Kmot

My Feedback: (24)

Oh wow!! [X(]

I built several P&W R-985 and R-1340 engines. I would give a certain part of my anatomy to have that miniature version!

eddieC

My Feedback: (2)

I couldn't believe the detail. Sorry for the poor quality, the glass played havoc with the auto-focus.

S.L.engines

For you Tom......


Luigi

radial1951

Kmot
I agree the BLACK is very smart. BUT, the SILVER is functional, like a real engine, easy to see oil leaks... just as well I don't need to choose a colour. Bella, Luigi !!!

Detlef, this thread might be under Glow Engines but there have NOT been complaints about references to non-radial gassers. All of this technology is applicable to radials as well, and very interesting.

Speaking of which, could you explain what valve timing for inlet and exhaust you have chosen for your V-4? My dream is to build a radial for myself, for flying, not just display. I have the basic design done, but cannot decide on the valve timing/duration. I have the valve specs for many engines, but they vary enormously. I'm sure other members here would also be interested to see your thoughts on the subject.

Regards RossG
radial1951

Cybertom

Luigi,

You HAVE to make a video of the SL 150 running WITH the EXHAUSE RING. In my experince the ring makes the engine run smoother and the sound is deeper especially at idle. I have got to hear it!

radial1951

WOW ! And WOW again !!!!

Beautiful engines and even more beautiful photography ! VERY IMPRESSIVE !

BUT, I can't hear the engine. Something is wrong with the sound.... Luigi, please fix !

Regards RossG
radial1951

stevesak

My Feedback: (27)

eddieC,

All of those beautiful engines that you saw in Phoenix are part of the collection of Paula and Paul Knapp. How lucky you are to have seen them on display! You can see many of the interesting engines in his collection and this history of his public displays here....

http://www.engine-museum.com/
http://www.craftsmanshipmuseum.com/KnappCol.htm

My understanding also, is that that Wasp Jr. that you captured up close is Paul's engine project. I'm not sure when they will be available for sale, but he is making several of them. What a beautiful thing!

He is also one of the most stand-up guys that I have had the pleasure to correspond with.


On another note... Attached you'll find a photo of much of my collection. It's a year old or more, so not so accurate anymore but nonetheless.....
Two Technopower 7As have been sold and The Wide Canyon is sold.
Added are the Seidel UMS ST-990, Brittish Magnum Vee twin, Valentine 3 cyl radial and 2 cyl Vee (Diesel), cox three cyl radial and a Technopower 3C. I'll have to make a new photo soon.

S.L.engines

S.L.engines

Guys you have to have patience we are making the new site and we are mounting the video will be online soon.
You must have patience because the work so much. And we very interested in the opinion of Americans.

The motors are silver and Blek but only on request. Normally they are all silver.

As for the timing of valve openings tomorrow I will send an MPV. who cares. I can not publish because they are business secrets.

eddieC

My Feedback: (2)

Stevesak,
Thanx, I didn't have time to catch the owner's details.
Northbrook. Next time I'm at Al's we'll have to chat! ;>)

Ed

77chickenhawk

vernal enginering makes the engine you see. the P/W

http://modelenginenews.org/vernal/index.html

Kmot

My Feedback: (24)

Luigi, the all black SL150 is beautiful! An instant classic, a masterpiece. Bravo!

stevesak

My Feedback: (27)

Begging your pardon, 77chickenhawk, but that engine is indeed built by Paul Knapp. A direct reference can be found at this link.

http://www.sherline.com/02prime.htm

The Vernal Wasp, castings produced by Bruce Satra with plans built by Bob Roach is similar, but in 1/6 scale. Paul's engine is also widely known (speaking relatively), but is larger at 1/4 scale.

More direct proof can be obtained by viewing eddieC's image of the engine next to it's cutaway carefully. The placards distinctly identify it as Paul's work.


Edited to include some photos of the Satra Wasp. and Roach Plans

Detlef Kunkel

Ross,
I dont want to spam your radial thread here more than I already did, but you ask, and I will reply. To make it more convenient , lets compare a radial with a cam timed engine like a twin or a Vee..
I dont think that the timing profiles ofthis Vee are useful for a radial. I have camshafts, a radial has a cam-drum (?? please help me with the correct term). With a camshaft you can achievefaster accelerations in your valve train, resulting in steeper flanges of your lift curve. In the mechanical situationof a radials cam-drum with tappets ( oh those terms again) the chance for high acceleration of your valve train is rather limited. This doesnt matter as long as you are not after high rpms. And so that is pretty ok for a typical radial model engine .

A very good example for this effect is the SAITO R325.
I had thisvery untypical radial engine some years ago. It has5 real camshafts, being truly an amount of 5 single engines. This engine behaved like a turbine, it loved rpms (prop 18x10 with 8500 rpm!!) , not so much it did like a big prop. Already with a 20x10 it didnt like to be combined, breaking down to under 6000 or so if I remember coorect. You could hear that the engine behaved much worse with that. The timing they used was of their singles, and those do rev between 8000 and 11.500 rpms, not made for 5800-1 (!)

