SUPERTIGER .15 PROJECT

Ken Cook wrote:                One of my club members has that particular  ST on a JR. Satan, it's pretty fast and more maneuverable then most I've seen fly.

I was just looking at a 1970s Model Airplane News
The ST 15 was $20 and a Jr Satan was about $4
To put those price into perspective I made $2 /hour  as a laborer [still in HS] and less than $200 / month once I enlisted in the Army.
A carton of smokes at the PX was $2.50

getback wrote:looks like one of those Russian jobs , With an Italian engine on it

YEP...!
I was copying the general layout of a Russian Ship but was too lazy to make a styrofoam leading edge.
I managed to use up a bunch of crappy mail order balsa that's basically too light for the way I like to build.
I have had good luck recently with National Balsa. They have a place where you can tell them what weight or stiffness you want. Plus they have a separate category on the menu  just for light weight balsa and another category for heavier balsa.

The "Junk Yard" piston and liner that I pulled out of the parts bin last night worked better than the original..so I was able to get a decent video today.

With that combination of combat plane and ST .15 engine, You truly fulfilled your moniker of @TD ABUSER!

I also use National specifically. I've had very good success using them for all balsa and ply needs. I switched to National after Lone Star Balsa burnt down which was a good many years ago.

GallopingGhostler wrote:With that combination of combat plane and ST .15 engine, You truly fulfilled your moniker of @TD ABUSER!

The engine sounded a little too lean while doing tight turns but I can't launch it any richer than that or it floods out.
I think there is enough of a crankcase pressure leak out the front to cause that.

I wonder how the ST .15s can be so durable but the  high performance ST .35s were so fragile...?

The old friend who gave me the .15s also gave me one of the ST .35 combat engines and it didn't take long to break the crank. I saw one of those ST .35s bolted to a plane that was just laying on the grass on a real hot day  try to fire up on it's own

TD ABUSER wrote:

Ken Cook wrote:One of my club members has that particular  ST on a JR. Satan, it's pretty fast and more maneuverable then most I've seen fly.

I was just looking at a 1970s Model Airplane News. The ST 15 was $20 and a Jr Satan was about $4. To put those price into perspective I made $2 /hour  as a laborer [still in HS] and less than $200 / month once I enlisted in the Army. A carton of smokes at the PX was $2.50

I think my high school days predate yours. In the late 1960's / eary 1970's, I was making $1.25 an hour at a chicken farm (egg layers and meat birds) in rural Hawaii. I enlisted at around $80 per month. By the time I could afford my first R/C plane (Top Flite Schoolboy), the radio (Ace R/C Pulse Commander) and a Cox .020 Pee Wee, I was a PFC earning a touch more. The cost of these was a month's pay, but I had a blast just the same. Since I didn't smoke, the cost of a carton of those cigarettes paid for the Pee Wee, bought in the hobbies section of the NX (Navy Exchange).

TD ABUSER wrote:The engine sounded a little too lean while  doing tight turns but I can't launch it any richer than that or it floods out.
I think there is enough of a crankcase pressure leak out the front to cause that.

I have no ST's, so really can't comment. The momentary sag in power seemed to be worst at changes in direction from say, inside to outside loop.

TD ABUSER wrote:I wonder how the ST .15s can be so durable but the  high performance ST .35s were so fragile...? The old friend who gave me the .15s also gave me one of the ST .35 combat engines and it didn't take long to break the crank. I saw one of those ST .35s bolted to a plane that was just laying on the grass on a real hot day  try to fire up on it's own

Sounds like maybe a design flaw, a manufacturing flaw, or combination of both. Ken warned me to be very careful on props for the 1950's Fox .09 Rocket side port, which had weak crankshafts, which can snap using higher inertia plastic props. Those engines should use wood only.

