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Old Oct 22, 2014, 05:26 PM
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Originally Posted by johnshannon View Post
Geoff, Maris, Bob, Brian,

I totally agree this is a very attractive engine. My wife did her interpretative translation and said the bore and stroke are 8 mm and 12 mm. I think a reasonably close set of drawings could be generated from the sectional view shown. I do have a couple of questions. How is the wrist pin held in place? It seems to be pressed into the piston. Dub and I were exceedingly unsuccessful with this on 1/2A speed engines. Secondly, how is the screw on cooling cap made to align the fins on top? With our single pointing CNC machines this is easy, but that was not in play when this engine was built.

Johnny
There is no problem with a pressed-in pin/cast iron piston setup. Many successful diesels use this method of pin retention.

It may not be possible to assemble the Argentinian MAX engine with a pressed- in pin, as the crankcase height will not allow the assembled piston/rod/pin sufficient rearward movement (at TDC) . The way to go here would be a floating pin. It appears that the single tfr passage in the case is at the rear and the use of two drilled tfr ports as in a Mills, mentioned in the text anyway, would allow an unbroken cylinder wall to maintain the pin in place.

If there is any interest, I can prepare a dimensioned mechanical layout for the MAX, based closely on the information available. This would leave the crankcase, finned head etc for others to interpret.

I do think the MAX has a lot of charm and would be a lovely little diesel for sport FF or RC.

David Owen
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Old Oct 22, 2014, 05:35 PM
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It's not that hard to do Johnny , I made 5 muffs for some Spary 5cc deisels we built as a team and each of those turned out exact . Except for one that my son ( world champion machinist , and he is ) did to show me the right way , wrong depth on the first cut and didn't lock it right down on the mandrel ,deep 1/16 groove right thru the comp screw hole and about 15degees off angle . That one went on my engine ,just to remind him when he forgets .
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Old Oct 22, 2014, 05:55 PM
DJS Johnny
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United States, TX, Houston
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Argentine Engine

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Originally Posted by Geoff Potter View Post
I don't read Argentinian ,but if one blows up the print you can actually follow the article very well . I would like to have a go at one particularley on a share basis where one makes this and another makes that and then put all the bits together to make 4/5 engines ,one for each participant . Would be a good exercise ,but would need to size it properly before cutting metal . Maybe drawings ,then 3D plastic to start , Browny needs a project to start for his new machine . I could do the p/L/Contra ,and crank , and sand castings from patterns ,I don't think it's machined from billit . I will also see if FFWCHAMP Roy S knows the guy in Argint . that did the article ,there might be one over there that can be measured ,if only for me to build . Geoff.
Geoff,

I would be in for a team effort! The parts you signed up for are by far the most difficult. I can do any of the other parts. That tank looks like a good CNC lathe part! I would suggest you find out who is interested and then parse out the work based on your experience.

On the design: I think the pictures and the Clinica de Motores article is for an engine built from barstock (no casting) and I would suggest this approach. I think the most difficult part will be the mating threads. For production work we use go no-go gages to endure all the parts go together. Additionally, we mate parts during each run. Maybe we are shooting for a bit better fit than normal, but it seems to work. Who can do English and/or metric threads is important. The backplate/case and cylinder/fins seem to be the critical interfaces. The engine article also has a round mounting plate.

Johnny
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Old Oct 22, 2014, 06:02 PM
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Welcome Back, David Owen ! (sabre250) Can we expect a rundown of the highlights of your overseas trip, Dave ?
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Old Oct 22, 2014, 06:10 PM
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A Star for Gluehand
So they came in bags...? ....didn't know that. That's still "NIB" though...


BTW: I've moved our "underwater activity" to HERE
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Old Oct 22, 2014, 06:49 PM
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Originally Posted by Twin Stack View Post
Welcome Back, David Owen ! (sabre250) Can we expect a rundown of the highlights of your overseas trip, Dave ?
Hi Bob,

Thanks for your welcome. Have been home now for 10 or so days and it is nice to be back in Australia after a long time away. Plenty of things to do to catch up on the house, and the usual attention to outstanding paperwork. Returned to the workshop this week. A number of engine jobs backed up while I was away and I'm going through those right now. Pushing to get back on the T2.5 diesels and have 18x in prep for delivery by Xmas.

Anyway, so far as the trip itself, too many highlights to recount here. We did spend a few wonderful weeks with Krafty near Bordeaux and Broken English up in the Loire. That was a major highlight for Celia and me and I cannot thank Ken and Anne, Brian and Dolores enough for their hospitality and friendship. In England, we did spend some time with Kevin and Hazel Richards and again I thank them very much for everything. I returned with a very rare engine of Kevin's, which he has entrusted to my care for repair. Will post a shot of it in due course and see if anyone has another example.

Following a pretty serious car accident in England, I was not so keen on driving down to Barcelona to catch up again with Manuel Rojo , or up through Italy to Prague (first time for me), then across through Germany and back to Paris. I'm really sorry that we were unable to see various friends on the way as originally planned.

So we decided to book a 12 day trip on the Hurtigruten Coastal Express (a truly beautiful ship) and let someone else do the driving. The voyage took us up through the Norwegian fiords from Bergen to Kirkenes, on the Russian border.
A truly wonderful and most relaxing trip which I would certainly recommend.

