Getting the pinch out of your Revo 3.3
09-06-2007, 02:10 AM
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RE: Getting the pinch out of your Revo 3.3
daverevo, daveg55 has been here a while, and on the glow scene longer then most people here have been alive, so his opinions are worth a lot to the people on these forums, me included there.
on the subject of the break in method, the big thing the sticks out to me is that the top of the cylinder expands more then the bottom, this is the reason for the pinch in a glow engine, as the engine warms up to operating temperatures to top of the sleeve expands more then then bottom, thus once the pinch is factored in the sleeve is fairly strait once at operating temps which is what seals the combustion chamber, by breaking the engine in cold instead of at operating temps the pinch is completely worn away, so once the engine is at operating temps and the top of the cylinder has expanded more then the bottom, to top is of a larger diameter, which leaves for an unsealed combustion chamber and little to no compression.
in a full sized, gasoline engine where cast iron and/or aluminum is used for the block and cylinder liners this might not be a problem, but for a glow engine i cannot see this break in method giving good results.
on the subject of the break in method, the big thing the sticks out to me is that the top of the cylinder expands more then the bottom, this is the reason for the pinch in a glow engine, as the engine warms up to operating temperatures to top of the sleeve expands more then then bottom, thus once the pinch is factored in the sleeve is fairly strait once at operating temps which is what seals the combustion chamber, by breaking the engine in cold instead of at operating temps the pinch is completely worn away, so once the engine is at operating temps and the top of the cylinder has expanded more then the bottom, to top is of a larger diameter, which leaves for an unsealed combustion chamber and little to no compression.
in a full sized, gasoline engine where cast iron and/or aluminum is used for the block and cylinder liners this might not be a problem, but for a glow engine i cannot see this break in method giving good results.
09-06-2007, 05:32 AM
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RE: Getting the pinch out of your Revo 3.3
thats daveOrevo ... all i'm saying is its no big deal just two different opinions and i agree with daveG55 anyway ... i think that the motor would be starved of lubrication during this process ... i don't know alot about nitros but i do know a thing or two about cars you know the big ones ... why can't we all just get along
09-06-2007, 06:04 AM
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RE: Getting the pinch out of your Revo 3.3
the comment at the top of the page taking an very aggressive tone with daveg55 for simply asking exactly how the cold break in worked, and when ddd couldn't explain exactly how it's better then a proven method such as the heat cycle, he got defensive, there was no need for that, it was in my mind very rude, sorry for misspelling your name there by the way.
09-16-2007, 08:22 AM
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RE: Getting the pinch out of your Revo 3.3
During the break-in process, the piston and sleeve wear into each other to form a precise fit. The engine needs to heat up to a certain temperature (around 200 to 215 degrees) to allow the piston and sleeve to achieve this fit properly. A precise fit between these two components is critical for proper compression, and optimum performance over a long period of time. This is especially important during the colder winter months, so when winter has past, and the engine is operated under warmer running conditions, they will continue to provide the best possible performance and wear.
If the engine is too cold during break-in, the piston and sleeve will not expand to their appropriate sizes for break-in, and this can lead to premature wear of these components. The engine may run fine for a short while, but the life span of the piston and sleeve can be shortened significantly. For instance, what could have been a five-gallon engine could quickly turn into a two-gallon engine due to improper break-in temperatures (of course this is just a scenario). The life of your engine solely depends on how it is treated through its entire life. This includes 'post' break-in as well.
If the engine is too cold during break-in, the piston and sleeve will not expand to their appropriate sizes for break-in, and this can lead to premature wear of these components. The engine may run fine for a short while, but the life span of the piston and sleeve can be shortened significantly. For instance, what could have been a five-gallon engine could quickly turn into a two-gallon engine due to improper break-in temperatures (of course this is just a scenario). The life of your engine solely depends on how it is treated through its entire life. This includes 'post' break-in as well.
09-16-2007, 02:32 PM
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RE: Getting the pinch out of your Revo 3.3
Having owned a few desiels in my time, I can see the benefit here - although I have a question with regards to the RPM.
