Author Topic: Changeover valve removal suggestions.  (Read 787 times)

Ted Goat

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Changeover valve removal suggestions.
« on: April 06, 2022, 11:31:10 AM »
Hi,
New on here, although been lurking here as a guest for a while and been collecting engines for 25 years.
Just aquired a lovely original CS 3-1 from a farm in Norfolk, it will fire up, but I'm going to strip it right down as the insides are absolutely blocked solid with sludge and bits of debris, I'm just not happy I can get it cleaned out properly without stripping it.
Anyway, all coming apart easily, flywheels etc off but can't get the changeover valve out .
The outer plug cap came unscrewed easily, but the inner parts are jammed solid with carbon etc. I've tried the "compression" method several times, and I'm not brave enough to actually start the engine to try to blow it out. My plan maybe to let it soak a couple of weeks in something that softens carbon (diesel or redex maybe) and if that doesn't loosen it may try to rig up a steel plate over the combustion chamber with a 1/8 grease nipple and use a grease gun to hydraulically push the chambers out.
Can't get in with any heat without risking damaging the valve stem or spring.

Hate the thought of destroying something that's lasted 70 years and replacing it with some Indian rubbish parts.

Anyone any ideas for getting it out?

38ac

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Re: Changeover valve removal suggestions.
« Reply #1 on: April 06, 2022, 11:49:58 AM »
You can try soaking but its never worked for me. If it wasn't leaking previously the  best advice I can give is to leave the inner piece alone. I had a couple that had to be removed and both were destroyed in the process. Good luck with it!
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Hugh Conway

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Re: Changeover valve removal suggestions.
« Reply #2 on: April 06, 2022, 09:33:56 PM »
My experience is same as 38AC's. Tried everything that I had ever seen recomended to remove the COV.......nothing worked. Had to destroy it to remove it.
YMMV......I hope you have success with a less destructive method.
Cheers
Hugh
JKson 6/1  (Utterpower PMG ) Off-grid
Lister 6/1 Start-O-Matic engine......running with PMG
1978 Royal Enfield (glutton for punishment by Indian iron)
1963 BMW R-27 project

mikenash

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Re: Changeover valve removal suggestions.
« Reply #3 on: April 07, 2022, 06:57:26 AM »
I have one that is troublesome too.  I'm considering just letting the engine run and work on "high".

I note the Indian clones don't have them - and with their quality control I would guess there are some engines running with very high compression and some with very low.  i haven't heard of failures because of excess compression - and i wonder if "high" compressions is within tolerance

Certainly, when it's apart you could measure the crush at the top, do a back-of-envelope on what would constitute a working compression  and fit base gaskets to suit?

I'd be interested in thoughts?  Cheers

mihit

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Re: Changeover valve removal suggestions.
« Reply #4 on: April 07, 2022, 08:15:30 AM »
Guess I got both the good ones. Never had an issue popping em. (I, also, like to have a base-line of maintenance)

Grease gun=12,000 PSI... Probably > Lister CS compression...eh.
Though I suppose you could build up pressure slowly over days, but then also the firing cycle would act on it like an impact driver/ slide hammer, so...

One thing that has twigged my curiousity (but never enough to invest in it) is Ultrasonic cleaning... find someone who knows the ins and outs of it and it could just work...

Ted Goat

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Re: Changeover valve removal suggestions.
« Reply #5 on: April 07, 2022, 11:38:17 AM »
Thank you for the suggestions so far, I'm hoping it won't be that badly stuck, as the rest of the engine is oily and has come apart really easy.
I'm going to give it a good long soak, (a few weeks) whilst I'm doing other things and go from there.

I've seen someone push a seized piston out with the grease gun method, but as you say, be very careful.
If it comes to that I'll probably use thick oil in the gun, for ease of washing out after and put a pressure guage in the line, wouldn't go more than about 800-1000 psi. (I think compression on high setting is about 600)
Thanks again and any more ideas are very welcome.

Ted Goat

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Re: Changeover valve removal suggestions.
« Reply #6 on: April 07, 2022, 11:44:30 AM »
I've used an ultrasonic cleaner before with siezed carburettor jets in corroded zinc casting carbs, and the vibrations and hot liquid have proved successful. The thing is finding someone with a cleaning bath big enough for a CS head, most are just big enough for a lawnmower carb.
Certainly another avenue to explore though, thanks Mihit.

38ac

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Re: Changeover valve removal suggestions.
« Reply #7 on: April 07, 2022, 05:12:29 PM »
I have one that is troublesome too.  I'm considering just letting the engine run and work on "high".

I note the Indian clones don't have them - and with their quality control I would guess there are some engines running with very high compression and some with very low.  i haven't heard of failures because of excess compression - and i wonder if "high" compressions is within tolerance

Certainly, when it's apart you could measure the crush at the top, do a back-of-envelope on what would constitute a working compression  and fit base gaskets to suit?