The ST .15 doesn't care for high pitch props. It runs well on 3 -4 pitch propellers. This would preferably be Rev-Ups if you have them because they're generally light on the marked pitch anyhow. I would think some of the combat F2D glass props might also be better suited for this engine.  I assume your running the stock needle? One thing that I do know is that they offered two different versions of the ST .15. One being a red venturi insert which could be a FAI engine whereas there was a gray venturi version. A forum member gracefully provided one to me some years ago. I have used it for similar projects but I never perfected it by experimenting.

                     Whenever I experience the sagging your mentioning, I increase the nitro and lighten the pitch load if possible . I find this helps with needle setting but the Tiger needle has always been so so with me in terms of achieving a decent needle. Yes, it works, but it doesn't work like a good OS remote needle which for this I use the no longer available O.S. 1A from the .10 carb.

Ken Cook wrote:The ST .15 doesn't care for high pitch props. It runs well on 3 -4 pitch propellers. .

That would be a good thing to try next....see if a APC 6.3 x 4 or a 7 x 4 works better.
I think APC really did their homework with the 6.3 x 4 the way they work with typical F2D Combat.

[quote="GallopingGhostler"]
I think my high school days predate yours. In the late 1960's / eary 1970's, I was making $1.25 an hour at a chicken farm (egg layers and meat birds) in rural Hawaii. I enlisted at around $80 per month. By the time I could afford my first R/C plane (Top Flite Schoolboy), the radio (Ace R/C Pulse Commander) and a Cox .020 Pee Wee, I was a PFC earning a touch more. The cost of these was a month's pay, but I had a blast just the same. Since I didn't smoke, the cost of a carton of those cigarettes paid for the Pee Wee, bought in the hobbies section of the NX (Navy Exchange).

Imagine making $80 / month..!

I had no real idea about anything model airplane related back then.
I had seen 2 Christmas morning Testors or Cox RTF planes crash on Christmas morning and that's about it.
I worked for a Warrant Officer who liked to talk about his RC Airplanes but I never saw them. It wasn't until 1985 that I walked into a well stocked hobby shop and laid eyes on several aisles of model plane supplies and kits.

TD ABUSER wrote:Imagine making  $80 / month..!

This is when the pay went up for the new "VOLAR" (Volunteer Army) recruiting campaign! The year prior, it was something like $60 a month! But the upside was, the Army provided free housing (the barracks, nowadays the kinder called "dormitory") and food (mess hall). One's pay was one's spending money.

TD ABUSER wrote:I had seen 2 Christmas morning Testors or Cox RTF planes crash on Christmas morning and that's about it. [...] It wasn't until 1985 that I walked into a well stocked hobby shop and laid eyes on several aisles  of model plane supplies and kits.

I had a tough time learning to fly C/L when I was a kid, because I had no one to teach me. I had several "one-shot" flights with Cox RTF's until in AIT, a classroom buddy helped me launch my built in barracks Sterling half-A Beginner series Fokker Eindecker with Babe Bee. I crashed many times flying on grass just outside the barracks. But the difference was, the balsa with music wire landing gear survived them instead of shattering. I had many flights before school end that the aluminum elevator horn's pushrod hole doubled in diameter from the engine vibration. Gave the plane to a friend day I graduated.

Back in '72 and prior (Dad was retired military) I had access to bases. Then, all bases had a model airplane hobby shop. One could basically buy kits, engines and supplies for wholesale cost plus. Basically cost was about half that of retail. Congress permitted this as the pay was so low. I saw those hobby shops close in mid-1970's. Then, the mail order houses were able to undersell the base hobby shops, they lost customers and thus lost justification to stay open.

I bought a half dozen Testors Series 21 C/L engines of various sizes, my younger brother did the same. They were on clearance for only $6 each. Regular price was about double. I still have a .40, my "yellow bird's bill to remind me of my greatest kill".


Taken in 2013, my Black Head .40 with a YS muffler field find on my test stand. Large chambered, it ran fine muffled.