With old, they produced more torque at lower RPM so could swing a larger prop, when converting for a Car do we need to change the gearing ?
P.S can't see any price lists for the Revo 3.3 conversion on your site ?
With old, they produced more torque at lower RPM so could swing a larger prop, when converting for a Car do we need to change the gearing ?
P.S can't see any price lists for the Revo 3.3 conversion on your site ?
09-16-2007, 08:25 PM
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RE: Getting the pinch out of your Revo 3.3
Bob Davis seemed a little hot-headed on this issue- then excused himself from further discussion- exactly what was his point?
I have not been in RC nearly as long as DaveG55, but I do have quite a bit of knowledge of internal combustion engines of all types, and, I'm sorry, but considering the fact that IC engines are heat pumps, it is pointless to attempt to break in one without heat, specifically heat generated by normal operation. So, on that note, I will continue to break in all my model engines per the specific manufacturer's recommendations.
DaveG-props you you- you are certainly one of the reasons this board remains informative and helpful to those that need guidance.
I have not been in RC nearly as long as DaveG55, but I do have quite a bit of knowledge of internal combustion engines of all types, and, I'm sorry, but considering the fact that IC engines are heat pumps, it is pointless to attempt to break in one without heat, specifically heat generated by normal operation. So, on that note, I will continue to break in all my model engines per the specific manufacturer's recommendations.
DaveG-props you you- you are certainly one of the reasons this board remains informative and helpful to those that need guidance.
09-17-2007, 12:51 AM
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RE: Getting the pinch out of your Revo 3.3
I don't agree with this cold lapping method for the previous reasons stated above. If it was that good why do people worry so much about the lack of cylinder taper (pinch) as engines wear? And then we have services (or DIY'ers) who restore this pinch which brings back restored power and an extended life on the mill.
09-17-2007, 01:34 AM
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RE: Getting the pinch out of your Revo 3.3
Just for future reference, Bob, when you're trying to hoc your crap on a forum, it's not a great idea to insult people. No one wants to buy anything from someone who talks down to them. Insulting Dave was probably a bad idea. He is well-known and respected here and has helped many of us.
If no one is understanding or they are questioning your method, perhaps it's not your audience, it's you. Your method may have worked for you, but we have yet to see proof of an engine that has been broken in using your method stand up to the test of time. There's a reason manufacturers have you break their engines in a certain way. By the way, piston and sleeve don't expand and contract at the same rate, piston is thicker, therefore does not get hot as quick as the thinner sleeve, and will have a variance in expansion. Your method on paper is filled with holes, real-world experience is likely to follow suit.
If no one is understanding or they are questioning your method, perhaps it's not your audience, it's you. Your method may have worked for you, but we have yet to see proof of an engine that has been broken in using your method stand up to the test of time. There's a reason manufacturers have you break their engines in a certain way. By the way, piston and sleeve don't expand and contract at the same rate, piston is thicker, therefore does not get hot as quick as the thinner sleeve, and will have a variance in expansion. Your method on paper is filled with holes, real-world experience is likely to follow suit.
09-17-2007, 09:38 AM
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RE: Getting the pinch out of your Revo 3.3
Part of what you say is true but its not the whole story here is the rest. First I must assume you have never heard of hand lapping piston to cylinder or the blue printing procces. This is a short cut version and it as worked for more years then I care to say. Try it you'll love it!!
09-17-2007, 01:57 PM
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RE: Getting the pinch out of your Revo 3.3
How much fuel have you put through a Traxxas 3.3 engine that has been broken in with your procedure? This method goes against the grain of conventional hobby wisdom.
09-18-2007, 12:54 AM
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RE: Getting the pinch out of your Revo 3.3
I have sent an e-mail to Team Losi, Traxxas, and OS Engines to verify this type of break-in. I will post the results.. here is a copy of the e-mail
I was wondering if I could bounce something off of you. Since you guys are manufacturers of your own engines, I figured you would have a good idea about this... I found it as a post in a forum from someone trying to do diesel conversions...
