HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Apr 03, 2012, 04:51 PM
William Hanshaw
Joined Jul 2011
13 Posts
MP Jet 040PB - Sleeve Orientation Question

Hello Guys...

I have a MP Jet 040PB and I've tried everything to get it running well. A friend has one that runs great and it's compression is about the same as mine, but we couldn't get more than about a very weak 2krpm out of mine. And swapping carbs didn't make any difference.

I'm wondering now about its sleeve orientation. My question is: should the small rectangular opening be turned to face the carb, or instead, should the larger round sleeve hole be oriented to the carb? Although the sleeve's larger, round hole is the same diameter as the crankcase's hole at the carb end, I still wonder if it should be that way because the sleeve's hole is beveled upwards, I'm guessing so it will direct the fuel air mix UP towards the combustion chamber. However, this orientation of the sleeve will place only the small rectangular hole to input fuel air mixture into the case.

Can anyone advise me on the correct orientation that the sleeve should be installed? The Czech engine seems to be in otherwise good shape and well-made...just want to get the little jewel running well! Sent it back to Ed Carlson and he said he got it running up to a respectable 8krpm, but I haven't gotten it to do that.

Thanks, Bill Hanshaw wghanshaw@sbcglobal.net.
william hanshaw is offline Find More Posts by william hanshaw
Reply With Quote
Sign up now
to remove ads between posts
Old Apr 03, 2012, 05:24 PM
Registered User
Canada, ON, Hamilton
Joined Oct 2005
2,532 Posts
Bill, a few pictures would be helpful.
ie) a picture of the present orientation that doesn't seem to work too well.
John
JohnAV8R is offline Find More Posts by JohnAV8R
Reply With Quote
Old Apr 03, 2012, 07:04 PM
Registered User
earlwb's Avatar
USA, TX, Grapevine
Joined Dec 2008
12,885 Posts
If it ran Ok for Ed Carlson then it is working OK. Unless you took it apart. If I remember right, the cylinder sleeve will tend to rotate when you loosen or tighten the cylinder top. So you have to use a clean wood or plastic stick through the exhaust to hold it still while you are tightening it up.

Generally on the engines that use the piston to control the intake, the lowest hole in the cylinder should match the intake tube nicely. The tallest port is the exhaust port.
The lowest hole is only exposed to the inside of the crankcase when the piston approaches top dead center and a little after. It is closed off the rest of the time.
earlwb is offline Find More Posts by earlwb
RCG Plus Member
Latest blog entry: My new Gaui X5 Rc Helicopter
Reply With Quote
Old Apr 03, 2012, 09:19 PM
"Unnecessary Necessity"
coriolan's Avatar
Canada, BC, Vancouver
Joined Sep 2006
5,759 Posts
Looked at it on Icare-rc's site, a very nice looking little classic diesel!Also saw that the MP JET .061 BB is availlable again(c/l&r/c) as well as some nice Super atom and Letmo reproductions.
http://www.icare-rc.com/diesel.htm
coriolan is offline Find More Posts by coriolan
Reply With Quote
Old Apr 04, 2012, 02:54 AM
Sticks, Tissue & old Diesels
brokenenglish's Avatar
France, Centre, Amboise
Joined Nov 2011
1,540 Posts
I think Earl is probably right. You seem to have a problem of cylinder rotation inside the crankcase.
I had this problem on a couple of repro Mills engines (so now I only use originals!).
Cut a clean strip of hardwood (ply will do) to the exact width of the exhaust ports. On the cylinder, make sure you know which port is induction and which is transfer (this should be easy just by careful observation, the transfer port will be slightly higher than the induction and should be facing forward). Insert the cylinder, making sure you have this correct fore/aft orientation. Then insert the wooden strip through the exhaust ports, right through the engine (in one side and out the other). This will prevent the cylinder from rotating while you tighten the head down really tight. You'll need a strap wrench to do this or, at a pinch (Ha-Ha!), you can use pliers WITH 1/16" soft alloy sheet between the pliers jaws and the head, but be very careful and don't try the pliers/alloy sheet method on an anodized head!
The whole operation shouldn't take more than 5 minutes. Let us know how the engine runs.
brokenenglish is online now Find More Posts by brokenenglish
RCG Plus Member
Old Apr 04, 2012, 03:38 PM
Voices through wires? Ha!
Chas's Avatar
Joined Feb 2003
1,658 Posts
William, here's mine poodling along for inspiration

