buzzingb

My Feedback: (2)

I recently read about the scooter and car guys modifying the 26 with reeds , porting, etc. Would these modifications work for airplane engines? They claimed around 5 or 6 horsepower. I know the torque etc. is different and we really need rpms but it seems like the hp gains they were achieving would be nice on an airplaine.

arobatx

I believe the most cost effective way to unleash the power of a G26 would be the correct use and installation of a tuned pipe. I cannot think of any other single modification that would affect the engine's performance anything like this one would. Some also put a thinner cylinder gasket (or no gasket at all). And some do pursue porting, polishing, lighter pistons...big bore kits....etc. You are probably talking about this one:

http://www.davesmotors.com/store/product60.html

Most folks using this engine for airplane use want the carb as close to the cylinder as possible, to fit in many cowls...usually this requires the use of a thinner, stronger spacer made from g10. This reed cage would send the carb even further out the cowl, which would turn off many modelers. For the $120...I would wager that the money would be best spent on the tuned pipe, vs this reed setup.

They are cool little suckers though...and it makes ya kinda want one just to see what it would do to a little zeonah turning a prop. Lots of popular gas engines for our hobby are reed valved, and rotary valved as well...whatever works!

Chad

karolh

I gave that conversion a long hard look for a Zenoah but decided against it due to the increase in engine bulk and weight. A suitable tuned pipe arrangement get the G26 turning 10,000 rpm on and 18x6 prop....that's a lot of go.

Karol

buzzingb

My Feedback: (2)

I think the people that offer what I saw were called Oneill Brothers or something like that. They offer stroker chanks, relief cut pistons, ported and polished cylinders, reed valves, different carbs, and etc. It would rack up quite a bill if a person went for all they offer but the hp rating would increase. I agree with you that the tuned pipe setup is the best investment, but what if you went all the way and purchased all the other mods too. It looks to me that this engine could possibly produce scarry hosepower.

This is the link that I was looking at.
http://www.oneillbrothers.com/rccar/motors.htm

karolh

More than likely they do produce scary power for their size, but ufortunately these engine conversions are almost specifically designed for cars/boats, and are just not suitable for our type of application, as they make their max power at very high revs which would more than likely require the use of small dia. props to get there .... such a pity.

Karol

arobatx

At least Oniel Brothers is cheaper, though it looks like a heavier unit too. Another thought I had, was that historically, modding an engine to squeeze every last bit of HP out of it tended to make it finiky, tempermental...etc. The zenoah has a profound history of being a very reliable engine, user friendly, and when properly cared for...they will outlast you and me easy. I would hate to sacrifice any bit of that, by going too far on mods. Another downside to squeezing out this kind of power would be the obvious money you could dump into it. By the time you are done, you could have purchased an engine 2-3 times its size, and produce more power yet. I suppose there are unique circumstances though, where the size of the engine itself is of utmost priority, and the pipe and additional costs of mods is of no consequence. I just haven't run into that project yet myself If you end up going with some out of the norm mods that we are not normally used to on here...definitely keep us posted on your success.

Chad

karolh

In my book an engine's reliability is very high on my list of priorities. Way back in my early modelling days when controline was all the rave, we use to hot rod the British made ED Redhead diesels for team racing, and sometimes we did end up with quite a bit more power than the stock unit, but most times at the expense of the engine's reknown reliability. A very bitter pill to swallow for the joy of a few very fast laps.

Karol

buzzingb

My Feedback: (2)

I agree, it wouldn't make practical sense to go to this extent, but if a person could make some of the modifications theirself for much less, then that is a different story alltogether. It might make sense to polish the ports, use a thinner head gasket, etc. if a person could do this. One thing that caught my attention with the 26 is its economical price and reputation.

karolh

Sometimes simple little mods can sometimes make a difference. On my very first gasser just a casual inspection of how the cyl.head's exhaust port matched an aftermarket muffler revealed that the muffler opening needed a fair amount of enlargement to match the port size.

I can't say that I noticed any real difference in how the engine ran but it must have helped some. It's possible that several such small changes when combined could make a very marked improvement.

Karol

Dr1Driver

They offer stroker chanks, relief cut pistons, ported and polished cylinders, reed valves, different carbs, and etc.

Keep in mind that if you do one modification, you usually have to do a couple more to get the full benefit.

Personally, before I'd spend all that money on aftermarket hop-ups, I'd simply buy a hotter engine to begin with.