"You will need an electric drill first take the engine out of the truck and remove the easy starter and the glow plug. now slip a piece of fuel line over the shaft and lock it onto the shaft. Next put a little light oil down the hole and make shure to do two thing run the drill so the engine runs backwards. Start the motor and go to high speed once you feel no restriction you may release the motor and let it hang inverted whilr running tape or tie off the trigger and run through two battery packs which should give you a few hours.
what you have done is called cold burnishing and it will give you a harder surface on the piston and a more perfect seal for better compression and power. "
Does that make sense to you? It doesn't to me, the piston and sleeve would expand at different rates (since they are of different thickness) and this would cause premature wear on the engine, right?
"You will need an electric drill first take the engine out of the truck and remove the easy starter and the glow plug. now slip a piece of fuel line over the shaft and lock it onto the shaft. Next put a little light oil down the hole and make shure to do two thing run the drill so the engine runs backwards. Start the motor and go to high speed once you feel no restriction you may release the motor and let it hang inverted whilr running tape or tie off the trigger and run through two battery packs which should give you a few hours.
what you have done is called cold burnishing and it will give you a harder surface on the piston and a more perfect seal for better compression and power. "
Does that make sense to you? It doesn't to me, the piston and sleeve would expand at different rates (since they are of different thickness) and this would cause premature wear on the engine, right?
09-18-2007, 03:01 PM
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RE: Getting the pinch out of your Revo 3.3
First E-mail was from OS Engines...
Hello,
Thanks for your email!
There are many ways to break-in an engine.
The proceedure that you listed would not be a good way to go.
Below, you will find some helpful hints about breaking in your nitro car engine . . .
Step One - Preset carb and lubricate engine
1.Set the main needle valve. Do this by turning the needle valve in until it bottoms out, then back out 2.5 turns.
2. Adjust the idle screw so that the carb is open about 1 mm when at idle. Do not set too high or you may damage your clutch shoes.
3. Remove glow plug, and apply a few drops of after-run engine oil into the combustion chamber. Then, turn the flywheel over a few times to spread the oil throughout the cylinder.
4. Replace glow plug.
Step Two - Fill fuel tank, prime engine.
Step Three - Start engine
Step Four - Allow the engine to run at idle for a full tank of fuel
1. Every once in awhile, pull the trigger to full very quickly just to clear out any oil.
2. Once the engine runs out of fuel, allow it to shut off , then rotate the engine so that the piston is at the bottom of its' travel(bottom dead center). Allow to cool.
3. Once cool, turn the needle valve 1/16 th of a turn lean, and repeat this proceedure 4 times. Watch so that the idle is not set too high, or you may cause damage to your clutch shoes.
Step Five - Drive slowly
1. Drive, staying at slower speeds, varying the speed often.
2. Remember, a little smoke is OK. It is an indication that the engine is running rich and getting enough oil.
3. Listen to the sound. You are after a "throaty" sound. If the sound is high pitched with no smoke, you may have it set too lean. At this point, it may be a good idea to try the "water drop" test. Place a drop of water, or in a pinch, try saliva. If the water droplet instantly boils away, then the engine is overheating and set too lean. In this case, allow to cool, then back the needle out about an 1/8th of a turn or more until it is not overheating any longer.
4. Run 2-6 tanks. You should notice your car perform better during each run. If you don't, try turning the needle valve about a 1/16th of a turn in to see if performance improves, but do not set too lean.
Once you reach this point, the final setting will be subject to the engine. Every engine has its' own particular setting, even among the same engine model.
I hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate to contact us at this email address. (Please be sure to copy all previous emails into any future questions.) You can also reach our product support technical team at 217-398-8970, or via fax at 217-398-7721.
DID YOU KNOW that our web pages now all contain FAQs? (Frequently asked questions) Please drop by and take a look! We hope you'll find the information helpful and valuable to you.
Thanks Again,
Nick A.
Product Support
Thanks for your email!
There are many ways to break-in an engine.
The proceedure that you listed would not be a good way to go.
