tuning

[Nitro Nerd]

Yeah whoever thinks that an internal combustion engine doesn't like heat has never studied thermal dynamics or metallurgy and has no idea why a piston and sleeve are engineered with the exact specific tolerance that they have. In over 30 years of tuning and racing nitro engines I've yet to see one perform and run better in cold weather vs hot.

Wow---30 years. You are obviously much more experienced than I am for sure! Not sure what you mean by "study" IC engines. I know how they work for the most part, and have 'fixed' a lot of them, rebuilt quite a few (sealed vacuum ports, head clearance and such--but I can't fully mod one or anything). But I'm still learning (and hope to 30 years from now). ;-)

I can just tell you my experience. Last winter (30's-40's) I think I broke in 3-4 engines, and had zero problems. However, I've noticed when the temps get very, very hot (105+) they become temperamental regardless of the plug. I guess I'm not seeing the downside to running them in the cold, but would love to learn. I see you are in Houston (I'm in Dallas) so imagine you know the type of heat I'm referencing.

[/quote]

I'd be hard pressed to even get a nitro started at those temps.

Are you saying you cannot start a nitro engine if the temps are between 30-40 degrees)? Not sure what to tell you other than I have zero problems starting them. What problems do you have starting them in those temps?

 

[BillyC74]

I've always heard cold weather was hard on nitro engines and I never really gave it much thought. I would usually put my trucks up for the winter. I going to take another look at running in cold weather because I would love to run year round. Nitro Nerd have you not noticed any ill affects of running in the cold? Are you getting good service life from your engines? Thanks

 

[smittyzz]

I have broken/ breaking in my motor in 30~40, and my motor runs amazing!
besides the NOISE I'm trying to GET you guys to help me with, but other then that I'm loving it!

 

[Nitro Nerd]

Nitro Nerd have you not noticed any ill affects of running in the cold? Are you getting good service life from your engines? Thanks

My engines run fine. Of course I have the typical problems anyone could have with plugs, fuel, pressure systems, etc. but I'm maintaining (I think) nine engines right now, so it's just part of it.

Again, not saying there are no ill-affects. I'm no expert. Just that I run them in the cold a lot (unless it gets low 20's or something). I'll just give them a blast with the heat gun until they get to about 140-150 and they fire right up and run fine. That's just my experience. As noted, the extreme heat is when I see most problems. I just learned a bad lesson on storing fuel in heat (whole other thread).

---------- Post added at 5:07 PM ---------- Previous post was at 5:04 PM ----------

I have broken/ breaking in my motor in 30~40, and my motor runs amazing!
besides the NOISE I'm trying to GET you guys to help me with, but other then that I'm loving it!

Have you checked your heat sink bolts? Also, could be something in your flywheel/clutch. Forgive me....is the engine new or used?

 

[alpinehyperlite]

I have broken/ breaking in my motor in 30~40, and my motor runs amazing!
besides the NOISE I'm trying to GET you guys to help me with, but other then that I'm loving it!

I'm glad you got a FIRM GRASP on things.

 

[smittyzz]

My engines run fine. Of course I have the typical problems anyone could have with plugs, fuel, pressure systems, etc. but I'm maintaining (I think) nine engines right now, so it's just part of it.

Again, not saying there are no ill-affects. I'm no expert. Just that I run them in the cold a lot (unless it gets low 20's or something). I'll just give them a blast with the heat gun until they get to about 140-150 and they fire right up and run fine. That's just my experience. As noted, the extreme heat is when I see most problems. I just learned a bad lesson on storing fuel in heat (whole other thread).

---------- Post added at 5:07 PM ---------- Previous post was at 5:04 PM ----------



Have you checked your heat sink bolts? Also, could be something in your flywheel/clutch. Forgive me....is the engine new or used?

I've checked flywheel, only does it when being compressed at tdc, pull glow plug and it stops, it's brand new, besides the about half court I got through it, it runs amazing, starts first pull when I remember to adjust the trim for some extra rpm till she worms up a little. and no haven't yet. don't have Allen wrenches, my tools were jacked couple months back...
as for compression it's pretty hard to pull still when starting but runs amazing.
I've got 2 washers on the glow plug also, and I can get it to make the noise with my fingure covering the glow plug hole.
I've read that it might be because of the motor being be and not fully broken in yet

 

[Rolex]

extra rpm till she worms up a little.

Absolutely. Always let it worm up.
Turbine engines need to spool up, nitro engines need to worm up.

I've read that it might be because of the motor being be and not fully broken in yet

If it might be because of the motor being be, you might be being believed.

 

[smittyzz]

Absolutely. Always let it worm up.
Turbine engines need to spool up, nitro engines need to worm up.


If it might be because of the motor being be, you might be being believed.

say what? lol

I meant, it might be because of it being a new motor, and there being so much compression, and not being fully broken in. does that sound logical?

 

[Rolex]

I'm used to interpreting your posts and figured out what you meant.

Worm up.

 

[smittyzz]

I'm used to interpreting your posts and figured out what you meant.

Worm up.

lol sorry this is all typed from my optimus g pro. so autocorrection kills me lol

but what are your thoughts on the motor?

