Project magnum
 

Project Magnum has begun.
MVVS GRRT in a Weston UK Magnum
www.philsrcworld.fsnet.co.uk
lets see if this pic link thing works
http://www.philsrcworld.fsnet.co.uk/...ghwithcowl.jpg

Cool!
 

Please keep me posted as I have a GRRT that needs a home-

Got pics?

james

Project magnum
 

pics and a full building review all on my site.
for tonight the canopy now fits with the engine and pipe in place, the nose needs engine bearers fitted ( damn needles being right on the same line as the lugs, anyone know of an engine mount that will will work or wont mind being hacked up a little? ) and the floor put in above the tank ( still enough room in there for a SLEC 6oz! )
The whole transformation has been quite easy really, and depending on results is definitely worth it if you have a West 50 and don't mind cranking the engine over and loosing a big lump of drag in the canopy.

lets have a poll IF i can work out how..... the fuz is loosing quite a bit of film and will need recovering.. i did think about redoing the whole plane a different colour and sticking back on the CF stickers.
can i only start a poll on the main thread? damn...
ok..

LEAVE YELLOW WITH STICKERS
RECOVER WHITE WITH STICKERS
RECOVER ( SUBMIT COLOUR ) WITH STICKERS

very bad quick photoshop of a white magnum.
Quite how you replace differnt shades of yellow with the same differance in white is way beyond me

Project magnum
 

just for fun heres a few colours in a Andy Warhole (?) style against a untypical Cornish blue sky.
leave the pic do its thing

Project magnum
 

I'd say if you plan on redoing the whole plane, take a real visible colour and leave those big stickers off... saves you some weight...

Can't you take a standard engine mount and put a couple of strips of alu under the engine mounting lugs to raise the needles above the bearers?

Project magnum
 

The engine is aready sitting very low to hide as much of it as possible, it means i cant lower the mount any. Im hoping to find a mount that is solid enough to cut a little away, most now have the two arms and just webs below.
I really think it needs the stickers.. tho i was going to put neon orange wingtips on the bottom or some more of the CF film for wingtips if i went white beause i have two sets of stickers. This would make it stand out better on our normally grey skys. The yellow Magnums do really stand out, im kinda torn between that, and having a white one.

Project magnum
 

i had some help today
http://www.philsrcworld.fsnet.co.uk/...es/helper2.jpg

Nose is shaped, more to come. keep checking the site for updates

Project magnum
 

page updated again and a little movie of a engine test added
http://www.philsrcworld.fsnet.co.uk/...RRTrunning.jpg

i also have a page with a Doppler shift speed measurer program to download

Project magnum
 

phillybaby

what prop are you running on your GRRT?

Project magnum
 

That was a APC 8x8, the GRRT has flown on that before and i know its not the right size, its was just something to use untill i can find the size i want

Project magnum
 

Okay I was wondering because it did not sound like it ever got up on the pipe. I am sure it would work pretty good with a little shaved off some.

Project magnum
 

it wasn't leaned out, tho it dosnt pick up much when i do. heres a list of props i can get hold of
http://www.alshobbiesstore.com/acata...ellers_67.html

Project magnum
 

maybe you are over propped. When you get up on pipe you should able able to tell a huge difference and a 7000 to 8000 jump in RPM's.

Thats the way mine does and its a GRRT. they should run the same. If it does not kick up on pipe it just sounds like a regular engine with a pipe hooked up to it. and no advantage from any other engine.

Maybe try shaving your prop some and see what kind of numbers you can get on the ground.

Project magnum
 

i don't think its the pipe that comes with the engine. whether this will make a difference i don't know. 7k jump is HUGE!!!!! like when it was running on the 5" fan :D
what should i shave it down to and how? i've never done that. i still have to get a balancer and taco. would the 7x8 be a better choice? 7x9?
i also currently have the 9mm carb on and i have to give it some more breathing room. i know this engine ran in this plane http://www.philsrcworld.fsnet.co.uk/...s_files/dd.JPG
on a 8x8 it was doing about 150 and with a 8x10 160-165 the figures may be wrong because i was standing in one point and timing a run between cones from a distance. however the difference in speed is accurate.

Project magnum
 

MVVS makes a pipe that is made for the GRRT. I would try that pipe out and see if you get different numbers.

If not shave of just the tips of the props like a 1/4" maybe a little more.. I did this with a 7.4 X 8 and finally got it up on the pipe. You will know when you have shaved enough because it will run WOT and have like a 2 second delay then get up on pipe. Well at least thats how it does on mine. It wont directly go up on pipe, it has a short delay. But you will know when your on it or not. It sounds pretty loud.

