Motor Break in. When is tight to tight

[J_Moore]

Hey Guys

Know this has been a topic before and have read alot of past posts on this. But when is a engine to tight to just heat up and heat cycle? Personally i have never done this heat cycling stuff. i have a new nova rossi that so tight at TDC that its impossible to move it past TDC with out a wrench and that is with the plug out. What are your suggestions? Can i still heat the motor up prior to starting when its this tight? Don't have a heat gun but what other means can i do to heat it up prior to starting? Any help would be great.

Thanks in advance

Jeff

ps i have had it started very briefly which it stopped very quickly. Nervous of all the strain being put on the motor

 

[Hydro Junkie]

I know what you mean. Last summer I took a new boat with a never started NR 21 to Indiana. When I tried to start it, using a 12 volt Sullivan starter, I hit TDC and the motor more or less siezed on me as well. It took a 24 volt Sullivan to start it the first time and, after that, if seemed like it started to loosen up a bit. I was using 30% helicopter fuel with 22-24% oil to make sure I didn't seize anything on the initial start. As far as the engine being cold, that wasn't the issue as the temperature was in the upper 90s that day

 

[RobertWurster]

Not sure if this is the right way but i put in a hot plug new and put the ignighter on it and let it sit it it got hot .put it at bdc and put the starter to it and it started with the plug loose.that might help .oh i put a few drops of aro in it and turned it buy hand with a rench a bunch of times first.

 

[Michael Costanzo]

you can also use a small propane torch,like one of thoise $30 one they sell at lowe's.just go a few times around the case and head,(watch the water and fuel lines)and that should put enough heat to get it started.do not run it so rich that it does not make any temp.

you want to feel a good amount of heat while still be rich,mike.

 

[glenng]

I don't go for the torch or heat gun. Just make sure it's very rich(you may need to leave the ignighter on) plug slightly loose. Run it on the stand without water till you cant hold your hand on the cooling jacket. Shut it off, make sure the piston is at bdc. Let it cool and repeat the process till the piston quits sticking at TDC. You may need to put many tanks of fuel thru it- be patient. When the piston quits trying to stick at TDC when shut off throw it in the water. Check the temp when you bring it to shore. If it's running cold- restrict the water a bit.

 

[Hydro Junkie]

Once we got mine started, we ran it until it died, more due to a loose throttle servo than anything else. Due to how rich I had the needle, I didn't run cooling water through the head as I felt it wasn't needed. Next time I run it, it's getting 50% nitro/18% oil boat fuel and, if I can get it warm enough, I"ll throw some water through the head as well

 

[Michael Costanzo]

I don't go for the torch or heat gun. Just make sure it's very rich(you may need to leave the ignighter on) plug slightly loose. Run it on the stand without water till you cant hold your hand on the cooling jacket. Shut it off, make sure the piston is at bdc. Let it cool and repeat the process till the piston quits sticking at TDC. You may need to put many tanks of fuel thru it- be patient. When the piston quits trying to stick at TDC when shut off throw it in the water. Check the temp when you bring it to shore. If it's running cold- restrict the water a bit.

hey glen,i have owned about a dozen or more N/R .12's that were almost $500 ea and .21's that were almost $700 all for 1/10 &1/8 scale model cars and everyone i had to use a heat gun on to get them started for AT LEAST the first 1/2 gal of fuel. i only reccomended the small tourch if he did not have a heat gun at the feild/lake.and yes i agree aqbout the water restriction,sorry i forgot to write that in the last post.but most of all,be patient and take your time and you will be rewarded with a great,long lasting motor,mike.

 

[glenng]

I don't go for the torch or heat gun. Just make sure it's very rich(you may need to leave the ignighter on) plug slightly loose. Run it on the stand without water till you cant hold your hand on the cooling jacket. Shut it off, make sure the piston is at bdc. Let it cool and repeat the process till the piston quits sticking at TDC. You may need to put many tanks of fuel thru it- be patient. When the piston quits trying to stick at TDC when shut off throw it in the water. Check the temp when you bring it to shore. If it's running cold- restrict the water a bit.

hey glen,i have owned about a dozen or more N/R .12's that were almost $500 ea and .21's that were almost $700 all for 1/10 &1/8 scale model cars and everyone i had to use a heat gun on to get them started for AT LEAST the first 1/2 gal of fuel. i only reccomended the small tourch if he did not have a heat gun at the feild/lake.and yes i agree aqbout the water restriction,sorry i forgot to write that in the last post.but most of all,be patient and take your time and you will be rewarded with a great,long lasting motor,mike.

