Eagle Flyer

My Feedback: (84)

I have a stock G62, New but run a couple hours. It is running on the stock mag, spring starter and a wrap around muffler. I want to keep this configuration. Is there any power hop ups available that aren't too involved? Who does them if they are some what specialized?
It's in a Byron Extra 28% model.
Any help is greatly appreciated.
Thanks

Panzlflyer

My Feedback: (15)

If you have a Bisson muffler cut the Rolled tips off as they restrict it quite a bit. The added noise is insignificant imo.

davewallace

My Feedback: (29)

Hi Flyer,
The biggest power gain will be had with a tuned and muffled pipe. There not cheap, but the big gain is there. A V-stack gives some gain on some installations also. People who have installed bigger carbs havn't gained much.

Dave

Tired Old Man

My Feedback: (1)

If you have already replaced the stock muffler (you know, the one that belonged on a lawn mower) with a quality Pitts or some other type, then you have already performed the simplest and most economical mods. All the rest require a lot of cash and effort for minimal gains. Do not use a Bennett or B&B muffler.

the Wasp

My Feedback: (1)

carbon prop,,, carbon props are very stiff, the stiffer your prop the easer it is to spin, my friend went from a 24x10 wood up to a 26x10 Bolly carbon on his older Sachs 4.2 and he gained almost 900 RPM, he must have gained 20 MPH on his 106 inch span 35 pound P47, and vertical is unreal,,, we were all very surprised in the different's !!

Jim

BillS

Tuned pipes offer the most benefit for two stroke engines. However pipes are usually expensive and large and clumsy to mount. In addition to a pipe most two strokes will benefit from longer intake and exhaust duration. Often there is enough meat between the top of the piston and top ring to increase the duration by cutting the top of the piston. Performance tuning is cut and try and you can expect many failures.

Bill

davewallace

My Feedback: (29)

Hi Flyer,
One advanced way to get power is to port the piston. This allows the trapped charge in the piston to flow into the cylinder while also cooling the piston from the inside. Here is a ported G23 piston.

Dave

bpryor

My Feedback: (45)

Please don't do this. If you are going to get into internal modifications, such as port timing, etc., have an expert do it. Hacking up the inside of your engine when you don't know what you're doing is most likely going to yield a performance drop, not gain. Please do not cut the piston top to change your port timing, you should raise the exhaust port to change the exhaust timing and shorten the piston skirt and/or lower the intake port on a piston port engine to change the intake timing, such as the G62. I would advise against any of these mods. Changing either the muffler or ignition is probably the only practical mod to make, otherwise buy another engine, it will be cheaper and you'll come out ahead in all respects.

If you want your G62 to run better, or just want an (VERY) informed opinion on what to do, contact Ralph at RC Ignitions(He can do wonders with a G62 for minimal dollars).

928 635 2455
www.rcign.proboards41.com
RCIGN1 on RCU

BillS

If you don’t know what you are doing you shouldn’t be cutting on anything. Motocross and kart racers have been cutting pistons for years. It works and is an acceptable method of experimenting prior to making more complex and irreversible cylinder changes. Pistons are easily replaced.

A performance report for a pipe would be good information.

Bill

bpryor

My Feedback: (45)

As I think I stated, I agree with you completely.

I can't speak to motocross racers, though I did own a Kawasaki shop for 7 years, where we sponsored(and built) a lot of dirt bikes and I know there was never a top of the piston cut, but of course that was back in the late '70's so I suppose things could have changed. I also raced karts from the 60's through the 90's and have had my hands in more than a few engines. Again, I would advise against ever cutting the top of the piston. It will both weaken the piston and lessen its cooling capabilities, and it can possibly create hot spots which can cause detonation or pre-ignition.

You know I was thinking about it, and I think I remember from my Hodaka days back in the 60's that some people did cut the top of the piston to change exhaust port timing. Are people really still doing this?

Sorry, I guess this is really getting outside the topic of this thread....especially since Eagle Flyer
asked for "simple" power hop ups. I really don't think these suggestions qualify as "simple".

As BillS has stated, don't get inside your engine if you don't know what you're doing.

I would agree that a muffler change/mod is about the only thing mentioned here that could possibly reap measurable results while keeping in the "simple" column.

BBW Walt

My Feedback: (11)

I was wondering whats wrong with a B&B muffler/diverter?

rmh

about half of the power available in a simple two stroke is in getting the exhaust system matched to desired powerband .
as example -using a typical on line thrust rpm BS calculator.
10000 rpm =4.5 hp--same prop at 8000 rpm 2.3 hp-
I only looked because I saw this loss using an (blank) in cowl device -commonly referred to as a muffler.
open stack losses vs. pipe are not that much of course -but who can stand the friggen noise?