Below, you will find some helpful hints about breaking in your nitro car engine . . .
Step One - Preset carb and lubricate engine
1.Set the main needle valve. Do this by turning the needle valve in until it bottoms out, then back out 2.5 turns.
2. Adjust the idle screw so that the carb is open about 1 mm when at idle. Do not set too high or you may damage your clutch shoes.
3. Remove glow plug, and apply a few drops of after-run engine oil into the combustion chamber. Then, turn the flywheel over a few times to spread the oil throughout the cylinder.
4. Replace glow plug.
Step Two - Fill fuel tank, prime engine.
Step Three - Start engine
Step Four - Allow the engine to run at idle for a full tank of fuel
1. Every once in awhile, pull the trigger to full very quickly just to clear out any oil.
2. Once the engine runs out of fuel, allow it to shut off , then rotate the engine so that the piston is at the bottom of its' travel(bottom dead center). Allow to cool.
3. Once cool, turn the needle valve 1/16 th of a turn lean, and repeat this proceedure 4 times. Watch so that the idle is not set too high, or you may cause damage to your clutch shoes.
Step Five - Drive slowly
1. Drive, staying at slower speeds, varying the speed often.
2. Remember, a little smoke is OK. It is an indication that the engine is running rich and getting enough oil.
3. Listen to the sound. You are after a "throaty" sound. If the sound is high pitched with no smoke, you may have it set too lean. At this point, it may be a good idea to try the "water drop" test. Place a drop of water, or in a pinch, try saliva. If the water droplet instantly boils away, then the engine is overheating and set too lean. In this case, allow to cool, then back the needle out about an 1/8th of a turn or more until it is not overheating any longer.
4. Run 2-6 tanks. You should notice your car perform better during each run. If you don't, try turning the needle valve about a 1/16th of a turn in to see if performance improves, but do not set too lean.
Once you reach this point, the final setting will be subject to the engine. Every engine has its' own particular setting, even among the same engine model.
I hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate to contact us at this email address. (Please be sure to copy all previous emails into any future questions.) You can also reach our product support technical team at 217-398-8970, or via fax at 217-398-7721.
DID YOU KNOW that our web pages now all contain FAQs? (Frequently asked questions) Please drop by and take a look! We hope you'll find the information helpful and valuable to you.
Thanks Again,
Nick A.
Product Support
09-18-2007, 05:01 PM
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RE: Getting the pinch out of your Revo 3.3
Hey Moderator I think its time for you to jump in here.--------------------
For those of you that believe this a responce form the party in question be advised this is not they are not allowed to respond to these things they have a spoksman and i'm sure you will here from him for creating this fraud. By the way if you go back and read my original post it says get rid of the pinch in the revo engine and that if you had an OS you would never experience the pinch as there is none.
Bob Davis
Davis Diesel
For those of you that believe this a responce form the party in question be advised this is not they are not allowed to respond to these things they have a spoksman and i'm sure you will here from him for creating this fraud. By the way if you go back and read my original post it says get rid of the pinch in the revo engine and that if you had an OS you would never experience the pinch as there is none.
Bob Davis
Davis Diesel
09-18-2007, 07:50 PM
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RE: Getting the pinch out of your Revo 3.3
ORIGINAL: ddd
Hey Moderator I think its time for you to jump in here.--------------------
For those of you that believe this a responce form the party in question be advised this is not they are not allowed to respond to these things they have a spoksman and i'm sure you will here from him for creating this fraud. By the way if you go back and read my original post it says get rid of the pinch in the revo engine and that if you had an OS you would never experience the pinch as there is none.
Bob Davis
Davis Diesel
Hey Moderator I think its time for you to jump in here.--------------------
For those of you that believe this a responce form the party in question be advised this is not they are not allowed to respond to these things they have a spoksman and i'm sure you will here from him for creating this fraud. By the way if you go back and read my original post it says get rid of the pinch in the revo engine and that if you had an OS you would never experience the pinch as there is none.
