Notices
RC Car General Discussions This forum is for all general discussions related to radio control cars. Check forums below for more specific categories if applicable.

what is normal nitro engine life?

Old 09-15-2012, 05:29 PM
  #1  
mattsauto
Member
Thread Starter
 
Join Date: Apr 2012
Location: otego, NY
Posts: 63
Likes: 0
Received 0 Likes on 0 Posts
Default what is normal nitro engine life?

i understand there are alot of valiables to this question but i put an lrp .28 spec 3 engine on my losi 8t truggy, broke it in properly (another argument), ran it very rich for about 1 1/2 gallon. then race tuned it ( seemed to be perfect tune & tune didn't change until problem occured) & ran it pretty hard on track with buddies for about another 2 1/2 - 3 gallons ( about 4 gallon total) when all of a sudden it started stalling upon throttle release(when warm). i did have the clutch bearings go shortly after & changed them with no change to running. it does still run strong other than that. (very annoying stalling after 1/3 tank). i did alot of research on this site for answers & only come up with motor getting weak. i tried sealing engine, retuning & every ajustment i could think of. i did just order another motor but was wondering what to do with this motor? should i try to replace piston & sleeve? (not cheap). or just scrap it? or maybe i did something wrong? any insight would be helpfull. thanks in advance.
Old 09-15-2012, 08:02 PM
  #2  
phmaximus
 
phmaximus's Avatar
 
Join Date: Jun 2008
Location: Adelaide, AUSTRALIA
Posts: 6,709
Likes: 0
Received 1 Like on 1 Post
Default RE: what is normal nitro engine life?

So everything seems ok on the motor? It's not overheating? Good compression?

One other thing to check would be the fuel tank cap seal and fuel lines
Old 09-15-2012, 09:20 PM
  #3  
HerrSavage
Senior Member
 
Join Date: Sep 2005
Location: Irgendwo, GERMANY
Posts: 10,292
Likes: 0
Received 5 Likes on 5 Posts
Default RE: what is normal nitro engine life?

As you said, ton of variables.. Fuel line, clutch bearings, tune, weather, plug, fuel, whatever...

I'm kind of in to nitro engines, so have a few of them. I tend to like to buy engines in the less-than-$225 range, and run them til they die and get a new one. They rarely die on me though, so they usually end up getting sold. Even when I like them and they run well.. There are always new engines coming out, and new deals to be had..

But generally, I think all engines should definitely do six gallons with no issues, maybe and hopefully eight, and if you're lucky, ten.. With that kind of life I think you should be happy.. All the rebuilding, etc.. I think only really make sense with the very expensive engines like OS Speeds etc., or maybe just if you have an engine you really like..

As for LRP's, they don't need a gallon break-in. Ten tanks and go easy-ish for half a gallon maybe, and then off you go... LRP's, 454's, Big Reds, etc.. are all for me in the price range of "run them til they die and get something else if/when they do.." My Big Red is like three years old and still going strong, and my silver Mach older than that..
Old 09-16-2012, 03:47 AM
  #4  
supertib
Senior Member
 
supertib's Avatar
 
Join Date: Mar 2004
Location: , MB, CANADA
Posts: 7,241
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

you may have gotten dirt in the engine......i work on hundreds of engines and see dirt in a very high number of them...dirt can come in thru the airfilter, as well it can come in thru the front bearing..................If a engine starts stalling and acting up you need to pull the engine down and find the issue..if its dirt it just may need to be cleaned out...................... However if there is something going wrong inside, all your doing by continuing to run is further the damage that is done.................When it comes to these small engines assume nothing, if it starts acting up then you need to find the issue, continuing to run it just does more damage........
Old 09-16-2012, 09:43 AM
  #5  
SLAYERDUDE
Senior Member
 
SLAYERDUDE's Avatar
 
Join Date: Apr 2009
Location: CHICAGOLAND, IL
Posts: 1,856
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

While you have the engine apart you need to check the pinch, if you can easily push the piston to the top of the sleeve or thru the top then the pinch is gone and you can either get a new piston and sleeve or send it to Ray A Racing and have it pinched for around $20.
Also with the engine together but glow plug removed, you should feel some type of resistance at TDC as the piston moves thru the pinch zone.
If the engine fails both these tests the pinch (tapered fit/seal) between piston and sleeve is worn and once the engine gets to temp it loses compression and will no longer start until cool.

