stevesak

My Feedback: (27)

Actually KMOT, if you see a single bank 4,6 8 or 10 cylinder radial it will almost always be a two stroke.... just like the one from your link. Even numbered two stroke radial are quite common because they are not constrained by the alternating cylinder firing orders that you see with 4 cycles.

I want to explain quickly to avoid boring everyone.... As we all know it takes two full revolutions of the crank for a standard Otto 4 cycle engine to generate a power strpke. (exhaust, intake, compression, combustion/power). This is accomplished optimally with an odd number of cylinders in a radial. The firing sequence alternates each cylinder and it is perfectly balanced. For example, 9 cylinders will fire in this sequence when the crank turns exactly 720 degrees... 1 Fires - (2 pauses) - 3 Fires - (4 pauses) - 5 Fires - (6 pauses) - 7 Fires - (8 pauses) - 9 Fires - (1 pauses) - 2 Fires - (3 pauses) - 4 Fires - (5 pauses) - 6 Fires - (7 pauses) - 8 Fires (and then it repeats, of course.) When it runs, the cylinders will fire in this sequence and the sequence ALWAYS skips a cylinder.

1-3-5-7-9-2-4-6-8-1-3-5-7-9-2-4-6-8-1-3-5-7-9-2-4-6-8-1-3-5-7-9-2-4-6-8-1-3-5-7-9-2-4-6-8.....

If the 4-cycle engine had an even number of cylinders, then it will have to look something like this (for a 4 cylinder engine)... 1 Fires - (2 Pauses) - 3 Fires - 4 Fires - (1 Pauses) - 2 Fires - (3 Pauses) - (4 Pauses) and so on... This configuration is not balanced.

With a two stroke (cycle) radial, this is not a problem. Because every down stroke is a power stroke, your firing sequence is very simple. There are no pauses, so the firing order would simply be 1-2-3-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9 (for two complete revolutions). A 4 cylinder would be 1-2-3-4-1-2-3-4....

This is an oversimplification because two stroke radials have their own set of complications to overcome like creating positive crank pressure to load the cylinders if using a standard master/slave conrod arrangement (usually with a pump). Another solution would be to confiigure multiple throws to have all cylinders simultaneously fire.

Because of semi-simplicity of the two stroke radial, it frees the engineer up to make them with an even number of cylinders as they please.

I think that I've also heard the term "real two stroke radials have even cylinders".... Only one of my two stroke radials has even cylinders, however.... oh well.

kochj

I may be picking up a ASP 5-cyl.
Do any of you know what the circuference of the outside of the heads are?
I need to find out how big of a cowl I need to conceal this thing.
Also, where do you find a manual in English?
Is the one that comes with it writen in multiple languages?


Also, how do you make a do-it-yourself onboard glow heater for the 5-cyl radials??

Also This was on youtube....
SIly amazing!
http://www.youtube.com/watch?v=Y1rjRmTV9qE

Thanks
Justin

the Gnome

Justin, regarding the glow driver, if You need one for Your test stand only, You can use several (minimum one per cylinder) NiMh or NC Cells (2000mAh or more) connected in paralel to supply the plugs. I use such a unit for my test stand, the batteries are connected via electric flying 4mm gold plugs and sockets un a rail, so I can disconnect them from the rail and switch them to a series for quick charging.

If You want a unit to fly with and don't want to buy one from MICROSENS or so, You can use a voltage regulator IC, the LT1084CP can be set from 1.2V to 30V and can stand 10A, so You could use two NiMh- or a single LiPo cell to supply the unit and set the output voltage to 1.5V. If You like to switch the glow plugs on and off at a speciffic throttle, You could use a switch unit connected to the receiver.

You can get both from CONRAD Elektronik ( www.conrad.de ) for instance, the voltage regulator has the parts number: 148202-33 and a rc switch unit You can find with the parts number 235377-62.

If You would like to have a wiring diagram, send me an email

gnome

Holm und Rippenbruch

Aluminum Overcast

I have a 400R I'm just readying for break in, possibly later today. I need to make a harness as well. Just for the break in test stand as I'll be using an on board glow made by elelctro dynamics for flight. I recall Kmot had posted a nice pic of a well executed Wiring rig a while back IF I remember correctly.....Can you repost or direct us to the message Kmot? I can't seem to find it.

kochj

Thank you guys!
I have thought it over....
A ASp engine I can get for about 900$
then you add shipping from china 78$
Then you add paypal 4% = 45$

You are wll at tab over 1050$............
The problem I see with this is 2-things....
1. The ASp 5-cyl engine is quite heavy
2. I has no warrenty from these importers....
Bad case .......
You end up with a expensive paper weight!!!

@2800 or 99 oz.... a 6lb one at that!!!
I think It would be worth my while to save a little more and get the saito 5cyl.

It is 5lbs( a poud less than the asp) which makes it easer to find a plane to place it in....
I thought about the Giant Aeromaster bi-plane. I believe that it would fly much better at a pound less weight and warrenty to boot!!
Also the saito seems to run better! Easier starting and just a better engine....
These are JMHO though....

