Cox Engines Forum
You are not logged in! Please login or register! Guests are limited to posting in the "General Questions (Guest Posting Allowed)" section only. Becoming a member is fast, easy and FREE!


Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Cox Engine of The Month
November-2017
MauricioB's

"Cox Tee Dee .010"



PAST WINNERS
Speed Contest 2018
CEF Traveling Engine

Gallery


Win This Engine!
The Traveling Prop
World of Aviation

A flooded old Pee Wee getting a throttle

View previous topic View next topic Go down

Wanted A flooded old Pee Wee getting a throttle

Post  fabersum on Fri Jan 01, 2016 11:40 am

Hello everyone

I am new here and new at Cox Engines.. I bought a Surestart to do my first experiments and a couple of Pee Wee that are the ones I am really interested in.

One of the Pee Wee was "gummed solid" so I put it into a glow fuel filled jar for a couple of days. Now it turns freely with what seems to be a good compression.
I would like to try to run it but of course now it's totally flooded by the dirty fuel and I don't know how to drain it out. Should I try to blow it away from the cylinder and crankcase with my compressor's  blow gun? Would I damage the Reed valve maybe? Should I open the tank's backplate to drain the fuel?
Should I just Mount it on a motor stand, put a propeller on, plug the starter clip and try to start it?

Any suggestion is very welcome!

Andrea


Last edited by fabersum on Tue Jan 05, 2016 9:03 pm; edited 1 time in total
avatar
fabersum
Moderate Poster
Moderate Poster

Posts : 17
Join date : 2015-12-07

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  getback on Fri Jan 01, 2016 11:49 am

WELCOME TO THE FORUM !!! Andrea , You will need to take it apart and clean the insides too, pick up tube , reed assy. be very careful with the reed as not to bend it and note the way the retainer is put in as to put it back the same way clip pointing out as not to pinch the reed ,, remove the needle and clear that passage , if it turns over fine I wouldn't worry with removing the cyl. / pist. Hope this helps sure there will be some others chiming in also . Keep us posted on the progress . getback Small Cox Logo
avatar
getback
Top Poster
Top Poster

Posts : 4272
Join date : 2013-01-18
Age : 60
Location : julian, n.c.

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  Kim on Fri Jan 01, 2016 12:19 pm

What he said!!!

AND....WELCOME TO THE FORUM ANDREA !!!!!!!

Yep, there's probably plenty of goop inside the engine that will still be there, so disassembly would be a good idea.  You may also have to look at swapping the gaskets and pick-up tube, since these tend to give up with age.

If the tube does look to be in good shape, I like to remove the needle valve, stick a small tube in there, and give it a hard back-flush with a fuel bulb to hopefully remove more stuff (this is with the tank removed, and holding the back plate over a pan or paper towel).

Good luck, and there will surely be others checking in shortly !!!


Last edited by Kim on Sat Jan 02, 2016 4:53 am; edited 1 time in total
avatar
Kim
Top Poster
Top Poster

I Support My Forum

Posts : 5716
Join date : 2011-09-06
Location : South East Missouri

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  xplaneguy on Sat Jan 02, 2016 12:44 am

Welcome to the forum Andrea! I'm glad you're here and getting great info from getback and Kim.

Looking forward to your results....best of luck! Smile
avatar
xplaneguy
Gold Member
Gold Member

Posts : 212
Join date : 2012-01-12
Age : 48
Location : Rosamond/Edwards AFB, CA

View user profile http://www.rcgroups.com/forums/member.php?u=263724

Back to top Go down

Wanted welcome

Post  happydad on Sat Jan 02, 2016 12:58 am

fabersum wrote:Hello everyone

I am new here and new at Cox Engines.. I bought a Surestart to do my first experiments and a couple of Pee Wee that are the ones I am really interested in.

One of the Pee Wee was "gummed solid" so I put it into a glow fuel filled jar for a couple of days. Now it turns freely with what seems to be a good compression.
I would like to try to run it but of course now it's totally flooded by the dirty fuel and I don't know how to drain it out. Should I try to blow it away from the cylinder and crankcase with my compressor's  blow gun? Would I damage the Reed valve maybe? Should I open the tank's backplate to drain the fuel?
Should I just Mount it on a motor stand, put a propeller on, plug the starter clip and try to start it?

