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The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Scale Model Gas Engines - Hit & Miss - Throttle Governed - Non-Compression – etc => Topic started by: MadeForThat on November 04, 2022, 07:24:49 pm

Title: Re: Holt H75 water pump repair
Post by: RedRyder on December 13, 2022, 04:28:47 pm
Thank you...!!!
Title: Re: Holt H75 water pump repair
Post by: MadeForThat on December 13, 2022, 10:56:52 am
You will want the 3x6x2.5
Title: Re: Holt H75 water pump repair
Post by: Fullraceflathead on December 13, 2022, 10:48:58 am
That's great I'm glad to see we have drop in options that are reasonably priced
Title: Re: Holt H75 water pump repair
Post by: RedRyder on December 13, 2022, 08:05:54 am
Quote from: MadeForThat on December 12, 2022, 09:46:26 am
Ended up ordering 2 of:
https://a.aliexpress.com/_mLhbId8 they delivered quick and you only really need 1 for the water facing bearing. I got a second as a spare, but with how quick these shipped and delivered I don't think it was really necessary. Will be throwing it in someday soon.
...

What size did you order?
I will likely need to do the same.

Gil
Title: Re: Holt H75 water pump repair
Post by: MadeForThat on December 12, 2022, 09:46:26 am
Ended up ordering 2 of:
https://a.aliexpress.com/_mLhbId8 they delivered quick and you only really need 1 for the water facing bearing. I got a second as a spare, but with how quick these shipped and delivered I don't think it was really necessary. Will be throwing it in someday soon.
Title: Re: Holt H75 water pump repair
Post by: wbernhard on November 18, 2022, 01:31:07 pm
To avoid rust in the cooling system, I filled all of my liquid-cooled engines with Glysantin antifreeze. In addition to stainless ball bearings, there are also ceramic ball bearings, which are a bit more expensive.
Title: Re: Holt H75 water pump repair
Post by: Fullraceflathead on November 09, 2022, 12:13:53 am
There is such a thing as stainless steel ball bearings you might be able to find a stainless steel ball bearing in the proper size for that application
Title: Re: Holt H75 water pump repair
Post by: MadeForThat on November 04, 2022, 09:29:18 pm
You know you are totally right! My only fear would be the pump having too much resistance for the oring drive belt, but that can be fixed.
Title: Re: Holt H75 water pump repair
Post by: Stoker on November 04, 2022, 09:07:22 pm
Perhaps consider abandoning ball bearings and use brass or bronze sleeve bushing for that application.
Title: Holt H75 water pump repair
Post by: MadeForThat on November 04, 2022, 07:24:49 pm
Heya all, while attempting to run this engine recently I noticed my whole water system was starting to rust. Naturally galvanic corrosion is working quick in these engines, even if you are using DI water. What it looks to have killed was the inside bearing of the water pump, and then spread little ball bearings through the water system (that all turned to rust) one plugged my radiator exit so no water was flowing, so I am glad it had a separate ignition issue that got me looking it all over.

Not sure how I will keep the bearings from corroding, or if I should just plan to drain it every time. Might try to get some heavy grease and an oring