Author Topic: Impellers (Read 4379 times)

BaronYoungman · « **on:** July 04, 2020, 19:16:51 »

Here's an illustration of the impeller situation.... Outside of the old gas eating away at the vanes see picture1 then there is the part just wearing out see picture #2 and #3 for someone definitely got their use of this impeller but you can see the steel shaft hitting into the aluminum impeller even with the extra hardness of the Chrome Center eventually just causes the impeller to totally round out making it useless as the shaft spins around it, or in this case pushes it into the housing and jams it , causing it to burn out. This is the reason I went to fabricating stainless steel impellers. Just my two cents Bob

SEB · « **Reply #1 on:** July 04, 2020, 21:28:02 »

Hi Bob
since the impeller broke in my almost new pump, the subject of impellers and Bosch fuel pumps became close to me. I lost a lot of time to find a new pump for a reasonable price. I noticed that also the same situation you have in US regarding the prices.

Since this time I know how important issue is the impeller- in fact it is the heart of the fuel pump.

But as user may I ask you a question? I understand that stainless steel is much harder than I do not know if this is a pure aluminium or what material?
But is your impeller not to heavy? Did you made some stress tests?

I am asking as a potential customer.
Sebastian

Benz Dr. · « **Reply #2 on:** July 05, 2020, 00:07:14 »

I've seen pumps with brass impellers. Anyone else seen that? It was in very good condition too.

SEB · « **Reply #3 on:** July 05, 2020, 08:00:42 »

Did you have seen the brass impellers in the Bosch short fuel pump? Because to tall Bosch pump had the impeller made from brass- and as far I know this kind of pumps are more resistant, but not any more produced. The tall pump was build untill 1968 and than replaced by the short pump.

specracer · « **Reply #4 on:** July 05, 2020, 12:05:57 »

Are your impellers available yet?

Quote from: BaronYoungman on July 04, 2020, 19:16:51

This is the reason I went to fabricating stainless steel impellers.

BaronYoungman · « **Reply #5 on:** July 06, 2020, 18:05:43 »

To answer the questions yes it is slightly heavier.
But because the majority of the force is used up in pushing the gasoline the weight difference of 12 grams(58g stock vs 70g stainless) is negligible. With my testing gear I found no difference after 15 minutes of running in the volume.
As for selling the stainless steel impellers I sold out my 1st two runs ( I posted here and was sold out in 2 days)and just have a few I use for my pumps.
If I do another run I will be sure to announce here first. Bob

specracer · « **Reply #6 on:** July 07, 2020, 10:09:11 »

Darn how did I miss that? Im here almost every day, and had expressed interest a year or so ago when you were kicking around the idea. Well if you make a "list" please include me, so I dont miss out again.

Quote from: BaronYoungman on July 06, 2020, 18:05:43

As for selling the stainless steel impellers I sold out my 1st two runs ( I posted here and was sold out in 2 days)and just have a few I use for my pumps.
If I do another run I will be sure to announce here first. Bob

Garry · « **Reply #7 on:** July 07, 2020, 12:00:49 »

I am in the same boat, on here every day and also interested but must have missed the post by Bob.

Garry

mdsalemi · « **Reply #8 on:** July 07, 2020, 13:24:07 »

I see you gave up on the titanium version? Wasn't one of the originals some kind of hardened aluminum alloy?

BaronYoungman · « **Reply #9 on:** July 07, 2020, 15:46:00 »

Michael I still have one of two prototype titanium set aside for you gratis for all your help. We just haven't run into each other for me to give it to you. I just found that the titanium version was almost twice the price of stainless steel and even with the titanium being lighter than the original aluminum there was no discernible difference in the flow and PSI. So it makes no sense to do impellers out of titanium when the same results could be achieved and solving all of the deterioration issues of the original with just using stainless steel. Bob

Benz Dr. · « **Reply #10 on:** July 07, 2020, 17:42:22 »

Quote from: SEB on July 05, 2020, 08:00:42

Did you have seen the brass impellers in the Bosch short fuel pump? Because to tall Bosch pump had the impeller made from brass- and as far I know this kind of pumps are more resistant, but not any more produced. The tall pump was build untill 1968 and than replaced by the short pump.

I think it was a short pump but maybe someone changed the impeller.