In my Vee, I have a reduction drive at the front end; allowing theengine to revv higher than a (non geared) radial.The engine has big valves, a compression ratio of 10:1, big inlet and exhaust ports and headers. This is again of influence on the timing curve. The engine will operate up to 9500 rpm, releasing (hopefully) a serious amount of horses. If you lay my timing curves over that of a typical model radial engine, the difference is eye-catching. Also, I have 3 different cam profiles for different applications, depending on if you are interested in driving a maximum big prop at lower rpm ( a torque profile) , or, on the other side, are in search of the maximum power output at high rpms. The range of timing I use is from 260 to 300°, the ovelapping ranges from 50 to 85 °. Valve lift is around 21% to 27% of the valve diameter, depending on the profile type as described above. The higher values of overlapping make only sense when you have the chance to tune the lenght of your exhaust and inlet port ( not really easy with a ring collector of a radial..)


If there is interest, I can post some details as soon as the engine is on its test bench, hopefully by the end of this year. But then I really will open a new thread for that...sothis radialplace will not longer be spammed

radial1951

Detlef, I don't see a problem. You used the word"radial"maybe9 timesand mentioned the Saito R325 as well. Thats not spam... or attempted Hijacking.

Well, you certainly made some interesting observations. Might explain how the Saito can have such a wild cam profile. As you say, a drum cam cannot impart rapid acceleration to the follower (tappet), like a shaft type cam is able to do, because of the large radius of the drum. Everything happens more gently because the tappet must have a radius in contact with the drum, unlike a car type follower which can be flat.

Interesting that you have special cams to suite various applications. Good idea.Hmm, it's back to the (radial engine) drawing board.

Thank you for your comments, I'm sure many of us look forward to more info on your V-4 engine developments. Please keep us informed.

Regards RossG
radial1951

Maxam

My Feedback: (62)

Well Folks, I ordered a seidel collector ring from Swift Models in the UK. I hope they are decent. I will be able to compare to the Keleo ring eventually. -Tom

Felix Barrao

[/quote]

I dont want to spam your radial thread here more than I already did, but you ask, and I will reply.
[/quote]

Please, Stay here with your comments, is dificult to find interesting threads like this !!

Regards.
Félix

SOUTHERNX

Hi Maxam,when I ordered the exhaust ring for the Seidel 7-70 from Swift Models.there was no picture of it on the site,now that there is a picture I am a little confused as to how this ring is fitted to the engine.It would appear that it may have to be brased/silver soldered/welded. Any thoughts after viewing the picture on the site? Mark.

Maxam

My Feedback: (62)

It better not be! Look closely, each exhaust stub is threaded so I hope they supply gland nuts for the pipes. -Tom

SOUTHERNX

Hi again Maxam,yes I can see a possible thread on the ends of the inlets,looking at the angle of these maybe the original exhaust pipes on the engine are used as part of the exhaust setup.I will not have my engine till next week,but looking at the picture on theHK site,it looks like if the exhaust stubs were rotated back from the transporting position they may line up with the Swift exhaust ring.Guess we will find out soon! Mark.

radial1951

Hi SOUTHERNX
I haven't run my 325 either, no need to rust it up any sooner than necessary... I also got the glow driver from McDaniels, quite nicely made and good service. It's going in a CMP 83" Zero, hopefully in the next couple of months. I like the big 450R3 too, it's on the wish list along with one of Luigi's SL150s !! I look forward to seeing and hearing the 450 in that BIG GeeBee!!

I want to start building my petrol radial soon (1st retirement project). Might have to leave the cam timing decisions till later, need more info, plenty of other bits to make before I need the cam drum!

ALSO:

Could someone tell me if the Moki, SL and Seidel gassers run straight petrol(gas, benzine) or do they they add a small % of oil for lubricating the internals. I think one of them has a seal between the crankcase and the cam drive housing which has its own oil reservoir. Not sure...

Just noticed you latest post: "it looks like if the exhaust stubs were rotated back from the transporting position they may line up with the Swift exhaust ring." You would still need a flange and union nut, or similar, to connect the exhaust stub to the ring... Hmmm. (If you zoom in, it is definitely is threaded)

Regards RossG
radial1951

Kmot

My Feedback: (24)

That collector ring for the 7-70 looks kind of odd. The stubs are all straight into the ring from the outside of it. I wonder how the existing exhaust stubs would be able to fit into it?

And, what's the big hole on the inside for?

Maxam

My Feedback: (62)

The big "hole" is a notch to clear the needle valve and the exhaust pipes supplied by the manufacturer simply pivot into the stubs and are held with a gland not and probably a nylon washer. -Tom

Kmot

My Feedback: (24)

Must be a very small diameter if it needs a notch to clear the needle valve? Looking at the stock exhaust pipes I cannot picture them pivoting into this collector ring. I am really curious to see it installed since my brain seems unable to figure it out.

Warbird Man

My Feedback: (95)

Anyone have one of these yet?

New OS FR7 420 Looks like one sweet 'lil engine

Very interested in its performance.