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Old 10-13-2009, 06:48 PM   #31
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Break in benches are used by alot of engine builders. There was some real good info on the now gone RB engine forums. It can be done in the car, but its easier in the stand.

Onroad guys seem to use them religiously. Thier cheaper engines start at $350 so that's got to say something. You spend 600-1100 for a single motor.......your going to learn to run it right.

I didn't invent this stuff on my own.

The run in bench helps prevent:
1.) Stalling. Running in an engine in your car with it rich, its going to stall if you screw up. Repeated starts aren't good for the engine early in its life.
The prop also has a nice fly wheel effect.

2.) Conrod stress. Hitting your engine with an airplane starter is alot gentler than your bump box. Air resistance of the prop is alot softer than the clutch in a car hitting. Want real gental, get a hotter plug and driver, flip the prop with your finger or a chicken stick.

3.) Running at idle to turn around or to check temp. You want to keep fuel flowing through the engine to flush it and you need to keep it at 230. Everytime you stop to idle that fuel flow is less, and its hard to temp a car thats in motion on a parking lot. Easy to control on a stand and you can keep the R's up and the fuel flowing.


I've cut my stand run-ins to 1000cc of fuel. I preheat and keep the engine slow for 125cc, I have to rev it a little every once in a while to clean it out. Then I lean the engine so it'll run and rev it till the temps come up to 230. Then I just vary throttle to keep at 230 for 750cc of fuel.

I removed the hudy stands trottle arm and installed a servo and Rx. I mounted a temp gauge I can see from across the garage. I can kick back and just pull the trigger on my radio to vary speeds to keep the temp right.

If the heads wrapped you'll be running artificially rich. You may have to lean the needles some, but you can watch the exhaust running rich easy.





I'm also thinking of haveing a machinist make a longer prop spacer. That way I can run an uncut larger prop that'll offer greater loads and lower RPM. Use the stand as a dyno. Much like testing airplane engines, watching temp and useing an RPM gauge to see if I can use the stand to get a baseline tune before dropping it in the car.

Last edited by Zerodefect; 10-13-2009 at 07:04 PM.
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Old 10-13-2009, 07:00 PM   #32
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Originally Posted by Joey Platinum View Post
I had afriend break in one of my GRP tuned.21 and a lot of the guys at the track frowned and said thats not the way to break in an engine.We broke it in out doors in a grassy area right near the track ... early in the A.M..... no one was running on the track and no-one else was even there. We could not attach an air filter.The prop would not clear it. We wrapped the head and heat cycled it for about 10 tanks. I feel we did everything right. the engine became un-tunable at about the 1 gallon mark. I pulled the engine and noticed the front seal was very very wet. Sent the engine back to Horizon and they said there had been se veral came back with defective front seals....... since it was a race engine no-warranty.The also said they would fix it for 180.00 half price.
They also said it had been run lean.... yeah no sh-t! when you have a front seal blow out they tend to get warm. well al the other guys at the track were saying ..man you don't break in an engine on a hudy bench.... you did not even have an air filter on it.Well do you know what?There were no scuffs on the P/S. Why do you guys even use a Hudy break in bench since they Suck????? personally I think they are a great tool but why all the haters???
Airplanes don't use air filters, niether to copters or alot of boats. If your not in dust..........

GRP sucks. That engine was defective. We all tried to tune that pos. Not only did that engine tune like poo compared to OS/RB, there was majik voodoo about the temps it was supposed to run as well. I don't see anymore GRP's anywhere. Word got out. Kinda like when Novarossi had that bad batch that killed themselves in 07.

On the other hand that was also during the POS RC8 fuel tank fiasco time period as well. Leaky tanks and tank filters that crumble and get sucked into the carb can kill a tune and ruin an engine fairly quick to.

But I love how Horizon admits that their front bearing sucks quite literally, but then deosn't stand behind their product. Greatplanes (OS) has no problem admitting they screwed up, and they take care of it and us. Nomore Horizon Hobby engines for me.

Lesson learned. Never again, I'll stick to the big three from now on. RB, Novarossi, and OS/Ninja. OS stands by thier engines more than anyone else, and RB and Nova.......really don't need to.

