11 year old TT .36 needs love...

[Holmquist]

I have a buddy who wants to get back into flying models but since he is currently busy with school I thought I would get his 11 year old original Raptor 30v1 going again for him. When purchased he only put about 8 flights on it. After sitting for so long the engine has kinda seized up. All the internal parts are in great shape due to the low run time but it needs to be disassembled and cleaned. Can I use denatured alcohol to clean the internal parts? Thanks

Austin

[Raptor30_V1]

Hello,

What you need to clean depends on what residue you want to get rid off ..

So if there are no real burned-in residues or your buddy did not use castor oil years ago, anything getting the old oil/ grease away is fine. Alcohol is hygroscopic, means it attracts water (and humidity). So if using alcohol, dry after cleaning your parts and put some after run oil on the parts.

If engine has burned in residues but no scratches on the piston nor liner and piston-ring looks nice, there is a simple trick. Put the parts with residuals (no parts with gaskets or the carb) into a cup of Diesel and let it do its job for a while, take a look from time to time, after some hours parts should look as of being new

As methanol is an alcohol as well and engine was stored for 8 years, pretty sure your bearings are not in a good shape anymore? You can buy this bearings at rc-bearings or bocca for little money and there are papers describing how to exchange the bearing.

carefully re-assemble the engine, clean the carb and run engine pretty rich at the beginning. I had a TT-36 in my first Raptor30 and there are 2 things I think are special:

- the first series of TT-36 carbs where not very reproducible to be set-up, so I guess I was not the only one that installed an OS-carb on it ? The improved carb-series has something like a special mark on it to distinguish from the first series (at least I remember something like this as it is a long time ago)

- this engine runs at pretty higher temps than a modern OS-37 or even a 50' size engine. At lower temperatures (100 to 110 degrees Celsius) couldn't get much power out of it (flying CP 15% nitro at that time and using Enya no.3) ..

Don't know if this information is of some value, keep us upgraded,
Best Regards,

Oliver

[Holmquist]

Thanks for the info. I appreciate your help! Do I have to use an after run oil when reassembling the engine? Oh yeah the rear at least needs to be replaced but I'll do both. I went to RC-bearings and the closest I came to the right bearings would be the TT .39. You wouldn't happen to know whether those would be the same bearings as the ones in the TT .36 would you?

Austin

[Raptor30_V1]

Hello again,

Normally, when a manufacturer modifies its engine for more displacement he wants to keep as much parts the same as possible - at least the things working well.

If in doubt, I always take a look into the engine's manual (surely you can download these somewhere) and compare the spare-part number (e.g. of the TT-36 and TT-39). If still in doubt, contact Paul McIntosh at rc-bearings by e-Mail, pretty sure he knows if this engines have the same bearings.

After-run oil: re-assembling I would put some drops of After-run oil into the carb, into the muffler-slot, in the rear and from the top and turn the engine a few times. I only use After-run oil when I know, that the engine will sit there for 3 to 4 days w/o being used. There are different oppinions and methods, I do not use some AR-oil after any day on the FF, but I take care to empty my tank(s) completely and ignite the engine until all fuel is through and exhaust gases are out of the fuel-tank/ engine system. As stated, AR-oil is only something if I know for sure my engine will sit around for more than a few days

Best Regards,
Oliver

[kenh]

Carb cleaner (spray cans) works pretty good to clean up old varnish etc. Do not soak o-rings in it as it will make the rubber swell. OK to clean them up thogh. Just wipe them off with it. Same for gaskets. If the engine will set for a bit I use automotive oil to store and even as an assembly lube. The small amount of oil will quickly be flushed out of the engine when it runs.

IMO... almost any oil will work as an after run or storage oil. All you are doing is "flooding" the engine with somthing other than methanol to displace anything that will attract moisture.

