Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: hydrobob on November 29, 2012, 10:43:29 am

Title: AA class motors
Post by: hydrobob on November 29, 2012, 10:43:29 am
What's available in this range? I know that BMPRS has raised the capacity limit but I don't recall seeing anything in those capacities either. All I've come across (apart from CMB..out of the question as I want to stay married) is  a Chinese 3 port job that looks to have reasonable power characteristics but I would welcome any other suggestions.

Cheers
Bob
Title: Re: AA class motors
Post by: tmbc on November 29, 2012, 01:36:36 pm
hi bob
mds do a .28 and look at buggy motors you can have cooling heads made ;0)
also checkout just engines

theres loads of aero and buggy just not to many marine

aa class is 0.1-.28 but upto .21 may use a gearbox .21-.28 have to be straight drive
mark


Title: Re: AA class motors
Post by: hydrobob on November 29, 2012, 03:02:43 pm
Hi Mark
I've been wondering about car motors as I've got 2 OS21 V-spec as spare/alternative stock car motors and I think that OS do or did a marine variant so I'll start looking . If anyone knows who might do marine heads......

Cheers
Bob
Title: Re: AA class motors
Post by: tmbc on November 29, 2012, 03:06:01 pm
hi Bob
 I can have marine cooling heads made if needed by arrow modelsport

Mark
Title: Re: AA class motors
Post by: hydrobob on November 29, 2012, 05:00:18 pm
Hi Mark

Thanks for that and I might take you up on it. I've put some feelers out about OS21 head swopping so I'll wait for results. How much does a wc head cost roughly?
Bob
Title: Re: AA class motors
Post by: scoop on November 29, 2012, 06:03:08 pm
What's available in this range? I know that BMPRS has raised the capacity limit but I don't recall seeing anything in those capacities either. All I've come across (apart from CMB..out of the question as I want to stay married) is  a Chinese 3 port job that looks to have reasonable power characteristics but I would welcome any other suggestions.

Cheers
Bob
Hi Bob,
 
Hyper 21, ASP 21, Force 21, Novarossi 21, MDS 21 and 28, Irvine 20, and of cours OS 20/21's, one of our members is running an OS 21 outboard  :-))
Take a look at the race results and our rules on our website www.bmprs.co.uk (http://www.bmprs.co.uk) to check out the winning engines/boat set up's  :-))  Most are available in the marine version, or like Mark say's he knows a man that can marinise an aero/buggy motor. I take it you are coming racing with us next season ?  :-))
 
Cheers
Scoop
Title: Re: AA class motors
Post by: hydrobob on November 29, 2012, 11:33:34 pm
Hi Scoop

That's the plan. Don't know how many meetings I can make yet. I've used MDS engines in tethered airscrew hydros with some success in the past but nobody seems to import them anymore and I've just fitted a Hyper into a new build rc stockcar. OS looks favourite at the moment.

Cheers
Bob
Title: Re: AA class motors
Post by: ids987 on December 01, 2012, 12:53:50 pm
V Spec should be a good choice. Looks like it's a four bolt, and also looks like it has a separate head button (heat sink sits on top of head button; rather than all in one heatsink and combustion chamber). Most of the four bolters have the same bolt pattern, and they're fairly common (most apart from CMB, Axe-Rossi, OPS), so a cooling jacket from a knackered engine could be a strong possibility. Also an easy item to make for anyone with a reasonable sized lathe / mill setup. Just a disc, with a big hole in the middle, bolt holes, and a groove cut into the "land" between bolt holes and plug hole; deep enough to drill into from the edge, and tap for nipples / fittings. If it's SG crank, then gearbox is preferable. The driving gear for most popular gearboxes will fit straight on a SG crank, whereas direct drive would require a custom flywheel, and probably either a custom or modified coupling too. VZ-M is the OS marine V Spec. The cooling jacket would probably fit, but may be pricey; partly cos it's OS, and partly cos it's trick; has a nifty cap in the middle, for water cooled glow plug.
Title: Re: AA class motors
Post by: ids987 on December 01, 2012, 01:17:42 pm
Or of course, what Mark said. You won't go far wrong there, I'm sure.
Title: Re: AA class motors
Post by: hydrobob on December 03, 2012, 01:26:54 pm
Thanks for all the info. I've thought about it over the weekend and I've come up with 2 options;
Convert one of the OS motors and use a gearbox or use one of the new GO28 6 port marine racing engines. Only draw back is I can't find an importer that handles their marine engines. Crescent RC don't and the one on ebay at the moment is the older sports 3port version. However, I've got a dealer on the case........
Further comments welcome and Mark, I've sent you a PM
Title: Re: AA class motors
Post by: martno1fan on December 03, 2012, 03:25:29 pm
http://www.hobbyking.com/hobbyking/store/__11151__ASP_21M_Two_Stroke_Water_Cooled_Glow_Engine_.html (http://www.hobbyking.com/hobbyking/store/__11151__ASP_21M_Two_Stroke_Water_Cooled_Glow_Engine_.html)
Title: Re: AA class motors
Post by: F1 madness on December 03, 2012, 03:44:36 pm
You can get the ASP engines from here,UK based and cheap 2
Seen a couple of these used and they perform really good also they carry spares which are not expensive either
http://www.justengines.co.uk/acatalog/A.S.P._Marine_2_Stroke.html (http://www.justengines.co.uk/acatalog/A.S.P._Marine_2_Stroke.html)
Title: Re: AA class motors
Post by: hydrobob on December 03, 2012, 04:19:38 pm
Thanks again. I've decided to have one of the OS's converted and see how that goes. Anybody got a gearbox they don't want?

Optimistic Bob