If you ran super rich for 1.5 gallons you also may have hammered the conrod and that will cause flameouts too.
Old 09-16-2012, 04:06 PM
  #6  
mattsauto
Member
Thread Starter
 
Join Date: Apr 2012
Location: otego, NY
Posts: 63
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

sounds like exactly what i had happen. started flaming out when engine warmed & wouldn't restart until engine cooled. maybe i ran it too rich for too long trying to make engine last from break in but i really put stress on rod & crank? at any rate i think with my next engine i will break it in with about ten tanks, race tune & run it like i stole it! haha. does that sound like a good theory? i like to run them hard. ps. i ran it today till the end, it ran good for about 5 minutes then started losing power & i said f-it & ran it till it would barely move ( it literaly got to 400 temp oops) haha. she's definately done now!
ORIGINAL: SLAYERDUDE

While you have the engine apart you need to check the pinch, if you can easily push the piston to the top of the sleeve or thru the top then the pinch is gone and you can either get a new piston and sleeve or send it to Ray A Racing and have it pinched for around $20.
Also with the engine together but glow plug removed, you should feel some type of resistance at TDC as the piston moves thru the pinch zone.
If the engine fails both these tests the pinch (tapered fit/seal) between piston and sleeve is worn and once the engine gets to temp it loses compression and will no longer start until cool.

If you ran super rich for 1.5 gallons you also may have hammered the conrod and that will cause flameouts too.
Old 09-16-2012, 05:42 PM
  #7  
SLAYERDUDE
Senior Member
 
SLAYERDUDE's Avatar
 
Join Date: Apr 2009
Location: CHICAGOLAND, IL
Posts: 1,856
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

There's a big difference between running way too rich and causing damage, and taking things easy by staying "on the rich, safe side"...
We have a guy at my track that runs waay too rich, we all tune it for him, give him tips, he still detunes it right back to being way overly rich.
His engines never run right.

I've always run my engines on the rich side, but they all last a very long time, in fact I've been into nitro for over 10 years and every engine I broke in still runs.
Recently Robin from ExtremeRCmods taught me that if an engine is run too rich during break-in, which results in lower temps, it doesen't allow the sleeve to expand properly and will actually wear the piston and sleeve fit too much to have a nice fit once a race tune is put on it and the sleeve fully expands under normal operating temps.
Makes perfect sense, engine is worn in at 160F and the piston/sleeve wears perfectly together, then you ramp the tune up and hit 220F, the sleeve will expand and fit loose on the piston.

You might want to inspect it and if the brg's and rod are okay, send it to Ray for a $20 pinch and report back, hell $20 is less than a gallon of fuel and you may get another 4 gallons out of it.
http://www.rayaracing.com/
Old 09-16-2012, 06:07 PM
  #8  
mattsauto
Member
Thread Starter
 
Join Date: Apr 2012
Location: otego, NY
Posts: 63
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

yea thanks slayer but i think i might have done it in today though ( got it to 400 because i knew it was about done & hammered it until it would hardly move. haha ). no i never ran too rich just a little on rich side. although i do run the hell outta of it when it's broke in. i will keep extremercmods in mind for the next one though.
ORIGINAL: SLAYERDUDE

There's a big difference between running way too rich and causing damage, and taking things easy by staying "on the rich, safe side"...
We have a guy at my track that runs waay too rich, we all tune it for him, give him tips, he still detunes it right back to being way overly rich.
His engines never run right.

I've always run my engines on the rich side, but they all last a very long time, in fact I've been into nitro for over 10 years and every engine I broke in still runs.
Recently Robin from ExtremeRCmods taught me that if an engine is run too rich during break-in, which results in lower temps, it doesen't allow the sleeve to expand properly and will actually wear the piston and sleeve fit too much to have a nice fit once a race tune is put on it and the sleeve fully expands under normal operating temps.
Makes perfect sense, engine is worn in at 160F and the piston/sleeve wears perfectly together, then you ramp the tune up and hit 220F, the sleeve will expand and fit loose on the piston.

You might want to inspect it and if the brg's and rod are okay, send it to Ray for a $20 pinch and report back, hell $20 is less than a gallon of fuel and you may get another 4 gallons out of it.
http://www.rayaracing.com/
Old 09-17-2012, 05:30 AM
  #9  
Ttowntoolman
Senior Member
 
Join Date: Jun 2007
Location: Theresa, WI
Posts: 587
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

I race dirt oval. I started this season with 12 gallons on my os 25 XZ running great. I am now up to 14 gallons and still running great. I pulled the engine off to clean chassis last night, I still cant roll the flywheel all the way around with my finger. I see no end in sight.......and I usually set TQ every week with it! Engine has never been apart for any reason.

