Gas Scale Motors

[Rich Jones]

What size motors are you guys running in Gas Scale (1/667)? This would be for IMPBA. I think they allow for up to 31cc, although I don’t know of any motors offered with that volume. Is 29.5 mod what most people run? Just curious. I have a back burner project to get to at some point that would race in that class.

 

[Lay26]

Rich u have to build it

 

[Rich Jones]

Rich u have to build it

Build it so it’s 31cc? I think I’d probably just roll with a smaller mod motor if that’s the case. I was just wondering if there was a popular choice from one of the companies out there like Gizmo, etc…

 

[Don Ferrette]

Build it so it’s 31cc? I think I’d probably just roll with a smaller mod motor if that’s the case. I was just wondering if there was a popular choice from one of the companies out there like Gizmo, etc…

You want the torque of the longer stroke 30.5 for gas scale. I have a real nice one for sale with spare carb-
https://www.intlwaters.com/threads/gzr-racing-zenoah-30-plus-engine.84423/

 

[Rich Jones]

You want the torque of the longer stroke 30.5 for gas scale. I have a real nice one for sale with spare carb-
https://www.intlwaters.com/threads/gzr-racing-zenoah-30-plus-engine.84423/

So the Gizmo 30 plus is legal for gas scale? I thought it was 36cc? Like when you account for the crank stroke etc…I may be interested in that but can you clarify the Cc thing, I guess I don’t completely understand it.

 

[Mike Hughes]

Yeah Don's motor is basically the 29.5 motor with the 1.6mm stroker crank in it. That puts it at eh 30plus range. Good motor. Run those in my twin.
Mike

 

[Rich Jones]

Yeah Don's motor is basically the 29.5 motor with the 1.6mm stroker crank in it. That puts it at eh 30plus range. Good motor. Run those in my twin.
Mike

What I don’t understand is that Gizmo bills this as a 36cc Motor. If the Gas Scale rules say 31cc, how can I use it in that class? Oh wait, now I think I get it. I read it again. It’s a 36 MM cylinder not 36 CC. So you’re saying it’s around 30.5 CC?

 

[Wally Duarte]

Pretty sure a 28.5 with a 1.6 crank comes out around 30.1 cc

28.5 - 1mm crank 29.5
28.5 - 1.6mm crank 30.1
28.5 - 2mm crank 30.5

 

[LohringMiller]

The engine we set the NAMBA 2 lap record with was built by Brian Buaas. It had a 36 mm bore cylinder with a 30 mm stroke and a 55 mm rod. It needed a spacer under the cylinder for the long rod. I believe we used a CC racing Beast pipe that's no longer available.

Lohring Miller

 

[Lay26]

It's a beast lots of torque...with the right pipe u get the rpm as well..

 

[SayMikey]

Ive ran a few but not a lot of Gas boats. My motor guy told me a 29.5 is the most reliable motor and its all I have ever ran. The Oly I ran was as fast as any I raced

 

[Jerry Muro]

I have to agree I run a 29.5 in my gas scale and it is plenty fast. Sometimes it is too fast and find myself slowing down to in the turns. I also run a Dragon Scale hydro which is full carbon fiber boat and is light for its size it only weights 15 lbs without fuel.
Jerrty

 

[Wasted wages]

Talk to Winton Artz....813-240-2130
ARP Racing...
I bet he can get you fixed up...

 

[Rich Jones]

Talk to Winton Artz....813-240-2130
ARP Racing...
I bet he can get you fixed up...

I will keep that contact Frank. Thank you. Right now I have some motors I’m going to try and as far as scale gas goes, I don’t even have a boat yet. All I have is a pile of frame parts and a cowl that needs heavy mods to work.

 

[Wasted wages]

I talked with Winton after I bought a motor here on IW... he ID's all of his motors and when I gave him the number off of it, he knew when it was sold, who bought it and all the details about the mods done to the motor.

He does very nice work and knows his stuff !

 

[Rich Jones]

I talked with Winton after I bought a motor here on IW... he ID's all of his motors and when I gave him the number off of it, he knew when it was sold, who bought it and all the details about the mods done to the motor.

He does very nice work and knows his stuff !

I talked with Winton after I bought a motor here on IW... he ID's all of his motors and when I gave him the number off of it, he knew when it was sold, who bought it and all the details about the mods done to the motor.

He does very nice work and knows his stuff !

Very impressive service it sounds like. It’s getting pretty rare in this day and age!

 

[Mike Hughes]

Pretty sure a 28.5 with a 1.6 crank comes out around 30.1 cc

28.5 - 1mm crank 29.5
28.5 - 1.6mm crank 30.1
28.5 - 2mm crank 30.5

My bad. That is what I meant. 28.5 with 1.6 stroker. The 29.5 is already a 1MM stroker. I stand corrected.
Mike

 

[Rich Jones]

Thanks everyone, I believe I understand it now. 30 plus seems to be the ticket.