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Where to get an impeller for 1990 70 hp engine

Hi racerone.
Your probably right there. I'll look into getting some brass to give it a go. I'll have to get some solid rod so I can drill the key way, so I hope that does not blow the cost out the window, but I'll definitely give it a go. I like the idea of a knurled finish as that would be easy to do and it would increase the strength of the bond by a huge amount. Thanks very much for your help and input!
I'll be sure to keep the thread updated with my progress.
Best regards,
Scott.
 
If folks can not get an impeller from the factory and you explain your -----------" quality replacement "------------Then money won,t be an issue up to a point.---------------Not everyone is a " Wallmart shopper "
 
You're probably right there too. I certainly don't mind any extra work involved too make sure the product is the best it can be and if I manage to buy the brass rod in long lengths, I imagine the price difference would not be over the top for each unit by the time I cut it down to 20mm pieces. I'll get some firm prices for brass rod tomorrow and pick up a knurling tool (any excuse to get another tool for the lathe).
Thanks again for your input.
All the best,
Scott.
 
I just looked at Ebay for some rough prices of brass rod and I would estimate an increase of $5 per unit to manufacture. That is certainly an option to make the core better than the original unit. I'll pick some up and turn them tomorrow.
All the best,
Scott.
 
Could not find any brass in my area at a decent price so I have some being sent to me. It worked out cheaper to get it delivered from the other side of the country than to get it from the nearest industrial area. The knurling tool is on the way too. It's killing me waiting for it to arrive, but I have some carbon fiber work I've been procrastinating with so that job is finally making headway. There's always something to keep me busy.....
 
TNT delivery tried to drop of the brass rod yesterday but I was not home. I went to them to pick it up but the driver was still on the road. I left them with permission to leave it at the door if I'm not home so I should get it sometime today. The knurling tool arrived so I can make a start on the brass cores today or tomorrow. I'll post some pictures of a core once complete.
The bottom half of the pump case is coming along nicely with a better water flow from the inlet up to the impeller. The existing lower half was picked up from the Engineer and he's done a great job of refacing it. Now I know the casts I make with be perfectly flat and smooth.
Best regards,
Scott.
 
I managed to pick up my brass rods today as you can see.


tDSSu.jpg

Two 500mm long brass rods.


They have to be solid so I can cut the key way. I'll dock them down tomorrow to fit in the lathe and I might get a chance to turn one to show you. No promises as I'm getting dragged into the last minute rush for Christmas but I'll try my best.
If I get the chance, Ill post a picture of the core after the knurling has been applied.

Thanks for reading this post and stay safe over the Christmas period.
All the best,
Scott.
 
I got stuck into the brass rods this morning and while it took a great deal more time to turn, the results are good. It was suggested by racerone that brass might be a better option compared with delrin so this is what the core will look like before the impeller veins or fins are bonded. The first one took nearly two hours to sort out the best tools and methods but the second core took an hour. I had better get the time down a lot more than that or it will not be worth making them. I have used a cross hatch knurling tool on this unit but maybe a deeper cut with a straight knurling tool would be better. I have ordered one regardless. I also turned a reduced section in the middle to give the fins a better mechanical key.

Q29er.jpg
 
Hi kimcrwbr1.
Yes, that is the impeller. I was hunting for one six months ago and could not find one. After doing the rounds I found one in a boat shop in Perth gathering dust. As it was new, I made a cast in silicon and made some spares for myself. Word got out and I started receiving orders. To be blunt, the early units that I made were awful. I was given the wrong materials for the cores, the blades and the wrong epoxy. It was a nightmare that I don't want to repeat. I nearly threw in the towel but I found a different supplier that actually knew something about the materials I needed. I talked to some Engineers and finally received the information I needed to make these impellers the right way. It's been a long and rocky road.
Anyway, sorry to wander off track, but those are the same impellers. If you need one, I would grab one of those quick smart as they are getting few and far between. I plan to sell mine for around the $55 mark but I want to run one of these brass cored impellers in my own engine for a while before I release them.
All the best and have a safe and Merry Christmas.
Scott.
 
Todays work on the impeller.
I made another mold from a new impeller and used urethane as the impeller veins. Usually the units would be pigmented black but I wanted to see if there were any air bubbles in the mix so I left it clear. After vacuuming the urethane and then curing it under pressure, there are no voids at all. I will wait a day or two before I pull the urethane from the core and apply the epoxy.

OxOxl.jpg


Best regards,
Scott.
 
I too have a Nissan 50c what I did was buy a Jabsco profile k impeller impeller number 4568-0001-p from wEst marine and took it to my friends shop and honed it out approx 30,000 and it works great Good luck
 
Scott I'm glad to see you are using new core material and better rubber. I would definitly like to try the new ones. Just advise when they are sent, I still have the two housing you sentrom before. Thanks
 
Hello Oldbert.