 

[Non Crimen]

It's an engine, it runs. You should record a video so we can hear it

 

[smittyzz]

It's an engine, it runs. You should record a video so we can hear it

Will do that tomorrow for sure!

 

[Nitro Nerd]

What plug are you using? It might not hurt to try a different one---plugs can also go bad during break in. And yes---a video will help one of us tell you if anything is wrong or not.

 

[smittyzz]

I'm mainly using an O'Donnell warm~ cold plug, the other one is a hot plug and last idk it came with motor. and gonna upload video now, I feel like I did a horrible job with my video as I'm still in work clothes and it not turning over easy, should have heated it up more and it had so much compression because my aro decided to dump into my carb on me last night on accident.
yea I'm also new so please be easy on me.
ohhhh. and I'm tingly lol

but video is uploading now

---------- Post added at 1:44 PM ---------- Previous post was at 1:36 PM ----------

update, video is 1.3gb and I have fair point which is garbage so won't be up for a few hours, if I have to I will upload it tomorrow at work!

 

[smittyzz]

https://www.youtube.com/watch?v=pPDkz1IrZ54&feature=youtube_gdata_player
here you go guys

 

[Nitro Nerd]

Okay, here are my thoughts:
1. It was incredibly flooded at the beginning (but you did the right thing by unflooding it). Anytime your pull-start "pops" like that....engine is flooded. Breaking a pull-start will ruin your day.

2. 7:06 you stated if you "give it the right RPM" it will start first try and then you opened your throttle trim. That is not how you want to do it. You should set the carb opening via your idle-stop screw. Let me know if that does not make sense...but all you'll be doing is fighting your engine if you continue that.

3. Based on your pinch test, you have it backwards. The longer to cut off the more rich it is--not lean. Ideally, the RPMs should rise in about 2 seconds. Yours took almost eight seconds---that is very rich as the engine is loaded up. Also....you really need to warm the engine up before you can get a good reading on that.

4. Finally---your engine sounds like it has some kind of an air leak in your pressure system somewhere. When you plug the stinger...how long does it take to cut-off? Does it sound kind of muffled and then stop...or does it stop immediately? If everything is sealed...it should turn right off. Sounds like either your fuel tank or exhaust not sealed.

Definitely post a running vid of it if you need more help.

 

[smittyzz]

Okay, here are my thoughts:
1. It was incredibly flooded at the beginning (but you did the right thing by unflooding it). Anytime your pull-start "pops" like that....engine is flooded. Breaking a pull-start will ruin your day.

2. 7:06 you stated if you "give it the right RPM" it will start first try and then you opened your throttle trim. That is not how you want to do it. You should set the carb opening via your idle-stop screw. Let me know if that does not make sense...but all you'll be doing is fighting your engine if you continue that.

3. Based on your pinch test, you have it backwards. The longer to cut off the more rich it is--not lean. Ideally, the RPMs should rise in about 2 seconds. Yours took almost eight seconds---that is very rich as the engine is loaded up. Also....you really need to warm the engine up before you can get a good reading on that.

4. Finally---your engine sounds like it has some kind of an air leak in your pressure system somewhere. When you plug the stinger...how long does it take to cut-off? Does it sound kind of muffled and then stop...or does it stop immediately? If everything is sealed...it should turn right off. Sounds like either your fuel tank or exhaust not sealed.

Definitely post a running vid of it if you need more help.

thanks fort he responce!
about the flooding, the other night I accidentally poured way to much aro in it and that was the reason. and the UN flooding I learned on here,

about the rpm, she isles fine when worked up, and starts first pull, but I sometimes have to use my trim to give it a little rpm to get it started then I slowly turn the idle down letting it worm up a little. and I will make sure to fully warm her up every time from now on.

and the pinch test I know I'm way off and she still needs tuning, I'm learning still! but I'm getting there!!

and about the air leak, you are right, the exhaust manifold to the muffler, the little rubber thing broke and my tubing wasn't a tight fit so there's noise air and gas coming out.

but what about the noise?

other then that how does my truck look since before? and how do you guys think I'm doing?
and an fyi I'm 21 lol

 

[Non Crimen]

As long as it worms up you're home free

 

[Rolex]

about the rpm, she isles fine when worked up

It idles fine when it's worked up, after being wormed up.

Your noise is most likely your exhaust leak.

 

[smittyzz]

no no no, listen when I pull my pull start, you hear a medal to medal noise I say hear it guys or something lol.
runs great, but I hate the noise when using pull start. and its in fact a pnp motor, are they any good?

---------- Post added at 2:48 PM ---------- Previous post was at 2:44 PM ----------

8:00 and listen

---------- Post added at 2:52 PM ---------- Previous post was at 2:48 PM ----------

you and about breaking pullstart, the one on my sh I broke 7 times before I went with a new motor, that was because that pull start is garbage! I broke the coil 4 times and had to refine it 3. I know how much of a pain it is lol. when I broke the coil I did slight bends and wrapped it around the peice that spins the one way then I shoved it in the housing and lined the coil up in its spot. I've had better days... lmao