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12a Rebuild: Rotor Housing condition question - water passages

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Old 06-07-14, 08:47 PM
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12a Rebuild: Rotor Housing condition question - water passages

Continuation....

I acquired two used housings with good chrome.
After cleaning the first one I noticed a rough area and some slight missing metal between the two water jackets. Images attached.

What should be my level of concern?

I did do a a through check of the second un-cleaned housing for similar conditions, but could find none.

Opinions welcomed.
Attached Thumbnails 12a Rebuild: Rotor Housing condition question - water passages-inside-nick.jpg   12a Rebuild: Rotor Housing condition question - water passages-nick.jpg   12a Rebuild: Rotor Housing condition question - water passages-rough.jpg  
Old 06-07-14, 08:55 PM
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The corrosion in water galleries is not bad and will be ok to use them , is caused by bad coolant and or bad earth cables ,Just make sure you keep coolant fresh and add some extra earth cables from engine to body
Old 06-08-14, 07:04 AM
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Thank you.
My original housing are missing significant chrome, but have none of the corrosion.

I'll make a point of making sure the ground wire is clean at both ends.
Old 06-08-14, 02:11 PM
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you may wanna look at the spark plug bosses and exhaust ports for pitting, but other than that those are ok. the water seal lands are the critical parts
Old 06-08-14, 08:31 PM
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Originally Posted by j9fd3s
you may wanna look at the spark plug bosses and exhaust ports for pitting, but other than that those are ok. the water seal lands are the critical parts
Will do.
I cleaned the other one today. I did not see anything unusual, but will double check.
Old 06-09-14, 05:49 AM
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Sorry to kinda jack the thread. But does anyone know what would be the best way to clean water passages that have rusted slightly more that the above pics? Would be for a display piece :P Haha.
Old 06-09-14, 06:43 AM
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Originally Posted by JSmall
Sorry to kinda jack the thread. But does anyone know what would be the best way to clean water passages that have rusted slightly more that the above pics? Would be for a display piece :P Haha.
From my previous thread.....

Quote:
Originally Posted by Jeff20B View Post
Fine brushes. Also a dremel with a small round brass brush. Or just get out what you can and don't worry about it. It's just a residue that won't really hurt heat transfer. Think about how thick and gross that was before you cleaned it, and it came out of a running engine that didn't overheat. You'll be fine.
Old 06-09-14, 09:42 AM
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Spray with engine degreaser and then clean with high pressure water
Old 06-09-14, 12:17 PM
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Ah sweet as thanks guys Must of missed that other thread aye Tim :o haha.
Old 06-09-14, 02:43 PM
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If Tim doesn't mind another hijack on his thread, I'd like to get the expert's opinions on whether this 12A rotor housing is reusable.

It has an excellent chrome finish, no flaking at all, but there was corrosion throughout the cooling passages in the engine which at one point ate into the septa between the coolant channels in one of the housings.

If this were your 12A rotor housing, would you use it to build an engine?

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Thanks for the post Tim.
Old 06-09-14, 07:59 PM
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Ray,
Not at all.
Thanks to you and others for your help.
Housings cleaned and put to bed until needed.
Attached Thumbnails 12a Rebuild: Rotor Housing condition question - water passages-dscn0878.jpg   12a Rebuild: Rotor Housing condition question - water passages-dscn0888.jpg  
Old 06-10-14, 10:21 AM
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Originally Posted by ray green
If Tim doesn't mind another hijack on his thread, I'd like to get the expert's opinions on whether this 12A rotor housing is reusable.

It has an excellent chrome finish, no flaking at all, but there was corrosion throughout the cooling passages in the engine which at one point ate into the septa between the coolant channels in one of the housings.

If this were your 12A rotor housing, would you use it to build an engine?





Thanks for the post Tim.
Yes you can use if you have it welded up and block back with mill or file
Old 06-10-14, 11:55 AM
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Welding could distort the metal right there. What would be gained anyway? I'd use it as is. I'd also check the spark plugs and exhaust port castings for leaks(pitting) like j9fd3s said.
Old 06-11-14, 10:20 AM
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Originally Posted by Jeff20B
Welding could distort the metal right there. What would be gained anyway? I'd use it as is. I'd also check the spark plugs and exhaust port castings for leaks(pitting) like j9fd3s said.
I have done it many times and got no distortion and motors have been running for many years since . When you cant find good housings sometimes you have to find a way to make them serviceable
Old 06-11-14, 10:55 AM
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My first impression when I saw that erosion in the septum was it was trash but maybe there is a way to reconstruct that part, kind of like a dentist reconstructs a tooth.

But then when I got to looking at things, I noticed the septum doesn't really do a whole lot, since the water passage opens up into a common channel in the iron anyway. The erosion in the septum just makes it open up a little bit sooner. I don't see how this could hurt, so I'm with Jeff on this one.

In other words, I think I lucked out and got a really nice 12A rotor housing out of a very heavily corroded 12A. And other rotor housing is in similar condition, but with less severe erosion in the water channels - both have excellent chrome. The Rotary Gods have been kind to me lately.
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