Project magnum
 

why don't i just buy a 7x8 then :confused: :confused:
how do you shave your props? chop off the ends and rebalanced or shave it back to the rough tip shape??
I'm a cheap skate ( loosing job dun help matters )... the Magnum was £30, the engine and pipe £15.. i have a pipe, i'll use it unless it explodes :p buying a new pipe isn't on the cards. its a hell of a pipe tho. my ears where ringing after that test run for at least 15 mins afterwards.
I have to order the servos so i'll get a couple of 7x8's at the same time. wonder if the APC will stand the RPM.. is there a thick hub option at that size? i gotta take it out to 7mm after all. if they cant take it i guess i'll have to go wood

Project magnum
 

well the reason I said to use 7.4 X 8 is because it is a Racing Carbon fiber prop. It has kind of a funny shape to it also.

The hub on it is a D1 instead of the standard C2. The D1 one hubs are much thicker and can take the abuse of a high revving engine better than a C2 hub.

I am sure you could just use a 7 X 8 prop from start. It would probably work too. But it is not designed for higher powered engines as the Carbon fibered prop is.

Shaving a prop probably is done different by each person that does it. What I do first is cut off the tips to a length I want. I am guessing what may work from start. You wont know until it is on engine. From there sand it to the shape of the prop as it would normally be at the tip. Then just balance it out and see how it works.

I am sure there are probably easier ways but this way seems to work with me. Sometimes it does not work and I have to take back off and shave off some more to get it right. But you will know when you have it by the increase in rpm's.

What RPM's are you getting right now by the way?

Project magnum
 

no idea what RPM's, i have no taco.. when i find where those nice and cheep pocket ones are i'll get one.. reminds me, i have to buy those servos and props today... i really didnt want to go carbon if i didnt have to, i saw one last one flight a while ago, a normal APC would have survived the slight ground touch it got on landing. too expensive to fragile

Project magnum
 

they have other ones that are D1 hub size but the sizes vary. to get a certain size it may be carbon or not carbon just to use that size prop. that is the only reason i ended up with the carbon prop. Was only because the size i wanted was only in carbon.

check out www.apcprop.com

Project magnum
 

shes done, shes almost a match for the West's and theres still more in that engine i know it
www.philsrcworld.fsnet.co.uk

Project magnum
 

Phillybaby,

According to your pic on post #14, I know that engine is NOT a GRRT Pylon 40. I have two of them, and the MVVS GRRT Pylon 40 is a Rear Induction and Rear Exhaust with open Venturi and a full wave tuned pipe. The engine should turn in excess of 21,000 rpm with 8x7 prop if it's a GRRT while running on the ground.

The engine you have look like a Sport motor with the exhaust turned backward. Also, MVVS don't make FAI Pylon Racing engine in Front Intake Rear Exhaust that I know of, at least for now. Hope this clarify it...

Project magnum
 

That pic is of the plane, not the engine, that plane did have the GRRT in it after this pic was taken with the tuned MVVS 40 and black mini pipe, this pipe was also used on the GRRT. if you look at the very first pic you can see it is indeed a GRRT, tho the pipe isnt a MVVS item which at the moment i think is robbing my speed, i've taken about an inch off it and its still not screaming like i've been told it should. can anyone tell me what the pipe length should be and where the reflect point is on the pipe as in pic one. it might be too long still, but without changing the plane i cant make it any shorter

Project magnum
 

Maybe you should learn how to tune a pipe, rather than asking, " can anyone tell me what the pipe length should be and where the reflect point is on the pipe as in pic one. it might be too long still, but without changing the plane i cant make it any shorter"

When you do know how to tune a pipe, Make sure you tune it BEFORE you install it. Just trying to lend a helping hand.

Don

Project magnum
 

I can tune a pipe, but with no throttle theres no jump to pick up on, its picked up from 14.8k to about 18-20k now with no real "on the pipe" jump in rpm i'd expect once i got it right, each 1/4 inch off has improved it, but having been told the GRRT can do 21k AND 30K with a 4K jump when you hit the pipe i have no idea what to believe. All i can do is keep chopping up the pipe ( have to get myself a taco to help with this bit ) and keep trying it, but with out knowing more i could make it too short, then have problems with over long silicon and a spacer ring which i don't have room for in the canopy, silicon entering the canopy i can manage ( as it is now ), further than this I'm screwed on space, making the pipe any shorted is also a problem. This is why asking people that know already is the best option.
This pipe isn't for this engine, so is probably the wrong length, and I'm not sure where the reflect point is for a full wave pipe as i've only ever had baffled pipes, I'm guessing at the stinger, but i could be wrong, i also don't know the piston to reflect point length for a GRRT, knowing this would help a lot and let me know if i've gone too far, or have to come shorter.
As you like to point out to me time and time again Don if you don't know the answer shut up.