I'll be sending you two units soon. I still have plenty of material to make some more cores so that will be todays job. The impeller I made yesterday will be ready for epoxy today or tomorrow and then I can try it in my engine. That will give me the all-clear to send yours. I'll be sure to lets you know when they have been sent.

Best regards,
Scott.
 
Hello Oldbert.
I managed to finish one of your brass cores today and started the second one but I pulled the pin early as it got to 108°F and a bit steamy in the shed. Tomorrow will be hotter but we are due for a thunderstorm later in the day so that will cool things down enough to do some more work.
I'll post some pictures for you once I have finished both cores.
Best regards,
Scott.
 
Well, I got out of bed early to get some work done before the heat. I managed to finish the cores for Oldbert so they are ready for putting in the molds.
As for my test unit, I peeled the urethane off the brass core ready for epoxy. I guess I could chemically etch the brass before applying the resin so I might go ahead with that as it takes little time and it will add even more of a key for the epoxy.
I was assured by the salesperson that the epoxy will not come off the brass with a sledge hammer, even without knurling, but after my last embarrassment, I'm not chancing anything.
Here are your two cores Oldbert awaiting their urethane fins.

x8VCA.jpg
 
No problems Oldbert.
I'm hoping to get the urethane fins on today all things being good.
Best regards,
Scott.
 
I wanted to test the bond on the cores with Delrin so I rigged up a test. Nothing elaborate but it should suffice for the purpose of the exercise.
As you can see, weights on the end of a piece of wire and the impeller held with vice grips. Very, very basic.
Anyway, here are the results.

wCyMP.jpg

2.kg or 5.5LB

NJUQr.jpg

5kg or 11LB

GBzjj.jpg

7.5kg or 16.5LB

Separation occurred at 10Kg or 22LB where the epoxy actually separated from the urethane, not the Delrin which was a surprise. The impeller blades did not break under this weight, they just pulled away from the core. There was a bit of a bouncing effect when releasing the weights so that obviously would not help matters much so all up I'm pretty happy with the results. The forces were in tension which is the worse possible scenario, but the impellers will be applying shear on the core and there will be a much greater surface area so I am not worried about these units thank goodness.
With these results, I'll probably still produce an impeller using Delrin as a core but there will be an option to pay more for brass if the customer wishes.
Well, that's todays update. I hope everyone has a happy and prosperous New Year and please stay safe over the Christmas holidays.

All the best,
Scott.
 
I have been working on making a better mold over the last couple of days and with that comes heaps of curing time. I cast the first copper cored unit yesterday with black pigment in the urethane so these are as the units will be sold. Everything went well and all the joins where the two halves of the mold come together line up perfectly. There is a bit of flash along the join but that can be eradicated by tightening the side plates of the mold. All up, a great result! I have the second impeller curing so I should be able to knock out one a day until I make some more molds. My compression tank has room for about 8 molds so I'll make a few more so I can cast some impellers and pump cases at the same time.

PFtKw.jpg


I have started a Facebook page on the advice of my plastics supplier. He said I should as it will broaden my contacts. I will start posting pictures of my finished products on there as well as take on other commissions.
All the best and thanks for reading the thread.
Scott. (karbonwerx on Facebook)
 
I have finished working on the lower half of the pump so they are now ready for molding. I have posted information about them on my Facebook page (karbonwerx) and here are some pictures. The lower part that holds the double sided seal has been machined to suit and 'off the shelf' seal and the top has been machined back 5mm and refaced so I can make a urethane plate in lieu of the stainless steel unit, as these are getting hard to find.

XINvo.jpg

The machined lower half of the pump.

SYwiH.jpg

The new plate that sits between the lower half of the pump and the impeller. It will take the place of the stainless steel unit.

Sorry that both units look like a patchwork quilt but I have been using different materials for filling and sculpting.
All the best,
Scott.
 
I just pulled out a copy of the top cover after making a new mold. I also made another new mold of the rubber tube that fits into the cover to connect onto the lower end of the water pipe that leads up to the engine. I have used a very stiff urethane and turned the inside of the cover to match the same diameter as the stainless steel cup that would usually fit into it. Now that the impeller runs directly against the urethane cover and as both units are made using urethane, the wear will be minimal as urethane has a self lubricating quality, especially when urethane is run against urethane. There will be very little friction and therefor little heat between the impeller and the cover. No more stainless steel cups required! :)

fAtvq.jpg
 
I just pulled out some casts for the lower section of the pump. I cast them in clear with no pigment so I could see if there were any air bubbles caught in the urethane, but there were none at all. I cast the lower half because the stainless steal guide plate that the impeller sits on is listed as no longer available as well as the double sided seal that keeps the gearbox oil away from the pump water. I have made an integral plate using urethane and I milled my master unit so I could fit off-the-shelf oil seals into it. I'll post some pictures here so as well as my Facebook site at Karbonwerx. So that completes the whole water pump now including;

1. Pump cover with the integral pump cup.
2. Rubber bung that goes into the pump cover called the seal rubber lower, water pipe.
3. Impeller with Acetal core and brass core with new keys for both models (M70A and 70A2).
4. Pump case lower with integral guide plate and revised oil seals.
 
