Stretched a conrod?

[Nitroaddict]

Well - I got the other used RZVO1B installed in my storm pro this weekend, and took it to my dads house to test run. Had it running a few slow laps then really got it up to speed. well, it sounded like it was winding out a bit on the slippery grass, but not too bad, then the engine just quit. tried to restart it and it wouldnt turn over. the flywheel, when turned by my fingers, goes back and forth about the length of a stroke and then stops abrumptly, ,like it was hitting something. Did i streatch a conrod, and the piston is now hitting the head? i can't take it apart now, ,as i dont have my tools with me, just curious if my suspisions are correct (hope they are not)

 

[imnotsure]

Are you saying it will not turn over at all? The reason I ask is because the tr I got will not turn over and it is new. It will go almost to the tdc and stop, but I have not forced it either. Still waiting on other parts. Have you looked at your clutch?

 

[Nitroaddict]

This engine is not new, this is the Used one that i also got. It will rock back and forth, but after about a 1/4 turn, it stops completely like its hitting a wall.

 

[imnotsure]

well, i understand it's not new, but what i was trying to get at is my new one does the exact same thing. now i have not started mine at all, just kinda looking at it waiting on parts. and it does the exact same thing you're talking about. the best thing to do is to take it apart and put an eye on it. i have a hard time believing you stretched a conrod. are you saying that the clutchbell is spinning freely?

 

[FastEddy]

Its hard to say without looking.
I had a bearing in my .12 cvr go out and it acted the same way. Until you take it apart you wont know.
Factoid: I replaced the bearing and nothing else. I was at a race and someone has an extra bearing bit no rod, sleeve, or crank. I have put over 12 races 15-20 tanks on the engine and it runs like a dream.

On the other hand it may be your paint job!
I didn't just :censored:ing say that did I?

 

[Nitroaddict]

Originally posted by FastEddy

On the other hand it may be your paint job!
I didn't just :censored:ing say that did I?

smarta** !! lol. Actually, this is the storm pro, not the EB-4, so paint wont do it,lol!

i will check the mill soon, the clutch is fine, sl\pins freely. it isnt as if its hard to turn over, it stops like it hit a brick wall after spinning about a 1/4 turn on the flywheel either direction.

UPDATE:

took the head off. The problem isnt there. Everything is free flowing and moving correctly in the upper section of the mill. Couls what Eddy said be true? could i have spun the conrod bearing?

Unable to check this here at my Dad's - but will check the bottom end of the mill when i get home. Any ideas, lemmi know

 

[FlyinRazorback]

Kinda hard to tell since you can't get into it. My first thought was a bearing also, but take a good look at the piston and let us know what you find out.

 

[Nitroaddict]

UPDATE =- found the problem. It was the conrod, wasn't stretched though, it was broken. the whole bottom half of it lay in pieces at the bottom of the block. question= how do u remove it? i am sure that u need to slide the crankshaft forward and pull the piston/rod out the top of the cylinder. but how do u slide the crank forward?

 

[Error401]

NA, you're gonna have to do this:

Pull the head off

Pull the cylinder sleeve out (it should have a key in the top so it only goes back in 1 way)

then you can get the piston out (it takes a bit of persuation)

now the crank can be removed thru the rear of the engine, but this may not be needed unless you want to check for metal in the bearings.

The pin in the piston that holds the top of the conrod is held in (or should be) by a tiny C clip. Remove this (one on either side) and slide the pin out. The f'd up conrod should come on out then.

Replace the conrod and reassemble.

The bearings are a pain to replace, so hopefully you won't have to.

Whitt...

 

[mcvickj]

I guess we know why you got that engine for free now. You can send it my way. I will be more than happy to rebuild it. The bearings are a very big PITA to remove. It helps to warm up the case if you plan on removing them. I also believe there is some type of tool you can buy to make the removal easier.

 

[Error401]

Believe it or not, I've pulle bearings with a modified Xacto blade and a wood dowel before. And you're right it is a PITA no matter which way you do it.

 

[NCNitro]

I found the easiest way to remove bearings is to heat the oven to about 300 degrees, then put the block on a cookie sheet in the oven for about 15 min, the bearings will almost fall out.

 

[Nitroaddict]

I was concerned with removing the conrod from the crank. Are you guys saying that i DO NOT need to manipulate the crank in any way to remove the con rod? I can remove the conrod and piston out the top of the block without moving the crank? The reason why i ask this question, is that the con rod looks to be wedged on to the crank quite well, without any play. i would think that to remove the conrod, i would have to slide the crank forward. This is not correct? i can just slide the conrod off the crank? lemmi know, cause this sounds easier than i thought

 

[Error401]

Right, NA. Think about it. You can't mocve the crank forward because of the rear bearing, and it won't move to the rear because of the conrod. You can't move the conrod back because the piston and the top pin wont let ya. So you have to make it so that you can move the pistong and conrod to the rear, that means taking the sleeve out. Once you've done it once, it's a snap. Like NC said, heating the engine makes it easier. Heat is your friend. One thing your gonna need is a popcicle stick to get the sleeve to come out. Very carefully use the wood stick to push the sleeve up by using the piston. Once it's up a bit, you can use your fingers or something to pull the sleeve out.

Let us know how it's comming along.

Whitt...

 

[mcvickj]

Hey NA. Here is an article from RC Car Action that goes thru the rebuilding process of an engine. Pictures and all!!!

http://www.rccaraction.com/rn/articles/ht_rebuild.asp

 

[Nitroaddict]

hey error - i had the sleeve out last night, it comes out fairly easy. so thats not a prob. just didnt know i could do what yall are saying. thats great, ,and it helps me alot. thanks for the help, its been a while since i have been completely lost and needed some rc help, ,and u guys came to my rescue.

MCvickj - thanks for the link!

 

[Nitroaddict]

UPDATE:


grrrr..... well, i took everything apart again for a closer inspection and.......damn! big ol chip outta the piston too. DAMNDAMNDAMN! thats the expensive part. Probably wouldnt hurt it to run it like that, but I'm sure there are also hairline fractures in the metal that i cannot see. now for the bad part......piston only comes with the sleeve. total retail cost for the piston, sleeve, and conrod? --- $155.00!!!! Good Grief!!!

Okay......some good news....my wonderful LHS says that they will get me all three for only 100.00, well that helps a lil bit. but.....great planes wont have them in stock until friday....which means i wont see them until tuesday. bummer. i have another 3 say weekend this week too. man, two three day weekends, and i havnt been able to try out the RZ in the storm yet! damn! now for the delima......my lhs says he can next day ship it and have the parts for me on saturday.....but.....the next day air charge is 24.00 and the sat delivery is another 10.00...so we are back up to 150.00 again......how bad do i want the parts this weekend.....

 

[mcvickj]

Man that sucks NA. As I mentioned I think we now know why you got that engine for free. I would suggesting talking to the guy and seeing what he says. Maybe you can play the guilt card and he will split the cost with you.

 

[Nitroaddict]

naw - thats not fair - there would have been no way for him to know the conrod was about to give. besides, it is used, and i would never hold a seller responsible for something used after i already ran it a few times. I'm just gonna bite the bullet on this one. oh well, at least i will have two brand new engines after i install the piston/sleeve/conrod.

 

[mcvickj]

I would at least talk to the previous owner and see how much fuel was ran thru that engine. Maybe you can talk to OS about getting it replaced. Who knows maybe they will say it was a defective engine. Of course they might want to see some paperwork. If so, that could be a problem.