Gas Power in Scale Racing. An Accepted Alternative to Nitro/FE?

[Ken Smith]

Hey All,

Just wondering what folks think about gas in scale racing. It seems to be making a strong comeback especially in the Northwest where there is at least one club dedicated to gas scale hydroplane racing at 1/7th scale I believe. Do you think other clubs will begin allowing gas to compete alongside nitro and electric? I'm mostly curios to see if the 1/8th scale hydro clubs will begin allowing gas to compete with the other powerplants. It seems like a more economical choice....just like with the big boats. Go piston power! Thx

 

[lohring]

The first gas sport hydros i saw were Muck 1/8 scale hulls with cowels cut out for the carb and exhaust. That's the problem with gas engines in 1/8 scale. There have been various experiments over the years, and the Pacific Northwest Thunderboat Association (http://www.pnwta.org/default.php) is running boats a little over 1/6 scale. That makes it possible to put even side exhaust engines under most cowels. Speeds should be faster than NAMBA thunderboats. Ron Buck just ran his thunderboat over 80 mph with a 30 cc engine at the LA SAWs. Costs should be less than nitro and the big boats can hold a lot of scale detail.

Lohring Miller

 

[jwo]

Check out our website. PNWTA.ORG . They are 1/6.667 scale. Engine disp up to 31cc. Gas only. They are a bunch of FUN. Very fast. The faster hulls in the club out run 1/8 scale nitro.

R/C Unlimiteds has been cunducting an experiment with FE 1/8 scale with limited voltage,motors and props. To compete against the nitro boats. It is a 3 year deal with the next 2 seasons to go. Last season proved that with the restricted voltages and props they can be very competitve with the nitro. The 2 power systems are fairly equal.

The 2 1/8 scale clubs R/C U and UNW will be hosting the Gas Scale Hydros at there evnts this season. The schedules are posted on all 3 sites.

 

[Ken Smith]

I've seen pnwta.org's site before and it looks very interesting. I just registered to see their for sale stuff. I love Marty's Budweiser. Saw a video of that at the Monroe lake and it looked great. I've not seen any engines that are 31cc. Do they just bore out a 26cc Zenoah? Also, I know ML Boatworks offers kits for this scale but where would one get cowlings and wings for 1/6.667 scale. Engines look pretty cheap on ebay....compared to .67 nitros and FE setups. Plus gas may be $4 a gallon but that still beats $50 gallon for nitro or expensive lipos. Thx

 

[jwo]

Here is my youtube link. A few vids of my U-95 and Tempo VII.

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Marty's Bud has a J&G 30 big block in it. My U-95 has a Mod Zen 26 as does my Tempo VII. The larger engine rule is new for this season. The U-95 will get a 29.5 sometime soon.

There are a few cowls available. I built my own for the U-95. R/C Boat Co. has a couple round nose cowls, Jeff Snell has the Oly/Notre Dame style cowl and the T-5 cowl. He also has molds for both style hulls. Phil Thomas has the 8255 style cowl.

I am sure more will be available soon as people build'em.

They are very economical to run. 2 gallons for a season compared to 2 gallons a weekend of nitro. Not to mention no more glow plugs. I am running the same spark plug that came with the engine when I bought it. When the day is done suck out left over fuel from the tank wipe it down and put it in the shop til next time. No more flushing and soaking the engine in oil. Easy to tune and leave it. No chasing the needle or pipe length.

I do run both Nitro and Gas. I enjoy both and will continue to run nitro but Hands down Gas is the way to go. John

 

[Ken Smith]

Thats a nice looking boat. What is the larger engine rule? Are 26cc now too small? Where does one get a bigger engine? Thx

 

[jwo]

Thanks, I will get some video up this weekend with paint on it. The Mod 26 zen is plenty of engine. With the right set up. The Big blocks can be purchased the same places as the 26's. I run Gizzmo Engines. CC makes a great engine aswell. J&G's are good but have not shown the same performance as the Zen. If you have the dough the QD.

