Nitro tunnel.. Switching to elec..?

[Mike whiting]

Alright got some questions maybe someone can help me. The lower unit is a k&b, are all k&bs the same size? I dont know much about outboards. I need to figure out what adapter to get to make brushless. The nitro motor on it says 75 or 7.5 don't know what size that is if it is a size. Don't know much about nitro. When I go elec I want to get either the turnigy 180 or the swordfish 200. 5.5 all around just need to figure out what motor. I want to be able to go stupid fast but be able to have good run times. I want to run up to 6s. I don't know what kind of boat it is but it's about 32" to 33" long and about a foot wide. It's kinda of heavy. Thinking the leopard 4074 1800 or 2000kv. Or just throwing this out there 4082 1500 or 2200kv. Any input would be great I am building for my uncle thanks

[siberianhusky]

http://hyperprod.bizhosting.com/7_5_electric_outboard_conversion_kit.html

these guys have the adapters and such, I don't have any big tunnels so I can't help out on motor choice.

[HTVboats]

http://www.intlwaters.com/index.php?showtopic=47083

A few of us over at International Waters contributed to this thread and put specifically in the outboard forum for tunnel guys converting.

Sounds like you have a .45 K&B which Hyperformance makes a neat mount with steering arms and adapter to the 3/16 (.187) cable. Your headed in the right direction with motors just match your KV's to what voltages you want.
4S (14.8v) 1800-2200 kv
5S (18,5v) 1400-1800 kv
6S (22,2v) 1200-1600 kv

I have run a Leopard 4074 1400kv on 5&6s and it had plenty of power on a larger 32" tunnel, stay below an m445 and your run times will increase.
On 4S with a 32-33" hull I think a 2000KV 4074 would work well with similar props X442-M445.
I have a 4082 1500 kv that I am going rig with 5 or 6S batteries for competition.
Hope this helps. Weigh your bare hull and post a photo of what your working with and we may be able yo make specific prop recomendations.
Mic

[Mike whiting]

Perfect I'll take some pics and try to get them up. Also try and weigh it first I need to strip it down. What speeds do u think you get with the 4082 1500 kv and run time

[HTVboats]

Without knowing what you have it is hard to say how yours will run. The hull I run on 5S with a 4074 1400kv runs low 50's and maybe 2-3 minutes at WOT on a 5300mah battery not going too stiff with prop load. A 4082 1550kv on 6S should run a bit faster but may have a shorter run time unless you go to 8000ma batteries. A good light hull design in race trim could hit low 60's. 8-10lbs. rigged with batteries.
Mic

[Mike whiting]

Ya for sure let me get those pics and weight

[Mike whiting]

Well I got it stripped down I measerd it and it is 31"L -13"W still haven't weighed it but I guess maybe it could weigh 5-6 lbs still got to get some pics up. So I think I decided to do the 200a esc still trying to decide with motors I mentioned earlier and want to be able to run 4 5 and 6s another thing is I might ditch the k&b and talk him into getting a new lower unit for elec so I have no exaust holes. I like the 7.5 bullet drive I just want to make sure it's the rite size before buying. My plan is to get all parts then need to do some fiberglass for making some water tight trays for elec. Build and prob ask more ?? Then paint when I got everything down

[Mike whiting]

Is the 4082 going to fit the 7.5 adapter?

[Mike whiting]

mikes phone 400.jpgmikes phone 401.jpgmikes phone 405.jpgmikes phone 402.jpgmikes phone 404.jpg

[Mike whiting]

mikes phone 408.jpgmikes phone 411.jpg

[Mike whiting]

the hull is in very good shape just needs some paint work. i just want to make sure that the 7.5 bullet drive from hyperformance is the same size as that kb. would the prop assem and flex shaft fit the 7.5 bullet drive from the kB?

[HTVboats]

A 4082 with a Hyperformance adapter will bolt right up yo your K&B lower. If you don't like the exhaust cavity just cut it all off as going to a hyperformance lower you won't gain anything but looks. I have used the Hyperformance and feel they don't go through the water as well as a K&B. Your hull appears to be a Prather on the deck and cowl. The bottom however looks like the original LeeCraft. I have the original mold from Lee and still build them fo myself. That being the case use some sort of setback mount. Rule of thumb is the pivot point or the swivel pin should be even or slightly in back of the rear sponson bottom.
If your planning to do 4-5-6S you will need different KV motors. Trying to jump from 14.8 to 22v just will not be efficient with a compromise motor. A 1500 would be ok for 5 and 6S but not 4S. An 1800 would do 4 and 5S but doing either of these would require a wide selection and knowledge of propellors. Pick a range and get the proper powerhead for each voltage range. Compromises will cost you time and burn you down at some point. I have no less than 20 Gas propellors and 50 Nitro propellors in my box and going into FE with similar tunnels to my nitro setups I have purchased and worked on another dozen props and I do not have everyone I need yet. I am looking for the optimum setup for racing but even sport running proper setup is balance of efficient power and puttin it to the water.
When you decide on an exact motor kv & voltage I can recomend props.
Mic

[Mike whiting]

All great info I appreciate it. Ya I was wondering about the 4s idea but I want to stick with 5 and 6s. I think I am pretty set on the 4082 1500 kv and either 180 or 200a esc none r in stock so I guess it's whatever comes in first. For the lower unit I was just thinking about looks but I think I will just stick with the kb I like the idea of cutting the exaust off but is there something else I need to do beside cutting it off? I think I would like to do that. What do you think of this hull is a good one to fix up?

[HTVboats]

I have a 1500kv 4082 Leopard on order and will try it on 5S first with a 200amp esc. An m445 should work well and if it heats at all rather than drop back to an X442 I also have Grimracer props 42X66,44X66 and 45X68 to run. Above an M445 I will go with an M545 or M447. From there I have several stiffer X448-452's with various cuts but they would be better suited for 1200kv on 6S. My total weight motor and batteries should be 9-10 lbs. and I hope for high 50's. Hope this helps. Going to 6S will allow the same props and maybe faster but will be heavier which hurts tunnel efficiency, they need to air our not run wet.
Mic

[HTVboats]

F-1 003.jpgF-1 005.jpg

Here is a 2200kv 4082 on a cut K&B lower Cowl is an old AMPS which they don't make anymore.