Question: What! Me Combat? MP Jet .061 Factory Race Special

It looks delicate.

Rusty, I flew a Gladiator for quite some time. I had them since John introduced them. I feel you engine weight will be of value here. The plane was incredibly tail heavy and most didn't survive. The main problem is that they're so twisted out of the box that when you fly it, the outboard tip on some is darn near sticking straight up . The covering of these are lacking and if this plane hasn't been flown, I would highly recommend placing clear tape over the leading and trailing edge. This will keep the covering in place to a degree. 25K won't be so bad, but if you can get into some higher rpm's the plane will fly much better. The control horn is very small and therefore a handle with line spacing no greater than 2" will suit you much better. You should really be able to fly this plane without even looking at it. If you never have flown anything like this, I would suggest pulling the motor out as far as possible, give yourself some offset, tape a nickel to the wing for a first flight, change the control horn to a larger horn ( At least 1"-1 1/4" tall). I don't know what APC prop your using, I would try a Cox rubber duckie and trim accordingly. The APC props will break extremely easy on grass on landing. Using the 5x3 stock might keep your speeds down initially. Don't worry about them holding up. I run the Cox props into the 34K range. Just inspect them at the root daily and prior to flying especially after a ground strike.

Shawn took one of our most recent Gladiator's and cut the tail off moving it forward approx 1". He rebuilt the center rib and sewn the tail back on. This worked extremely well. Make sure the pin holding the bellcrank in is secure. The pin can slip right out allowing the bellcrank to come out. Ken

Thanks Ken. Mike covered most of that with me. He said they're unflyable in the out of box form. I will screw a small bellcrank to the top outside, extend the beams, clip the tail to less area and weight, tape it up, etc. I just stuck a prop on it for show, I have rubber duckies too. It should be entertaining if I can keep it in the air.
Rusty

I have only run them as RC and diesel and they are certainly great engines.
They can be really tight when new, helps to pre-heat the cylinder although they are not ABC engines...

What prop did you run to get 25000rpm?

What the he// I looked up the engine to see a better look and there he was .... Yoda right in the middle of the page , Ian you sure get around ,, Rusty looks like your going to get back up to speed real soon!! Does your club have others that are in to combat as well ( someone to play with)???   Eric

Surfer_kris wrote:I have only run them as RC and diesel and they are certainly great engines.
They can be really tight when new, helps to pre-heat the cylinder although they are not ABC engines...

What prop did you run to get 25000rpm?

Kris, I think it was an APC 5x2.  Maybe too small for that engine, I only let it run up that fast for about 15 sec. In my video I show it running 21.7k with an APC 5.5x2.5.

Since I have the mounts, I'll bolt these up side by side and run them. I'll see if that 25k can be reproduced, plus the FRS needs a break-in run too. I think you're supposed to do it with FAI fuel, and i have some left over from breaking in the first one.

RknRusty wrote:I think you're supposed to do it with FAI fuel, and i have some left over from breaking in the first one.

FAI fuel is usually 80/20 with all castor. It is better to add little castor though to get 25% (all castor) for the running in, I think that's what they recommend in the manual too.

A little nitro (5-10%) doesn't hurt, but you should use extra headshims then.

There are also remote needles for these engines, the stock position is scary close to the prop...

Surfer_kris wrote:FAI fuel is usually 80/20 with all castor. It is better to add little castor though to get 25% (all castor) for the running in, I think that's what they recommend in the manual too.

A little nitro (5-10%) doesn't hurt, but you should use extra headshims then.

There are also remote needles for these engines, the stock position is scary close to the prop...

80/20 is what I have mixed up. As I recall I had to prime it with a drop of nitro fuel to make it easier to crank. It sure is close to the prop. The newer of my two has a remote NV.
Rusty

Are the MP Jets still available? If so, where can I get one? I wouldn't mind having an R/C version.

Shawn

Try this. Looks like they have them in stock.
http://www.icare-icarus.com/Diesel-Glow-Engines_c_19.html
And they might be still available through Owen Engines in Austrailia.
http://oea.modelenginenews.org/pricelist_2012-07.pdf

RknRusty wrote:Try this. Looks like they have them in stock.
http://www.icare-icarus.com/Diesel-Glow-Engines_c_19.html
And they might be still available through Owen Engines in Austrailia.
http://oea.modelenginenews.org/pricelist_2012-07.pdf

Thanks for the links Rusty. I didn't realize they were so pricey. But I like the way yours ran in your video so I might end up getting one to use on a future 1/2a version of the Quickie 500 Pylon Racer.

Shawn

sdjjadk wrote:
Thanks for the links Rusty. I didn't realize they were so pricey. But I like the way yours ran in your video so I might end up getting one to use on a future 1/2a version of the Quickie 500 Pylon Racer.

