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Part built Allchin 1.5 inch

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derek blake20/09/2019 20:57:49
457 forum posts
119 photos

Many thanks for the suggestions, I shall have a mess around this weekend for sure.

derek blake22/09/2019 21:04:24
457 forum posts
119 photos

Evening all,

so I had another go with the foot pump, the valve was so tight it couldn’t seal and my engine came alive!

exciting for sure, unfortunately there are some issues and that’s leaks, to be expected of course but I have leaks from the 4 bronze studs under the nuts.

the other studs so far seem fine, slightly annoying but maybe I could put some copper washer under the nuts?

i also have another leak which I hope is from the valve chest cover and not the valve chest itself!

have any of you ever had leaks from the studs? I can’t remove the studs as I’m sure you will all know from my previous posts.

derek blake22/09/2019 22:13:39
457 forum posts
119 photos

I give up on the old tinternet, have spent 2 hours trying to find 4BA copper crush washers..I’m not sure of any other way to seal the threads.

Paul Kemp22/09/2019 23:59:32
308 forum posts
11 photos

Derek,

Try twisting some PTFE tape (plumbers use it!) into a string and then wind that round the stud (clockwise) then screw the nut down on it, any that extrudes out past the profile of the nut you can trim off with a craft knife. It's a relatively low pressure so should do the trick.

Paul.

derek blake23/09/2019 10:28:27
457 forum posts
119 photos

Right OK thanks Paul, there’s not a lot of stud sticking out so I will have to use very small amount but we’ll worth a try.

thank you

derek blake23/09/2019 12:58:41
457 forum posts
119 photos

Can you use fibre washers with steam?

derek blake24/09/2019 20:38:22
457 forum posts
119 photos

Not a lot of progress, steal trying to seal leaks.

air escaping from valve chest cover at the moment, no matter what gasket i use.

i haven’t seen any leaks from the valve chest joins yet which is critical, as I can’t remove the cylinder again.

Jeff Dayman24/09/2019 22:32:37
1621 forum posts
40 photos

Hi Derek, did you use some silicone sealer or other gap-filler at the screw heads shown in the pic below with the red arrows? If not air may be getting by the heads or the screw slots out the side, under the gasket. You could add some sealant by removing only the valve chest cover. Some socket head capscrews or philips head machine screws would be better here than slot heads, because with those there is no leak path across the head. There may still be a gap above the head though, needing extra gasket or some sealant, or both.

dereks-steam-chest.jpg

derek blake24/09/2019 22:45:34
457 forum posts
119 photos

Thank you Jeff, on these screw head I actually added some JB weld as the counterbore had made a gap under the chest cover and I filed off level.

is it actually possible that air could be creeping up the fixing studs then, I assumed as they were under the plate it would be sealed.

i haven’t tried sealant yet, but that’s only because the valve isn’t fully set yet.

a leaking valve cover isn’t an issue that can’t be fixed from your suggestions, I was trying the air route to put my mind at rest about the valve chest itself wasn’t leaking and worse still the cylinder saddle as both can’t be removed now.

as the sealant can be easy cleaned off I will try a thin layer tomorrow and see if it’s a fix, I did add some washing up liquid around the area and it does seem to be out the top where valve chest cover fits.

derek blake24/09/2019 22:48:50
457 forum posts
119 photos

I will add a layer of sealant under the gasket tomorrow as this can still help before fixing sealant on all surfaces when the valve is set.

derek blake24/09/2019 22:58:40
457 forum posts
119 photos

Looking at your suggestions Jeff, I didn’t add JB to the top fixing screw for some reason and that’s where it leaks so I shall do the same to that one tomorrow and try again. I think you may have just hit on the reason for the leak! 🙏

Jeff Dayman25/09/2019 00:47:41
1621 forum posts
40 photos

My fingers are crossed here! Good luck tomorrow.

derek blake26/09/2019 20:27:47
457 forum posts
119 photos

Small amount of work done, screw heads sealed and new gasket added and valve chest leak seems sorted but still small amount of others to do but looks like none on cylinder saddle or valve chest itself yet but only running on around 20psi presently.

short but noisy video added to YouTube if your interested in viewing, listed under “Allchin first air test”

Edited By JasonB on 26/09/2019 20:45:29

JasonB26/09/2019 20:46:08
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Moderator
16240 forum posts
1717 photos
1 articles

Looking good

derek blake26/09/2019 20:55:29
457 forum posts
119 photos

Many thanks Jason, that means a lot.

derek blake26/09/2019 22:04:43
457 forum posts
119 photos

Many thanks for adding the video Jason.

Jeff Dayman27/09/2019 04:08:05
1621 forum posts
40 photos

Well done Derek! Like a Swiss watch!

Paul Kemp28/09/2019 00:03:17
308 forum posts
11 photos

Derek,

Not much wrong with that! Nice and regular impulse on the crank. Well done. Little challange for you, see how slow you can get it to run on your 20psi, good slow running is harder to achieve than having it whizzing round and a very good indication of how good your valve timing is. I reckon you will get that just creeping round!

Paul.

derek blake28/09/2019 08:40:08
457 forum posts
119 photos

Thank Paul, for some reason the regulator not working yet.

i suspect the leaks etc are not allowing the pressure to hold it against the face so the speed is the speed at the moment.

but hopefully as I work through the leaks I will have more and more control, even to see the engine come alive after a year is a good feeling as I was concerned it wouldn’t work.

Ron Laden28/09/2019 08:52:35
avatar
1354 forum posts
240 photos

That looks a very sweet runner Derek, you must be pleased with that.

Ron

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