Thanks all
Justin
So I might order that up soon....

Ram-bro

My Feedback: (101)

sounds like good reasoning to me.

the Gnome

and who was it posting those terrible things concerning quallity and wear of the internal parts of the ASP just after break in several sites before? I think, there are good reasons why chinese "goodies" are not so expensive and their market grows that much...

gnome

Holm und Rippenbruch

Kmot

My Feedback: (24)

Jan, one person posting a problem with an engine does not make an entire production suspect.

Aluminum Overcast, here are some photos of my first test stand ignition system.

kochj

I in no way was implying that ASP were bad engines... that wasn't my intent...
If it was a ASP 1.60 I would not give it a second thought because I know that Hobbypeople will back up the products 2-year warrenty....
If I bought it from this Hi val website, they would give me nothing but a "ohh Too bad, Here is the Manufacters number to order new parts"
I think that if Hobbypeople brought that engine over it would be a good seller, but I also think that it might be a nightmere ... Who really knows?
Piece of mind is a real big thing in my book. I worry like crazy anyway,,,, I would be a wreck!

Justin

rslstft

My Feedback: (10)

kochj,
Sonictronics (www.sonictronics.com) has a McDaniel on-board glow driver for 5 cylinder engines. I have used their glow drivers on single and twin cylinder engines for years and always have worked perfectly. Not the cheapest, but then again, what's $130.00 when you think of the cost of the engine?

Russ

TURBINATOR

I went through this same reasoning and bought the Saito. I have never been more satisfied with a motor. It is the best motor I have ever owned!

Jeff

Aluminum Overcast

Saito is a great company with great products, no doubt. I can personally attest to that as I have many of their engines of all different sizes and vintage. Many flown hard and often......for years. I'm just in the process of rebuilding an old standby (Saito .56) in my zero warbird. This engine and aircraft (.45 sized EZ Zero arf) combination has well over 800 hours (not a typo!) of flying time over a six year or so period. Awesome power from the little .56 and 30% Omega fuel. In fact, most of the time I'm actually a good bit faster than the .60 size Hanger 9 / Saito 100 combination the rest of the guys are flying with at the club field. At 8.5 lb. it's a very heavy plane for it's size but after six years I have learned to use the weight and power of the engine to keep ahead the larger birds. I did consider the big 3 cylinder Saito for the CMP 50cc Zero I'm working on for this coming spring. I chose the ASP because it has more torque and the added weight of the engine over the saito 3 means no lead will have to be added to get the ship to balance properly. If you have a scale radial aircraft the original design takes into account a short nose moment and a heavy radial. That is scale!

The guy I bought the ASP from on ebay does give a 1 year warranty actually but even without it you could almost buy 2 of these and still be less than a five cylinder made by another brand. In other parts of the world where the engine is sold (sometimes under a different name) it does come with a warranty and as such, consideration on issue of reliability and durability has been addressed at the design stage.


Furthermore, if you plan to fly the engine regularly, the ASP is a great value in that you are only jeopardizing a grand or so, not 2,3, or 4 times that. If you are just going to collect and use them for display and only occasionally run them if ever then reliability is moot isn't it?

Ram-bro

My Feedback: (101)

I got my ASp because I wanted a radial for my Aeroworks pt-17. I looked into the OS and the Saito and they were gonna cost an arm and a leg as you all know. I happened upon the one on ebay and for about 1/3 of the cost. I figured I had nothing to loose . It now resides in my Skyraider waiting for paint and some nerve. I think the ASP has brought more radial flyers into the market and into this forum. I know I have learned alot and got to interface with people I never would have . I feel I am miles and yrs ahead of the game .....So far the reports we have all received have been promising on this engine.

Aluminum Overcast

I plan to run mine tomorrow mid day or so and will post an update. The engine has never been run. Any idea s to where the low speed needle should be? Mine is almost all the way out. I think there was a very bumpy road involved in its long journey to my doorstep!

kochj

800 hours of run time!!!
Well, then if you go by that reasoning, there isn't a duabt in my mind that paying 400$ more for a saito 5-cyl is worth the difference.....

I wasn't able to find anyone that gave any warenty,,,
I also do not have a plane to support a 6-lb engine.
It is hard to do. I think it is great that you found one that can,,, (CMP zero)
I might just start off with the saito 200TI inline twin for my GP hawk... and see how that goes...

Sandman Norway

Back to the Seidel ST-770 again :-)

Been doing some more bench running. and have a few observations..

First its a PIA to start at low temps, we have aprox 2-5deg C and this cold weather certenly does it hard to start.
Maybe 5% nitro is in order..?

Another thing is, that I reach max RPM (6K with a 22x10 Menz Ultra) at a little over halv max throttle setting. If I open
the carb more it start to "stutter", and loose RPM.. I have the OS carb on mine.. Is this normal...?
I have not leaned the engine out, but i runs strong, with instant trottle respons...

I`m still running 10% oil, and zero nitro. The engine has now seen 5L of fuel, and I*m about to switch to 6% oil...

