NITRO Vs. GAS - RC Groups
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Aug 18, 2002, 09:59 PM
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Which one will be the winner? i have a bet with my local hobby store owner. He is putting together a large Nitro powered boat; it is about 42 inches with I think a 90 or larger engine. I am building a 45 inch Gas powered beast. He has know how, i have money. I decided on a Quickdraw engine from BH. Hanson. With a Aeromarine Laminates Canard. I believe my prop size and pitch is where I need to put the most emphasis on because of the higher torque gas engines. What do you guys think? I need all the input I can get. Regardless of your Ideas, let me know.

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Aug 19, 2002, 07:26 AM
Dr John
pmpjohn's Avatar
Sounds like they will both be winners. If you are talking about racing gas vs nitro that is a different story! While the Quickdraw is about as good as it gets in the gas engines, alcohol and nitro pack more punch than gasoline and oil. I figger he will have 10-20 mph on you.
Aug 19, 2002, 08:01 AM
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I was under the impression that nitro did have a higher rpm, but gas had a little more torque which would enable it to run a bigger prop and also one with more pitch. That would also mean it was less likely to bog down under heavy load. Also, I did entertain running alcohol in the QD. I am not sure if that is an option, and if it is how much of a difference it would make.
Aug 23, 2002, 12:12 AM
Angering mobs since 1980.
Twmaster's Avatar
The one element you are forgetting. Driver skill. Put a good driver is a slower boat he will almost always win over a super fast boat with an inexperienced or poor driver.

Which hobby store? GPA?

Aug 23, 2002, 06:59 PM
Dr John
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Yes gas will have more torque mostly because it is a larger displacment engine. Twisting a larger diameter high pitch prop will introduce it's own problem, prop walk. Assuming you are using a surface drive as opposed to a subsurface drive ( most really fast boats do ) as the blade comes into contact with the water it will not only push the boat forward but also pull the transom to the left. I have seen boats with such a severe case of prop walk that it was impossible to keep them going straight.
Twmaster also makes a good point. A 42" hull with a nitro 90 and a 45" hull with a QD are both seriously over powered and will require a competent driver to keep them prop side down even in calm water. We have done several custom QD installations for customers but they have all gone into larger hulls. The Magnum is 57" and the Manta Ray is 55" Click the www button below to see these boats.
If you still think you need more power by converting to alky we can help. All the rubber parts inside the carb need to be replaced with parts that won't fall apart when subjected to alcohol and a serious rejetting will be needed as well as the proper fuel mix.
Won't this void your gas vs nitro bet ?
Hope this helps.
Aug 23, 2002, 11:33 PM
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You didn't include the link.
Aug 24, 2002, 07:12 AM
Dr John
pmpjohn's Avatar
Use the www button at the bottom of the post or
Aug 25, 2002, 12:32 AM
Function Over Form
BillH's Avatar
The nitro boat will win, but the gas boat will be much funner!
Aug 25, 2002, 02:27 AM
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There has to be a way to get this Gas/Alcohol engine to spank the Nitro. someone here must know the secret. There must be more to gas than just reliability?????????????
Aug 25, 2002, 07:01 AM
Dr John
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In the begining the whole purpose of gas boating was to make a user friendly, reliable. inexpensive to operate model for those who didn't want to have to carry a van load of support equipment, burn $40 a gallon fuel and be continualy messing with a touchy needle setting. The clutched gas boat also allows easy one man launching and the ability to dock the boat at a safe speed. The performance level of gas boats in the last 20 years has gone way up, from about 20 mph for the first gassers to over 40 mph for a nice sport boat and over 70 mph for a tricked out boat with one of the specialty engines.
No matter how you do the math nitro contains more BTU than gasoline. If there was a way to make gas produce more power than nitro the gas altereds would be spanking the AA fuel dragsters on the 1/4 mile. I guess this is an example of expirience being more valuable than unlimited $$$.
Enjoy your gas boat and the advantages it offers over nitro and hope the nitro flames out during the race.
Aug 26, 2002, 03:33 PM
Registered User
Gas is catching glow at a much faster pace than glow ever dreamed of. A perfect example was IMPBA District 1 were a gas boat took first place in F mono (a glow class). Two years in a row if memory serves me correctly.

There will be new gas innovations coming soon. There just might be some gas setups to top the 100mph mark in the next year or so. I would go as far as saying before the end of 2003. There is reports of 90+ with rigger and hydro setups now.

I am not knocking or even downing glow in any means. I have great deal of respect for glow drivers. If it was not for them, there would be no point in advancing design or skill and some of the hull designs would not be on the water today.

The disadvantage gas has is the weight to horse power ratio. It is much harder to design a hull that can keep the HP to weight ratio in perspective. Gas (in general and in the upper end engines) has a much higher HP to weight ratio than glow.

I have no experience with canards but a well setup gas rigger with an experienced driver is mighty hard to beat with any type of boat, glow or gas!
Aug 26, 2002, 06:11 PM
Registered User
I haven't heard too much about the alcohol setup. Is anyone familiar with the characteristics of alcohol? Is that the best option for a weed wacker motor, a metamorphisis to alcohol? aka steroids!
Aug 30, 2002, 09:35 AM
Registered User
Alcohol is for drinking not racing......

The carb must be converted to accept the fuel (there is a few manufactures that have them in stock and one of them I believe is Mid-west Engines). The engine will run cooler and faster but will not last very long. The alcohol is not good on internal moving parts, i.e.. bearings. It also will require a synthetic type oil I do believe.

That and it is not legal to race in either the IMPBA or NAMBA originations.
Aug 30, 2002, 10:26 PM
Registered User
I just had an idea, what about adding a gear box! Is there a transmission available with a 1-2 or 1-3 gearing. I know they are available in cars, what about one for a boat with a gas engine. The gas engines do have the torque to make it work... Does anyone know if such animal is available?
Aug 31, 2002, 09:20 AM
Registered User
I don't know of to many places that make a box but this gentleman has them. He is out of Texas and belongs the the Dallas RC Thunderboaters club.
Dustrm is the gentlemen that you would need to contact for additional information.

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