direction of this water pump turns the correct direction.
Look at the impeller well it is off and compare it to the old one, and that the belt is routed correctly, sorry had to say it.
10-18-2010, 05:51 PM
#135
Rennlist Member
The pump failed, it wasnt air in the system. air only makes the system heat transfer to the t-stat, flakey at best. air in the sytem is fixed by squeezing the hoses like you are milking a cow, until all the air is out through the overflow container. you feel it when its good. nothing else to do after that. just seal it up and go. you will never need to open the reservior again.
Its not usually the "stats" fault, its the water or lack of water around it so that it will open. usually, even if that is a problem, it only happens during cold start up or on a cold day. but after its warm, even air in the system can circulate the water just fine. just ask scot, who used to race on 4 quarts low after it was pushed out the overflow do to a head gasket leak. (actually planned). water still flowed until it was reallly low on water.
Its not usually the "stats" fault, its the water or lack of water around it so that it will open. usually, even if that is a problem, it only happens during cold start up or on a cold day. but after its warm, even air in the system can circulate the water just fine. just ask scot, who used to race on 4 quarts low after it was pushed out the overflow do to a head gasket leak. (actually planned). water still flowed until it was reallly low on water.
If the cooling system is good,
then it is either air locking which I have seen some different models do to the degree that the front of the car had to be on a ramp and the throttle had to be WOT blurped on and off, to force the air out.
Another area is a leaking head gasket putting air into the system.
The Stat I am sure you have check 2 or 3 times.
Have you made sure that the direction of this water pump turns the correct direction.
Look at the impeller well it is off and compare it to the old one, and that the belt is routed correctly, sorry had to say it.
then it is either air locking which I have seen some different models do to the degree that the front of the car had to be on a ramp and the throttle had to be WOT blurped on and off, to force the air out.
Another area is a leaking head gasket putting air into the system.
The Stat I am sure you have check 2 or 3 times.
Have you made sure that the direction of this water pump turns the correct direction.
Look at the impeller well it is off and compare it to the old one, and that the belt is routed correctly, sorry had to say it.