There was still Pete's Model Hobbycraft in the Ala Moana Shopping Center, Waikiki. However, I saw it close too, when I was in college. They closed around 1979. Pete sold his business to one who didn't understand the hobby market. They increased the retail price, stop stocking "unpopular" items, became a waste of time to visit (not just for me but other customers, too).

After, I bought items from Hobbietat in the Kaimuki District, fuel and building supplies. Kept my college years fun. Would carefully strap my flight box to the package rack on my 1971 Honda CB100, the T/F Ken Willard Schoolmaster or Airtronics Q-Tee on the pillion side of my motocycle seat. Travel up over the Pali Pass to the public model plane field on the other side. Helped me to blow of steam between classes.

getback wrote:If thats to slow for you , I dont know what to tell ya .. not much sagging i could see but did look like a little smoke stream came out when a tight turn was done

Yep.
The smoke stream is puzzling. Now I think I've got bad fuel...with water in it. I tried another engine on a different plane and it's doing the same thing. Flies OK flat and level then it tries to quit in the maneuvers....even though you can still see quite a lot of exhaust spray.

GallopingGhostler wrote:


Back in '72 and prior (Dad was retired military) I had access to bases. Then, all bases had a model airplane hobby shop. One could basically buy kits, engines and supplies for wholesale cost plus. Basically cost was about half that of retail. Congress permitted this as the pay was so low. I saw those hobby shops close in mid-1970's. Then, the mail order houses were able to undersell the base hobby shops, they lost customers and thus lost justification to stay open.

I

WOW imagine having a hobby shop on post and 1/2 off everything...!!
Where do I sign up..?
What a great way to spend your spare time in AIT too.
I had a Testors .40 and it ran well. I just ran it on cheap hobby shop fuel which probably wore it out sooner than if I knew enough to add some oil to the fuel.

TD ABUSER wrote:WOW imagine having a hobby shop on post and 1/2 off everything...!! Where do I sign up..? What a great way to spend your spare time in AIT too. I had a Testors .40 and it ran well. I just ran it on cheap hobby shop fuel which probably wore it out sooner than if I knew enough to add some oil to the fuel.

There are few here who are intimate with the Testors red heads and later Series 21 black heads.

Instead of the tougher Iron Mehanite alloy pistons used by the other manufacturers, Testors resorted to a softer iron for their Red Heads. Plus, they were on the cheap so fit and finish was iffy between engines, some good, some with not much starting compression. The softer iron was easier to damage with wrong fuel and lean running conditions.

Yet, I found that at least mine that ran, they seemed to run better and handle better than the Foxes. There is a cult following with the Red Heads.

The black heads were changed to a Dykes piston ring fitted at the very top of the piston, so they didn't seem to hold much compression until you ran them. Problem with the BH's is that Testor changed the crankcase design making the engines heavier. Heavy is not good in a C/L plane.

Some with access to machining facilities have used Black Head piston and cylinder in the Red Head crankcase with some re-machining to accommodate.

Being "on the cheap", I've acquired a number of unsung heroes, the K&B Stallion .35. Metallurgy is better, Ken has pointed out some of their weaknesses and how to mitigate so one has decent runners. I bought them because they can be had at reasonably cheap prices, and reasonable durability. The .35 Torpedoes tend to be too expensive. I bought one I thought reasonably priced, but someone had manually hacksawed the piston skirt attempting SPI. That ruined what might have been a good engine.

But regarding cheap in the day of the military hobby shops run by the services squadron (on Air Bases), I remember Scientific Half-A C/L kits for around a dollar or two. In AIT, a pint can of model plane fuel was near the size of a can of Brasso, so it was easy to hide in the barracks built into wall, wall lockers. Then, the staff had no issues with so-called today's HAZMAT stuff.

I remember even in 6th grade, bringing in a cigar box, some razor blades, Xacto knives and Comet parts printed sheets, cutting out wing ribs, tips and fuselage bulkheads during break times. Try doing that today. Parents will be picking up their modelling enthusiast kid at the police station as a dangerous delinquent.