RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   Speed - RC Nitro Boats (https://www.rcuniverse.com/forum/speed-rc-nitro-boats-117/)
-   -   Engine decide (https://www.rcuniverse.com/forum/speed-rc-nitro-boats-117/5472213-engine-decide.html)

31thundercat 02-25-2007 12:09 PM

Engine decide
 
1 Attachment(s)
I need help deciding what size engine to put into this deep vee. It is wooden 32 inches long and 11 inches wide and about 5.75 inches tall. I was give this boat from one of my friends it was a kit. The boats make is a dumas thats all that i know about the boat.

wave waker 02-25-2007 12:32 PM

RE: Engine decide
 
too big for nitro motor,,,u need gas engine on that beast,,like zenoah 23-26 cc or higher,,,check the gas boat forum,,,,

pardon me thought 5.75 tall ur referring to lenght in feet,...forget it...21-.40 engine can give a good push.

piper_chuck 02-25-2007 12:38 PM

RE: Engine decide
 
It's a good thing you updated your post, I was about to ask if you forgot the smileys! ;)

It's definitely a .21 size boat. Something like the OS .21 RG-M, or the side exhaust OPS would be good choices that won't break the bank. A more expensive engine would probably be overkill.

31thundercat 02-25-2007 01:13 PM

RE: Engine decide
 
I belive the boat is a dumas deep vee 40. So that would mean put a .40 in it? It seems pretty big for that boat.

oldlugs 02-25-2007 02:06 PM

RE: Engine decide
 
A side exhaust .40 like the old K&B .40, is what the boat was designed for. A good .21 will make close to the same (or more) power, but at higher RPM and with slightly less weight. Nothing wrong with the old K&B .40 for sport use though, or like Chuck suggested, an inexpensive OPS or OS .21.
A 32" vee hull is quite commonly used in .21 mono racing these days.

Duane

31thundercat 02-25-2007 02:48 PM

RE: Engine decide
 
How much do you think that will cost? I found one for 190$ http://leadingedgehobbies.com/oscomm...roducts_id=593

BB Modss 02-25-2007 02:57 PM

RE: Engine decide
 
http://www.funrcboats.com/ProductInf...uctid=OS211624

piper_chuck 02-25-2007 03:08 PM

RE: Engine decide
 

ORIGINAL: 31thundercat

How much do you think that will cost? I found one for 190$ http://leadingedgehobbies.com/oscomm...roducts_id=593
I was going to suggest buying it from Tower since they've got a $30 off special if you buy $200 worth of stuff. Unfortunately, the .21 RG-M is now discontinued at Tower! [X(] Bummer. Anyway, you can get the OPS .21 for $185, including pipe, from [link=http://aeromarinerc.com/]Aeromarine Laminates[/link].

31thundercat 02-25-2007 03:09 PM

RE: Engine decide
 
Thanks. How fast do you think it will get this boat moving?

glennb2006 02-25-2007 08:46 PM

RE: Engine decide
 
Fast enough to get you hooked into wanting something faster - welcome to the addiction.....

G

31thundercat 02-25-2007 10:24 PM

RE: Engine decide
 
yea i have a thunder cat that i already want to make fast. But do u think that this boat could do 40?

piper_chuck 02-25-2007 10:30 PM

RE: Engine decide
 
Is the boat fairly light, or is it a brick? With the right engine and prop, you should be able to get in the 30-40 range. How well it handles at those speeds is going to be the question. As the speed of a mono, or any boat, picks up, all sorts of handling issues develop. The newer monos are designed for higher speeds than the older designs.

31thundercat 02-25-2007 10:56 PM

RE: Engine decide
 
1 Attachment(s)
it is a pretty light weight it is wooden. Seeing that this is a deep vee will I need "spin fins"

oldlugs 02-26-2007 11:37 AM

RE: Engine decide
 
If you're looking for inexpensive power: [link=http://cgi.ebay.com/K-B-40-RC-Marine-Engine-B_W0QQitemZ110096735981]NOS K&B 40 MARINE[/link]

Duane

31thundercat 02-26-2007 06:48 PM

RE: Engine decide
 
1 Attachment(s)
If i were to get this engine NOS K&B 40 MARINE I need to know a tune pipe to run on this engine that is pretty long. I don't think i can use the pipe it has now. This engine was made for this boat and fits in the mount perfect. I have the same engine but for a plane.

(i had to put the pipe upside down)

oldlugs 02-27-2007 01:00 AM

RE: Engine decide
 
Take a look at the [link=http://www.macspro.com/headers_side.asp]MACS PRODUCTS[/link] site; it's header # 2533 that you'll need, and for a muffled tuned pipe, maybe their # 1230 aero pipe. Those K&B 40s aren't timed to make use of their 7.5 marine pipes. Of course, you could get a used .40 aero pipe for less $, but you'll still want that Macs header....

31thundercat 02-27-2007 03:11 PM

RE: Engine decide
 
Do you think this will work?http://www.quicktechhobby.com/Airpla...c_products.htm then go down to MAC1930


All times are GMT -8. The time now is 10:02 AM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.