pyroman_27

Hi everyone. Its been a little while since my last post. Just wanted to ask a quick question. My engine compression seems to really have increased since the last run with my tornado XP. I checked the clutch spring, thats not it. I took the glow plug out and pulled the cord and no problems pulling. It seems to have way too much compression with the plug in. Ive never seen anything like this. i havent attempted taking it apart yet. Theres nothing in the cylinder and Im still using the factory supplied glow plug. And by the way, all other parts are still the same. I havent had a gear or clutch problem yet, with the exception of an A-arm when a stop sign just jumped right in front of my car. If anyone has any ideas on how i got so much compression,please clue me in. Oh, by the way, I did start the car one more time by loosening the glow plug about a half turn then retightened it after i got it going.

nbluehell

exhaust blockage? is it possable to have too much compression in a stock motor w/all stock parts? how does it run?

Trav 09

is your engine flooded try takeing the glow plug commletely out and pull the cord a few times fast then put the plug back in and see wat happends hope this helps

ehroof

did you change the plug with a deeper one that would cause more compression?

pyroman_27

there is no exhaust blockage and it is not flooded, and im using the plug that came with it. i know, sounds weird, its got me completely stumped

pyroman_27

and i forgot to mention it wont start unless i unscrew the glow plug about 2 turns and then tighten it back in after starting

Trav 09

im baffled to but i guess more compression is better than less

Himoto Racing Canada

Hello

Just a thought ... have you removed the heatsink button or the head on your engine ?

Answer #1
If yes did you put all the head shims back ?? If no the go to answer #2

Answer #2 Is the washer still at the base of your glow plug. You must have a brass washer to seal the plug. if yes then go to #3

Answer #3 Your last run before this happened did the engine run lean at very high RPM, You could have stretched the connecting rod in your engine.

I would tear down the engine and have a very careful look at what exactly is binding.


Regards

ehroof

I like your answers Himot Racing Canada guy. You need to come here and help out more often.

Popper252

good point with answer 2. I didn't think about that, but it makes perfect sense.

pyroman_27

there is nothing binding, the washer is still there, and everything else is normal. it just has a lot more compression than it did when i got it. its kinda like when u first get flooded, but its not flooded.

pyroman_27

i dont know what to say fellas. i took the head off the engine and everything looked fine. i put it back together and took it out to run. the compression was still there. it ran better than ever. i think im gonna switch this with the motor thats in my HPI MT. This motor is screaming and running nice and cool. spit bubbles for about 4 to 5 seconds. itis got tons of low end and screaming high end. and what surprised me is its running a little rich. who knows maybe i did stretch the connecting rod, must of been just the right amount, lol. guess i was just lucky this time. thanks for the help fellas. and if anyone is interested in a redcat tornado minus the engine email me at [email protected] , we can negotiate the price. i can even toss the HPI .15 motor in there from my MT. the only thing wrong is one broken front lower A-ARM, and the gears are showing a bit of wear, but theyre still working. id like $100 for everything including the radio and HPI motor. If not Ill put it on ebay soon. [email protected]

chubbysuncle

??? I'm sorry but I don't get it. The most force applied to a connecting rod is a compressing force not an extending one. Even if it were to get hot enough to make Aluminuim plastic enough to stretch it seems to me it would take tremendous force pulling it apart and even then would break very quickly. I think maybe the piston return spring is broken and the piston isn't returning to BDC. Flush the engine in a bucket of Prop Wash and it sure be good. LOL . Maybe the engine is perfectly broken in? Or more likely the sleeve shrunk from a quick cooldown and now the pinch is tighter. Does this engine have alot of compression everytime you start, Hot or Cold? Do you use afterrun oil? It could be possible that the piston and sleeve are perfectly mated and, depending on the fuel you're using,the oil blend and carb settings are perfect? I'm not trying to bash anyone but I've worked on alot of engines, big and small, and have never heard of anyone ever stretching a connecting rod in a single cylinder engine. I can't see how it's possible. [&:]

Himoto Racing Canada

chubbysuncle

Must be that i am a crazy canuck (Canadian) but i have stretched 2 connecting rods in 8 years of hobby.

One in my trainer with an os LA .40 doing a nose dive ( involuntary nose dive that was) engine just started doing a very funny clunking noise and stalled.

The second one was an HPI .15 SS while i was cleaning out the exhaust after flooding it , i just over reved the engine too much. Had to add 2 head shims for it to run again.

Must be the cold air and my hot head !!

ThunderbirdJunkie

My Feedback: (3)

I have decided that I've kept my big mouth shut long enough.

