2LikesGo-Tech Engines Thread
10-08-2009 | 07:04 AM
#8836
Tech Adept
iTrader: (-1)
Joined: Dec 2007
Posts: 155
It's actually not harder than with any other engine out there. There are certain design approaches that GO has made and formed a very competitive engine lineup. In most cases guys just don't listen what they are being told to nor disregard the info and then blame on the gear if it fails.
Be it the GEN 5/5.5 or the new GX series engines, just do the basic steps:
Install run-in shimm
Put in hot plug (like OS P3)
HEAT the engine to +100degC meaning BOTH the heatsink and block is in +100degC
Loosen the plug
Prime the engine
Start it
Fasten plug
If engine tends to stall screw in LSN 1/4 turn and that should do the trick
It's not difficult and in most cases people dont really heat engine enough (use hair dryers or something crap), don't have starter box batteries fully charged or the car is not aligned correctly so the wheel touches chassis or something stupid like that.
When speaking of the con.rod stress. I think atleast 9/10 reason for rod giving up is that the user has not made sure the engine stays in +100degC when running in. If done properly you don't have problems with rods and for all racers it should be normal to change the rod anyway when the engine has bedded in. It's not a cost issue as you already have saved a lot by not buying a "high end mill" for nothing and considering the Go spare prices it's really not a issue to anyone. People are just so lazy and it's easier to blame on the engine than yourself not maintaining it.
Be it the GEN 5/5.5 or the new GX series engines, just do the basic steps:
Install run-in shimm
Put in hot plug (like OS P3)
HEAT the engine to +100degC meaning BOTH the heatsink and block is in +100degC
Loosen the plug
Prime the engine
Start it
Fasten plug
If engine tends to stall screw in LSN 1/4 turn and that should do the trick
It's not difficult and in most cases people dont really heat engine enough (use hair dryers or something crap), don't have starter box batteries fully charged or the car is not aligned correctly so the wheel touches chassis or something stupid like that.
When speaking of the con.rod stress. I think atleast 9/10 reason for rod giving up is that the user has not made sure the engine stays in +100degC when running in. If done properly you don't have problems with rods and for all racers it should be normal to change the rod anyway when the engine has bedded in. It's not a cost issue as you already have saved a lot by not buying a "high end mill" for nothing and considering the Go spare prices it's really not a issue to anyone. People are just so lazy and it's easier to blame on the engine than yourself not maintaining it.
I had to screw mine by 1 1/2 full turn to keep the engine runing when i give trottle.
If i only screw the LSN 1/2 turn in from flush, forget it, not able to give trottle, the engine always stall.
10-08-2009 | 11:18 AM
#8837
I always find 1 turn in from flush on the LSN is about right for a first time start..I have had 6 GO motors now and not one would tickover for more than a few seconds with both needles flush.. I think the pinch problem is a thing of the past with the new GX and all subsequent motors MG66 included..GO have relaxed the really evil metal to metal pinch that made first starting these mills such a destroyer of starter boxes..still preheat to around 100ºC at least for the initial run in procedure but having put 2 galls on the MG66 it has lost nothing in compression by not being quite so tight initially..I also think this will also remove some of the initial stress on the conrods..I presume the GX series like the MG66 has a thicker heavier run in rod fitted at the factory and the lightened "knife edge' rod for replacement once run in is complete..
10-08-2009 | 07:20 PM
#8838
10-08-2009 | 07:24 PM
#8839
Does anyone make "unpinch" tools yet? A cylinder hone or some other more precise tool might be useful with these Pro engines.
When I added the break-in shim to my new .25 I rolled the piston up the cylinder. It started to pinch pretty far down the cylinder. It shocked me a bit even after considering the button. Break-in just seems harder on the engine than it needs to be.
*shrug* Oh well...I love a good challenge. It's totally worth the pain
A cylinder hone or some other more precise tool might be useful with these Pro engines.When I added the break-in shim to my new .25 I rolled the piston up the cylinder. It started to pinch pretty far down the cylinder. It shocked me a bit even after considering the button. Break-in just seems harder on the engine than it needs to be.
*shrug* Oh well...I love a good challenge. It's totally worth the pain
I can actually reduce the pinch in a motor but I would not do it with a new motor, I do it when I fit unmatched pistons and sleeves together. The Gx are supposed to be lighter in pinch.
Rex
10-08-2009 | 09:32 PM
#8840
Tech Elite
Joined: Nov 2007
Posts: 2,983
From: Auckland, New Zealand
10-09-2009 | 12:18 AM
#8841
Tech Master
Joined: Sep 2002
Posts: 1,027
From: UK
Just completed the Conrod swap @ 1 1/4 to 1 1/2 gallon. Couldn't get over how close the tollerences still are. It made getting them swaped over quite a pain, But I'm really pleased there's so little wear. I guess these new relaxed piston and liner tollerences really help the motor out during breakin.
At the time I also changed out both bearings as I wanted to try an Answer Rc ceramic rear and after "baking" the case to get it out wasn't about to use the front again. Really looking forward to seeing if I can tell a difference on track.
Great motor
Rod
At the time I also changed out both bearings as I wanted to try an Answer Rc ceramic rear and after "baking" the case to get it out wasn't about to use the front again. Really looking forward to seeing if I can tell a difference on track.
Great motor
Rod
10-09-2009 | 07:56 AM
#8845
Tech Fanatic
Joined: Aug 2008
Posts: 891
From: Texas
Just to clear a few things up:
- The crankcase, head button, and bearings are the only carryovers without modification.
- Pinch. The GX series is still pretty tight on the top end. You will need to heat up to 190-200 degrees Fahrenheit. This will also help when running rich during breakin.
- Break in. I've seen several different techniques on here, and they're all pretty sound. I do like Rex's approach at preheating to 240 deg (F), and then turning over. I recommend going to at least 190, but do not exceed normal running temperature. If the piston gets stuck at the top, heat it up more.
10-09-2009 | 10:30 AM
#8847
10-09-2009 | 01:15 PM
#8849
the new line of gx series motors are lot easier to start than the older ones there is a lot less pinch in them for sure 
doesnt really matter what make the motor you always need to put heat in them when firing them up the first time anyway
doesnt really matter what make the motor you always need to put heat in them when firing them up the first time anyway
10-09-2009 | 01:58 PM
#8850
Just to clear a few things up:
- The crankcase, head button, and bearings are the only carryovers without modification.
- Pinch. The GX series is still pretty tight on the top end. You will need to heat up to 190-200 degrees Fahrenheit. This will also help when running rich during breakin.
- Break in. I've seen several different techniques on here, and they're all pretty sound. I do like Rex's approach at preheating to 240 deg (F), and then turning over. I recommend going to at least 190, but do not exceed normal running temperature. If the piston gets stuck at the top, heat it up more.