I'd be interested in thoughts?  Cheers

India does build COV equipped engines and they are available through parts. They do a very good job on the valves and they function and appear same as OEM. However if the COV is not specified on the order they will ship the enines with the 8/1 type blanking plug no matter the spec asked for.

The bump for COV equipped and non COV equipped engines is different. When correctly set the resulting compression ratio on the non COV 8/1 types is about halfway between the high and low compressions on a COV equipped engine.
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mikenash

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Re: Changeover valve removal suggestions.
« Reply #8 on: April 07, 2022, 08:13:28 PM »
https://www.youtube.com/watch?v=63420EHuZ3g

Yes.  See link?

I have an old 6/1 running with an Indian head with that plug.  I have long since forgotten what the squashed-solder clearance piston-to-head was.  Iirc I may have used a couple of lead shot?

Anyway, regardless. It seems like you could possibly sneak another base gasket in and run the engine with the COV stuck in 'high"

It wouldn't be the "right" solution.  But if you measured the squish before and after, and if it was a bit more than spec with an extra base gasket in place . . .

Just a backyard person's view on a fix

Cheers

38ac

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Re: Changeover valve removal suggestions.
« Reply #9 on: April 07, 2022, 09:45:16 PM »

 It seems like you could possibly sneak another base gasket in and run the engine with the COV stuck in 'high"

It wouldn't be the "right" solution.  But if you measured the squish before and after, and if it was a bit more than spec with an extra base gasket in place . . .

Just a backyard person's view on a fix

Cheers

Yes you could do that no problem. The blanking plug gives the same compression ratio as the COV screwed in.

Maybe I didn't understand the original question? I thought he had the COV out and was ha ing difficulties with the piece behind it?
Collector and horder of about anything diesel

Ted Goat

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Re: Changeover valve removal suggestions.
« Reply #10 on: April 07, 2022, 10:37:02 PM »
38ac,
No, just to clarify, the threaded piece has unscrewed, ( the part with the large fine thread into the head, with the square head on, together with the handwheel, ) but it will only back out as far as the end of the threads, I can pull it maybe 1/2" more against a spring, but that's it .
So I'm guessing that both halves of the combustion chamber are jammed in, with the valve stem head between them .
Looking at the parts book, the 3-1 COV is slightly different to the
5-1/6-1, so I'm not even sure that an Indian replacement COV would fit, hence I need to make sure I don't damage the original.

mike90045

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Re: Changeover valve removal suggestions.
« Reply #11 on: April 09, 2022, 01:24:11 AM »
I don't know if ultrasonics will get that deep through the mass and around corners.    In our shop in the USMC, we had an ultrasonic cleaner for teletypes, to get all the ink, paper dust and dried grease off them.  Took about 30 min or so, for what is essentially an open frame typewriter.   
  I've heard ATF and Acetone, 50/50 is a good soak agent, but you will need a sturdy tank with a lid to keep the acetone from evaporating away ( and sucking humidity out of the air - leaving you with water and ATF ) and a safe place to park it for days, maybe shake it a bit daily, move the crud around.    Auto transmission shops often have a hot tank cleaner, for aluminum transmissions, likely safe for Iron.  Get the worst off before your month long soak.

  I don't recall if hot Lye will cut carbon, but it will eat anything non-iron

Ted Goat

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Re: Changeover valve removal suggestions.
« Reply #12 on: April 09, 2022, 10:10:58 AM »
Thanks for all your suggestions so far.
I had a small but useful victory last night.....
Tried unscrewing the end cap, and holding the handwheel still at the same time, essentially using the fine thread as a jack to pull on the valve stem. After going tight, another nudge with a long spanner had something give, and it continued to turn out.
So I now have the handwheel, valve stem and the first half of the chamber out, with no damage.
I'm going to leave the inner chamber soaking before trying the compression method again, and if that doesn't shift it, then I'll decarbonise where I can and leave it alone.

Thanks again.

mihit

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Re: Changeover valve removal suggestions.
« Reply #13 on: April 12, 2022, 03:01:56 AM »
I've used an ultrasonic cleaner before with siezed carburettor jets in corroded zinc casting carbs, and the vibrations and hot liquid have proved successful. The thing is finding someone with a cleaning bath big enough for a CS head, most are just big enough for a lawnmower carb.
Certainly another avenue to explore though, thanks Mihit.

Looks like you're making headway with it, but just a further comment on the UHF (I still have no idea if it would actually work)

There are units available for ultra-sonically anti-foulling yacht hulls. One of them on the side of a garbage pail/ fishbin/ tub, dialled in to the right number, with the right chemichal/ pH/ hardness water and I'd expect something to happen.

I'm going to have to find a project for this and give it a go myself, for science.