Project magnum
 

Phillybaby.... nice homesite by the way!!! Very cool vids!!!

Project magnum
 

Thanks :)
stay tuned for a new review that'll take longer to write than the kit to build this afternoon!

Project magnum
 

are you running a header on your GRRT or is does the pipe clip directly on the engine?

See for my GRRT there was no tuning or cutting. The pipe was one length and that was it. All I did from there was experiment with props until i it that sweet spot.

Project magnum
 

i don't have a header, its the round exit type, the pipe came from a OS46 DF i think and when i used the fan on it it went like hell, the prop loads it up more and this is when i found I'm not close to this magic 25-30K
i've got a bit of silicon linking them about 1 1/2 long which is as much as the space can take, theres no gap between the engine and pipe, making it too short and then having to lengthen it would be a disaster space wise.
it has improved with each bit taken off but I'm not sure what rpm to expect on a 8x8, yes i know, 7.2x8.6 but i have a 8x8 :p I'm almost as fast as the west 50's so i dun wanna shorten more and rebuild the canopy area unless there IS more to come. will have to get the ground RPM next time out but it dun sound much.
when flying i've not heard it come on and off the pipe, just constant so I'm not there yet, tho i thought it might have touched it in a dive but soon came off. normally means to short?, weird.

Pic of the plane not pipe
 

I gotcha, Phillybaby!

As for the little Mini Pipe, you're wasting your time on it.
Why not buy the GRRT original pipe that was tuned for it?

If not and you want to tune a pipe for the GRRT, then take notes...

1. Get a tach and ears plug
2. Get a prop that the GRRT could pull (i.e. 8x7 or less)
NOTE: NOT 8x8, a GRRT can not pull that prop!
3. First, run the engine with no pipe with the 8x7 prop and take note on rpm
4. Now, run the engine with pipe installed and take note what rpm you're getting (NOTE: rpm will be less with pipe on if it hasn't been cut yet)
5. Next, start cutting pipe length 1/2" at a time until rpm reach above the rpm you get from engine run without the pipe
6. From there, start fine tuning the engine by cutting 1/4" at a time until the rpm no longer increase or dropped off. Once that's completed, you back the pipe by 1/2" to relieve the engine.
7. If you follow these instruction, you're good to go and can run different props with no problem's at all.

Note: There are many variable, but this is a standardize procedure to tune a piped engine. And most importantly, make sure the engine have a minimum of .015 head clearance for piped engine. Otherwise, you will be blowing plugs left and right.

Hope this help!

Project magnum
 

wow, what a noisy way to to do things lol
8x7, shouldnt be too hard to get hold of, i just worry about normal props on this engine, tho APC say the 8" is safe to 25K, so add a bit to that and im ok... When my mate ran his mini pipe he used 8x8 and 8x10, very quick, i dont have that pipe.
right, first job get taco. head clearence, i do have a shim, but the plug is holding out great so far.
I'll give it a go and let you all know the results.
thanks SSAN

Project magnum
 

yeah waiting to hear how it goes! And when you do get it up on pipe and it unloads in air your love the sound it makes. And it will tear through the sky with no problem.

Project magnum
 

lol, i like the way it goes already, its my fastest plane yet, but dosnt feel it.
when we played with pipes my mate tried his pipe from his West 50, our club chair woman was standing near when i fired up, right away to full rpm with the venturi and she said "it's too lould" lol and that wasnt the full wave pipe. what is fun is you get little puffs of air hit you as you stand behind it.
great noise inthe air, high pitch, but other planes make it sound ok and not too lould.
more RPM yet hey, YER BABY!

Taco ordered with 2 8x7's and 2 8x8's i know for sure the 8x8 is working well at the moment, even the 8x7 does work better, pleanty of friends here use 8x8's and will have them.
might be here for tomorrow :D

Project magnum
 

YEAH BABY! :cool:

I'll take two. And I prefer Taco Bell over Dell Taco. :D :D


PS
All fun and joke only

Project magnum
 

The little bugger burnt my hand when i touched the pipe by accident!
anyways my ears are ringing here's the results.
8x8 without pipe, ouch ears, 3 turns richer to allow for no pressure, 16.5K cant cut by putting hand over the exhaust, 1 it wont let me, 2 its damn hot
8x8 with pipe, 16.8k a low rpm, im surprised i kept with the West 50 Magnums, this aero dynamic pipe set up must work well.
8x7 no cutting yet 17.2 i expected a bigger jump than this
8x7 12ish mm cut off 17.8-18 better, wonder if the extra 1k will make up for dropping an inch in pitch
8x7 9ish mm cut off, 18k tiny improvement so i'll leave it here as it must be about right. the pipe now hits the canopy and i'll need longer screws to make sure it dosnt come off like last flight, i'll also use the sealing tape this time.
whats the propper GRRT pipe look like anyway?i have a little MVVS thing here... is it part 3247?

