How about a 180 (30cc) glow motor?

[Ian Inverarity]

Finne,

Considering most good 90's these days are rated in the 6-7hp range, that means that 12-14hp should be obtainable for a 2 cyl 30cc engine. Maybe with a bit of work 15hp is not out of the question.... 8)

Nitrocrazed racing: 14hp isn't twice as fast as 7hp. Pity....

 

[David Singleton]

Ian

Sorry to take soooooo long to get the info for John Hyders tethered hydro 30cc engine but here it is

Bore - 32mm

Stroke - 31.8mm

Exhaust - 185

Transfer - 130 (2 main, 1 boost)

Inlet - opens 40 ABDC

closes 60 ATDC

Venturi - 14.5mm

Pipe - 360mm plug to max diam (65mm)

25mm header pipe

15 to 16mm tail pipe

Single sided crank with 10mm x 10mm crank pin

Crank is cut away with counter weight

Hydro has recorded 125mph so it works for John

At the last meeting he had his triple engined (3 x 10cc OPS Red Heads) running coupled together using an enclosed gearbox, sounded triffic but was unable to record a speed due to the bungie mounting rotating which prevented him from launching the hydro successfully :'(

Hope this helps

Regards

Dave

PS Had the A90 timed at 112mph on its first run without any mods to the timing so when I am happy with the set up I will open the intake to 65 ATDC and see how it goes

 

[Ian Inverarity]

David,

Thanks for the info! ;D

Sounds like an interesting motor! 125mph is moving along pretty well!!

Good to hear your A-90 is going well! 8)

Ian.

 

[Ian Inverarity]

I just thought I would drag this post out again for the benefit of some of our new members, and to see if anyone has more thoughts. It gets totally off topic, and is very long, but is one of the more interesting threads I have been involved in... B)

Nitrocrazed racing: Bringing back the old threads...

 

[TimD]

Ian,

I agree,well worth the bump!

Sorry for not responding to your email yet - I'm on a break from training right now but start again in 30 mins..... WORK SUCKS.

Tim.

 

[AndyBrown]

I'll jump in on this one a little later after I've had time to get up to date on past posts.

 

[Ian Inverarity]

Tim,

No worries, I know that feeling!

I just got a brand new stock A100, so this thread could be useful again! B)

Andy,

I look forward to your input! B)

Ian.

 

[[email protected]]

[SIZE=14pt]Hoping this winter me and a friend will build the P-I-P 180 I solod him. Where looking to put it in a cat and get that motor screamin' my only fear is I've noticed that the carburetor set up kinda sucks. I'll need to actually use a hi-torque servo to operate the carb, go figure![/SIZE]

What are you guys setting the pipe length out at? And what prop is a good starting point?

 

[Ian Inverarity]

I used a cable for the throttle linkage.

It is always hard to give advice on pipe length, but it should work with the pipe lengths used normally for 90's. Off the top of my head I dont remmember what I had.

Ian.

 

[Mark]

Hi Nitro,

Haven't been on here for a long while. I've been promoting and importing a product to Australia called Semenex, it is a powdered drink that makes your semen taste sweet, makes for some good fun in the bedroom, anyway have some time now to post, noticed Andy Brown has taken some interest in the 180. I was also thinking about turbine power as someone else has posted and spoke to some suppliers about it. It is very beneficial and very expensive about $5000 for a big power engine, but you would have to get it running reliably and then you would find it hard to get enough people to get one to race against but on the flipside ducted-fan aircraft events are mostly running turbines now, they get so much power increase, no vibrations and sound realism that the benefits far outweigh the expense. These things sound absolutely awesome.

How far have you got with your engine idea?

 

[mark poole]

LOL...nice way to run up your post counts!!! Too bad you are going to lose your eyesight!

 

[davo]

how about twin 180s. now that will be cool. But to bad im scared of my 67 :unsure: put em in a rigger a bit bigger than the twin 90's .thats gotta break 170.

 

[Mark]

Davo,

With the cost of twin 180's you might as well chase the turbine idea and get the benefit of being the pond hero and doing mean SAW passes that will blow your ears.

 

[[email protected]]

he said "SEMENEX"....LOL...COOL...Chicks dig it....LOL

I hope as the salesman you guys aren't required to taste sample it....ROMFLOL :lol:

 

[Turbosun]

I guess this thread is snaking everywhere....

Just wanted to mention the 22.5 cc 5hp Nitro engine from MHZ:

MHZ 22.5cc Nitro engine

 

[Scott Schneider]

<_< While that MHZ is neat, It's allready outdated by the new Zenoah 4 port engines that are getting @ 6 HP on gasolene once modified.

Been watching this thread for some time. I think one BIG point others have talked about but no one wants to accept is the fact that a 30 cc engine is NOT going to rev much more than or even get to the 20K range.

:angry: This is only a problem for the handling issues associated with ANY engine that has lots of torque with limited revs. You can pull HUGE props with lots of pitch and diameter but have to deal with the Hull getting out of shape due to prop torque wanting to flip hull upside down !!

:blink: As far as effeciency go's, two engines running smaller diameter props at higher rpm will not have the handling issues that a single would in an equal size hull.

:unsure: And as for reliability issues think about all the sizes of nitro engines and how well they hold upto racing? .21's by far the hardest to break and .90's the most fragle if over reved. :unsure: Is a single cylinder 30cc engine really a good idea? Would you really be happy with one that if not keep under a mechanical limit would BLOW UP!

For Me, I think not. But if you have the money for one and money for the parts support then why Not? Most good running twins would smoke your ass in a race so long as the fire stays lit in both engines. Yes twins have issues too. :lol: Scott

 

[Mark]

Hi Scott,

Just wanted to point out that some people like myself think it would be a good idea to have a twin cylinder 180 meaning two 90 cylinders on the one crank shaft so you can still get the revs, I think that two 80 cylinders would work best, if you want to get absurd you could think up 3 or 4 cylinder engines with a high performance layout, not just something that has 4 cylinders thrown together for the sake of being different but the weight factor and cost factor seriously becomes a problem. Remember the cost of a turbine around AUS$5000 just for the engine and computer and starting gear, that doesn't include a gearbox you would have to manufacture to reduce the 80,000 to 100,000rpm on the shaft to get down to the prop shaft of say 25,000 or 30,000rpm so you can run a prop that is commercially available.

 

[Hap Mulvany]

To build a strong gear train use an internal and a spur gear 80 percent tooth ingagement only two gears and does not change rotation.

 

[Mark]

Hap,

I'm thinking you would have to use a conventional type gear reduction with a layout the same as full-size boats that use a v-drive because of the height of the turbine shaft and who knows where the engine would be best placed on the hull. But your gear layout is a great idea, very compact.

 

[Scott Schneider]

:blink: Why we talking turbines? They are NOT realistic to be used in RC boats if you race, Because there illegal !!!

A multi cylinder engine of @30cc's is no differant than a twin engine. lose the fire in one jug your screwed.

Loose any mechanical aspect of one of the cylinders and the other running one tears it apart before the engine stops.

If I was a gambling man and was hell bent on making the 30cc limit I would take a twin 15cc engine set up over a single 30cc

And if really smart about it stay with a single 15cc and build it light like the .21 hydro guys do. That way you get the best possable chance to go fast with a high rpm engine and have greater reliablity than your other options. :unsure: Scott