Honda-SOHC

SOHC.co.uk Forums => Anorak's Corner => Topic started by: AshimotoK0 on August 21, 2023, 11:54:35 AM

Title: Blasting a complete engine !
Post by: AshimotoK0 on August 21, 2023, 11:54:35 AM
Here is what I did to blast the outside of a CB350K1 engine and prevent any media ingress. ;)
Everything sealed ..pressurise pipe on breather to a few p.s.i. locked in. Make sure pressure doesn't decay significantly and check all sealed areas with soap solution for sealing.
Blast clean whist still pressurised. Blast with airline..Wash with solvent.. blast with airline again.


[attachimg=1]
Title: Re: Blasting a complete engine !
Post by: McCabe-Thiele (Ted) on August 21, 2023, 12:12:37 PM
Very impressive Ash - what are the red/brown areas around some of the screws out of interest?
Title: Re: Blasting a complete engine !
Post by: AshimotoK0 on August 21, 2023, 01:23:45 PM
Greased fibre washers Ted
Title: Re: Blasting a complete engine !
Post by: Oddjob on August 21, 2023, 05:10:24 PM
Is it me or does that screw/bolt under the spark plug look too long and is bottoming out on the barrel fins?

Presume you did because finding gaskets is hard?
Title: Re: Blasting a complete engine !
Post by: AshimotoK0 on August 21, 2023, 07:54:36 PM
Is it me or does that screw/bolt under the spark plug look too long and is bottoming out on the barrel fins?

Presume you did because finding gaskets is hard?
No it wasn't..  they were just a motley collection of any old bolts and screws to fasten everything together with no engine internals inside. But it shows that a complete engine can be blasted. It may also reveal any leaky seals/gasket faces.
Title: Re: Blasting a complete engine !
Post by: McCabe-Thiele (Ted) on August 21, 2023, 08:09:54 PM
If I understand you correctly you have slight pressure in the engine as well Ash neat idea like a toxic fume cupboard in reverse?
Title: Re: Blasting a complete engine !
Post by: Johnny4428 on August 21, 2023, 09:53:42 PM
Great idea Ash! Internal positive pressure.👍
Title: Re: Blasting a complete engine !
Post by: Oddjob on August 21, 2023, 10:32:28 PM
No offense Ash but just because it can be done doesn't mean it's a good idea. I'd sooner dismantle the engine but I can see that getting gaskets etc might be a problem.
Title: Re: Blasting a complete engine !
Post by: AshimotoK0 on August 21, 2023, 11:28:29 PM
No offense Ash but just because it can be done doesn't mean it's a good idea. I'd sooner dismantle the engine but I can see that getting gaskets etc might be a problem.

I fully agree Ken .. all of my engines I strip regardless of mileage due to unknown history, hardening of rubber parts, gumming up of rings  etc. If you notice the engine in the picture was assembled with no internals so I could blast everything on the outside without getting any blast media on the inside surfaces. I posted this because there was a meeting of the 'SOHC Debating Society'  ;D ;D yesterday where this was discussed but the commenting was suspended for some strange reason and I couldn't reply. Very unusual and a bit draconian for this forum. As Dylan would say "without freedom of speech, I might be in the swamp." ;D

Update:

 Steve PM'd me and explained to me why he had ended the thread. Let's hope we don't  give him cause to do it again. This is still the best forum out there IMHO and to the original poster  .....please stick around with us we are a friendly bunch really
Title: Re: Blasting a complete engine !
Post by: Oddjob on August 22, 2023, 02:09:08 AM
I think Steve had his reasons Ash.
Title: Re: Blasting a complete engine !
Post by: AshimotoK0 on August 22, 2023, 07:21:12 AM
Here is a scenario where blasting a complete engine without stripping would be a reasonable way to restore the outside finish. A friend has a few lovely bikes, which he has meticulously restored over the past 30 plus years. However, he rides all of them so he knows their history and that they were rebuilt properly. Problem is if you ride them then inevitably the engine finish can deteriorate plus there are now alternative techniques to refinish them ( like the 2k clear coat I recently used on my 400-4 wheel hubs. In this case he would be much better blasting like I described, rather than strip an engine he knows is running beautifully with no real  issues internally.
SimplePortal 2.3.5 © 2008-2012, SimplePortal