Pond Skipper

I like the inverted vertical stabilizer incorporated in the fuselage. Im sure it helped your V tail shark tracking smooth.

I do have an untested vintage CS .049 could be used in a future 1/2A speed project It has as larger dia intake than a TD 049 and the fuel nipple is almost twice the ID. This one was originally intended for CL use but could be adapted to RC. Considered a sport engine at that time.
Im not sure how much the original CS engines can provide RPM wise. 18-22k?
Shown with a 4.1x4.1

combatpigg

My Feedback: (3)

The VA I used was the RC version so it had less power than the VA combat engine. The RC version VA ran well enough to shear off the crank pin..! The VA would be worth more in the hands of a flyer who wants a .049 with a nice carb and muffler but not run with 4.2 x 4 props or with electric starters. It's a shame it broke because it really was a good runner.
The VA combat engine is right up there with the Norvel AMEs. I don't know exactly how they rate against each other but the VAs of certain vintages had lower end failures. A local CL flyer made a high strength rod as a fix for the VAs but I don't know if crank pins were a commonly failed item or not. Norvel AMEs were prone to cylinder / piston gouging...so just about all of these engines had their faults. This is why I say the Russian combat engines are the best money spent for the long haul if you want to go fast. No more tackle boxes and coffee cans full of ruined / salvaged parts, no rod reset tools. The Fora used to be 1/2 the price of the Cyclon and was just about the same power. I owned one for 7 years and never had the backplate off of it. It still ran strong when I traded it for the VA RC .049.

Pond Skipper

Thought I would cut the carb throat down at an angle add a pressure tap and re thread for a nelson plug. I could trim the piston.
The casting looks first class everything fits well and the piston is pinned to the rod no bearings as a sport engine.
If anyone has data on the CS 049 please pipe in.

combatpigg

My Feedback: (3)

That's a pretty engine..!
I think it is the forerunner of the Brodak..but not sure.
If this is what I think it is it has an iron piston...?

Pond Skipper

Yes Brodak starting selling them. I did some research this was bought and shown to be 049.
Some say the Red Heads are 061's. The early versions had iron pistons this one does not have a cast iron piston appears as pressed steel.
The bottom skirt is cut out appearing U shaped on both sides to conpensate for the weight of the cylinder rod pin. It has a lot of compression way more than my best cox 1/2A's.

Doing a search I found the following by Aspeed who has some actual observations:
"CS was real bad until I made a new turbo plug head, then it was good. The fuel was 10 or 15% and a 4.2 - 4" prop was used with no muffler on all of them. TD 22,900 rpm, GZ 17,000 - (21,000 with the turbo head) "CS 27,000", early split case RYOT VA 22,900, Stels 23,800, Norvel 22,500
ref;
http://www.rcuniverse.com/forum/1-2-...-va-049-a.html

At some point should tap out the head for a nelson plug with the venturi mod there is hope of a lasting muffled engine able to turn up reasonble rpm with a 4p prop / 25% nitro. Note the intake diffrence with the TD .051. The muffler is acually two piece the smaller tube unscrews making the exhaust tone louder than expected.

combatpigg

My Feedback: (3)

27,000 is getting into serious performance with that prop.
Who sold them in the USA..?

Pond Skipper

I dont know I suppose some folks had bought them from the source back in the day my guess.

[TABLE]
[TR]
[TD]4
[/TD]
[TD]Propeller Pitch ( in Inches )
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]27000
[/TD]
[TD]RPM (if at 10/15% nitro)
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD]- no muffler
[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]102.3
[/TD]
[TD]Maximum Theoretical MPH
[/TD]
[TD][/TD]
[/TR]
[/TABLE]

Additional options:
3.8 x 4.5 115 mph
3.6 x 5 - 128 mph
3.3 x 6 - 154 mph
2.8 x 7 - 179 mph


There is a way to go super light and fly fast to use a small prop if you dare an IFO type framed as a fast Delta wing frame to go over a hundred.
I have noted flying a past IFO type when at neutral incidence they always speed up like getting on ice slipping up to a new speed very quickly and then abruptly settles in at its new pace.
I would want the fabric tight if expected to surpass 100 mph. This type of craft can pan cake in at slow speeds
allowing smaller wings to further reduce drag weight. Since ripstop nylon should be easy to clean off the goo.
Could do a simple exhaust throttle by using the threaded hole for the muffler. Nip the intake down flar out the exhaust port / skip the throttle to squeak out some more top end.

Pond Skipper

If I cut back the firewall to install the TD 020 the spot for the existing fuel tank goes away. I could adjust the CG some leave the firewall as is and add the modified TD with a pee wee tank and leave the original tank in for additional fuel. I would imagine with the existing 1/4 oz tank and the pee wee tank I should get good run time. The tank as shown has a breather tube at the moment and the tank dia is suitable match to the front end. A aluminum plate could be cut to suit the existing engine mount screws with 4 drilled tabs to bolt on the pee wee tank footprint only the bolted tabs would stick past the fuselage. Note the dia to the stock TD tank. Would need to plug up the fuel pickup nipple inside the tank and reed / or tap and thread into the reeds air intake for a fuel pressure line.

aspeed

The CS .049 I have is totally different. That one may respond well to a new head, but this one is ABC BB and shares the case with an .06 model. The stock TD doesn't need pressure, just if you open up the venturi.

Pond Skipper

Thank you for checking in Aspeed, yes major difference
I would imagine the CS engine I have will be down in the low 20's at best with a nelson plug, cut down venturi and on a pressure tap from the muffler running on 25% nitro.