Bob Davis
Davis Diesel
Sorry to say, Bob, but break-in is break-in... they all use the same methods... they all use the same type of piston and sleeve assembly... and the laws of physics remain the same. You have been proven wrong, now it's time to just give up. We were skeptical from the beginning, and I have sought out the advice of a professional engine support technician for confirmation. When making a claim that is out of the ordinary you should be able to produce proof of your claims or prepare to be called out on it. Your information could have lead to newbies ruining their $200+ engines by following your advice.
09-19-2007, 01:18 AM
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RE: Getting the pinch out of your Revo 3.3
ORIGINAL: jkdv8
they just tell you that to cover there a?@. doesnt really prove anything. not taking sides just f.y.i.
they just tell you that to cover there a?@. doesnt really prove anything. not taking sides just f.y.i.
Then, I'll take the manufacturer's recommended break-in, which is easier, more fun, and makes more sense, and let you know how many gallons I get (so far, 2.75 out of my TM323... and still running VERY strong...)
09-19-2007, 03:42 AM
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RE: Getting the pinch out of your Revo 3.3
running the traxxas break in i have gotten 6 gallons out of TRX 3.3, which is still going hard enough to pull wheelies in my brother revo.
09-19-2007, 01:48 PM
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RE: Getting the pinch out of your Revo 3.3
i wasnt saying to use his method. open your mind not your mouth. i will say this: my first nitro was a 4-tec with the pro.15. kinda cut a few corners on the break-in (in a hurry to go fast). well i still have that motor (9 years later) and running strong on my scrap maxx. now with the t-maxx pro.15 i got a few months later i actually went through the traxxas break-in method and it ended up being the biggest piece ever(sitting in piece's in my spare parts bin hoping i can salvage some of it). some of those parts (carb) i was able to salvage and are on the scrap truck. coincedence or not. he should of labeled the thread "getting some of the pinch out" why yet you dont want to remove all of it it is the key!!
09-19-2007, 02:55 PM
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RE: Getting the pinch out of your Revo 3.3
Your statment "get some of the pinch out of the Revo" is very good and discribes it better and more to the point so some of those nit pickers that have nothing better to do then throw cold water on anything they either don't understand or that they simply don't believe, what a waste of mind power. As I said in one of my posts if you blue print an engine one of the things that is done is the piston fit is improved if necessary by hand lapping in the cylinder to get rid of excess tightness. (Pinch) Most model engines do not have excessivley tight piston fits the best example is OS.
Bob Davis
Davis Diesel
PS I doubt if many people on the internet would say some of the things they do if they used their real names rather then monicurs.
Bob Davis
Davis Diesel
PS I doubt if many people on the internet would say some of the things they do if they used their real names rather then monicurs.
09-19-2007, 03:56 PM
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RE: Getting the pinch out of your Revo 3.3
im sorry but no its not a lot of people on forums will tell you there names if you befriend them i usually sit back and read posts and let them go if its an isolated thing but no you cant believe thatYOURE WRONG SO DEAL WITH ITI WANT TO SEE HOW MANY TANKS THAT ENGINE RUNS TILL IT DIES itxpl...... oops i mean logan out[>:]
09-19-2007, 03:57 PM
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RE: Getting the pinch out of your Revo 3.3
just wish i would of bought stock in some of these rc companies awhile back like i was going to. people are making a killing off the ill informed. although back then people knew what they where doing(not saying that no one does now its just few and far between). now with all the noobs its like a monopoly. kinda makes me want to leave the hobby after 18yrs. its destroying everything that it was. not to mention that people(again not all people) that can get a nitro engine to run act like they are a rocket scientist or something.
09-19-2007, 08:03 PM
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RE: Getting the pinch out of your Revo 3.3
Got an e-mail from Traxxas support today...
Hello Dustin,
That sounds like a really good way to wear an engine out and get rid of all your compression.
Best regards,
Stephen Lindholm,
TRAXXAS Customer Service
That sounds like a really good way to wear an engine out and get rid of all your compression.
Best regards,
Stephen Lindholm,
TRAXXAS Customer Service