Here are the pictures of the parts for the lower pump unit. I have cast them in clear as you can see. I have only just pulled them from their molds so please forgive me for leaving all of the left over flashing on them. I will remove all of the flashing before testing the unit.

UlmyE.jpg

The underside where the new oil/water seal will go as the original double sided seal is no longer available from Tohatsu.

XhMDU.jpg

The top face of the unit. This face shows the water galleries and this is the side that will receive a gasket prior to the next piece being placed above it.

FZNVn.jpg

This face is the mirror image of the one above as it will come together to form one single unit. This thin section has the integral urethane guide plate built in so there is no need for the stainless steel guide plate that is no longer available from Tohatsu.

ldgvq.jpg

This is the face that the urethane impeller will run against.
 
Scott, that really is some terrific work going on over there. Thanks for all the updates on here also as i dont use facebook. The brass hub is a great idea, but we should note that the stock impeller from tohatsu is not brass, not sure what it is made of but either way it looks like you got it all figured out.
 
Hi Jermbos.

Thanks very much for the feedback. I greatly value your input and comments. My Facebook page basically says the same thing here but I also include other projects I am working on. One project is for an ink press where the letter stamps are no longer available, so a client has given me some originals that they want me to recast for them. I'm not sure if I have posted pictures on Facebook yet but that will be soon. I'm also doing some carbon fiber work but that is not on Facebook yet as I'm still making the fiberglass molds. The Facebook page is really just for showing clients how varied my work can be and what I can take on. I love restoring old parts to new condition as I have a love affair with old machinery, so the thought of helping someone get them working again is a great inspiration for me. My page is 'Public' so I'm not sure if you have to actually use Facebook to log onto my page. I have not been using it for very long so I'm not really sure. This is the link. http://www.facebook.com/notifications?id=292823397429965#!/pages/Karbonwerx/292823397429965
You are right about the brass hub. I have two original units here and they are made from a material similar to Acetal, possibly Nylon. The only way I can find out is use my plastics identification chart, but some of the procedures are damaging to the plastic so I worked my way down the chart until I got to a procedure that would damage the impeller and then stopped. After that I started asking the professionals. Most of the units I make have Acetal (Delrin) as their core as shown in the pictures during the stress test. I used Acetal for the test as it has the worst possible surface for bonding to. The Epoxies worked well with Acetal so the brass will be even better. I started making the brass cores as racerone mentioned that it might be considered superior to the Acetal so I offer both. Unfortunately, the stock brass material is very expensive so I have to charge more for the brass cored units. The price jumps from $55 for the Acetal to $85 for the brass cored Impellers.I
just received a new knurling tool today so I will be able to apply a straight, deeper knurl to the brass and the Acetal cores. I've been waiting on that tool so I can make a better core before I start sending them out. I know Oldbert has been waiting a long time for his and I have had the core here with the cross hatched knurl, but I have been holding back waiting for this new knurling tool. Sorry Oldbert. I'll be making your new cores today and the urethane impellers have been sitting for a while so I can get them off in the post either tomorrow or the next day.
Well, that's my spiel for today. Sorry to be a bit long winded. I have to go and pick up some parts another client wants me to make for his old tractor and then I'm back here to do some turning on the lathe.
Thanks to everyone who has been keeping up with the progress and I hope the New Year is treating you all very well and finding you in great health.

Best regards,
Scott.
 
I have just started listing my items on Ebay but at the moment you will need to click on the Worldwide option to see them I can't seem to make them come up on the first screen. The only item I have not listed is the lower half of the pump as I have not tested it yet, but I am fitting one now so hopefully I will have some results soon. My eBay name is redscott33. Thank you all for your time.
Best regards,
Scott.
 
Hi Jermbos.
I'm afraid not. I put the lower half of the pump in for testing and I decided to give the leg and lower leg a birthday present which includes a rub down and respray.
I'm spraying the lower leg tomorrow and I also have to make a gasket that goes between the leg and the engine, then I'm off for a test run. I've marked the gasket onto a sheet of gasket paper so I just have to punch it out and install it. Other tasks like making a new workshop and keeping stocks running has slowed me down, but the real killer this year has been the eight heat waves we have had! No air conditioning has really slowed everything down.
I'll make sure I leave the results here. :)
Thanks for asking.
All the best,
Scott.
 
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