Any suggestion is very welcome!

Andrea

Welcome to the forum. Ask questions and get answers. It's easy.

This Site Rocks! I Love This Forum!

Welcome Welcome Welcome Welcome Welcome Welcome Welcome Welcome     and

  welcome

happydad RC Plane         Futaba Radio Jeep
avatar
happydad
Platinum Member
Platinum Member

I Support My Forum

Posts : 1158
Join date : 2012-05-28
Age : 72
Location : Escondido, CA

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  Ken Cook on Sat Jan 02, 2016 5:10 am

A major problem with most Cox engines is the castor goo that accumulates in the crankshaft area in the case when left dormant. While you might be successful in freeing the crank and engine to the point of running, it may not reach it's full potential. The crank sometimes needs to be removed and all the varnish needs to be mechanically removed. What happens is that this varnish like goo heats up as the engine is running and it tends to grab a hold of the crankshaft like a brake not allowing the engine to come up to full rpm's. Certainly it's worth a shot to run the engine to see if it's satisfying but as I mentioned, this procedure might be necessary.
avatar
Ken Cook
Diamond Member
Diamond Member

Posts : 2819
Join date : 2012-03-27
Location : pennsylvania

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  ARUP on Sat Jan 02, 2016 9:25 am

Welcome aboard from one newby to another!
avatar
ARUP
Gold Member
Gold Member

I Support My Forum

Posts : 179
Join date : 2015-09-13
Location : Kentucky

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  fabersum on Sat Jan 02, 2016 1:01 pm

Hi everybody!

First of all, many thanks for the warm welcome! Then, thanks for your instructions. I still don't have any .020 wrench so I cannot fully disassemble the engine but I should be able to do what getback suggests. So I will start from there and see how the thing looks inside. Will keep you informed :-)

Since I found such a bunch of kind guys, let me take full advantage with some more question..

How much is an used PeeWee RC Worth?
Would it be possible to make a good work at machining a standard Peewee cylinder to provide the required precision fit with a matching machined exhaust throttle?
Does the Pee Wee have the same internal structure as a Babe Bee?
Would it be possible to modify a Pee Wee to work with an "Ace" kind of throttle like the one for the .049? https://www.coxengineforum.com/t5486-049-reed-valve-venturi-throttle?highlight=049+throttle

Thanks again to everyone! Have a nice Sunday!

Andrea
avatar
fabersum
Moderate Poster
Moderate Poster

Posts : 17
Join date : 2015-12-07

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  fredvon4 on Sat Jan 02, 2016 2:05 pm

Andrea

With good precision machining tools most any modification is possible

I think you are asking about reducing the cylinder diameter to fit a exhaust throttle and only have this to say... Sub Piston Induction (SPI*) on some of these engines interferes with muffler type throttles because the engine receives dirty hot exhaust gasses instead of clean air to add to the fuel mix

If this engine has SPI it is better to try and throttle by the method you suggested and yes a "ace" type would work but I have never seen one offered for the dinky engine BUT exceeding easy to fabricate if you want. Or find and fit a non SPI piston and cylinder combination ...truth is I don't know enough of the PeeWee engines to know if they even exist


SPI is a way to add additional cool clean air to the fuel air charge by lifting the piston skirt bottom a few thousands above the bottom of the exhaust port as the piston rises towards TDC...on the next down stroke there is a larger volume of air and fuel in the crank case to be compressed and shot up the fuel and boost ports... a very effect system for un muffled engines to gain a bit of power and rpm
avatar
fredvon4
Diamond Member
Diamond Member

Trusted Seller
Posts : 2215
Join date : 2011-08-26
Age : 62
Location : Lampasas Texas

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  roddie on Sat Jan 02, 2016 2:33 pm

fabersum wrote:

Would it be possible to modify a Pee Wee to work with an "Ace" kind of throttle like the one for the .049? https://www.coxengineforum.com/t5486-049-reed-valve-venturi-throttle?highlight=049+throttle

Thanks again to everyone! Have a nice Sunday!

