Hey folks...any thoughts on breaking in these engines in a stand? I ask because A) I have a break in stand I've used for a number of years, and B) I have so little time to get out and run cars these days, but could do the run in here at night if doing it on a stand is a viable option.

Don't want to waste a good engine, but I don't want to spend my outdoors driving season breaking in a single engine either.

I've also thought about getting something easier to break in and holding the Go until I have the time, but I'd love to see it flying across a parking lot sooner than later.

If the stand is an option, any thoughts on how to proceed? I've always just used a version of Ron Paris' heat cycle method on the stand, but the Go's seem to like a different method for their run in. I could hook up a receiver and throttle servo and run it like it's on the ground if that would help, I just don't have a good feel for how a prop load translates to an actual car on the ground load.

Any and all help, ideas, experiences, etc would be greatly appreciated.

Our GO dealer in NZ Shane runs in the GXII motors for his customers on a run-in bench, i'm sure he will have some info for you when he logs on today.

What I do know is the motors are not fully run-in on the bench, the guys have to put another few litres through them and lean the mixtures as required, i've run-in quite a few just in a buggy and they are easy to do, the main difference about GO engines to others is the tune changes greatly from cold to hot, even when run-in, for example even after the first litre when the very tight pinch is starting to go the motor will run well (ehen up to temp) at a still semi rich setting...let it cool right back down then fire it back up (even with heating a bit) and it may be so rich it will hardly run, I have found it helps to lean it an 1/8th for warming it up the first few minutes then when up to temp go back out an 1/8th, and keep the motor at a good temp also to reduce stress on the piston, gudgeon pin and rod...the competition heat engine warmer are very handy for getting the temp up to avoid those harsh cold starts
It is a bit time consuming I know but if you have an good flowing little curcuit like a part of a track its not too boring then.

Craig

A mate is running a GX II 5 port and is having issues with the exhaust gaskets. Gaskets are doing a race or 2 and they are fried. He run the earlier version of the 7 ports and had the same issue. Tried the original Go gasket the RB orange and black, the purple venom and OS gaskets and they all suffer the same fate all though some last a bit longer. What gaskets do you run and what life do you get out of them.
Thanks in advance
Dave

The GO exhaust gaskets have been quite durable.

A mis-aligned exhaust will often cause cuts/tears in the gaskets. Try disconnecting the exhaust hanger at the front of the pipe. Is the pipe now in a different position when allowed to "align itself"? If so, try to position the pipe as close as possible to it's "natural" position when you fasten it.

I run a Mugen. The standard manifold supplied with most pipes can cause very little room for pipe alignment on these. I can't recall which manufacturer makes a manifold particularly for Mugens. I made my 2072 fit by modifying the mudguard slightly.

+1 what Moto said about the alignment of the pipe/header.

Also check there is no flashing or sharp edges on exhaust port
(excess material when casting casing)

And to answer your question about gaskets and MY life span;
I use GQ on the exhaust port and use Lucky 7 between the pipe and header.
In some cases they have been on engine for months.

We have developed a proven run-in method for the GO engines here with the engine mounted in the buggy.
It utilizes the heat cycle method, combined with pre heating.
It's on the Tech Tips page at http://www.go-racing.co.nz

I do all the pre delivery run-ins using the Hudy run-in bench system.
The GXII's seem to bed in very nicely using the run in bench.
Biggest thing is again pre heating (we use the Competition Heat unit).
Also with the wash of the prop,you need to ensure the engine temperature is kept up at around 220 - 240 F during the run in period.
It is important to cover the heat sink, but also to cover the crankcase area as the crankcase fins are very effective at keeping the motor temperature down.
I use a foam tube, cut out to fit down over the crankcase like a tea cozy, then held in place with a long cable tie.
The other method you can use is to place a cardboard or plastic sheet across the front of the motor to keep the prop wash off the crankcase and heat sink.