A few days then with friends near Paris, dropped the car off and we were back on the plane home. Latter part not much fun, as you will know, but you do get over it fast.

regards
David
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Old Oct 22, 2014, 07:16 PM
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No David ,as you get older you don't get over it fast I'm afraid ,after my last . Istanbul /Sydney . 2 and a bit years ago still working on it , even tried a couple of Sydney /Wellington Sydney's , didn't help ,NEVER AGAIN . John ,I don't chase people , if they want in ,please do ,but THEY have to want to . The mounting plate would be made into the back plate , that's easy . Screw in Venturi ?
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Old Oct 22, 2014, 07:51 PM
DJS Johnny
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United States, TX, Houston
Joined Aug 2007
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Argintine Engine

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Originally Posted by Geoff Potter View Post
No David ,as you get older you don't get over it fast I'm afraid ,after my last . Istanbul /Sydney . 2 and a bit years ago still working on it , even tried a couple of Sydney /Wellington Sydney's , didn't help ,NEVER AGAIN . John ,I don't chase people , if they want in ,please do ,but THEY have to want to . The mounting plate would be made into the back plate , that's easy . Screw in Venturi ?
I would think you would want the mounting ring to be a separate piece so the mounting screw holes can be aligned as desired. I would think a pressed in venture would be easy.
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Old Oct 22, 2014, 07:57 PM
DJS Johnny
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Originally Posted by sabre250 View Post
There is no problem with a pressed-in pin/cast iron piston setup. Many successful diesels use this method of pin retention.

It may not be possible to assemble the Argentinian MAX engine with a pressed- in pin, as the crankcase height will not allow the assembled piston/rod/pin sufficient rearward movement (at TDC) . The way to go here would be a floating pin. It appears that the single tfr passage in the case is at the rear and the use of two drilled tfr ports as in a Mills, mentioned in the text anyway, would allow an unbroken cylinder wall to maintain the pin in place.

If there is any interest, I can prepare a dimensioned mechanical layout for the MAX, based closely on the information available. This would leave the crankcase, finned head etc for others to interpret.

I do think the MAX has a lot of charm and would be a lovely little diesel for sport FF or RC.

David Owen
David,

It might be possible to press in the wrist pin and still get it to go together. A layout is probably in order. At TDC almost half the piston is out of the case. This increases the available angle to get it on the crankpin. Additionally, I use a chamfer on the forward side of the rod to provide a little lube reservoir and allow a radius at the bottom of the crankpin to reduce stress risers.

Johnny
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Old Oct 22, 2014, 10:29 PM
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Welcome home David ...

You have a croaker, yet to be a Prince Charming waiting in a box next time I come down ... which will be hopefully next week if ok with you, will bring the latest (5th) variant of my favorite engine - the Owen Mate with me. By then will hopefully have test flown a model with the little PAW 06 RC, what a beaut little engine.

Ed
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Old Oct 22, 2014, 10:29 PM
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Australia, NSW, Wollongong
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Quote:
Originally Posted by johnshannon View Post
David,

It might be possible to press in the wrist pin and still get it to go together. A layout is probably in order. At TDC almost half the piston is out of the case. This increases the available angle to get it on the crankpin. Additionally, I use a chamfer on the forward side of the rod to provide a little lube reservoir and allow a radius at the bottom of the crankpin to reduce stress risers.

Johnny
Hi Johnny,

The chamfered big end bore and the fillet on the crankpin are standard good practice.
But an excessively angled conrod will have to be drifted over the crankpin and unless the end of the pin is radiussed, a small chunk of conrod is usually chiselled out.

regards
Dave
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Old Oct 22, 2014, 10:31 PM
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Originally Posted by edholly View Post
Welcome home David ...

You have a croaker, yet to be a Prince Charming waiting in a box next time I come down ... which will be hopefully next week if ok with you, will bring the latest (5th) variant of my favorite engine - the Owen Mate with me. By then will hopefully have test flown a model with the little PAW 06 RC, what a beaut little engine.

Ed
I certainly look forward to seeing you, Ed. A number of people o/s commented very favorably on your Twin.

cheers
Dave
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Old Oct 23, 2014, 01:40 AM
DJS Johnny
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United States, TX, Houston
Joined Aug 2007
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Argintine Engine

Quote:
Originally Posted by Geoff Potter View Post
I don't read Argentinian ,but if one blows up the print you can actually follow the article very well . I would like to have a go at one particularley on a share basis where one makes this and another makes that and then put all the bits together to make 4/5 engines ,one for each participant . Would be a good exercise ,but would need to size it properly before cutting metal . Maybe drawings ,then 3D plastic to start , Browny needs a project to start for his new machine . I could do the p/L/Contra ,and crank , and sand castings from patterns ,I don't think it's machined from billit . I will also see if FFWCHAMP Roy S knows the guy in Argint . that did the article ,there might be one over there that can be measured ,if only for me to build . Geoff.
Geoff,

I would be up for the (14) tank, (no #) tank screw, (13) tank seal washer, (7) backplate, (17) mounting ring, (11) prop drive and (10) prop nut.

Johnny
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Old Oct 23, 2014, 01:49 AM
DJS Johnny
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United States, TX, Houston
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So True, So True

Quote:
Originally Posted by sabre250 View Post
Hi Johnny,

The chamfered big end bore and the fillet on the crankpin are standard good practice.
But an excessively angled conrod will have to be drifted over the crankpin and unless the end of the pin is radiussed, a small chunk of conrod is usually chiselled out.

regards
Dave
Dave,

You have perfectly described the Kosmic 15 assembly before you get the bearings in the right spot to center the rod under the piston. Such a nice engine, but every one I had needed bearing spacers. Or, maybe they just liked using the crankpin as a broach.

Johnny
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Old Oct 23, 2014, 03:54 AM
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So all we need are people to do crankcase ,cooling muff ,Venturi ,nva, compscrew , and we have a go. Of course someone to put all the bits together.
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