SureWasp049, Cox & AP hybrid
 

With the recent head swapping thread,
I'd like to consolidate some of the info we have on using AP Wasp parts on Cox enngines.. the SureStart049 in particular.

We have a great thread on replacement heads, including the WaspHead [link=http://www.rcuniverse.com/forum/m_7282911/tm.htm]here[/link].


I know someone was mounting an AP061 Carb onto a SureStart...
who's got the skinny on that project, so I can put that link here too.

Lets see some of those Frankensteins you guys have put together.
It doesnt have to be a SureStart/Product engine, I just listed that as an eye catcher. But it is easier to mangle a $7 engine in the name of science than a $50+ out-of-production one.

Lets see those carb additions,
maybe someone could fuse 2 AP mufflers with a CoxCylinder hole bored down between them
(L&R dual exaust SS? [8D])
what other AP parts can we use on our cox?

RE: SureWasp049, Cox & AP hybrid
 

Sure enough, that was me that did the AP .061 carb on the Sure Start. When we move in the next few days - to a week, and get situated in our newly build log home I will post some pics. The engine is at my mother-in-laws home as storage, along with all my other rc toys. My wife and I lived there briefly over the winter and that is where I did the mod.

If you take off the rear upright tube on the Sure Start there is a port that contains the needle valve. Remove the needle valve and its parts entirely. Now attach the AP carb directly to the port via silicone (or rubber tube) that is tight enough to secure around the outside diameter of the carb and port. I used little tiny hose clamps (purchased at the local hobby shop) to ensure that the hose would stay attach to both the carb and the port. Yes, it does work - very well; the AP carb has roughly the same diameter as the port. However, it doesn't have a muffler. My idle is around 2-3k while the top end will max as intended for the Sure Start.

RE: SureWasp049, Cox & AP hybrid
 

How well does it work in the air? Without muffler pressure, I would expect a giant "bog" if you open the air valve too quickly.

RE: SureWasp049, Cox & AP hybrid
 

I would like to see a surestart that does 2000 rpm reliably... Large prop?

I've tached a sloppy CS 0.061 down to about 2500, but that was on a 7x3 prop...

RE: SureWasp049, Cox & AP hybrid
 

What about adding rotational momentum without blade air drag with a heavy spinner
... well, a big spinner rather than 'heavy',
to put the mass further out as well as the adding of spun mass for better idle rpms


What kind of material could we use for a custom snorkle replacement that will bolt onto the engine normally, and has an inlet reamed to accept the AP carb (with a few orings for frictionfit or some mounting goo/glue). Seems one of the machinist guys here could whip out some 3/8 flatstock (alum/plastic?) bored for air passage, countersunk for the AP carb, and the 4 holes for the #2 screws... to just replace the snorkle

RE: SureWasp049, Cox & AP hybrid
 

Maybe one with a light rotor instead of a reed?

RE: SureWasp049, Cox & AP hybrid
 

My Sure Start has 1.5 inch spinner and I am using 7x3 and 7x4 props. Also, the fuel tank is a little brass 1/2oz - no pressure line at all. It will idle reliably (no stalls) around 2800 rpm. I did, however, through trial-and-error use a pressure line that worked by catching the prop wash (wind). I ran a line from the tank to a clip that I made to wrap around the cylinder jug. The end of the line had a little cone (much like the venturi on a carb) to catch the air in a larger area - this worked great, but I found out it wasn't needed at all. It works basicly by gravity feed. The tank needs to mount roughly a 1/2 inch above the carb where ever it is placed with the fuel line facing down from the tank.