Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin  |  Contact Global Moderator
September 16, 2019, 04:38:00 AM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: [1] 2   Go Down
Print
Author Topic: Heron 1cc diesel - help needed  (Read 1217 times)
0 Members and 1 Guest are viewing this topic.
Manne
Silver Member
****

Kudos: 0
Offline Offline

Australia Australia

Posts: 105


Topic starter


Ignore
« on: February 21, 2012, 10:00:44 AM »

Hi Everyone, can some body help please?
I have an old Heron 1cc diesel which I am trying to get back from the dead. The last time I ran a diesel was when I was about 13 (many, many years ago. Here's a hint, Ian Smith had not declared UDI in Rhodesia)
The engine has been cleaned and I have managed to get it to fire, but only after priming a little fuel in the port. I do not know what the correct setting for the needle valve or the compression should be. I have initially set the needle valve to 3 turns open and the compression at a point where the engine fires.
Can anyone give me some pointers?
Logged
TimWescott
Platinum Member
******

Kudos: 14
Offline Offline

United States United States

Posts: 1,004



Ignore
« Reply #1 on: February 21, 2012, 11:13:48 AM »

If it sounds like it's running nicely on the prime, then that means that your compression (and a lot of other things) is at least good enough for it to run.  But if it then doesn't continue to run, it means that there's something wrong with the fuel delivery system.  Given that it runs on a prime, it's almost certainly too lean.  So either you just haven't been adventuresome enough with cranking the needle open, or you've got an obstruction in the spraybar or needle valve, or for whatever reason your tank is not delivering fuel.

If you're confident in your tank, I'd make absolutely sure that your needle valve is clean and flowing fuel.  At the very least I'd take out the needle and squirt some fuel through the spraybar; if it's easy to take out I'd do just that, and make sure that the spray hole is free of dirt.  If you're not confident in your tank, make sure that fuel can flow, then watch the fuel tube going into the spray bar -- look for bubbles, just plain no fuel, etc.

I don't fly diesel engines a lot, but I do always find it a challenge with a new engine to get the right combination to get it started.  Once that's done, though, I've always found it reasonably easy to get them tuned the way I want.
Logged
Daithi
Gold Member
*****

Kudos: 36
Offline Offline

Ireland, Republic of Ireland, Republic of

Posts: 628


Simplify - then add more lightness



Ignore
« Reply #2 on: February 21, 2012, 12:03:30 PM »

3 turns is normal on the needle - but check that the pinhole isn't clogged up (remove it and soak it in meths or similar - dried oil can turn gummy and that will block the fuel getting through).

Attach a piece of tubing and try blowing through - if your face turns red and nothing happens, that's the problem Wink
Logged

It's not that modelling is in my blood. My blood is on a LOT of balsa Wink
TimWescott
Platinum Member
******

Kudos: 14
Offline Offline

United States United States

Posts: 1,004



Ignore
« Reply #3 on: February 21, 2012, 12:53:29 PM »

Note that testing the spraybar hole by making sure that fuel will draw if it's fully choked isn't enough -- that hole can be partially clogged and draw fuel up just fine, yet still have a problem with fuel draw.

Blowing air is better.

Disassembly and actually cleaning the spraybar -- if you can do it easily enough -- is best.  I'm not familiar with that engine (the US is culturally backwards when it comes to model diesel engines), so you have to decide if it's worth it to take it apart.
Logged
Mark Braunlich
Platinum Member
******

Kudos: 75
Offline Offline

United States United States

Posts: 1,022




Ignore
« Reply #4 on: February 21, 2012, 01:56:51 PM »

Might be some new info here for you:
http://www.rcuniverse.com/forum/m_7968234/anchors_7968503/mpage_1/key_/anchor/tm.htm#7968503


http://modelenginenews.org/cardfile/ME_heron.html
« Last Edit: February 21, 2012, 03:31:11 PM by Mark Braunlich » Logged

Mark
dputt7
Platinum Member
******

Kudos: 90
Offline Offline

Australia Australia

Posts: 1,981




Ignore
« Reply #5 on: February 22, 2012, 01:55:41 AM »

Hi
I had a Heron in a free flight Albatros C 111, It was great until the day it wouldn't start anymore. same thing as yours run on the prime but not enough crankcase compression to keep it running, just plain worn out. Hope that's not the case with yours, one thing amongst the good advice given is to make sure the hole in the spray bar points down to the crankcase if its a one holer or if it has 2 holes they should be horizontal ( front and rear ) Good Luck
regards Dave
Logged
Manne
Silver Member
****

Kudos: 0
Offline Offline

Australia Australia

Posts: 105


Topic starter


Ignore
« Reply #6 on: February 22, 2012, 04:11:08 AM »