Dr.1

karolh

I guess if someone likes to tinker and has the necessary equipment it's okay to have a go, but for me my tinkering does not stretch that far. I would just get myself a bigger more powerful engine.

Karol

arobatx

It's kind of like lightening an airframe to take advantage of a smaller, lighter engine, and end up with the same thrust to weight ratio, but coming in at a much lower AUW, making it a better flying package. Carbon landing gear, wing tubes, removing cockpit floors, lightening formers, using single high end servos on surfaces as opposed to ganging multiples, single quality batteries rather than redundant systems...and so on. Any one or two of these mods won't make a desireable difference, and thus not be worth the money. Make all of the mods and the change is significant, but sometimes quite costly. Its all up to the owner, and how they get their enjoyment out of the hobby.

Thankfully regarding this engine, one or two mods DOES make a huge difference. For the money, and ease of modification, I would say the two most significant things you could do that seem to have no negative affect on the engines reliablility, is use a thinner cylinder gasket, or just permatex ultra copper without a gasket, and a tuned pipe. These alone will make a huge difference in performance...like Karol stated earlier, 10,000 rpm on a carbon 18x6...wow!

Chad

NM2K

My Feedback: (14)

My motto is, "More flyin' - less buyin'" <G>

One of these days, I'll actually try to put it to use.


Ed Cregger

Dr1Driver

"Speed costs money - how fast do you wanna go?"

Dr.1

arobatx

Buzz...what are you thinkn of puttn this 26 in?

blkbird68

My Feedback: (19)

Ralph just got through putting an ignition on my reed valved and stroked G26. You should ask him what he thought of it when he test ran it.

karolh

How much bulkier than stock is it and how much does it weigh. How about a picture ... it's worth a thousand words.

Karol

blkbird68

My Feedback: (19)

The O'neill Brothers Reed block adds just over 5oz. However a friend of mine that is a machinist is making a new body for it out of 3-6 nylon which should knock a big chunk of weight off. The whole setup fits inside the cowl of an Ultra R/C Katana Xtreme. (barely!) As soon as I get it finished up (hopefully by the end of the week) I'll get some pics and some tach #'s on it.

arobatx

I think i have talked with you before BlkBird68...didn't you have your cylinder wall race-coated as well, and make your own cannister? Lol, I remember talking to you about having the most expensive G26 in the world! I don't have our old emails anymore, so I don't remember your name, but I am pretty sure it's you.

Chad

blkbird68

My Feedback: (19)

yep...that was me....This latest reed valved motor tips the scale at about $600

karolh

That is one expensive toy you've got there. Sure hope it lives up to your expectations, and please keep us posted on how it performs.

Karol

arobatx

Ya gotta give these guys credit that want to hold onto an engine, and try every possible way to increase its performance. Some succeed and some fail, but either way they are getting something out of the hobby, and they love it. I remember Blkbird running a prop designed for an electric on this engine, and with his homemade cannister, getting incredible RPM and thrust figures. Give us an update on the current condition of the engine, prop, and performance specs. Didn't you have it installed on a biplane last time we talked?

Chad

blkbird68

My Feedback: (19)

Yea, the original tweaked G-26 is on a 25% Ultimate. On my canister with a WT-256 carb., a Mueller header and a Skorepa 18x6 E prop I was getting 10100. This latest one is too wide for the Ultimate because of the reed block. It is installed on an Ultra R/C Katana Xtreme with a Mueller header and a ESComposites Carbon fiber tuned pipe. I am also giving the WT-813 carb a try on this one. The WT-813 is the same as the 256 except the 813 has an accelerator pump.

I plan on testing the reed valve engine with an assortment of standard (not E)Skorepa props. 18x6,18x8, and 19x6

arobatx

Sweet, keep us posted!

Chad

blkbird68

My Feedback: (19)

Yes, the piston was dry film coated on the skirt and the piston top was ceramic coated to prevent heat build up. The cylinder was coated with a heat dissipation coating and the combustion chamber recut by Doug Johns. That was for a 2mm stroked motor for the Ultimate. I got side tracked with other projects, so that one has been sitting on the self. However it will be completed soon.

On the reed valved motor, it uses a O'Neill Brothers reed block, 2mm stroked crank, reed porting in the piston and cylinder was cut by Doug Johns at Earth Surfer Products. Doug also recut the combustion chamber to accomodate the stroked crank as he did for the "coated" engine. Ralph's ignition of course, and a WT-813 carb.