I find 10 tanks of heat cycle on the bench normally gives a nice motor that still has pinch, but is easily started and once warm will perform nicely.
As Craig mentioned we usually suggest a few more easy tanks leaning each time to a race tune before going full out with the motors when they come off the bench.
You can judge how "done" the motor is by flipping over the prop immediatly after a tank has run out while the motor is hot.
If it flips over with just a tiny bit of pinch at the top then it's pretty well ready. If it's still catching on the flip over - do some more tanks until it free's up a bit more.

Hope that helps with your questions.

Hey Dave, yes the gaskets don't seem to last as long as they used to and we use a few different brands, some can be very hard to fit also...is your mate running the chrome 2072 GO pipe? i've changed to the black hardcoated 2072 and they are lasting a lot longer maybe the chrome pipe retained more hear or ran hotter?

The black pipes look cool as they change colour, they first go a dark copper colour at the header but still black down the pipe, it slowly works its way down the pipe the more you run it, then the copper colour turns to a copper/gold colour... the hotter you run it the faster it will change, i do a bit of tuning on some of the guys motors and I can tell who's running lean or not .

He is running the chrome pipes. Looking at using a longer pipe mount to ensure the pipe is not loading up on side of the gasket aswell. Thanks for the information.
Dave

Posted this in another thread, no reply from anyone, maybe this is the thread for it?

I'd been breaking in the engine (GX-5R), and have probably ran 2.5-3 litres of fuel through it, and had it out of the car for other reasons, so I took the time to replace the conrod. When I looked at it, the upper hole in the conrod seemed slightly oval. I measured it at 4.08mm top to bottom, and 4mm side to side.
Was this conrod really in need of replacement or not?

I had bought a new conrod, but it is not exactly the same as the original one.
The original one had two oil holes in the top hole, one from the top and one from the bottom.
The new one only has a single top oil hole in the top. Does this matter? It is a genuine Go Engine part, I figure there are probably revisions of these.

Any ideas?

Next time I was thinking to use the slightly 2nd hand conrod I have now from the break in, for the next break in? would that be allright? Then I don't have to waste another rod?

Most engines will have somewhere between 0.01-0.02mm clearance for the rod/piston pin. 0.08 wear at the bushing means it's toast. To my knowledge, GO con rods cost less than ANY other manufacturer. They are so inexpensive that if you're ever in doubt, replace it.

As far as one oil hole vs. two, I can't recall seeing one with two oil holes, but my stock of GO rods is depleted.
I'm sure Shane (Grizz) will speak to this.

I just read this and thought to myself I remember reading this some where before, and also remembered someone replying hence the red ?, so Out of curiosity I checked other thread and sure enough I was correct



http://www.rctech.net/forum/offroad-...hread-947.html

page 947 post 14205

Hi Guys,

Bit slow on the replies this week sorry. Flat out pumping more GXII's, G5T's and NZ Spec .25 truggy motors out into the marketplace. Crazy demand for GO here right now.

I have never seen a 2 x top oil hole GO rod. Perhaps the rod had been swapped out for another brand in that motor ?

I just quickly checked through the 40 odd 21-0600 Pro Series rods I have here (some old stock and some just arrived a few days ago), and they all have a single hole in the top groove directly above the top end bush, plus the normal bottom end hole at the end of the oil groove just above the big end bushing.

Hey Flanno, your onto it bro !!

It did ring a faint bell in the old head, but I didn't have the time to track back and scroll the pages. If anyone would know, Massive would

Out of curiosity I just checked mine too, and hadn't realy taken much notice before, and mine are the same as Grizz, one hole rite at the very top of the rod leeding into the top bushing for pudgen pin lube, and the usual one at the bottom of the groove down the length of the rod leeding into the bushing for crank pin lube.

True... however some of the earlier fins resonated at the same frequency as the engine vibrates at certain RPMs, causing them to flex. I was told they revised the center portion to prevent the flex, but who knows?


Anyone know what's going on with amain? I see parts, but no engines. Perhaps they're waiting for the new carburetor? I put a lot into making Go name better, so I'd hate to see it go to waste after I sold the business