BaronYoungman · « **Reply #11 on:** July 08, 2020, 01:05:37 »

Dan I have never seen one in brass. And the two impellers ( long pump and short pump) are not interchangeable. But brass is stronger than most aluminum (depending on grade) so that would make for a good idea. Most brass contains some aluminum. Bob

SEB · « **Reply #12 on:** July 08, 2020, 11:23:19 »

Hi Bob,

But what about the interaction of the stainless steel impeller with the aluminium housing. Did you made some tests for the durability of this combination? And if the stainless steel do not wipes the housing?
Thank you!
Sebastian

mdsalemi · « **Reply #13 on:** July 08, 2020, 14:00:11 »

Quote from: SEB on July 08, 2020, 11:23:19

...what about the interaction of the stainless steel impeller with the aluminium housing...

I cannot answer for Bob as to what he's done testing wise, but understand this project began in October 2017 so he's been at it for a long time.

There is a known interaction between stainless steel and aluminum, when in the presence of an electrolyte. An electrolyte is a compound containing

Sodium
Potassium
Chloride
Calcium
Magnesium
Phosphate
Bicarbonate

I'm not a chemist, but I don't believe that petroleum has this characteristic. Gasoline or petrol is a complex hydrocarbon. In our fuel pump, the impeller is bathed in petrol/gasoline.

SEB · « **Reply #14 on:** July 09, 2020, 09:04:38 »

Hi Michael
I am asking about this all details because Bob is doing a great job. I am interested to have at least one such impeller on stock (just for any case) for my cars.
Sebastian

yves · « **Reply #15 on:** July 09, 2020, 09:16:58 »

+ 1 ....!

stickandrudderman · « **Reply #16 on:** July 09, 2020, 15:01:21 »

I have two long pumps in pieces right now and both have brass impellors.
One of the failure signs is fuel coming from the small orifices in the side of the pump but I haven't yet worked out what it is internally that must fail in order for that to happen. Do you know Bob?

PeterPortugal · « **Reply #17 on:** July 09, 2020, 15:24:41 »

Colin,

If you are talking about the little pipe stub that sticks out from the side of the pump body then that is what handles leakage from the mechanical seal. The seal keeps fuel out of the motor area. Any leakage past the seal (ideally there should be none) will be routed to the pipe.

Hope this helps.

Peter

mrfatboy · « **Reply #18 on:** July 09, 2020, 15:52:49 »

Quote from: stickandrudderman on July 09, 2020, 15:01:21

I have two long pumps in pieces right now and both have brass impellors.
One of the failure signs is fuel coming from the small orifices in the side of the pump but I haven't yet worked out what it is internally that must fail in order for that to happen. Do you know Bob?

When my long pump failed, indicated by fuel leaking out of the side pump the problem was a broken 20 cent o-ring on the shaft. Replaced o-ring and pump still is going strong 4 years later. I also had to replace it 20 years ago.

PeterPortugal · « **Reply #19 on:** July 09, 2020, 16:05:11 »

MrFatboy,

You are right with that as the mechanical seal is a push fit over that o-ring.

Regards

Peter

stickandrudderman · « **Reply #20 on:** July 09, 2020, 16:37:48 »

Quote from: PeterPortugal on July 09, 2020, 15:24:41

Colin,

If you are talking about the little pipe stub that sticks out from the side of the pump body then that is what handles leakage from the mechanical seal. The seal keeps fuel out of the motor area. Any leakage past the seal (ideally there should be none) will be routed to the pipe.

Hope this helps.

Peter

Not that stub Peter, the two small holes just below the joint between the motor body and the pump body.

thelews · « **Reply #21 on:** July 09, 2020, 16:50:36 »

my long pump is brass, this one is original.

I had leakage out the vent holes and fixed it with the small O-ring on shaft.

PeterPortugal · « **Reply #22 on:** July 09, 2020, 17:05:30 »

Colin,

I thought the pipe stub was an obvious question from a man with your experience but I have never noticed the two small holes close to it before.

They seem to be lined up with the two inserts inside the pump body.

Photo attached to show the inserts. The holes are on the adjacent exterior part of the pump body.

Hope this helps you find an answer from other posters Colin.

Cheers

Peter

PeterPortugal · « **Reply #23 on:** July 09, 2020, 17:15:18 »

Colin,

Out of interest do you know anyone who can helicoil a pump body as I have made a mess of one trying to drill out sheared bolts?

Cheers

Peter

stickandrudderman · « **Reply #24 on:** July 09, 2020, 17:45:26 »

I would do it here and use timecerts, not helicoil.
As for the leaks, yes it's coming via those two inserts. I've only had a cursory glance at it (this used to be a delegated task.....) but there only appears to be the O ring on the shaft to prevent the passage of fuel. I'm sure that can't be the case and I just need to get my specs on and have another look.

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Author Topic: Impellers (Read 4379 times)