Andrea

Hi Andrea, welcome to the forum! If you want to try this.. I would suggest obtaining a spare Pee Wee backplate first, to experiment on. The Ace style throttle is basically a piece of music-wire with a round taper ground on one end. It slides through a firewall-guide on center with the air-intake on the back of the engine.. but there's a small mesh-screen that must first be removed by using a sharp sewing-pin/needle. NOTE though.. that removing the screen can allow dirt/grit to enter, which could get stuck under the reed. This can cause the engine to run erratically.. or not run at all. That's one drawback. Another drawback is designing a firewall mount on the model, for the tapered-plunger to pass through.. and serve as a guide so that the plunger moves straight into/toward the air-intake. The Pee Wee may have a smaller diameter air-intake than the .049 (Bee) engine.. I'm not sure because I don't have any Pee Wees. If the hole is smaller.. you may need to make a plunger/needle to fit. I have some common T-pins having a .046" diameter. The Ace plunger measures .062" and fits completely inside the Bee engine's air-intake; past the taper.. without binding. This allows stopping the engine by completely cutting off the air.

Cox "did" make an exhaust-throttle/cylinder set for the Pee Wee; as can be seen in this photo below.



avatar
roddie
Top Poster
Top Poster

Posts : 5462
Join date : 2013-07-17
Age : 57
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  fabersum on Mon Jan 04, 2016 10:14 am

Hello again!

I opened the two peewees as per your instructions - they didn't seem all that dirty, one of them was almost perfectly clean - and I realized I don't have to modify the backplate at all to try making an "Ace Venturi" throttle!
I took a look around the workshop for suitable steel and found one piece that's one breath wider than 1 mm (sorry, metric system here :-D) and it seems to fit the Pee Wee's venturi intake just fine.
So I am actually tapering steel needles..

Looking for an RC Pee Wee with the stock exhaust throttle in the while...

I'll update with some picture later.

Cheers!

Andrea

avatar
fabersum
Moderate Poster
Moderate Poster

Posts : 17
Join date : 2015-12-07

View user profile

Back to top Go down

Wanted Going Full Throttle!

Post  fabersum on Tue Jan 05, 2016 8:46 pm

Hello folks

here some picture of my pee wee opened and cleaned and some of the contraption I put together to test an "Ace Venturi" throttle.









two videos of the throttle needle moving




Hopefully Tomorrow I'll test the thing with the engine running.

By the way: how much nitro? 20% castor and it's fine.. I want these engines to last as long as they can so I am tempted to stay quite low on nitro.. 15%? I'll use a 5030 (5" x 3") propeller as per Cox suggestions (from the original pee wee leaflet)  but I have a 4.5" x 2" to try too.

have a nice weekend everyone!

Andrea


Last edited by fabersum on Tue Jan 05, 2016 9:01 pm; edited 1 time in total (Reason for editing : videos added)
avatar
fabersum
Moderate Poster
Moderate Poster

Posts : 17
Join date : 2015-12-07

View user profile

Back to top Go down

Wanted Lots of nitro

Post  706jim on Tue Jan 05, 2016 9:19 pm

25-35% is fine with these small engines. They run a lot better with higher nitro content.
avatar
706jim
Gold Member
Gold Member

Posts : 187
Join date : 2013-11-29

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  Surfer_kris on Wed Jan 06, 2016 7:46 am

In my experience a 5x3 prop is a little too much load for the PeeWee. Even with extra head gaskets the engine will run a little too hot and you end up chasing the needle (during a bench run). It will never finish the tank completely once in the air. The 4.5x2 works better in that respect, but even then can it be hard to run out the full tank for each flight...

I have had much better runs when I converted it to diesel fuel. It then spins a 6x3 with authority and finishes the tank each time. Smile

avatar
Surfer_kris
Diamond Member
Diamond Member

Posts : 1384
Join date : 2010-11-20
Location : Sweden

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  fabersum on Thu Jan 07, 2016 10:05 am

My trials wee totally unsuccessful.. none of my two pee wee wanted to run.
Waiting for new glow heads and wrench from the other side of the pond now..
avatar
fabersum
Moderate Poster
Moderate Poster

Posts : 17
Join date : 2015-12-07

View user profile

Back to top Go down

Wanted Re: A flooded old Pee Wee getting a throttle

Post  Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum