My Chargecooler Impeller...

[Harald/Austria]

Good Evening,

 

I was doing my Chargecooler Impeller today ... see how it was look like - there was all blades gone.

 

What makes me wonder is that the Impeller Housing isnt all round look at the Picture on 

12o  Clock Position. Are this just Lotus Tolerance or is it a bad part from Factory ?

 

Regards

 

Harald

[Bibs]

It's "eccentric", that's how it's meant to be. 

 

You'd be much better off going to an electric pump as most people do but either way make sure you give the system a very, very good flush to get the old, disintegrated blades out if you can.

[glynherron]

Been playing with mine today and starting to reassemble the engine when a though occured to me as to why these impellors fail.

According to the manual, when working on the timing you have to back up 90 degrees. Well the rubber impellor doesnt enjoy going backwards and puts a lot of pressure on it.

This could be a mode of failure...

Glyn

[ramjet]

Eccentric as Bibs said is normal. You are absolutely correct Glyn. The impeller is not designed to go backwards at all. There is a part pf me that would suggest removing the impeller to do the timing and then reassemble once done. A pain, but..........

[glynherron]

I pulled the pump out of mesh with the drive ☺

[ramjet]

Same effect and easy solution.

 

Saves breaking the pump open.

[lotus4s]

When changing a timing belt, the belt should already be disengaged from the pulleys when you rotate the engine back 90 degrees. The impeller should never be rotated backwards....

[Chillidoggy]

What's the speed range of the impeller?

[Zolder]

What's the speed range of the impeller?

As it runs off the redundant distributor shaft, I have always assumed one revolution of the pump equals one engine revolution..... I might be wrong though.....

[glynherron]

When changing a timing belt, the belt should already be disengaged from the pulleys when you rotate the engine back 90 degrees. The impeller should never be rotated backwards....

Correct!

However there may be occasions when it is accidentally rotated, for instance when loosening the crank pulley bolt...

[Escape]

As it runs off the redundant distributor shaft, I have always assumed one revolution of the pump equals one engine revolution..... I might be wrong though.....

 

In a 4-stroke, the distributor and camshafts run at half the engine speed (pulleys twice the size), so the impeller should be rated to about 4000rpm.