Old 09-17-2012, 05:35 PM
  #10  
mattsauto
Member
Thread Starter
 
Join Date: Apr 2012
Location: otego, NY
Posts: 63
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

is there a secret to longevity on a nitro engine like keeping it on the rich side or a different breakin? my lrp ran awesome for like 4 gallons ( i did run it very hard on big track). is it the brand of motor, fuel i use (s&w 20%)or maybe my tune? i kept my race tune the whole time after breakin without having to change it (weather stayed the same) & it never got over 260 in temp & ran awesome. i am still new to rc (about 9 months) but have been working on full scale vehicles, snowmobiles & dirt bikes all my life so i got a pretty good sense of tuning but still learning. thanks for help it is very appreciated.
ORIGINAL: Ttowntoolman

I race dirt oval. I started this season with 12 gallons on my os 25 XZ running great. I am now up to 14 gallons and still running great. I pulled the engine off to clean chassis last night, I still cant roll the flywheel all the way around with my finger. I see no end in sight.......and I usually set TQ every week with it! Engine has never been apart for any reason.

Old 09-17-2012, 07:44 PM
  #11  
The_Shark
Senior Member
 
The_Shark's Avatar
 
Join Date: Jun 2007
Location: Plainfield, IL
Posts: 7,163
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

my JPX that has probably 5 gallons on it only needs a con-rod to continue for another 5 or so (the one now works but too much play)
dirt kills engines, so does running too lean, and actually, running too rich/ cool can also be bad since the tolerences stay too tight= more friction= possibility of wearing down the sleeve/piston.
Old 09-18-2012, 12:04 AM
  #12  
HerrSavage
Senior Member
 
Join Date: Sep 2005
Location: Irgendwo, GERMANY
Posts: 10,292
Likes: 0
Received 5 Likes on 5 Posts
Default RE: what is normal nitro engine life?


ORIGINAL: mattsauto

is there a secret to longevity on a nitro engine like keeping it on the rich side or a different breakin? my lrp ran awesome for like 4 gallons ( i did run it very hard on big track). is it the brand of motor, fuel i use (s&w 20%) or maybe my tune? i kept my race tune the whole time after breakin without having to change it (weather stayed the same) & it never got over 260 in temp & ran awesome. i am still new to rc (about 9 months) but have been working on full scale vehicles, snowmobiles & dirt bikes all my life so i got a pretty good sense of tuning but still learning. thanks for help it is very appreciated.
ORIGINAL: Ttowntoolman

I race dirt oval. I started this season with 12 gallons on my os 25 XZ running great. I am now up to 14 gallons and still running great. I pulled the engine off to clean chassis last night, I still cant roll the flywheel all the way around with my finger. I see no end in sight.......and I usually set TQ every week with it! Engine has never been apart for any reason.


Variables variables variables... A decently run in engine that isn't hammered too lean for too long should last 6-10 gallons.. And I think that goes for most brands.. LRP's (like the OS mentioned above..) don't have so much pinch when new like most race engines.. Your next LRP could last four, or ten... I say keep it rich-ish, with something more like 220ish as an ideal running temp.. I think with nitro there really is no replacement for experience. You can read stuff on the internet til you're blue in the face - sometimes it can be helpful too. But you really need to just have a feel for it, and that comes from being out there and burning nitro - there needs to be good smoke, performance needs to be good, and most of all it needs to sound right.. I've had lots of engines at this stage, and currently run about 6-7 of them, and am still learning how to tune to be honest.. The main thing in tuning is finding the right balance between the idle gap and the LSN.. The HSN is easy.. - get the other bit right, and then just richen and lean according to how it runs..
Old 09-18-2012, 03:00 AM
  #13  
mattsauto
Member
Thread Starter
 
Join Date: Apr 2012
Location: otego, NY
Posts: 63
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

well said herrsavage. maybe i had it tuned a touch onlean side normal temp was 240-250? i'll just keep playing & see if i can improve my luck with experience. thanks for input all.
ORIGINAL: HerrSavage


ORIGINAL: mattsauto

is there a secret to longevity on a nitro engine like keeping it on the rich side or a different breakin? my lrp ran awesome for like 4 gallons ( i did run it very hard on big track). is it the brand of motor, fuel i use (s&w 20%)or maybe my tune? i kept my race tune the whole time after breakin without having to change it (weather stayed the same) & it never got over 260 in temp & ran awesome. i am still new to rc (about 9 months) but have been working on full scale vehicles, snowmobiles & dirt bikes all my life so i got a pretty good sense of tuning but still learning. thanks for help it is very appreciated.
ORIGINAL: Ttowntoolman

I race dirt oval. I started this season with 12 gallons on my os 25 XZ running great. I am now up to 14 gallons and still running great. I pulled the engine off to clean chassis last night, I still cant roll the flywheel all the way around with my finger. I see no end in sight.......and I usually set TQ every week with it! Engine has never been apart for any reason.


