Author Topic: Cleaning crankcase halves?  (Read 15346 times)

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Offline skishyishy

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Cleaning crankcase halves?
« on: March 28, 2008, 03:19:35 PM »
Greetings all!

Got my crankcase split and I'm staring at the filthy halves with nothing but the crank bearings and cylinder studs intact.  What is the best way to clean these suckers?  Theres a lot of info here about engine treatments but I'm having trouble distilling it into something appropriate for the case halves only.

Can I drop them at a shop and ask them to dip them in the hot tank for a spell or is this something best handled at home?  What about removing all the old flaking paint?  I've heard mention of glass bead blasting as well?  Is that worth it?  Can any treatment be done with the bearings left intact?  Do I need to worry about my studs?

This engine is getting the full treatment and I want it to look fantastic when its done.  That means I want to remove the crappy old paint for sure. 

Can you all please share the wealth of the vast knowledge and experience here?


Offline mystic_1

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Re: Cleaning crankcase halves?
« Reply #1 on: March 28, 2008, 06:37:45 PM »
I'm in the process of reconditioning some crank cases right now myself, here's my approximate plan:

1. Soaked in engine degreaser, both halves, inside and out.  Let sit several hours.
2. Bag up parts, off to the local carwash.
3. Foam brush, pressure wash, rinse.  Be careful not to fling your parts across the carwash with the pressure washer.  Put down a towel to protect the mating sufaces.
4. Return home, dry thoroughly. 
5. Strip old paint.  Aircraft stripper works wonders, but wear gloves and a mask, this stuff is powerful.  Could have done this first, but removing crud makes stripping paint easier.  Apply stripper, allow to sit 20-30 min, brush firmly with brass brush.  Rinse.  This should get you down to bare metal.
6. Re-clean thoroughly to remove all paint and stripper residue.
7. Inspect and clean all tapped holes.  Use long brushes to clean all oil passages and galleries.
8. Inspect and clean (and if necessary, hone) all mating and gasket surfaces.
9. Send parts to be hot-tanked.  Afterwards clean with residue-free cleaner and dry thoroughly.
10. Mask and paint with two-part engine enamel.  Cure paint.
11. Final cleaning of all holes and surfaces.
12. Begin reassembly.

best of luck

mystic_1
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Offline mattcb350f

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Re: Cleaning crankcase halves?
« Reply #2 on: March 28, 2008, 07:14:08 PM »
Take the bearings out before you get at cleaning. If you're going to use the old bearings, make sure you mark them so that they go back into exactly the same spots. Don't mix them up. I would get 10 ziploc bags and put each bearing in a bag and label each one as "Brg #5 upper case" "brg #5 lower case" etc... as long as you make sure you understand where they go when you are putting it together.

The way I cleaned my cases was at a shop with a hot water parts washer. It took any grease/oil off and what was left of the paint.

Then I glass beaded the cases to remove any stuck on paint and it gave the cases a nice textured finish for the paint to stick to.

Thing to remember is: Make sure that all the oil galleries and every little nook and cranny is perfectly clean before reassembly. If you glass bead them, the little glass particles will get EVERYWHERE!!!! I must have washed my cases three or four times with hot water and soap letting the garden hose run through the oil galleries for at least ten minutes. And then did it all again over and over.

Glass bead particles will destroy an engine in seconds if they are left in there. But as long as you clean the cases properly after doing it, it leaves a very nice finish.


Here's a pic of my finished cases:


 Matt.

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Offline Steve F

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Re: Cleaning crankcase halves?
« Reply #3 on: March 28, 2008, 07:26:43 PM »
There's something about a nice, clean, freshly painted engine, sitting there waiting to be put back in the frame.  Nice job, Matt!
I TOTALLY agree with the glass beads getting in every hole and such.  That's why I'll stay away from glass beads!  I had a built (assembled) engine blasted with plastic media, and that was easy to clean up. I just plugged up the intake and exhaust ports, protected the seals around the output shaft and the shifter shaft and plugged up a few holes and I was good to go.  As far as cleaning the inside of the cases, you're best off not using any kind of abrasive material anywhere near it.  It's just too easy getting into trouble with dirt and grit.

Offline City Boy

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Re: Cleaning crankcase halves?
« Reply #4 on: March 28, 2008, 11:36:30 PM »
If you have access to a good pressure washer,give it a shot .I have a 4000 psi unit with a 13 horse Honda .Cleaned a set of 900F cases with it.Strip completely cept for cyl. studs ,hold down so water pressure doesn't blow it across yard and blast away.Nothing will resist cept solid baked on paint.It can stay.Afterwards,rough up any paint that remains and feather any transitions with a 3m pad.Fresh coat of black and they looked like new.Best feature is you can do it outside,nothing to clean up after,and no fear of abrasives lurking.Leaves the insides looking like fresh castings too.AS always,Rock On
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Offline lordmoonpie

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Re: Cleaning crankcase halves?
« Reply #5 on: April 08, 2008, 10:49:12 AM »
I vapour blast (glass beads) every time. Yes there's a cleaning overhead but the glass beads also pein the surface of the metal making it nice and shiny and it lasts too. Guess it's horses for courses though  :)
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Offline Bodi

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Re: Cleaning crankcase halves?
« Reply #6 on: April 21, 2008, 01:35:03 PM »
Wear your rainsuit and some goggles at the pressure wash bay. The assorted curves and hollows in the cases send the spray back at you at least half the time you're spraying. Alternatively, you could wear a swimsuit... or nothing... but remember the goggles, carwash soap burns like mad in the eyes.