Just broke in 2 Novarossi N21b's, RB WS7III and a Novarossi+4 on that bench. Looking forward to 10+ gallons without repairs again as usual.

Last edited by Zerodefect; 10-13-2009 at 07:11 PM.
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Old 10-13-2009, 07:03 PM   #33
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Originally Posted by Zerodefect View Post
Break in benches are used by alot of engine builders and modders. There was some real good info on the now gone RB engine forums. It can be done in the car, but its easier in the stand.

Onroad guys seem to use them religiously. Thier cheaper engines start at $350 so that's got to say something. You spend 600-1100 for a single motor.......your going to learn to run it right.

The run in bench helps prevent:
1.) Stalling. Running in an engine in your car with it rich, its going to stall if you screw up. Repeated starts aren't good for the engine early in its life.
The prop also has a nice fly wheel effect.

2.) Conrod stress. Hitting your engine with an airplane starter is alot gentler than your bump box. Air resistance of the prop is alot softer than the clutch in a car hitting. Want real gental, get a hotter plug and driver, flip the prop with your finger or a chicken stick.

3.) Running at idle to turn around or to check temp. You want to keep fuel flowing through the engine to flush it and you need to keep it at 230. Everytime you stop to idle that fuel flow is less, and its hard to temp a car thats in motion on a parking lot. Easy to control on a stand and you can keep the R's up and the fuel flowing.


I've cut my stand run-ins to 1000cc of fuel. I preheat and keep the engine slow for 125cc, I have to rev it a little every once in a while to clean it out. Then I lean the engine so it'll run and rev it till the temps come up to 230. Then I just vary throttle to keep at 230 for 750cc of fuel.

I removed the hudy stands trottle arm and installed a servo and Rx. I mounted a temp gauge I can see from across the garage. I can kick back and just pull the trigger on my radio to vary speeds to keep the temp right.

If the heads wrapped you'll be running artificially rich. You may have to lean the needles some, but you can watch the exhaust running rich easy.





I'm also thinking of haveing a machinist make a longer prop spacer. That way I can run an uncut larger prop that'll offer greater loads and lower RPM. Use the stand as a dyno. Much like testing airplane engines, watching temp and useing an RPM gauge to see if I can use the stand to get a baseline tune before dropping it in the car.
Very interesting. I always take temps at the block too even when I am running the head can lie. So do you do the heat cycle in 3-4 min intervals or just burn through 1000cc of fuel all at once.
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Old 10-13-2009, 07:19 PM   #34
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Very interesting. I always take temps at the block too even when I am running the head can lie. So do you do the heat cycle in 3-4 min intervals or just burn through 1000cc of fuel all at once.
I believe the heat cycling is to heat treat the parts of the engine for greater durability. If the heat cycleing you referring to is run to 230 then shutdown and cool. At least thats what I was told.

On the stand there isn't much shock. So I don't need that extra stength yet.

The most important part of runin is to mate the piston and sleeve at a good temp. I get that done and burn through 1000cc in one hit without shutting down even once. Plus shutting down and restarting repeatedly when the engine is so new is really hard on the rod, piston, etc.

Then after that critical step is complete. I'll heat cycle.


The fact that I can't get real good temp readings on the surface of the block because of the props airflow cooling the blocks surface, is another reason I cut my run ins down to 1000cc.

I can only read the head as its wrapped up so no air blows through it.
I use 2 different temp gauges and some spit. Sometimes I'll get my Fluke 189 with a contact probe out and stick it down the cooling head next to the plug.

1000cc is Just enough to get the engine safe to drive with a slightly rich tune.

Last edited by Zerodefect; 10-13-2009 at 07:57 PM.
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Old 10-14-2009, 01:02 AM   #35
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Paul, i'm not sure how soon your wanting to run the motor if you want you can send the new os back to me and i will run the motor to break the pinch, that way you wont need any heating to get going, free of charge just pay the shipping, offers there if you want it.
Brian, thanks for the offer, much appreciated.

Given the cost of S&H from where I live, the issues we had at the US customs with the initial shipment, the fact that I have to involve my brother-in-law to have it shipped back to switzerland to escape the customs, and the fact that I don't want to have you working for free on my bottomless time/money pits OS, I'll pass for this time... Thank you though, I'll keep your kindness and professionalism in mind.

Paul
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