Another thing, or more like a tip: I had one of the cam-follower stuck in the bronze/brass nut/bearing. Leaving the intake in open position... THIS is not a good thing.. I would imagine that the piston would hit the valve, but it did not apair to happen..

I removed the little bronze/brass bearing with the stuck cam follower, and did som small lapping of the surfaces, to get it to run
friction free.. After this, i oiled them all.. Dont want this to happend again... I have run the engine after this happend, and it runst strong. But I*m a little concerned about damage to the valve/piston... Should I pull the cylinder apart for inspection..?

Does any of you have opened up a seidel before..? It looks labour intensive, and I*m afraid to screw up the timing...

Best regards

Sandman

the Gnome

Hello Sandman, first a hint to make cold starting more easy perhaps: If You are running Your ST770 without exhaust collector, i.e. with the exhaust stacks only, You can primer the upper cylinders by injecting some drops of fuel into the exhaust stacks and then turn the engine backwards two revolutions. My ST710 starts emediately after that, even when it's cold outside.

Regarding the effect with max rpm at half throttle, does Your carb have the extra venturi inside the throttle?, it should have about 6.5mm in diameter. Mr. Seidel sais, that, may be sometimes, he forgets to fit it to the carburettors, so,may be it's missing on Your engine as it was on mine.

To the stuck tappet, my Seidel had an incorrect adjusted valve timing, so that the intake valves, when play was adjusted correctly, just hit the piston at TDC. This did not harm the valves or pistons, after correcting the timing it runns very strong now. So I think You must not be affraid, if Your engine has about the same compression at each of the cylinders TDC and it runns strong, everything should be ok and I would not take it appart.
For the case You want to split it though, better don't try to unscrew the cylinder heads, Seidel uses a special tool for that, not to harm the cooling finns.

gnome

Holm und Rippenbruch

Sandman Norway

Hi Gnome...


Your recomendation on priming the upper cylinders makes sense.. By handflipping, it looks as the lower
gets too wet, and the uppers are too dry, for an instant start-up. When warm, this must be the most easy engine I have ever
started.. to point of being dangerus. I made a mistake once, as I was to turn the prop slowly to a better position for a "clean" flip,
and it started rapid. Me, the idiot, had the ignored that the glow was active....

I dont think I will split the engine... The engine runs good, and the compression feels similar on all strokes..

I dont have a insert in the carb throat, but this does allso make sense. I had once a OS 120 pumper, that behaved similar.
The fix was to reduse the intake diameter.. Is this insert a cylindrical reducer..? If so I could easy make my own..

When you say: Unscrew the cylinder head. You mean the dismantling the head from the cylinder..? I have allways wondered
about how the cylinder was attatched to the head. I guess its srewed on, but that must involve some presicion cut treads so
that the head aligns with the cylinder base.. The more I know about the labour behind these engines, the more I love it..

You could say I got bitten by the Seidel bug :-) Wish I had the founds to collect them ;-(


Thanks again Gnome..


Mfg Sandman

the Gnome

Sandman, yes, the heads are screwed to the cylinders by a very fine thread and fixed with a small pin to prevent it from loosening. I'm not quite sure, but I think they mill the bottom of the cylinder after screwing the head on.

And yes, the venturi is made of a small brass tube, the inner diameter is about 6.5mm, with conical reduction at the ends. I made a little drawing to explain it.

gnome

Holm und Rippenbruch

nilsreinert123

Hi , I ran my asp 400 for the first time acouple of months ago ,and was wondering abit on the low speed needle ,mine was also almost all the way out ,but that is actually in the area where it shall be. It starts easy!

Anyone that know of any good and easy to fly FW 190 `s for this engine. I have looked a bit on the meister scale 102" version ,looks great.
Are there any light ARF versions in balsa that could fit?

Aluminum Overcast

Thanks for the info Nils! My Manual on the 400 R says low speed should be two revolutions out from tight so I'll start there and richen as needed....I'm off to the field!

nilsreinert123

Yeah ,my manual too ,but only 2 turns ,my engine did not get fuel ,so i had to screw it many turns out to make the engine run. I dont rember how many ,but the top of the screw should be out of the "hole"

Aluminum Overcast

Thanks, I'll try that.

the Gnome

Hi everybody, I just finished my self made collector ring for the Saito, it's made of "Krumscheid" ( www.krumscheid-metallwaren.de" ) quarter bows. I used the silver hard soldering material they supply and it was really easy to put the parts together. The exhaust flex-tubes are the ones that came with the engine, I jhst shotened them to about three inches and soldered them onto the Krumscheid tubing. I think its best to wait with the collector exhaust until I have the engins fitted to the model, so that I can set the position to the speciffic shape of the cowl.

What a pitty I cannot hear it without the finished outlet tubing...

Is there any supplier of stainless steel tubing with a drop profile in the US to make such a collector from?

gnome

Holm und Rippenbruch

MarvinE255

My Feedback: (10)

My asp 400 low speed needle is out about 12-13 turns to run well. If you take the carb off and look at the spray bar 2 turns hardly allows any fuel to enter the engine.