Offline City Boy

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Re: Cleaning crankcase halves?
« Reply #7 on: April 21, 2008, 01:54:21 PM »
Touche Bodi.You ain't kiddin!!!
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Offline mystic_1

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Re: Cleaning crankcase halves?
« Reply #8 on: April 21, 2008, 01:55:24 PM »
Bring shampoo, kill two birds with one stone :)

mystic_1
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Offline City Boy

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Re: Cleaning crankcase halves?
« Reply #9 on: April 21, 2008, 09:02:21 PM »
Theres a reminder in my owners manual for boots and gloves also."Do not spray near fingers or toes,it will remove them."
'52 Kiekhaefer Mercury Rocket Hurricane KG4H
'70 750/RC 1000 Original Owner
'83 1100F

Offline WanderingWombat

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Re: Cleaning crankcase halves?
« Reply #10 on: August 22, 2013, 11:59:26 AM »
So after seeing Matts case all clean i started thinking it might be nice to do a case with a clear coat. Has anyone done this successfully?

Offline Lazerviking

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Re: Cleaning crankcase halves?
« Reply #11 on: September 29, 2013, 11:05:46 PM »
This gives me clean case envy....

Offline thirsty 1

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Re: Cleaning crankcase halves?
« Reply #12 on: October 26, 2013, 10:15:15 PM »
Take the bearings out before you get at cleaning. If you're going to use the old bearings, make sure you mark them so that they go back into exactly the same spots. Don't mix them up. I would get 10 ziploc bags and put each bearing in a bag and label each one as "Brg #5 upper case" "brg #5 lower case" etc... as long as you make sure you understand where they go when you are putting it together.

The way I cleaned my cases was at a shop with a hot water parts washer. It took any grease/oil off and what was left of the paint.

Then I glass beaded the cases to remove any stuck on paint and it gave the cases a nice textured finish for the paint to stick to.

Thing to remember is: Make sure that all the oil galleries and every little nook and cranny is perfectly clean before reassembly. If you glass bead them, the little glass particles will get EVERYWHERE!!!! I must have washed my cases three or four times with hot water and soap letting the garden hose run through the oil galleries for at least ten minutes. And then did it all again over and over.

Glass bead particles will destroy an engine in seconds if they are left in there. But as long as you clean the cases properly after doing it, it leaves a very nice finish.


Here's a pic of my finished cases:


 Matt.

+1 for the glass bead blaster. +10 It will destroy and engine seconds if its not cleaned perfectly. I'd like to add that a person needs to tap every threaded hole in the cases when your done. The beads get stuck in the threads and will gall instantly if you don't tap them out.
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Offline jsedacca

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Re: Cleaning crankcase halves?
« Reply #13 on: December 06, 2013, 04:36:05 PM »
I used a kerosene in a spray bottle with assorted brushes to clean my case halves.  Afterwards, everything was doused in carburetor cleaner, and cleared out with an air hose.  This was repeated 3-4 times for spotless halves.

Offline calj737

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Re: Cleaning crankcase halves?
« Reply #14 on: December 06, 2013, 06:05:25 PM »
+1 on glass beading IF you have access or finances to do it. It makes a beautiful finish and prep for paint.

+1 on Aircraft stripper if you want todo it yourself and save money.

Either method works, if you send out for glass beading, shop should be competent to clean the case afterwards. Double check all tapped holes though for extra measure.

The other option is Soda Blasting. Much like glass beading, non-destructive, non-abrasive. Cleans up completely and leaves cases very clean. Rinse/clean with soapy water and denatured alcohol. Then paint away. Can be much cheaper than glass beading.
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Offline tino montreal

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Re: Cleaning crankcase halves?
« Reply #15 on: December 16, 2013, 09:33:44 AM »
OK Sandblasting newbie here....is Soda Blasting actually using baking soda with the gun?
I'm ready to blast my cylinder block fins and if this is a less abbrasive method to clean those ugly fins, I'm in.

My block shown...

Thanks.

Offline joe p

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Re: Cleaning crankcase halves?
« Reply #16 on: December 17, 2013, 04:27:57 AM »
I go to SAM and get the big bag of Soda. I put my line to a air gun in the bag. I cleaned a set of carb for my kz and they look like new inside and out and it cleans up just using water. I have not try it on something big yet.  I'll try my honda cases next.
« Last Edit: December 17, 2013, 04:36:17 AM by joe p »

Offline calj737

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Re: Cleaning crankcase halves?
« Reply #17 on: December 17, 2013, 04:39:47 AM »
OK Sandblasting newbie here....is Soda Blasting actually using baking soda with the gun?
I'm ready to blast my cylinder block fins and if this is a less abbrasive method to clean those ugly fins, I'm in.

My block shown...

Thanks.

Yes, it is essentially Baking Soda, but a commercial formula. You can do it yourself at home with similar results. Best results if you degrease the engine first. You'll need pretty good air pressure to be effective.

The waste is just lost, not recirculated. So you'll have a large puddle of soda outside wherever you do it. WEAR EYE PROTECTION!!
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Offline dragracer

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Re: Cleaning crankcase halves?
« Reply #18 on: January 03, 2014, 05:55:51 PM »
What brand case paint are you guys using?. I'd prefer the stock looking finish. Got a K model i need to restore in the near future. More time than money on my hands- lol.