Good to hear from you Mike and I should clarify something- my experience is limited to the .45-.91 Marine motors.Glenn

 

[Hydro Junkie]

You're lucky then, Glenn. My boatyard has everything from .18 to .67 and includes multiple manufacturers

 

[Michael Costanzo]

hey glen,good to here from you too. the thing with the N/R motors, they pick only the best fit P/S which is great,but you have to break them in right. i have a .12 that must have 8 gals of 30% nitro/11% oil

and it still has great fit!

 

[anthony_marquart]

IMO, heating up the engine before the first few starts just makes life a bit easier.. It does help... You can even just use a hair dryer.. get it a little hot.. it will start WAY easier...

yeah, we've said it a million times... but the break in on these NR's is critical on how long they last.. took forever on mine... but it's been running great fore a few years now... especially when I don't muck with it!!!

 

[Jim Allen]

Modern day ABC & AAC engines use metallurgy that requires a tight piston liner fit. High silicon aluminum piston materials, such as RSP-444T6 (30% silicon), will need a tight fit. This is because of the piston's low expansion rate when compared to the liner's higher expansion rate. Liner materials such as #360 brass, C54400 phosphor bronze, 4032 silicon aluminum or the tri-metal liner materials used in engines will require a tight fit when fitted at room temperature.

To facilitate more rapid break in time, use an airplane propeller with no water cooling for break in. A 10" X 7" pitch, left hand APC propeller, cut to 8" X 7" pitch works for a .40 cuin outboard type engine. A reliable tachometer should be used to determine the needle setting for maximum RPM. Fuel used is 15% nitro with 5 ozs of de-gummed castor added to each gallon of fuel. 21/2 to 3 gallons of fuel running at WOT usually is sufficient to break in a .40 size engine.

Jim Allen

 

[J_Moore]

Thank you all for your input. I did get it started and ran it slobbering rich on the bench for two tank fulls. On thing is that i could not get it to go higher than 150 F. If i leaned it out yes it would start to climb but was getting to lean and starting to rev up more than i was comfortable with for this break in. Someone sayed about it to me to be about 200 F to 220 F for the break in. I was not running any water through it. Is the 150 F ok for the break in or am i over thinking this whole thing and just keep running it rich for the first half gallon or so? I break the motor in on the same fuel i race with which is 60%

 

[J_Moore]

PS also i wasn't running it more than 1/4 throttle

 

[glenng]

I think you're doing it right. A lot of fuel moving thru the engine will keep it somewhat cool. Avoiding high rpm's is good.

 

[Hayden Bright]

Thank you all for your input. I did get it started and ran it slobbering rich on the bench for two tank fulls. On thing is that i could not get it to go higher than 150 F. If i leaned it out yes it would start to climb but was getting to lean and starting to rev up more than i was comfortable with for this break in. Someone sayed about it to me to be about 200 F to 220 F for the break in. I was not running any water through it. Is the 150 F ok for the break in or am i over thinking this whole thing and just keep running it rich for the first half gallon or so? I break the motor in on the same fuel i race with which is 60%

What your doing is fine, maybe try putting it in the pond now without water cooling because the extra load will help build heat in your engine, leave your needle rich and run it WOT through the best part of a full tank then just check your temps, if your running rich you won't overheat the engine....piston at bdc till cold then repeat process.

 

[J_Moore]

Yes thanks for reminding me. Ya with no load on the engine it will not build the heat that i'm looking for. Next trip is to the pond. Thanks for the feed back now that i know im on the right track. Been at this 24 years now and haven't had to break in a engine since about 10 years ago. Thanks again

Jeff

 

[Hayden Bright]

10 years since your last engine break in!!! maybe you need to be giving the advice lol

 

[Hydro Junkie]

Just went back into my private messages and found this one from Glenn Quarles on starting set ups for pipe and needle:

4 turns out seems like a pretty good place for the initial crank up...if it doesn't sound crazy rich for the first tank (on the bench) then richen it up.

 

For the pipe measurement I go from the side to the head straight back to the high point...4" is a very consertive setting, 3.5 inches is probably around where you will end up.

 

Remember...make sure it gets up to temp during the breakin. I don't use any water cooling for the first runs (maybe 10 or more runs) until the needle is lean enough that the motor is getting too hot to touch after you bring it in.

 

Glenn

 

[anthony_marquart]

mine never ran well until I took the water off for a few runs... and before that it was really too tight... (just what I think)..

Head to the lake... run real real rich ,. no water... 3-4 tanks... lean it out and add water.. Mine is restricted to 0.050 in the head.