Does anyone have a magazine engine test report on the ST-35C, stunt and combat engines?
Hothandle:)
ST-35C, Stunt and Combat engines
Stuka Stunt Main Forum · 7 of 7 known posts recovered
LAST EDITED ON Jul-23-03 AT 10:32 AM (CDT)
I am NOT an expert, but I have used ST C35's and like them a lot.
Please E-mail me and I will give you the benefit of my meager wisdom.......
Also I am sure there are a LOT of guys here with more knowledge than me.......
Please tell us what you want to know.
I am NOT an expert, but I have used ST C35's and like them a lot.
Please E-mail me and I will give you the benefit of my meager wisdom.......
Also I am sure there are a LOT of guys here with more knowledge than me.......
Please tell us what you want to know.
Dave Moffitt
Hi Hothandle,
Starting back in the 60's, I flew a ST 35 Stunt plain bearing. It had good power and a 4-2-4 break but is nearly 8 oz. I tried to attach a ST ad/report but I don't think it worked. I can tell you that the stunt (baffle piston) claims .55 HP @ 13000 and the combat(flat top piston) claims .65HP @ 17000 rpm. They are 20 mm bore and 18 mm stroke. Generally a good quality engine, but not so good with a muffler because they have sub piston induction. I can try to email you the pdf files if you send me yours.
[email protected]
Starting back in the 60's, I flew a ST 35 Stunt plain bearing. It had good power and a 4-2-4 break but is nearly 8 oz. I tried to attach a ST ad/report but I don't think it worked. I can tell you that the stunt (baffle piston) claims .55 HP @ 13000 and the combat(flat top piston) claims .65HP @ 17000 rpm. They are 20 mm bore and 18 mm stroke. Generally a good quality engine, but not so good with a muffler because they have sub piston induction. I can try to email you the pdf files if you send me yours.
[email protected]
John O. Wright
I have an Aeromodeller review of the ST 35S somewhere. As I recall, it was about 1000-1500 RPM up on a Fox stunt 35 with the various 10 x 6 props they used.
On the subject of mufflers and subpiston induction, George Aldrich did not think it made any difference. He said he had set up an engine with muffler, run it, then recut the exhaust port for considerable subpiston induction and found that it made no difference in how the engine performed. I'm just repeating what he told me, as I have no personal experience with the subject.
Jim Thomerson
Jim Thomerson
Interesting. I would have thought s.p.i. would have reduced rpm when a silencer is fitted. That is perceived wisdom, is it just a folk myth?
Someone of George's stature, and his opinions, command respect. When in doubt all we can do is repeat the tests, both static and flying.
Peter Chinn's tests of engines in the ST G20 series with spi showed serious rpm loss when fitted with the muffler. The 1952 Tiger Mk.2 (diesel) replica I sell also suffers significant rpm loss when so fitted, and this also has significant s.p.i.
I've held off getting involved in this thread because I thought Dave Day might have some comments. He won the Brit. Vintage Championship at our Nats with a PB ST C35 in a Box Car Chief. I assumed it was the baffle engine, but on asking he told me it was the flat top. I can vouch it performed well.
In this thread, make sure you are comparing the PB engines and not the G21/35 BB Hotrod!
E.&O.E. Regards to all, Ian R.
Someone of George's stature, and his opinions, command respect. When in doubt all we can do is repeat the tests, both static and flying.
Peter Chinn's tests of engines in the ST G20 series with spi showed serious rpm loss when fitted with the muffler. The 1952 Tiger Mk.2 (diesel) replica I sell also suffers significant rpm loss when so fitted, and this also has significant s.p.i.
I've held off getting involved in this thread because I thought Dave Day might have some comments. He won the Brit. Vintage Championship at our Nats with a PB ST C35 in a Box Car Chief. I assumed it was the baffle engine, but on asking he told me it was the flat top. I can vouch it performed well.
In this thread, make sure you are comparing the PB engines and not the G21/35 BB Hotrod!
E.&O.E. Regards to all, Ian R.
I have had some success running McCoy Redheads on mufflers, and they have sub piston induction. The trick is to use a chamber muffler with little back pressure. If you use a tongue muffler with lots of backpressure, exhaust, instead of air, is induced and a loss of power is the result. In recent years, I have tested my ST C35 Stunt and had good stunt runs, but not killer power. For my 35 ships, I have therefore opted for the O.S. Max 35S. It is lighter, has a good stunt run, and comparable or better power. But I still love my ST 35's.
John O. Wright
Hi Hothandle
I have a ST 35 C that I've had since I was a kid. When I became interested in Stunt I called George Aldrich and asked him about the performance of the ST 35. He said to add head gaskets until it ran a 2-4 break. He sent the gaskets and I did as he said. The engine is still running with plenty of power for a 35 and runs a sweet 2-4 break and is dependable as always. I don't know anything about motors but Georges advice worked for me.
Greg
I have a ST 35 C that I've had since I was a kid. When I became interested in Stunt I called George Aldrich and asked him about the performance of the ST 35. He said to add head gaskets until it ran a 2-4 break. He sent the gaskets and I did as he said. The engine is still running with plenty of power for a 35 and runs a sweet 2-4 break and is dependable as always. I don't know anything about motors but Georges advice worked for me.
Greg
Greg L. Bahrman