 

[Dasboatman]

Hey Ken,

PNMTA made a change to their Gas Scale Unlimited Hydroplane Engine Specifications upper limit on 9JAN12 to accomodate the new RCMK K-30 centerline and side exhaust engines, and the new Zenoah 29.5 engine. The RCMK K30 RZ engine (pic attached) appeals to some of us old nitro guys because the engine exhaust straight back over the shaft, and the carb extends forward. This is a Specialty Class at present, no Sanctioning activity approval. CHEERS !!! Bob

 

[Ken Smith]

Interesting. The head on the RCMK K30 RZ almost makes it look like a nitro. I'm guessing that would fit in the belly of an 1/8th scale without any cowl mods. Found this on ebay. Is this a typical modded Zenoah? I've seen the basic Zenoah run around the $200 mark (I think these are the models that were in the 1/8th scale ProBoat hydros). Is the basic Zenoah still competitive? If not, is it easy to mod? I'm guessing the cylinder needs to be bored to 29cc for starters. Thx

http://www.ebay.com/itm/Redline-Full-Mod-Zenoah-29cc-1mm-Stroker-Motor-RCMK-/200534346902?pt=Radio_Control_Parts_Accessories&hash=item2eb0c74c96

 

[Roxyflash]

Stock Zenoahs are around 200 modified from 400 to 600 depends on what you want.Then theres the RCMK there great engines too.Prices are a little more then a stock Zenoah but theres more to pic from.The good thing is gas is coming out with more aftermarket parts then the nitro.Prices are coming down.I like both but sticking with gas.I still run nitro but for the average guy the gas is easier.The basic setup is about the same but after its built is real easy on the wallet.

 

[Mark Poole ModVP]

So, having Gas Thunderboat class is not enough and what you would like is to be able to run a slightly larger hull to accomodate a gas engine and race it in 1/8 scale hydro? Why is it that most gas racers think it is perfectly ok and fair to run a 30 cc engine against an 11 cc engine. We run the Gas Thunderboat class here in many of the races. I like it but mixing it with 1/8 scale nitro? Please......

And 2 gallons of gas in a season? You must have a short season. I have burned 1/2 gallon of gas in a gas mono on a Sunday afternon.

 

[lohring]

The gas scale class is run completely apart from the 1/8 scale nitro boats. I'm not sure they really need 30+ cc engines, but the Brian Buaas modified 30 mm stroke x 36 mm bore engine Ron Buck ran is ready to drop into my U-21 $ Bill hull for a two lap record try. Until then the boat will run fine as a thunderboat with a stock Zenoah or as a gas scale boat with a variety of G1 and GX1 engines. I love dropped sponson round nose boats and this is a scale, light weight, wood version of my Channellock Insane thunderboat. They're both almost exactly the same dimensions. We'll see if an old style round nose will keep up with modern hulls. There's at least one other gas scale round nose that will.

The Pacific Northwest is home to a lot of scale classes thanks to Roger Newton. The largest NAMBA club runs 1/10 scale electrics. There are 1/7 scale electrics, gas scale boats, and two large 1/8 scale nitro groups. Some have been experimenting with electric 1/8 scale along side the nitro boats. All together, these groups provide some of the best racing available.

Lohring Miller

 

[Ken Smith]

Hey Guys,

I'm aware of the clubs dedicated to gas as well as the ones dedicated to electric. I have no problem with this segragation. The reason I bring up gas as a powerplant for the 1/8th scale clubs are two fold. A). we are seeing electric creep into the 1/8th scale nitro clubs as an alternate power source so why not gas? The electric testing that folks have mentioned here is to make sure the competition is fair...the electrics, unchecked, would blow the cowls off the nitros. That said, why couldn't they do similar testing with gas engines so they are on par with nitros? 2). The obvious price savings on gas vs nitro combined with the simplicity of operating a gas engine leads one to conclude that the popularity of gas will only increase over time. Whereas nitro may become a less viable option over time. 1/8th scale is still the most popular scale racing class. If folks who have been running in this class for awhile decide to switch to gas there only option now is to change classes (from 1/8th to 1/6th scale hydros). Having a second option to remain in 1/8th and change to gas may be more appealing to some. Thanks

 

[Andy Greene]

Here is my youtube link. A few vids of my U-95 and Tempo VII.

http://www.youtube.com/watch?v=s3umtMcG9-k&context=C4da0a8aADvjVQa1PpcFNd_-SF24DszeFTBxnLJJtB-i6oMV3li3Q=

Marty's Bud has a J&G 30 big block in it. My U-95 has a Mod Zen 26 as does my Tempo VII. The larger engine rule is new for this season. The U-95 will get a 29.5 sometime soon.