Eagle Flyer

My Feedback: (84)

As stated earlier I prefer to keep the standard in cowl muffler and mag it has on it. Porting etc. isn't beyond my capabilities I wouldn't think. But I have never done it. And prefer not to learn on this one. If some one has the proper experience and know how I wouldn't mind letting them do it, for a reasonable price of course.

Any body know of any one who works on this sort of thing?

bpryor

My Feedback: (45)

Hi Eagle Flyer,

I do not currently know anyone specifically who does this type of mod on the G-62...but the G-62 has been used in racing, and I remember there was a guy in LA(Los Angeles, CA) that was well known for tweaking G-62's. I'll see if I can turn up a name or contact info for him. Ralph at RC Ignition is certainly capable, but I don't think he typcially does this type of work.

I'll say again, before going to this much trouble/expense, I think it makes a lot more sense to switch engines.

rmh

Not to discourage anyone -but all the internal rework in the world will not make anywhere close to the performance gain of a good exhaust setup.
It is simply the nature of the beast.
If you are doing an open exhaust racing setup - yeh different ball game - if you are sport or aerobatic flying- a good exhaust is the real power builder.
Yes I have owned G62--and added good variable timing ignition . good, strong engines .

Antique

My Feedback: (4)

I don't do it because I don't know how..the guy in the L A area was/is Ken Laski, don't know if he is still into it...
FastRatPorting on here somewhere says he can do it, try a search...

bpryor

My Feedback: (45)

That's the guy I was thinking of Ralph. Thanks. I had a G-62 he had massaged a few years back, and it did run very well, but I'm totally on board with Dick; if you don't want to change engines, come up with an improved exhaust setup. If you can't improve on your in-cowl muffler(you haven't said what type that is either, which would help) it just isn't that hard to retrofit a pipe or canister...unless your plane is scale, or you're a purist, but you didn't say what plane it is in and it may not be practical.

Antique

My Feedback: (4)

.www.toni-clark.com
All things Zenoah

bpryor

My Feedback: (45)

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Rcpilot

My Feedback: (78)

What about using a thinner cylinder gasket between the jug and the case?

Wouldn't lowering the jug with a thinner gasket increase the compression ratio?

Of course, it would effect your intake and exhaust duration. It would effectively increase the intake duration and lower the exhaust duration.

I don't know how the engine would react to those duration changes.

In my experience--best thing to do with ANY Zenoah is to let it spin. Remember, they are industrial engines and are factory ported and timed to run at higher RPM than your typical DA/3W/ZDZ.

I have my G-62 engines propped for 7200--7400RPM. I'm guessing they unload to 8000RPM in the air.

You can prop your G-62 for 7500--8000RPM and run it like that untill you crash it. You'll never hurt it running it up in the higher RPM range. You'd be amazed at how much power they will produce when you get the RPMs up in the powerband.

Antique

My Feedback: (4)

Not much difference and ot much room between the piston and combustion chamber at the top anyway..I have seen some with heavy carbon on top of the piston, enough to hit at TDC...
A 20-10 black MA prop will turn 8000 muffled and 8400 unmuffled..Fast but less thrust that a 22-10 or 24-8...

Tired Old Man

My Feedback: (1)

Way back when there were almost no aftermarket exhaust products available on the market, the B&B/Bennett diverters were just about all that was available for most of the gassers out there. They were called mufflers but did little to that effect. However, they did perform the function of re-directing the exhaust just fine for the time. At the time they were fairly restrictive and actually reduced power output a little. I used one again not all that long ago a came to the conclusion that the current crop of mufflers available on the market are far superior, both in noise reduction and performance, than the older designs. If they were to open up the can a bit and increase the diameter of the stacks they could get up there with everyone else.

the Wasp

My Feedback: (1)

in the past I ported many small gasser motors for RC boats, simply put it's a pain in the back-side, to do it right you need a degree-wheel and once your done you need to find a carb to match up with your mods,,, if you really want it done I suggest you send it to Air Hobbies, see link,,,

http://www.aero-sports.com/airhobbies/services.html

Jim

Diablo-RCU

My Feedback: (1)

Simple hop up?
Enlarge the jets in the carb with a drill...about 2.5 times the area.
Change fuel lines to silicone rubber.
Install a 40-50 oz tank.
Run methanol + 5% Klotz.
About 20% more power

rmh

reminds me of simple hop up for Ford
remove hub caps -place on Chev - go race -
The simple approach if apparantly a poison topic - add a pipe
On cars - we went thru same thing - "what's a simple hopup?"
mill the heads -add dual carbs - add a cam etc..
the really simple hop up?
add a blower -even a little blower .
The simple tricks do the needed end result-in one fell swoop.
Increase the fuel charge density.