j240z

I'm in the process of breaking in a new OS TR turbo .12 engine in my ntc3. It seems to lock up quite a bit. I've tried heating it up with a hair dryer but it really gets stuck with the piston at the top of the stroke. Even with the glow plug out the piston still gets stuck at the top. I was able to get 2.5 tanks through it when it seemed to finally loosen up a bit when it flooded and died. I then tried to restart it while it was warm, and once again the piston was stuck up top. I've let the engine cool down and it's still doing the same thing. Is this normal? I've never broken in such a stubbornly tight engine. Any tips?

B

iTrader: (13)

Yea that is very normal. An european (novarossi, etc) is even tighter IMO. You are going to encounter that with every high performance engine you get in the future.

Just make sure you are using a strong starter box

j240z

Thanks. Dual 550's in the box. Getting my money's worth out of them right now. It seems to be getting a little easier now after the 5th tank. Thanks!

B

iTrader: (13)

no problemo

Yah, as you go through more tanks it will get better. Have fun with that engine, it is a good one.

wtp

iTrader: (2)

hi all,currently i using 25% fuel to break in the os-tr turbo ver.is there any need to add in extra shims between head clearance,or is there any tips to proper break in this gem.

j240z

I didn't add or remove anything from my tr-T before or during break-in. I ran just like it came out of the box. Mind you the pinch was super tight and starting it wasn't always easy, especially when cold. Do yourself a favor and get a heat gun or hairdryer and warm up the block if it's hard to turn. It took me 2 days before then engine was easy to start, and that's with a hairdryer. I'm not sure about head shims but I wouldn't mess with them until you're done breaking it in.

Marcos.J

iTrader: (239)

the TR comes already shim for 30% it has a .2 and a .1 shim .

Darkseid

iTrader: (9)

I would just say follow OS's instructions and stick with them and eventually everything will loosen up to the proper tolerances. I had a OS TR and it was easy to start from the very get go and never died on my once all through the break in process...which is very unusual for any engine.

ziggy12345

Hi

There was a great post on the Nitro Engine Thread but it looks like its gone now.

The only way to see what your head clearance is is to take out the plug and insert a piece of solder in the head. It should be bent to poke under the head between the piston and head. Rotate the flywheel until it goes over TDC. Remove the solder and measure with a vernier.

For 20% Nitro 0.018" is good. Go to 0.022" for 30%

As the piston aproaches TDC the mixture is compressed and increases in temp. At some point the mixture will react with the glow plug and ignite.

For a colder plug this will be sooner rather than later. and later rather than sooner for a hot plug!!

So you need to balance the compression with the type of plug to achieve a the correct mixture burn.

A colder plug will give you better bottom end where a hot plug will be for high end power

Hope this helps

fastharry™

iTrader: (4)

heres the link...

http://www.rctech.net/forum/showthre...m&pagenumber=1