Project magnum
 

It should look something like this...

That engine doesn't even make half the power it could make at 17K rpm.... if the engine is in good shape and with the proper pipe and prop of course it should really get going at 25K rpm, or more...

Project magnum
 

well.. the front bearing dun sound all that great after a run, but the engine is tight, starts and runs like a dream.
however i loose half a tank of fuel from flooding while getting ready, bloody thing leaks all over the place.
anyways, yep, the pipes look like that on the Just Engines site, but mine looks like..........
umm comparing lenght, i feel like a sub-man LOL
thing is, when i got the pipe ( look on 1st page ) it was that length, but only got 14k!!!!!

Project magnum
 

Where's the pipe retainer clip thingy?
Normally you shouldn't have to use silicon tubing to hold things together....
Yes the pic I posted comes from the Just Engines site.... It was just to give you an idea what the pipe should look like in general... It can't be the pipe for the GRRT IMO, because there is no flange for the pipe retainer... Or there would have to be a screw on type flange on the pipe...that's posssible too...

If you are unsure about the pipe length, try running the engine with a smaller prop first, so it revs up more easily...
That way it is easier to listen to it and determine if the engine-pipe combo is going into resonance...and at what rpm it does.

Then after you get a general idea of where you're at with your pipe length, you can start experimenting with props...

Pylon engines can be rather tricky on things like bearings...if you've got a worn out bearing, it might be the thing that's keeping you from getting full power from this engine...
A bearing that's not in brilliant shape can take a few 100 rpm off from your average sport engine...but on a fai pylon engine it can be disastrous...

About the leaking problem....since you haven't got a carb you'll have to use hemostats or a shut off valve or something to keep your fuel where it should be...

Oh and by the way.... I can see what you mean with having troubles with space... :p:p

And another thing... if you haven't blown a plug yet, your engine isn't tuned the way is should be...
When you're running this thing close to its maximum power output, you're bound to blow a plug every now and then...:p

Project magnum
 

my clip thing must be on a propper GRRT pipe ;) this isnt, its from a OS 46DF i think.
yep, the GRRT pipe dun look like mine anymore, im very mcuh shorter, i might try a long bit of joiner and see if it improves any.
im currently on a 8x7, any smaller and 1. the prop might fly apart, and 2. if i drop to 8x6 even a few extra K wont keep me up with the West 50 Magnums anymore. im close with the 8x8 at 16.8k, dont see how a 8x7 at 18 can be any faster let alone a 8x6 a couple of K higher.
it sounds damn fast now, the only resonance i hear is in my head lol. when i lean out from rich start i dont hear any big jump on the pipe
i think the noise is just because its a roller bearing, dosnt feel gritty or loose.
leaking... i keep it nose up untill i wanna start lol once it primed tho you have to start quick before Niagra starts up lol
yer, its all a bit crampped in there, if you look at post 1 you can see even with the pipe at full length space was tight, now the main bit is closer, its too much

Project magnum
 

phillybaby, check out my post I put on the other post about your GRRT.

Your rpm gain from off pipe to on pipe will not be gradual. It will top out off pipe then with a slight delay kick in fully to max rpm's. there will be a 7,000 rpm difference from off pipe to on pipe and it jumps right there. There is not in between. either it is on pipe or off pipe. It is not a gradual transition.

Kind of like an on or off switch

Project magnum
 

Yep....

Starting the engine should be something like this:

Close the pipe with your finger, and apply your starter motor to prime the engine.
Apply glow power, and again apply starter motor to start the engine...
If the engine hesitates but runs, close of the pipe a few times with your finger to get it going a little more...
Now your engine should be doing something like 18000 rpm (give or take a 1000...) and running erratic...

Now you start closing the needle valve to lean out the engine until the engine jumps on the pipe.... it will go from waaaabwaaaawraaaa to whiiiiiiiiiiiiiiiiiiiiiiii.....:p:p
The moment the engine jumps on the pipe, open up the needle valve again to prevent lean running...

You should really get a big jump, so much even that the person who is holding the plane should be aware of this, because when the engine jumps, the plane jumps forward also...