[Sandmanhover]

Hi Raptor 30 V1, I just got a V1 w/36 TT, Not having much luck getting the carb. to do right, do you know which OS carb fits? Thanks, Sandman>>>>>>>

[Raptor30_V1]

Hello,

I have my old TT-36 dis-assembled by parts in box - at least I hope so ..

Let me take a look what is written on the OS-carb. In 2000/ 2001 the only nitro 30'class engine from OS was the OS-32, let me check if this is correct.

Best Regards,
Oliver

[Raptor30_V1]

Hello Sandman,

I took a look in my engine box and the OS-carb for the TT-36 seems to be the Type *40C* ..

I took a look at heliproz.com but could only find the carb-body itself, maybe someone knows where you can still get such a carb.

Enclosed you will find the manual for this carb. If a buddy has an old OS-32 laying around, ask him, if you can try (regarding fit) his carb. I guess the OS-32 has a *20C* carb type - so my comment in my last post might be wrong..

Best Regards,

Oliver

P.S: The *40C* seems from the OS-46 Ring helicopter engine, but maybe a *20C* should work as well ?

[Sandmanhover]

Thanks Austin for starting this post & thanks Oliver for info. I got this V1 off ebay,the owner only hover it & it still looks new,the motor & thr. arm was stuck & got it lose, the TT36 would always go dead about 1/4 to 1/2 stick, did get it to hover & would run fine a few times. Well last night,took it apart & clean it, only thing I see is the offset cut on the thr. barrow which makes it rotate in & out is to wide causing to much end play, at A high idle you can push it in & kill the motor. Well, took it out today & mess with it for a hour & thought I had it, run a half a tank, idle to almost taking off, sounding good, Soooo, I shut it down to refuel & guess WHAT,same old bull??.. Came in & went to digging, a TT 46 Pro carb. wont fit but a OS 50SX will,(had to cut thr. stop screw down to clear head.) took a remote main off a OS40 FP, took it out & dail it in,refuel & ran two tanks hovering in the yard & sounds sweettttttt. Will take it to the RC field for more test, but it starts,idles & revs up & did I say it sounds SweetTTTTTTTTT. Later All. <<<<<<<<Sandman>>>>>>>

[Holmquist]

I pulled the engine apart today and its looking okay but Im going to need at least a rear bearing and some serious cleaning. The bottom of the crank is wicked rusty and the lower bearing. Do you think I am going to be able to clean the the rank well enough not to have to replace it? I'll post pics shortly. Also I had it in the oven to get the cylinder sleeve out and the crank but unfortunely the lower bearing did not come out with the crank. So what is the best way to get the bearing out now? Thanks

Austin

[Raptor30_V1]

Hello Austin,

There is a guideline from John Beech how about to exchange engine bearings (and one about carburators) ..

You will find the link below for download:

http://www.genesishobby.com/whitepapers.aspx

It's about the OS-50 SX, but this doesn't matter as you can apply this on most nitro-engines. I made a picture manual as well about that matter (for my buddies) - unfortunatelly it's not written in English so won't be of big help.

BTW: The (larger) rear bearing never comes out with the crankshaft (using a plastic-hammer) - you need to put the whole housing with the rear bearing still inside in the oven. Temperature start with 120 degrees Celsius and increase if required. Many times the rear bearing will pop out on its own, if engine's front part (the smaller part) is facing upwards. Put the stuff in the pre-heated oven and if after 30 minutes nothing happens increase to e.g. 150 degrees Celsius.. sometimes it's required to take an oven-glove (watch out - engine will be very hot), to take the hot engine out of the oven and strike it, with the rear bearing side facing downwards, to hit plane on a sheet of wood. The wood should not be to hard, not to demolish the engine housing..

To take out the front bearing (the smaller one) is normmally way easier.

Sure, to install a new bearing (rear bearing) proceed the same by putting the engine housing into the oven and the bearing itself into the fridge (e.g. -22 degrees Celsius) ..

Best Regards,
Oliver