MP Jet Run.MPG (0 min 23 sec)


also gave the AM15, DC Sabre and ED Bee an airing; and why I prefer a 4k idle on a PAW 19, keeps it smooth and can idle indefinitely, and on a 10x5 the pitch speed is still only 20mph...I do not want to fly a Jackdaw slower than this! By contrast the 2.8k idle is staccato and can only be held safely for a minute or so in the air, if you hope to throttle up and warm up to full revs again. Although, a lot would depend on cowling, ambient temperature, etc.

AM 15
AM15 Run.MPG (0 min 41 sec)


ED
ED Bee Run.MPG (0 min 26 sec)


DC
Sabre Clip.MPG (0 min 55 sec)


PAW 19 TBR, burpy
PAW 19 2.8k.MPG (0 min 24 sec)


and steady
PAW 19 4k.MPG (1 min 5 sec)
Chas is offline Find More Posts by Chas
Last edited by Chas; Apr 04, 2012 at 04:54 PM.
Reply With Quote
Old Apr 04, 2012, 06:24 PM
Closed Account
Joined Nov 2009
2,653 Posts
On eBay UK...
http://www.ebay.co.uk/itm/GB-15-Dies...item43aebb671e
Twin-Stack is offline Find More Posts by Twin-Stack
Reply With Quote
Old Apr 04, 2012, 08:01 PM
Registered User
Canada, ON, Hamilton
Joined Oct 2005
2,532 Posts
We all seem to like our little diesels

Posted before, but now another look.
One is soon to have company!

The crank cases are all made by a similar process, but the OT just seems a little smoother, or is it my imagination?

At the time (1974,5?) I did not realize that the OT was re-worked, a used MKIV Oliver, tuned by George Copeman in 1972, with correct lighting flash and date stamps on crank case.
Why anyone would re work an OT is beyond me.
John
JohnAV8R is offline Find More Posts by JohnAV8R
Last edited by JohnAV8R; Apr 04, 2012 at 08:13 PM. Reason: added picture
Reply With Quote
Old Apr 04, 2012, 08:53 PM
Voices through wires? Ha!
Chas's Avatar
Joined Feb 2003
1,658 Posts
Quote:
Originally Posted by JohnAV8R View Post
Why anyone would re work an OT is beyond me.
John
Just a lightening of the piston and a smoothing of the ports. Olivers were sent out with "stepped" transfers, George smoothed and polished these with diamond abrasive. There is always someone who thinks that an extra 300 rpm will get that extra cut on a 20oz Dominator
Chas is offline Find More Posts by Chas
Reply With Quote
Old Apr 05, 2012, 02:39 AM
Sticks, Tissue & old Diesels
brokenenglish's Avatar
France, Centre, Amboise
Joined Nov 2011
1,540 Posts
Quote:
Originally Posted by JohnAV8R View Post
Why anyone would re work an OT is beyond me.
John
John & Chas,
Another important mod made by George was that, as you know, Olivers were made for team racing, which means setting up the crankshaft bearings fairly tight, to avoid losing fuel through the front bearing. This costs a little power and a slight increase in rpm can be obtained by setting up the front bearings fairly loose. On a combat model, this also offers the added advantage of keeping the front bearing clean as it's permanently being washed by outgoing fuel!
So, if you notice that George's engine is losing a bit of fuel out of the front bearing, it probably isn't due to wear, it's meant to be that way!
brokenenglish is online now Find More Posts by brokenenglish
RCG Plus Member
Last edited by brokenenglish; Apr 05, 2012 at 02:54 AM.
Reply With Quote
Old Apr 05, 2012, 03:42 PM
Registered User
United States, CA, Thousand Oaks
Joined Sep 2010
204 Posts
Question for Chas

Thanks for posting the videos, Chas. What props are you running on your Sabre and .040? I've only run mine using 8-4 wood propellers, but your video appears to show larger clubs being swung. Both are really sweet engines, not big on power, but very easy to start and tune. Just curious!

