F1-Rocket EVO by Great Planes.

Dear friend András, thank you again for accompanying us on this virtual trip!
Hopefully one day I can meet you and shake our hands!
Regarding the engine, this is an engine that I bought second hand and I did maintenance on it.
Castor oil is very good, in my experience synthetic is very clean, but the combination of the two is what really works and although some fuels reach 18%, I modify them by taking them to 20% lubricating oil, then, for a 4T 20% is ideal.
Here are the photos of the maintenance of the O.S. .70 4T. what did I do.

Like always, you did a great job Mauricio..that engine must have sat for long, allowing the internals to corrode..very little soot in the cylinder and on piston top indicates the use if synt oil by the previous owner..my OS had a totally sooted piston top and engine head when I disassembled it for cleaning, thanks to all-castor lubrication. ( I have used home blended COX fuel with 20% castor, and given the much higher compression ratio and combustion temperature in the OS FS than in a COX engine, a great part of castor burns and blackens the engine internals)

Nitro leaves behind water condensed on bearings, leading to corrosion..I am wondering why the steel crankshaft of COX engines do not rust as quick as the ball bearings of 4-strokers?

Nice job like new y tink cox wil rust les du To its smal crank case volume iternal size spi open exaust port welp dry moistur water left inside dry faster than closed engine wit bearing wit lots room for water To stay trap long and make parts rust wit time is wy y place m'y engines exaust port open after use bether dust litle than rust inside

Thanks Dave yes your assumption i.e. less volume of condensed water left in contact with the COX crankshaft will cause less corrosion makes sense.

Well, today I flew my models with 4-stroke engines and they are undoubtedly a pleasure in many respects. Here is a flight video with my Yak 55 M from Great Planes converted to Glow.

Nice job on the rebuild came out looking Great !! The Yak 55 M flies gracefully through the paces , enjoyed the vid , Did you run the rebuild surpass 70 ? I have a OS 46-46 ? four stroke i don't remember if it has been run but hope its good inside .

Great flight Mauricio..I wish I could fly my Denight 50 with one of the OS FS56 engines I have..I love the sound and brute power of that engine. Very stable and low rpm idle too.

My Denight 50 is a bit nose heavy and tends to flip over after landing even if I keep a full elevator up when taxiing. Will change its running gear to a longer than stock so as to make it more stable while taxiing on uneven terrain.

getback wrote:Nice job on the rebuild came out looking Great !! The Yak 55 M flies gracefully through the paces , enjoyed the vid , Did you run the rebuild surpass 70 ? I have a OS 46-46 ? four stroke i don't remember if it has been run but hope its good inside .

Friend Eric !! .... yes I have started the O.S. .70 4T and it is a beast !! ... beautiful engine ... I will be showing the assembly steps of the model and we will be able to see it work.
Hey, is it possible that your engine is a .48 4T ?? .... it would be nice if you put some photos, it is always nice to see engines.
Well, don't worry, just remove the rear cover and its carburetor and you will be able to see there the state of the rear bearing and crankshaft, if something is not right, you will notice it there immediately!

.. and here is a video of the O.S. FS .20 4T.
Another mechanical marvel .
I hope you enjoy the video ...

Well, I start with the modification of the cockpit, because the pilot is relatively to scale in this model, but it turns out that in static I see it located very forward, so I decided to take it a few centimeters further back to give another general aesthetic.
I have also printed a board (since this kit does not bring it), the board is a copy of the Yak 55M board from its Great Planes brother and it really fits perfect.
For this I have built a wooden support and it is hollow, something to lighten everything.
I have also decided to change the background color, since it comes in a gray tone, I like the black color better for this sector, leaving the cabin much more elegant ... here are some images.

Good scale upgrades 4stroke sound Good like the vidéo of the yak 55

Well, I have done a review with the heat iron for all the decorations and monokoteado (draped with monokote) of the model. You have to be very careful when doing this work, since any line may be deflected, the decoration or fabric can be a visible problem.


After this, then I started with the installation of the servos and aileron controls, here are photos...

With the aileron servos installed on the half wings, then I will continue with the process of gluing the parts together with the stress bayonet.

mauri ... very good job as always.
I would like to ask you how you have cleaned the engine to make it look like new. Looking at the final photos and without having seen the dirty parts, this engine would look like it was right out of the box.
again congratulations on the quality of the work.
a big greeting to you and all the members of the forum in this 2021.

Thanks nico010
The liquid that I use to clean these engines is automobile coolant containing ethylene glycol, you must be very careful with this product, namely, the vapor that it gives off attacks health and if liquid is spilled on the fire flame, everything can catch fire, for this reason you must be very careful in the procedure.
Steps:
You should heat the coolant in a ventilated place or better in the open air.
You must have control of possible spillage.
You should have a fire extinguisher or a damp cloth to smother the fire in the event of an accident.
Once the coolant reaches the boiling temperature, you must submerge all the parts of your engine for 30 minutes, then extract it and you must brush with a plastic or bronze brush, the dirty parts. You will quickly notice the cleanliness of the parts.
You can repeat the operation in case of doubtfulness.
This liquid does not attack plastics or rubber, so the oring and plastics, if they exist, will not be damaged.

Perfect work, very good craftsmanship as always

Thank you very much dear friend Levent !!

ok, I have already put epoxy on the central bayonet and its halves, now it is time for the glue to cure, in the meantime I will continue with the fuselage...


The drawer that holds the motor, from the manual indicates to place the bench directly, but in my experience, I consider it very good to place fiberglass and epoxy, so that nothing detaches or disassembles by the engine running process here is the placement of the fiberglass.





After gluing the fiber with the resin, plastic adhesive tape is placed to compress the whole assembly so that the fiberglass perfectly copies the structure of the box ...

Now it is time to cure that part of the box that supports the motor ...

Going over the socket joints with epoxy can improve safety, since many of these models arrive poorly in glue, that is, from the factory some parts may notice that there is no glue.

After the epoxy has cured, I remove the plastic tape and sand the surface to dust some rough edges ... after that process is finished, I apply epoxy again and everything is there without being noticed, that is, an extra invisible and neat reinforcement!

Plenty of good tips, Mauricio, with the epoxy reinforcement. Do you also apply it not only on the engine firewall, but on the root of the box that is attached to the fuselage?

Excellent work Mauricio , i have never seen the way you wrap the epoxy / glass with the black tape i would have thought it would have stuck to it . Very clean and strong too .

balogh wrote:Plenty of good tips, Mauricio, with the epoxy reinforcement. Do you also apply it not only on the engine firewall, but on the root of the box that is attached to the fuselage?

A = all these pieces are integral, they cross the F1, therefore it is not necessary to place fiberglass at the intersection or root of the same with the F1, in addition to existing triangular wood indicated with green arrows, which makes the whole set is extremely strong.
The fiberglass is applied in sectors indicated with red color.

Now I have placed a piece of monokote in the central sector of the wing, this is to give a better appearance, and prevent fuel from penetrating into the sector over time.
From the original manufacturer's manual they do not indicate to place anything, but if you find something similar, close the sector and you will avoid problems over time!