Pond Skipper

Could use the aluminum mounts sold on ebay and back to back they provide more fuel vol. note both insets provide additional room for fuel. You just need to source some threaded nipples to tap into the top and bottom. Can add a 1/4 thick rubber gasket for more vol. would need 1in long bolts. Stock screws shown.

combatpigg

My Feedback: (3)

That's an inventive solution..!
A good running TD with the built in tank mount can be some serious fun and make certain model design ideas easier to execute.

Pond Skipper

Yes 2 of those options have the engines snugged up close to the firewall with half or more of fuel tank tucked away will help with CG. Clear case of necessity giving birth to invention. The option with just aluminum matching engine mounts - weight 24.8g. if with brass backplate 28.3g

aspeed

Kind of like the Norvel large tank. http://www.nvengines.com/index.php?p...mart&Itemid=67 The smaller one was nice because it would fit the Cox reedy bolt pattern, and you could upgrade to the Norvel with it only being more nose heavy and much faster.

Mr Cox

Oooh no, not the CS engines again...
These CS sports engines are just a pile of crap...

CP had one with a casting defect in the piston. AndyW turned his into something useful by keeping the crankcase only, and possibly the crank, but replacing everything else with Norvel parts...

I have one (.061 RC) with a casting defect in the case (i.e. a hole). I have put some of my findings in this thread; http://www.rcuniverse.com/forum/1-2-...i-give-up.html

combatpigg

My Feedback: (3)

I remember now. Mine had a poorly fit P/L. Andy's solution was really creative and he made a silk purse out of it.

Pond Skipper

Thank you Mr. Cox that is a eye opening look at the mess your engine was in. I have gone through the engine have not spotted any problems as of yet other than the back plate is a tad undersized and all though it does screw in tight it may need some gasket goo if it starts to vibrate loose. Mine came with no plug I have a short plug on it at the moment seems ok. Will have to crank it up soon with a 4.1 x 4.1 and run rich for 1oz. then go from there.

aspeed

I think all of the older CS stuff was spotty. I have two CS .049s. This one never went as good as a TD until I made a new head after trying two other stock ones. One looked good, it was not a standard type conversion type. The other one was piped. It would not turn over at all. I bought it for a project for slightly less than retail from someone that gave up on it. I lapped it and it seems good. Since then I haven't put it in a plane but It seems good from a test stand run. Some of the Old Ucktams and other Russian stuff was like that too. Pay your $40 and try and build it yourself. I sorted through about five before I found one that I could use. It is pretty good really. I felt sorry for the other 4 customers that would sort through the rest to pick the better one. Pond Skipper, I think the 4.1" prop is way to small for the type of motor you have there. Maybe a 6-4, 6-3" or something would be more suitable. It is kind of old school.

Pond Skipper

lol yes I bought mine for 42 bucks as a just to see what it can do thing. I know some had modded th Brodeck versions Im not sure where
I stand with this vintage example.
Perhaps a 5 x 4 Apparently the engine is more robust than a TD physically in appearance at least.
I will have a shutter exhaust throttle to coax it up to speed.
I need to source a tap in my arsenal of tools - 11/32" x 32" for the nelson plugs I have 6 spares and one in use at the moment.

combatpigg

My Feedback: (3)

Does it hold compression if you slowly bring the [oiled] piston up to TDC for more than a few seconds..?
I've talked with at least 1 old timer who claims you can "grow" an iron piston. It's all about the right amount of heat and the correct quench I'm told.
Last time I looked it was either McMaster Carr or Enco...[or both] who had the 11/32" tap.
Sometimes Grainger can come through on stuff like this for less money, too. It's usually worth it to try them.

Pond Skipper

Yes I used Grainger in a pinch the other week for 9mm External Retainer Clips or the .010 throttle sleeve.
I say pinch as there is a fastener commercial supplier that has a lot of cheaper prices. I pulled the head off to check the piston size and type
it appears to be a .061 with a small squish cone the short plug almost fits flush.
I really need to buy a pressure gage there appears to be no loss past the piston after a few mins with this simple test also oiled the head threads prior.
Engine has good pop and compression.

Heres a pic.

combatpigg

My Feedback: (3)

It sounds like you have something to work with then. I have a model engine compression gauge but I'd trade it for a 6 pack .
If I was "in the business" it could come in handy to evaluate a batch of engines during assembly. What IS handy is having a way to pressurize the crankcase with air while you have the exhaust port blocked off. Air can be introduced through either the glow plug / spark plug hole or through the intake while the engine is under water. You can watch for air leaks where they shouldn't be. I watched a small engine repair guy test a bunch of used weedeater engines this way to quickly diagnose where they had problems. I made my own "tester" and it works good. I simply blow into a tube with modest pressure. The tube is sealed off at the carb with clay.

Pond Skipper

If I tap and thread a 2 mm grub screw into the exhaust throttle to screw on the existing threaded hole next to the engines exhaust port I can use it like a set pin to keep things lined up - will still use additional support by way of a strap or bracket. Engine should gain rpm in lieu of the stock muffler / exhaust tip shown for comparison. This is a 1/2A cox product stripped from its grey plastic housing for reed engines. Note the extra aluminum in the corners of the box could round file in some deep notches for a simple clip on wire keeper.

Pond Skipper

Could lose 10.2g of dead weight by ditching the stock Cox muffler and gain rpm with the leftover CS muffler. QB -110g / 09 -107g
The arched cut suits the dia of the muffler. I think the single allen head bolt will be enough.

combatpigg

My Feedback: (3)

What I do not think anyone has ever done is to build a miniature "mousse can pipe" for an .049 that actually provides a big boost.
For example...I built one from plans for a LA .40 and got [IIRC] a 1500 rpm boost with a 11 x 4 prop.