Ron’s Jowitt Popett Valve Engine

[Ron LadenParticipant @ronladen17547]

Jason,

I am guessing you must have produced your own metric fastenings for the engine, they look different and much better than off the shelf types.

Ron

[JasonBModerator @jasonb]

Well they were off the shelf but you need to be looking on the right one, though as there are not many you could make up your own.

They are a smaller and taller hex than the usual mass produced ones, Polly models in the UK sell them but I go direct to the people they buy them from in Germany GHW

[Ron LadenParticipant @ronladen17547]

Thanks for the links Jason.

Started the cylinder shaping using the exact same setup as Jason shows in his build thread, it works a treat.

One pass for each turn of the R/T handwheel (4 degrees) it certainly produces a good radiused finish, cant see it needing much work with the files to blend in.

[BOB BLACKSHAW 1Participant @bobblackshaw1]

Ron

The dividing head you have on the SX2p mill can you tell me what it is as I am looking to get one soon. I have a rotary table and find that the fixing bolts are a problem with the mill table lining up but I made adjustments to make it fit, that is why I have not got a dividing head at the moment. Sorry that this is not about your thread but looks a good set up.

Bob

[Ron LadenParticipant @ronladen17547]

Hi Bob,

Its not a dividing head its a Soba (Indian) 5 inch rotary table which I bought from Chronos, it comes as a set with tailstock, 80mm 4 jaw with mounting plate and a set of dividing plates.Its mid priced I guess at £324, I couldnt afford anything more at the time.

Its very good, in one or two places its a bit rough around the edges but overall good. The table has no play, backlash or float, the drive is very smooth and best of all it is accurate.

What really sold me on it was the size 5 inch which I think is a good match for my SX2P, 6 inch is too big and 4 inch a bit small.

Ron

Edited By Ron Laden on 28/02/2020 12:57:55

[Ron LadenParticipant @ronladen17547]

The most involved part just about there, things should speed up a bit now.

[JasonBModerator @jasonb]

Looks good Ron and as you say the hardest part out of the way

[Ron LadenParticipant @ronladen17547]

Thanks Jason

I did enjoy making it and it is probably the most interesting part I have made to date and I am learning from parts like this all the time.

This morning I made the frame ends and feet which turned out well and the next job is the main bearings and caps.

Ron

Edited By Ron Laden on 02/03/2020 08:00:21

Edited By Ron Laden on 02/03/2020 08:01:04

[Ron LadenParticipant @ronladen17547]

Found a few screws just for a trial fit of the parts made so far, thought I had better check and all seems ok.

[Ron LadenParticipant @ronladen17547]

Well my first mistake, I turned up the piston today and bar one all dimensions are spot on to the drawing The diameter, the length, the wrist pin position, the ring groove width/depth are all good. Also the bottom ring groove position is good but the top one is 0.5mm too high, the groove top edge should be 2.0mm from the piston top but mine is only 1.5mm.how I managed that I,m not sure but thats what it is.

I am thinking it may be ok and not a problem in the operation of the engine, I,m sure Jason will be along to tell me yes or no. I can make another one if need be, not a problem but it seems a pity to bin it with all the main dimensions tight to the drawing.

[JasonBModerator @jasonb]

That will be fine Ron so you can keep up the good progress.

[Ron LadenParticipant @ronladen17547]

Thanks Jason, thats a relief, I will press on.

[Ron LadenParticipant @ronladen17547]

Progress so far, not had much shop time this week but its coming together slowly, slowly.

Just added the main bearings, the bearing caps and the crankshaft, the crank is a bit longer than the drawing as I havnt decided on the flywheels yet and dont want to find it short.

[Henry BrownParticipant @henrybrown95529]

Looks good Ron, I'm enjoying your trials, tribulations and especially the successes!

[Ron LadenParticipant @ronladen17547]

Thanks Henry, I hope I dont have too many trials and tribulations but if you enjoy any I do have then thats fine.

To be honest it would be difficult not to make a success of the Jowitt and the credit really goes to Jason for his design, a good set of drawings and his step by step build thread. I have followed Jasons methods for producing the parts and all turns out as he suggests, so there is not that much skill on my part but I am learning from it.

Ron

[Jeff DaymanParticipant @jeffdayman43397]

It's looking good Ron! Well done.

[Ron LadenParticipant @ronladen17547]

Thanks Jeff, I am enjoying the build, interesting and fun.

I have been thinking about adding a personal touch to the engine but I dont want to change the design in any way so today the opportunity presented itself, the conrod. I have used brass instead of steel, the keep and the bearings will be bronze and the rod needs a good polish but I think it should look quite good when finished.

[mal webberParticipant @malwebber91786]

Just had a catch up on this thread Ron, looking very nice.

Mal.

Edited By mal webber on 08/03/2020 17:59:04

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[Ron LadenParticipant @ronladen17547]

Jason,

I am about to start the split big end bearings would appreciate knowing the best approach for soft soldering the two halves, do you tin one side and lay the other on top and re-heat or is there a better method.

Ron

[JasonBModerator @jasonb]

Either tin both then sweat together or put a small amount of soft solder pain onto the joint and put together then heat.

When tinning apply a very small amount of solder and wipe off excess while still liquid.

[Ron LadenParticipant @ronladen17547]

Thanks Jason

Its the first time I have soft soldered any pieces of metal together, I dont have any solder paint only some 1.5mm solder wire. I cut a 1/2 inch piece of that which I pressed flat as not to hold the pieces apart too much and used a tiny amount of flux, seems to have worked a treat. The picture is almost a spot the joint, mind you it looks so thin it may well fall apart when I touch it with a cutter..lol

[Chris GunnParticipant @chrisgunn36534]

Ron, just built 4 of these engines, 1 for each grandchild, so keep on going. If you intend to use the flywheel castings Jason recommended, I have a spare set, I had to buy 5 sets to get a good price. If they are any good to you you can have them at what I paid.

Chris Gunn

[Ron LadenParticipant @ronladen17547]

Posted by Chris Gunn on 09/03/2020 16:11:12:

Ron, just built 4 of these engines, 1 for each grandchild, so keep on going. If you intend to use the flywheel castings Jason recommended, I have a spare set, I had to buy 5 sets to get a good price. If they are any good to you you can have them at what I paid.

Chris Gunn

Thats good of you Chris, yes I would be interested I will send you a PM if thats ok.

Ron

[Ron LadenParticipant @ronladen17547]

A bit more added, I will need to have play with the main bearings though as they are a tad tight, better than sloppy I guess. I have reamed them since de-soldering but to be honest I think my 10mm reamer has seen better days and lost its edge. Apart from the flywheels I think that is all the more involved parts finished, simpler parts now.

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