-Mark
Moeregaard is offline Find More Posts by Moeregaard
Reply With Quote
Old Apr 05, 2012, 05:31 PM
Voices through wires? Ha!
Chas's Avatar
Joined Feb 2003
1,658 Posts
Hi Mark !
Yes I'm a bugger for pushing the prop envelope, but frankly I would not usually use the 9x5 as I did in this case on the Sabre. However I was stuck with the aluminium anodised spinner (no propnut) and the crankshaft protruded into the nose, so I had to use a prop of maximum hub thickness - anyway I was curious to see how the engine would handle it. Not bad, about 5k, but it was way too much pitch. Normally a 9x4 I would regard as maximum.

The .040 is swinging a 7x4 , again about the limit I would think, but this time perfectly flyable.

The .19 is turning a 10x5 Graupner grey, AM15 and ED Bee both 8x4
Cheers Mark
Chas is offline Find More Posts by Chas
Last edited by Chas; Apr 05, 2012 at 05:53 PM.
Reply With Quote
Old Apr 05, 2012, 06:55 PM
Registered User
United States, CA, Thousand Oaks
Joined Sep 2010
204 Posts
Thanks for the quick response! I've never run my .040 with anything but an 8-4 Rev-Up prop, and it seems to like it. I'd planned to put it in a Tomboy, but the thought of losing what's become something of a collector's item keeps me from doing this. I have two Sabres, so maybe I'll build something around one of them.

-Mark
Moeregaard is offline Find More Posts by Moeregaard
Reply With Quote
Old Apr 06, 2012, 02:55 PM
Registered User
Stuttgart, Germany
Joined May 2001
44 Posts
Taifun HURRIKAN 1.48 ccm Diesel

Hello Guys

my new item, never used and complete.

Regards
Dieter
Dieter Doerr is offline Find More Posts by Dieter Doerr
Last edited by Dieter Doerr; Apr 06, 2012 at 03:05 PM.
Reply With Quote
Old Apr 06, 2012, 07:16 PM
Registered User
earlwb's Avatar
USA, TX, Grapevine
Joined Dec 2008
12,885 Posts
Quote:
Originally Posted by william hanshaw View Post
Hello Guys...

I have a MP Jet 040PB and I've tried everything to get it running well. A friend has one that runs great and it's compression is about the same as mine, but we couldn't get more than about a very weak 2krpm out of mine. And swapping carbs didn't make any difference.

I'm wondering now about its sleeve orientation. My question is: should the small rectangular opening be turned to face the carb, or instead, should the larger round sleeve hole be oriented to the carb? Although the sleeve's larger, round hole is the same diameter as the crankcase's hole at the carb end, I still wonder if it should be that way because the sleeve's hole is beveled upwards, I'm guessing so it will direct the fuel air mix UP towards the combustion chamber. However, this orientation of the sleeve will place only the small rectangular hole to input fuel air mixture into the case.

Can anyone advise me on the correct orientation that the sleeve should be installed? The Czech engine seems to be in otherwise good shape and well-made...just want to get the little jewel running well! Sent it back to Ed Carlson and he said he got it running up to a respectable 8krpm, but I haven't gotten it to do that.

Thanks, Bill Hanshaw wghanshaw@sbcglobal.net.
I took a look at my PB-40 engine and the two rectangular ports are the exhaust ports. The transfer port looks round and it is higher than the intake port that is piston controlled. Also the intake port is not exposed above the piston crown, so it is lower than the transfer port.

In other words, The two rectangular holes were the exhaust ports.
The round hole pointed towards the front of the engine.
The round hole was almost even with the two exhaust port holes.
The other fourth hole faces to the rear and it is lower down, not as high up with the other three holes.

I hope that helps you out.
Earl
earlwb is offline Find More Posts by earlwb
RCG Plus Member
Last edited by earlwb; Apr 07, 2012 at 09:10 AM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Need help with two diesel engines ! cosmin Engines 4 Apr 18, 2014 07:18 PM
Diesel Engines Aeromister Engines 8 Sep 01, 2009 07:17 AM
WTB-Model Diesel Fuel slogo Aircraft - Fuel - Airplanes (FS/W) 3 Nov 13, 2004 09:42 PM
scale model of engines dw1122 Life, The Universe, and Politics 2 Apr 23, 2004 05:43 AM
diesel engines wyflyer_55 Fuel Plane Talk 7 Apr 22, 2002 02:45 AM