The engine he has does not have any shims from the factory. Also, if there were, compression increase would be BARELY noticeable, if at all. You've apparently never reshimmed an engine.

If the washer was NOT at the base of his glow plug, OR upside-down, it would have LESS compression. that's what the washer is THERE for.

No, it wouldn't be stretched. Stretched connecting rods have not been a problem in RC since almost ALL companies stopped using crappy BRASS connecting rods like this:



And with an aluminum rod, in any situation where it WOULD stretch from being overrevved, THIS happens


Himoto Racing Canada, I would REALLY appreciate it if you would please, in the future, avoid giving Redcat customers erroneous information. a difficult-to-pull pullstarter could be a number of things, none of which would be what you mentioned. ehroof, go ahead and flame me.

My first guess (yes, GUESS, because this is a RARE problem, unless it's flooded) would be that your engine is flooded. remove glow plug, pull pullstarter over a few times (look away and/or close your eyes to avoid fuel getting in em).

If there's no fuel in there, and the engine is still difficult to pull over, the only other thing I can think of is that your crank bearings are fried. Have you let the engine sit for any significant amount of time? if so, fuel could have gunked up in the bearings. this happened on one of my TRX Pro .15s.

Eric

Kemo

that there be a traxxas engine no?

ThunderbirdJunkie

My Feedback: (3)

Aye, matie. I have what's left of that piston/rod sitting here on my desk...I have a pro 15 piston/rod on my keychain...

pyroman_27

i dnt know uys, its running better and cooler than when i got it. im actually gonna put the engine in my HPI MT. it has compression comparable to a weed wacker. i checked the pull cord and one way bearing when i tore it apart. iti doesnt sem to be a problem. it runs better than ever and its faster and running cooler than it ever did. as for the tornado i think im gonna put it on ebay with the HPI .15 in it. i just cant believe the way this motor is running. its so strong right now bottom and top end and doesnt stall unless i want it to quit. its perfect. just very tight and lots of compression. im not complaining anymore. i thoughti had a problem that i shouldnt run te car with. well i ran it anyhow and its great!!!!!! im new to nitro but have been running RC cars for a long time. the engines only problem is starting. eventually im gonna break the starter cord if it doesnt loosen up.

pyroman_27

and by the way its definitely not flooded. i took the engine apart with no fuel in it and had the same compression. forget i asked. its running better than ever and its running cool and rich right now. im gonna leave it where it is until it getts cooler out and then richen it uop as needed for the weather. ive never seen such a strong small nitro engine

jguitarsandcars

TBJ...I don't mean to sound negative as you've been cool with me, and I have got a big red X where the pic should be loading, but it sounds like you are saying stretched connecting rods are a thing of the past because companies have stopped making them out of "Crappy Brass"...However, the first thing I noticed when I took my Infiniti engine apart (twice) was that it had a connically shaped brass connecting rod instead of a traditionally shaped aluminum one I had planned on knife edging....Maybe I just misunderstood what you were saying, but that's just the way it sounded to me that you were calling a certain design crappy, but yet my car had that design....

ThunderbirdJunkie

My Feedback: (3)

Well...it's not so much crappy, it's just that the industry has swung the other way, which is less prone to stretching when overrevved.

I know the Infinity .05 in the Tremor has the brass connecting rod, but I was assuming that the Infinity .18 was using a more traditional (nowadays) machined aluminum rod (haven't taken one apart yet though).

Was it the picture of the rod that showed up as a red X, or was it the one that showed what usually happens to an alumium rod?

BTW-don't worry about sounding negative, if you've got questions or you think i'm giving incorrect information, let me know by all means.


Also, Pyro, it's entirely possible that the head was incorrectly installed previously, and you put it on right....who knows? as long as it turns over and fires, it's all good:P

ehroof

Hey TBJ, take your foot out of your mouth yet?? I dont have to flame, you take care of yourself enought as it is, you know how i feel about you!!!! btw, why did you have to mention my name??? i didnt refer to you at all, you look to make trouble.

ehroof

hey eric, why dont you help out cartronics on his thread about engine parts, he's been waiting 3 or 4 days for an answer from you. stop worrying about someone trying to help out.

Kemo

did anyone ask what ehroof had to say? Little troll, just be quiet. EVERY post i read where YOU have to add your 2 pointless cents to TBJ turns into a flame war. Words of wise, dont speak, or just block him and keep the peace at the forums.

*looks around thread* nope, not that I can see at least! And I'm now at 60% full vision... wow.

Team Knowitall

If I had an answer to give, I'd give it.