Thanks one and all for the replies.
Dave, the spray bar is a 2 holer and yes it is orientated across. I hope it is not worn out. I will give it another go this afternoon and see what happens.
Manne
Logged
Manne
Silver Member
****

Kudos: 0
Offline Offline

Australia Australia

Posts: 105


Topic starter


Ignore
« Reply #7 on: February 28, 2012, 10:27:39 AM »

After 10 million flicks, a tired arm and only a short run, I am beginning to wonder if the engine is worn out.
Would additional ether in the fuel make a difference?
Manne
Logged
Daithi
Gold Member
*****

Kudos: 36
Offline Offline

Ireland, Republic of Ireland, Republic of

Posts: 628


Simplify - then add more lightness



Ignore
« Reply #8 on: February 28, 2012, 11:45:52 AM »

I would doubt it very much - the fact that it fires shows that there is ignition.
It does sound as if the fuel just isn't getting into the cylinder. It could be lack of compression and just possibly a rebore may help, but it's not certain
Logged

It's not that modelling is in my blood. My blood is on a LOT of balsa Wink
gossie
Platinum Member
******

Kudos: 49
Offline Offline

Australia Australia

Posts: 1,725



Ignore
« Reply #9 on: February 28, 2012, 03:45:09 PM »

Try lots of castor, and more ether........you just may be lucky. 
Logged
glidermaster
Gold Member
*****

Kudos: 16
Offline Offline

Canada Canada

Posts: 853




Ignore
« Reply #10 on: February 28, 2012, 04:00:29 PM »

Assuming you have fresh fuel, Gossie is right.

If your fuel's old, you could just add a little fresh ether.
John
Logged

Gliders are a part of me.
Manne
Silver Member
****

Kudos: 0
Offline Offline

Australia Australia

Posts: 105


Topic starter


Ignore
« Reply #11 on: February 28, 2012, 07:25:05 PM »

Ok, thanks guys.
In this over regulated society it is going to be fun finding the ether, but who knows, I may find a sympathetic chemist.
Manne
Logged
glidermaster
Gold Member
*****

Kudos: 16
Offline Offline

Canada Canada

Posts: 853




Ignore
« Reply #12 on: February 28, 2012, 08:25:48 PM »

I believe Bradex 'Easy Start' (for recalcitrant car engines) is almost pure ether.
Logged

Gliders are a part of me.
TimWescott
Platinum Member
******

Kudos: 14
Offline Offline

United States United States

Posts: 1,004



Ignore
« Reply #13 on: February 29, 2012, 09:58:06 AM »

In the US, John Deere starting fluid is supposed to be almost pure ether.  I'm not sure if it's sold in the UK (I assume that's where the engine is), or if it is if it's the same stuff.

Also in the US, you can look at the safety warning label and figure out the ether content of your starting fluid, which turns the task of finding one with lots of ether into a tedious task, instead of an impossible one.
Logged
Daithi
Gold Member
*****

Kudos: 36
Offline Offline

Ireland, Republic of Ireland, Republic of

Posts: 628


Simplify - then add more lightness



Ignore
« Reply #14 on: February 29, 2012, 10:17:09 AM »

Easy Start is high ether content - but it's in a pressurised can and VERY dangerous if you try to open it.

TBH, I'm not convinced ether is the problem here - the fact that the engine DOES fire would suggest that there is enough ether in the mix - the fact that it stops running would lead me to think a lack of compression (and it's not sucking the fuel up)
Logged

It's not that modelling is in my blood. My blood is on a LOT of balsa Wink
TimWescott
Platinum Member
******

Kudos: 14
Offline Offline

United States United States

Posts: 1,004



Ignore
« Reply #15 on: February 29, 2012, 11:33:10 AM »

To extract the product from any aerosol spray can, grab a pint jar or paper cup or other open-mouthed container that won't melt with the stuff.  Go outside (preferably on a dry, breezy day), point the nozzle at the edge of the cup and into the cup about 15 degrees.  Spray.  Most of the stuff will end up at the bottom of the cup.

This may work better with a narrow-mouthed jar -- but I haven't tried it.

Does the engine seem to run out the entire prime, or does it just splutter and sput, maybe just giving you one weak fire on one revolution?  If it runs out the prime lustily, then the top end is good, and you've probably got compression in the crank case as well.  If it just splutters and sputs, then you may be temporarily sealing it with the fuel, enough to fire, but not enough to go on.

To check for compression, rotate the prop by hand over top dead center.  You should get a definite push coming down from TDC.  The longer you can hold the engine at TDC and still have it push down, the better the seal is -- just a fraction of a second is good enough for glow engines, but I know that diesels need better (and I don't know how much).