Shawn

That would probably be right in its sweet spot. They aren't just sport engines. More like an AME .061, I think. I'm excited to see how the Factory Special runs. I'll probably have some video of it within a week. I'm going to see if it will cooperate with a bladder without modifying anything. If not I'll tap it like they say to.
I hope you can get one.
Rusty

After re-watching my movie, I notice I mentioned how insensitive the needle is. That must mean it's a pretty fine thread. Even the Cox guys that run crankcase pressure use KK valves. I'll unscrew this one tomorrow and get an idea of the thread count. Hell, I'll probably run them tomorrow, I've got the itch now. Damn, if it wasn't so late....
That engine on the first prop was really smooth. It's just barely broken in and will no doubt get faster like the Norvels do. I was afraid that APC wasn't aligned properly so was afraid to turn it up any more. It sounded unsteady at 21.7 or whatever it spun

BREAKING NEWS! THIS JUST IN!
Stay tuned! I'm declaring tomorrow MP-Jet engine run day. I gotta see if I can reproduce my earlier claim of 25k or thereabouts. That one caught Kris's eye. It was probably on a cold day but we'll have a one man tach race.
Rusty

I ran my oldest MP Jet on the bench yesterday. It is an RC, twin needle, BB version with the black painted muffler. With the muffler on it makes 19700rpm on an APC 5.7x3 prop (using 10% Nitro). This is even a little stronger than a Norvel .061, if I remember correctly...

The twin needle version has a very strong coupling between the two needles, so it takes some time to get it just right throughout the whole throttle range.

I just noticed that the head in the Video above is on "backwards" or rather rotated 90°, like it would be on a car?
Usually one puts the fins along the airstream for better cooling...

The broad needle setting might come from the lack of pressure feed, the RC version with muffler pressure is quite sensitive.

Surfer_kris wrote:I just noticed that the head in the Video above is on "backwards" or rather rotated 90°, like it would be on a car?
Usually one puts the fins along the airstream for better cooling...

The broad needle setting might come from the lack of pressure feed, the RC version with muffler pressure is quite sensitive.

I don't remember what nitro I was running but more than likely it was 25%. Maybe the RPM quest is a bad idea? I have 35, 25, 20, 15, and 10% fuel. I also have some 5/29 which may be a good break-in fuel for the FRS-BB after the first few runs with FAI 75/25 mixture.

The head was on backwards. Actually in the introduction scene it's on correctly, and when I ran it it was on wrong. It was a cold day and I had added a third gasket. It's on correctly now. I have run it since then. It will be 100F tomorrow, so I'll probably run two gaskets in the PB and one in the BB with no nitro.
Rusty

Yes, don't focus too much on the rpm quest, it is interesting to see numbers but a bench number doesn't mean much, it is the performance in the air that counts. These engines are really good, there is no doubt about it, treat them well and they'll last for a long time too.

Oh, I just saw that these engines are available at radical RC; Glow BB RC

I think these are from the latest run that MP Jet did, the didn't make any of PB ones then, only the BB. The carb might not have the second needle installed, I have seen that on some engines, but one would have to get one to know for sure...

Surfer_kris wrote:Oh, I just saw that these engines are available at radical RC; Glow BB RC...

That's a good hobby shop. $3 shipping in the US and lots of supplies.

RknRusty wrote: I was afraid that APC wasn't aligned properly so was afraid to turn it up any more. It sounded unsteady at 21.7 or whatever it spun

It might just be the prop, but if you watch the video and look at the prop disk of the APC, you can see some blade separation.

RknRusty wrote:
BREAKING NEWS! THIS JUST IN!
Stay tuned! I'm declaring tomorrow MP-Jet engine run day. I gotta see if I can reproduce my earlier claim of 25k or thereabouts. That one caught Kris's eye. It was probably on a cold day but we'll have a one man tach race.
Rusty

Cool, I can't wait to see more video.

Shawn

RknRusty wrote:

Surfer_kris wrote:Oh, I just saw that these engines are available at radical RC; Glow BB RC...

That's a good hobby shop. $3 shipping in the US and lots of supplies.

Thanks for the link Rusty. That's a great price. I have a B-Day coming up in a few days so I'm going to give a hint to my "Financial Advisor" A.K.A., My Wife. LOL

I also have a 22" balsa sheeted foam core wing laying around that needs a plane and engine.  
Hmmm now my wheels are turning!  

Shawn

The foam packing in the box the new engine came in had deteriorated and made a mess.


Here it is all cleaned up


Now I have a question. On the remote NV, have I got the line in from the tank and the line from the NV to the venturi plugged in correctly?

Hey Rusty, I'll try to get some pictures/video at the Bladder Grabber this weekend for you. Three days of Big Block Bashing!!!!!! Sorry no Cox engines at this one.


Fred- Wish you could have come this year. Hope you are still recovering well.