There are a few cowls available. I built my own for the U-95. R/C Boat Co. has a couple round nose cowls, Jeff Snell has the Oly/Notre Dame style cowl and the T-5 cowl. He also has molds for both style hulls. Phil Thomas has the 8255 style cowl.

I am sure more will be available soon as people build'em.

They are very economical to run. 2 gallons for a season compared to 2 gallons a weekend of nitro. Not to mention no more glow plugs. I am running the same spark plug that came with the engine when I bought it. When the day is done suck out left over fuel from the tank wipe it down and put it in the shop til next time. No more flushing and soaking the engine in oil. Easy to tune and leave it. No chasing the needle or pipe length.

I do run both Nitro and Gas. I enjoy both and will continue to run nitro but Hands down Gas is the way to go. John

Man that boat looks like a ton of fun to drive, I know the nitro scale purist wont admit it- but I for one like it.

Andy

 

[Dasboatman]

Hey Ken,

I don't really think you can shoe horn a side exhaust, side carb gas motor and pipe into many 1/8th scale hulls - maybe a Thriftway Too.

I believe R/C Unlimited has been experimenting with running 1/8th Scale FE with their nitro boats. To the best of my knowledge, they are the only group. Both IMPBA and NAMBA 1/8th Scale Unlimited Hydroplane Rules specify NAMBA Class "C" or IMPBA Class "E" engines. My experience with gas powered boats is limited, I only have a Classic Thunderboat with stock Zen 260 presently. I could not fit that Zen 260 into my 1/8th Scale boats and conceal the pipe anywhere near inside the cowl. I do have an RCMK K30RZ in house now and will build a WOF Gas Scale this year.

When I first started running R/C boats in 1970 we ran boats with the same size power plant, monos and hydros together because there were not many boats racing back then. Through the years we have seen the classes explode - - Nitro, Gas and Electric. I have only seen Nitro, Gas and FE hulls run in an open Hydro or an Open Mono/Offshore classes.

I know that NAMBA gives the districts latitude to do almost anything they like within their District. I would suggest that you pole the Scale boaters in your District and see if there are exceptions to running different power supplies together.

I have lived in East Texas for the past 10 years. I have seen 1/8th Nitro Scale race exactly once in that period. I have never even seen a 1/8 Scale FE. At last weekends LSMBC race, I believe they had 10 Classic Thunderboats entered. NAMBA District 3 - Florida didn't have enough 1/8th Scale or Sport 40 boats to qualify as a District High Points Class in 2011.

If your district wants to run Scale boats using different power sources together, that's up to your District as far as I can see. I believe both Sanctioning activities National and International yearly contests will comply with classes as described in their Rule Books, CHEERS !!! Bob

 

[Mike Cathey]

Hey Guys,

I'm aware of the clubs dedicated to gas as well as the ones dedicated to electric. I have no problem with this segragation. The reason I bring up gas as a powerplant for the 1/8th scale clubs are two fold. A). we are seeing electric creep into the 1/8th scale nitro clubs as an alternate power source so why not gas? The electric testing that folks have mentioned here is to make sure the competition is fair...the electrics, unchecked, would blow the cowls off the nitros. That said, why couldn't they do similar testing with gas engines so they are on par with nitros? 2). The obvious price savings on gas vs nitro combined with the simplicity of operating a gas engine leads one to conclude that the popularity of gas will only increase over time. Whereas nitro may become a less viable option over time. 1/8th scale is still the most popular scale racing class. If folks who have been running in this class for awhile decide to switch to gas there only option now is to change classes (from 1/8th to 1/6th scale hydros). Having a second option to remain in 1/8th and change to gas may be more appealing to some. Thanks

To be totally scale appearing you need to be able to hide the spark plug under a cowl or fake motor. 1/8th scales were not big enough. We had to shave the spark plug boot on Martry's gas Oly to get the cowl to drop in place. I'm building an 82 Gilmore and putting a belly pan in for more clearence. The 1/6th scale boats are just getting going and on average there are enough to run one heat (5-6 boats) in each of a 4 section race. It will be awhile until there are enough boats and people really get them figured and there is the type of competition that there is in the other scale classes. That is however part of the fun of developing a new class.

