Can an engine with a bad bearing still run perfectly?

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11-26-2011, 03:31 PM

#16

MattP

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Quote:

Originally Posted by inferno13

i had a nova plus 4 that did this, i found out the pinch was tight and the knocking noise i heard was the pistion hitting pinch really hard. sounded like a rod knock in a 1:1 car. after engine was broken in after to tight of a pinch it no longer made the noise

It's broken in so it has a good amount of compression/pinch but nothing like a new engine does.

11-26-2011, 03:31 PM

#17

MattP

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Quote:

Originally Posted by awdcameolsx

Check if your crank pin is out of round with some calipers. If its not then pick up a rod from a tecnopower engine they are compatible with the ole GRP engines I belive. However check for corrosion or looseness of the rear bearing, I have had one that felt good but the car ran like crap till I changed it. However what your symptoms are sounds to be the rod. Previous owner may have had a run-away, or simply lied about engine age.

Just checked the crank and it isn't out of round at all.

11-26-2011, 03:32 PM

#18

MattP

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Quote:

Originally Posted by stallen50

ascendancy g5 rod will fit the grp

I will look for one real quick.

Amain doesn't even stock the parts for that engine. Where else could I find one?

11-26-2011, 03:34 PM

#19

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Quote:

Originally Posted by tracktearer

If its engine noise. Its could be that your conrod bushing or the crank pin are worn. Check also the main bearing for play. These conditions will make the conrod hit wall of the crankcase resulting a loud noise and tuning issues. This happened to my picco(bearing) and grp(conrod).

I checked the bearings and all seem good. The crank is good. The conrod has a tiny bit of play in it but I'm not 110% sure how much is acceptable in a 2-3 gallon old engine?

Also inside the case looked good and I couldn't visually see any hit or wear marks on anything in the engine at all.

11-26-2011, 03:35 PM

#20

MattP

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Quote:

Originally Posted by romax

TQ speed lab rods will fit as well. Don't know if they are still available.

I already looked and couldn't find any.

11-26-2011, 03:51 PM

#21

R/C Lidz

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Quote:

Originally Posted by Lille-bror

Simple check on the rear bearing if you can hear a abnormal sound when the engine are running: At idle hold your hand on the head - don't burn yourself! If the abnormal sound disappears the rear bearing are defective. Change the front bearing at the same time.

I have a Picco doing the same thing- lots a noise. This trick worked just as written.

Thanks

On the other hand, I can't find any documentation that this engine ever existed, much less find a bearing for it. I guess I'll "run 'er till she blows"

11-26-2011, 06:59 PM

#22

j_blaze14

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i had a cracked head that made a noise before on a go 5port. once the middle fin broke off the noise went away.

11-27-2011, 04:25 AM

#23

MattP

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Quote:

Originally Posted by R/C Lidz

I'm definitely going to try this trick today.

11-27-2011, 04:26 AM

#24

MattP

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Quote:

Originally Posted by j_blaze14

i had a cracked head that made a noise before on a go 5port. once the middle fin broke off the noise went away.

I will take a good look at the head today as well. It was bought used to so it could have taken some good hits that I don't know about.

11-27-2011, 05:53 AM

#25

tracktearer

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Quote:

Originally Posted by MattP

There should be no visible play. If there is:
New crankpin=5.00mm, replace conrod
Bad crankpin =4.95mm, replace both

11-27-2011, 06:12 AM

#26

blktransam

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Quote:

Originally Posted by R/C Lidz

On the other hand, I can't find any documentation that this engine ever existed, much less find a bearing for it. I guess I'll "run 'er till she blows"

just pull the rear bearing out and measure it

then go to a-main or boca or avid and type in the size

Ryan

11-27-2011, 06:24 AM

#27

Maximo

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Quote:

Originally Posted by R/C Lidz

the Picco will use the same standard bearings a V-Spec would

11-27-2011, 07:37 AM

#28

R/C Lidz

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thanks Neal!

11-27-2011, 07:44 AM

#29

MattP

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Quote:

Originally Posted by tracktearer

There should be no visible play. If there is:
New crankpin=5.00mm, replace conrod
Bad crankpin =4.95mm, replace both

Well to my surprise after running more fuel through it today the noise went completely away.......

I bought this engine used. Is it possible it had sat for so long that the bearings were rusted or gunked up causing engine noise and after I put some fuel through it that they got lubricated and quit making noise?

I just put a whole tank through it and it never once made a noise.....

11-27-2011, 07:56 AM

#30

beidle99

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Good to hear. With your described sounds I was leaning to to rear bearing going. When I flew helis the os 50 would make the same type of noises when the rear bearing was going. It would look OK bt sound very bad when running and if it went it would wipe out everything.

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