Variables variables variables... A decently run in engine that isn't hammered too lean for too long should last 6-10 gallons.. And I think that goes for most brands.. LRP's (like the OS mentioned above..) don't have so much pinch when new like most race engines.. Your next LRP could last four, or ten... I say keep it rich-ish, with something more like 220ish as an ideal running temp.. I think with nitro there really is no replacement for experience. You can read stuff on the internet til you're blue in the face - sometimes it can be helpful too. But you really need to just have a feel for it, and that comes from being out there and burning nitro - there needs to be good smoke, performance needs to be good, and most of all it needs to sound right.. I've had lots of engines at this stage, and currently run about 6-7 of them, and am still learning how to tune to be honest.. The main thing in tuning is finding the right balance between the idle gap and the LSN.. The HSN is easy.. - get the other bit right, and then just richen and lean according to how it runs..
Old 09-18-2012, 08:45 AM
  #14  
Ttowntoolman
Senior Member
 
Join Date: Jun 2007
Location: Theresa, WI
Posts: 587
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

I think there is a difference in quality between engines. I like to buy OS or Nova but I have two sons that race with me........one of my sons just recently got into nitro latemodel 1/8th scale and needed an engine. He did not want to buy an expensive OS or Nova or Werks for that matter, he bought a dynomite 26 mach 2. Essentially the same as the lrp etc.... I broke this engine in for him using the heat cycling method as I do with every engine I have broken in. I could tell imeadiatly that this engine does not have as tight of a mechanical pinch as my usual engines do. Break-in completed and it is running great but I can roll the flywheel all the way around already......I actually could almost do that imeadiatly. Dont get me wrong, this thing runs great for a $140.00 engine, it is fast as anyone else out on the track. I just dont think it will last half as long.

Old 09-18-2012, 09:48 AM
  #15  
HerrSavage
Senior Member
 
Join Date: Sep 2005
Location: Irgendwo, GERMANY
Posts: 10,292
Likes: 0
Received 5 Likes on 5 Posts
Default RE: what is normal nitro engine life?

My SH engines live eight+ gallons easily.. Ultimately, who cares how it feels when rotating the flywheel when it's not running?.. It's how it runs that counts.. No doubt the more expensive - and touchy - "race engines" are better for racing.. But that does not mean that SH- engines (LRP, Dynamite, Losi, Nosram, SH, etc..) engines suck.. - not at all.

Furthermore, engine for engine, if anything the lower-pinch SH engines might live longer than some high-pinch race engine. The pinch is what makes conrods give out, right? Leading to damaged, if not dead engines...
Old 09-18-2012, 01:40 PM
  #16  
Ttowntoolman
Senior Member
 
Join Date: Jun 2007
Location: Theresa, WI
Posts: 587
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

Herrsavage, I agree, nothing wrong with SH engines. I also agree they like a richer tune than say an OS. I would like to ask you though, how do you check to see if an engine is used up or still good without tearing it down, short of a compression test? I simply roll the flywheel around with the glow plug in to see if there is a mechanical pinch left, or at minumum compression left. I would venture to guess that the OP can spin his flywheel all the way around with little to know resistance what so ever. Almost as if it had no glow plug left in it.

I understand your theory of lesser pinch equates to less stress on the conrod, makes good sense. I dont think the OP has anything wrong with his conrod, sounds like it has little to no pinch left.

I dont really see a difference at the end of the day.......you spend $150 on an SH based engine and it lasts 6/8 gallons. You spend $300 on an OS engine and it lasts 14/16 gallons. I dont think you could be wrong with either choice, it's a wash.

Old 09-18-2012, 01:48 PM
  #17  
HerrSavage
Senior Member
 
Join Date: Sep 2005
Location: Irgendwo, GERMANY
Posts: 10,292
Likes: 0
Received 5 Likes on 5 Posts
Default RE: what is normal nitro engine life?


ORIGINAL: Ttowntoolman

Herrsavage, I agree, nothing wrong with SH engines. I also agree they like a richer tune than say an OS. I would like to ask you though, how do you check to see if an engine is used up or still good without tearing it down, short of a compression test? I simply roll the flywheel around with the glow plug in to see if there is a mechanical pinch left, or at minumum compression left. I would venture to guess that the OP can spin his flywheel all the way around with little to know resistance what so ever. Almost as if it had no glow plug left in it.

