Upgrading a snap p1 720ep

[JuniorCruz]

Hi guys...new in the boating scene here.Got some questions on this boat.Its a 29' FG hull,stock motor is 2836 2636kv motor.Can i upgrade the motor to a 3660 2600kv motor??Is there gonna be a difference in speed?I used a 3s 2200 in parallel on this boat....

[martin]

This boat will run on a 3660 motor & will be faster as a larger prop can be used, however their are problems getting a 36 size motor in as its not a straight forward motor swap. The problem is with the larger diameter motor & jacket the motor wont sit low enough in the hull for the flex to line up with the motor, you need to fit a new motor mount to take the larger motor so that the motor is higher up. you then need to mod the stuffing tube or fit a new one to raise the flex to line up with the motor. Another potential problem is the boat only uses a 3mm flex which can be problematic on the larger more powerfull motor.

[Fella1340]

If your serious about it upgrading and making the effort keep asking questions and you will get great information. Posting pictures of current configuration inside boat and a picture of the transom showing the drive and your esc type and max amps will get people helping. Not many will will know the details of the hull without pictures to help you in the proper direction. Yes of course you can upgrade your motor but everything else needs to be looked at to determine what else will need to be done so it's successful. Get some pics up!

[martin]

The info ive given is based on having the Snap 720 but pics will help with those not ofay with the boat.

[JuniorCruz]

These are some picz of the motor i used....surprisingly the motor i had can fit in to the original mount...the motor screw holes have 2 which is wider and the other 2 fits right in...Aniway,i forgot to mentioned that i used a 120A esc and the stock D36 3-bladed prop...tried a 2-bladed prop but it planes slower on 2-blade.....Is my setup ok?or is something gonna blow??i have a 3660 2200kv motor too....but on 2200kv,i need a bigger prop rite?

[martin]

Most 36 size motors with conventional fitting jackets wont clear the bottom of the mount, also the hole spacing on most 36 size motors are 25mm wide which also wont fit the narrower mount holes. The motor you have their is an FSD 36 series that are different to most motors with an integral jacket that is very short allowing the motor to sit lower in the mount, the FSD motor also uses 2 sets of hole widths ie 25mm & 19mm allowing the motor to fit the stock mount. Most other 36 size motors will not fit with a straight swap though.

[martin]

Just a heads up, I notice you have added a water pickup tube up the rear edge of the rudder. By adding this tube you have formed a radius up the back edge of the rudder, wedge rudders need to have sharp square edges to them like the original rudder had. With the now round shape it creates all sorts of turbulence behind the rudder which causes unnecessary drag.

[Savage Skidoo]

Good eye martin , square edge is a must , water like's to exit cleanly off the back , turbulence is wasted power .

[lenny]

What are your goals for this boat ?
What speeds are you getting with the stock 2636 motor ?
Also I see from the pictures that your flex shaft is hanging out the stinger a lot,
Why is it out so far ?
The gap from prop dog to stinger should be the Od of the flex shaft.

The other 2600kv motor has 36kv less so should be a little slower than the stock one,
Also if you put a 2200kv motor in you will need to run it on 4s,
To get to the same speed the boat run now on 3s with the 2636kv motor.

[JuniorCruz]

martin-thanks for the heads up,didnt know i need a squared edge at the back.
Lenny-As for the prop being so far back,im actually afraid to cut the flex shaft shorter...so i just install it to test first

[JuniorCruz]

What size prop can i use on my current setup ?
Stock is d36-3Bladed....So on a 2600KV,3S...biggest size i could used?

[iop65]

before ordering props :check the size of the hub
i helped a guy fix his problems with a arpro speedboat a few years ago (same manufactor)

if i remember right the prop had a rather unusual size

about your motor ;don't expect too much
they are cheap 2-pole motors that produce not only rpm's but especially a lot of heat

[JuniorCruz]

Im using 3s setup with this particular motor and mod a cooling line for the esc and motor individually...Is gonna help with this motor's heat dissipation right?

[JuniorCruz]

This is the exact motor specs:
2600 KV
36mm diameter
56 mm can length
68mm long including water jacket
44 mm diameter including water jacket at large end
5mm shaft
water cooled
325 grams
max voltage 5 lipo cells
idle current 5.3 amps
resistance 10 amps

Btw,how do i check for max amps on rc boats?
I do know how to check max amps on rc planes using wattmeter though.
Do i submerged boat with wattmeter attached or what do i do?

[martin]

The stock prop has a 4mm bore, you can use Octura 3/16" bore props if you sleeve the 3/16" hole with 3/16" od K&S brass tube.