I have one (glow) engine that'll hold compression like that for several seconds.
Logged
Manne
Silver Member
****

Kudos: 0
Offline Offline

Australia Australia

Posts: 105


Topic starter


Ignore
« Reply #16 on: February 29, 2012, 07:50:59 PM »

Thanks for the input.
Tim, you may have something there. I will try the compression test by using a little heavier oil in the port. That should provide a better seal around the piston, then if it is worn the oil seal would give a good compression, which I compare with a fuel 'seal'.. (We used to check for valve leak and compression in auto engines that way).
I am not sure if any of the ether based starters are available in Aus.
Manne
Logged
Daithi
Gold Member
*****

Kudos: 36
Offline Offline

Ireland, Republic of Ireland, Republic of

Posts: 628


Simplify - then add more lightness



Ignore
« Reply #17 on: February 29, 2012, 07:58:07 PM »

Oil in the port will give you a false indication (it was an old trick used when selling a clapped-out motor).

With the oil it seemed that the engine had good compression - when you put any fuel in though, it was useless
Logged

It's not that modelling is in my blood. My blood is on a LOT of balsa Wink
Manne
Silver Member
****

Kudos: 0
Offline Offline

Australia Australia

Posts: 105


Topic starter


Ignore
« Reply #18 on: March 01, 2012, 08:45:52 AM »

Hi Daithi,
You have a point, I realize that, however it will give me an indication if there is a lot of wear, or am I fooling myself? How else can I gauge the wear factor?
Logged
Mark Braunlich
Platinum Member
******

Kudos: 75
Offline Offline

United States United States

Posts: 1,022




Ignore
« Reply #19 on: March 01, 2012, 10:37:02 AM »

Manne,
Are you using the attached tank?  Can you get any fuel draw by flipping the prop with or without finger over the air intake?  Try using separate tank and elevating the tank a bit to give you some fuel pressure at needle valve.  You could possibly just use a length of transparent fuel tubing to give you the head of pressure. If you have clean NVA and you're not getting fuel draw, you have a pressure leak in the crankcase.  Make sure your gaskets are good.

Also, is the red anodized cylinder head red or pink?  I've read that the red anodize on some diesels (McCoy) can turn pink with a lot of heat cycling....a way to know the engine has seen a lot of use.

Mark



Logged

Mark
Manne
Silver Member
****

Kudos: 0
Offline Offline

Australia Australia

Posts: 105


Topic starter


Ignore
« Reply #20 on: March 01, 2012, 11:06:04 AM »

Hi Mark,
I did manage to get the first run with the attached tank, but it tended to draw air, and I aso think that there is a leak in it.
The fuel does draw when I choke the intake. I did install a separate tank and did elevate it, which did help initially but then it flooded so I took it back down to neutral.
NVA? May I ask what you mean?
The head is still quite red, so I dont think it has had too much heat.
Logged
Daithi
Gold Member
*****

Kudos: 36
Offline Offline

Ireland, Republic of Ireland, Republic of

Posts: 628


Simplify - then add more lightness



Ignore
« Reply #21 on: March 01, 2012, 11:35:44 AM »

One check is to screw down the contrapiston hard so that it actually stops the piston from moving. Then back it off a couple of turns, turn the engine by hand and see if it moves the contrapiston and then check to see how far it actually moved (if it fails, then there isn't enough compression)

It sould be able to push it back a couple of turns on the compression screw
Logged

It's not that modelling is in my blood. My blood is on a LOT of balsa Wink
Mark Braunlich
Platinum Member
******

Kudos: 75
Offline Offline

United States United States

Posts: 1,022




Ignore
« Reply #22 on: March 01, 2012, 12:26:46 PM »

NVA= needle valve assembly

or
Normandy Veterans Association

or
North Vietnamese Army

Take your pick Grin
Logged

Mark
Ployd
Gold Member
*****

Kudos: 19
Offline Offline

Australia Australia

Posts: 297




Ignore
« Reply #23 on: March 01, 2012, 04:56:46 PM »

Hi Manne

I see from your profile you are located in WA and not far from Perth so you should be able to contact the local control line fliers regarding a source for ether, I will try and dig up Charlie Stone's contact details and he should be able to help with your engine problem.

Ployd in OZ
Logged

"So I collect engines, what's your problem?"
Manne
Silver Member
****

Kudos: 0
Offline Offline

Australia Australia

Posts: 105


Topic starter


Ignore
« Reply #24 on: March 02, 2012, 04:01:03 AM »

Hi Ployd,
Thanks for the help. I have been in contact with Phil Trueman at TARMAC and we have been communicating about it.
If Chas Stone can help, that will be great. I will look him up on the AWA website.
Regards,
 Manne
Logged
Pages: [1] 2   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!