I understand your theory of lesser pinch equates to less stress on the conrod, makes good sense. I dont think the OP has anything wrong with his conrod, sounds like it has little to no pinch left.

I dont really see a difference at the end of the day.......you spend $150 on an SH based engine and it lasts 6/8 gallons. You spend $300 on an OS engine and it lasts 14/16 gallons. I dont think you could be wrong with either choice, it's a wash.


I can't imagine any engine lasting 14-16 gallons without a new rod, bearings, etc.. Again, new for new, with equal maintenance, I don't think an OS is going to last longer than an SH.. Just my opinion though. In fact, I hear pretty often that OS - great engines that they are - require quite a bit in the conrod, rebuild, bearings, etc.. dept.. to last..

As for how I check, I just run them til they don't run well anymore.. Never really had any die.. A couple Sportwerks .26's got difficult, so I just sold them for spares(they each got a good six though I would say...) But three Machs, an LRP Spec 3, and a Dynamite Big Red 28 all got about eight-ten gallons on them with no issues.. Also currently running a Losi 454 and LRP 30X now, and they run great..
Old 09-19-2012, 07:16 AM
  #18  
mattsauto
Member
Thread Starter
 
Join Date: Apr 2012
Location: otego, NY
Posts: 63
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

update on my engine. i tore it down last night & found the inner crank bearing has enough play in it when it's warm that it was allowing the rod to srape the bottom of the crank case (ie: stalling when warm). so i'm thinking i may be able to just replace both crank bearings & be ok because everything else looks fine & the pinch is still great. what are your thoughts?
Old 09-19-2012, 08:00 AM
  #19  
The_Shark
Senior Member
 
The_Shark's Avatar
 
Join Date: Jun 2007
Location: Plainfield, IL
Posts: 7,163
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

I won't plop down more than $150 on an engine, I either gamble and buy used, or get cheap OS/hyper/ofna engines, most budget engines today have enough grunt to keep up with the high end mills (this I know because I own a $375 NOVA that had maybe a gallon through) sure if your a top-end racer where every millisecond counts, a high end engine with 10% more power is going to matter, but for most people, you don't need all that power and effcientcy.

sure a low end engine may not last as long, but a top dollar engine isnt going to outlast it by 2-3 times to make it worth it.

sometimes you do get what you pay for, especially cheap small block mills, some of those detonate pretty easily.
Old 09-19-2012, 09:13 AM
  #20  
Anthoop
Senior Member
 
Anthoop's Avatar
 
Join Date: Feb 2007
Location: Somerset, UNITED KINGDOM
Posts: 2,324
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?


ORIGINAL: mattsauto

update on my engine. i tore it down last night & found the inner crank bearing has enough play in it when it's warm that it was allowing the rod to srape the bottom of the crank case (ie: stalling when warm). so i'm thinking i may be able to just replace both crank bearings & be ok because everything else looks fine & the pinch is still great. what are your thoughts?
Yes if the bearings are the only problem then replace them both...but if it will need a crank/rod or piston sleeve also, then it is better to check the prices first.
Old 09-19-2012, 02:24 PM
  #21  
mattsauto
Member
Thread Starter
 
Join Date: Apr 2012
Location: otego, NY
Posts: 63
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

thanks anthroop. i did check rebuild prices before i tore it down & to totally rebuild it would be almost as much another engine. i did buy another lrp .28 because i like the motor. however everything in motor still looks very good so decided i will buy the bearings ($15.59 for both) & see how much more i can get out of it.
ORIGINAL: Anthoop


ORIGINAL: mattsauto

update on my engine. i tore it down last night & found the inner crank bearing has enough play in it when it's warm that it was allowing the rod to srape the bottom of the crank case (ie: stalling when warm). so i'm thinking i may be able to just replace both crank bearings & be ok because everything else looks fine & the pinch is still great. what are your thoughts?
Yes if the bearings are the only problem then replace them both...but if it will need a crank/rod or piston sleeve also, then it is better to check the prices first.
Old 10-07-2012, 02:11 AM
  #22  
cobra26
Senior Member
 
Join Date: Oct 2003
Location: Wildwood, NJ
Posts: 552
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what is normal nitro engine life?

I have not kept track of the amount of fuel I run through each of my engines. I do know I consume 4-6 gallons of fuel a year, but that is among a group of 7 buggies, trucks, a Kyosho car, and truggies that I regularly run. I have been running an Associated O.S. powered GT-10 and two Raze buggies for over 8 years and they all still run strong. I don't lean them out to the extreme and I use after-run oil after each session. I guess I am just lucky...

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.