RCU has had some electrics run with them and they have some advantages such as being able to run in a roostertail or get going again after they have crapped out or come off plane-something a nitro can't do very well if at all. I think they made some rules regarding that. In Unlimiteds NW I doubt very much that electric boats would ever be allowed. Beisdes, I think NAMBA has in place or in development a dedicated 1/8th scale electric class.

My guess is what will really affect all model boat racing is the cost of the gas that goes in your car/truck just to get to the races.

 

[Hydro Junkie]

Ken, let me add some more background into this. Back in the mid to late 90's, Roger and several of us tried to start a class of true 1/6th scale boats in the Puget Sound area. Some of them were completed and actually ran though, according to some, no where near fast enough. The problems were the extreme size and weight of the boats as well as low power the then available Zen G230 could produce. To get an engine with side mounted carb and WTC header to fit, the boat had to have either totally open construction under the deck or an engine bay 7" wide. I know two of these big 60" boats are now at the hydro museum, both round nosed hulls, while I still have my 75% built 57" 73 Pay'N Pak in the garage. While Pro Boat was able to shoe horn a Zen into a scale sized hull, the cowl had to be distorted to make it work with only poor results in performance in the stock configuration. To get a Zen or RCMK into a scale boat will require a major redesign to the hull and, unless it's powered by an RCMK with the front/rear carb/pipe arrangement, major surgery to the cowl. What was done in designing the gas scale and thunder boat hulls was to scale a hull up to the smallest size range the gas engine would fit into without major rework. That being said, by comparison, electric power can be fitted into a 1/8th scale hull without any required rework while being "tuned" for a comparable performance level to a nitro powered boat.

 

[lohring]

I feel electrics are the way to go as a substitute for 11 cc nitro engines in 1/8 scale boats. The spec motor concept can be used to keep equipment costs in line and limit performance. The 1/7 scale electric class has a very good power system. I've posted about my 20 year old Executone conversion. Below are a couple of great Jerry Dunlap pictures. Many existing nitro boats could be converted in this way. I don't feel nitro and electric boats will be able to run together as equals. Electrics have completely different power characteristics.

Lohring Miller

 

[jwo]

Here is my youtube link. A few vids of my U-95 and Tempo VII.

http://www.youtube.com/watch?v=s3umtMcG9-k&context=C4da0a8aADvjVQa1PpcFNd_-SF24DszeFTBxnLJJtB-i6oMV3li3Q=

Marty's Bud has a J&G 30 big block in it. My U-95 has a Mod Zen 26 as does my Tempo VII. The larger engine rule is new for this season. The U-95 will get a 29.5 sometime soon.

There are a few cowls available. I built my own for the U-95. R/C Boat Co. has a couple round nose cowls, Jeff Snell has the Oly/Notre Dame style cowl and the T-5 cowl. He also has molds for both style hulls. Phil Thomas has the 8255 style cowl.

I am sure more will be available soon as people build'em.

They are very economical to run. 2 gallons for a season compared to 2 gallons a weekend of nitro. Not to mention no more glow plugs. I am running the same spark plug that came with the engine when I bought it. When the day is done suck out left over fuel from the tank wipe it down and put it in the shop til next time. No more flushing and soaking the engine in oil. Easy to tune and leave it. No chasing the needle or pipe length.

I do run both Nitro and Gas. I enjoy both and will continue to run nitro but Hands down Gas is the way to go. John

Man that boat looks like a ton of fun to drive, I know the nitro scale purist wont admit it- but I for one like it.

Andy

Thanks Andy, It is a blast to drive. Here is a video from last weekend testing some props.
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[Ken Smith]

That boat looks great John. You have to be proud Is that Pine Lake? Lohring, that boat is not 20yrs old. Its too nice HJ, thanks for the history on the clubs here in the Seattle area. Didn't realize you were working on a larger scale Pak. Love to see some pics. I realize the biggest hurdle with gas in the 1/8th scale class is the larger side exhaust engines. However, there are some engines, as Bill pointed out earlier in this thread, that are rear exhaust and front carb. Seems these would fit assuming you had a cowl tall enough to cover the spark plug boot as Mike pointed out. Nothings perfect of course. However, the hurldles seem workable if one really wanted to make it happen. I'm sure someone will try this eventually. Whether it catches on...only time will tell Thx