Another P-lim motor question

[zooma]

A friend just installed a Dynamite A3650 2000kv 6 pole motor in his P-lim boat (note mfg's dimensions are 36 x 56). He said that it is NAMBA approved. I don't remember seeing this one discussed here. Is there a way for me to verify its approval, so I can tell my club members about it. We are still using the Leo 3660 2050kv motors.

Horizon link https://www.horizonhobby.com/dynm3831

[dethow]

Neither the Dynamite A3650 2000kv or the Leopard 3660 2050kv motors are in the NAMBA rule book. So neither are "NAMBA approved".
With that said... clubs can run whatever they want. The list of motors are those utilized at national events which are capable of national titles and records.

Here is the page out of the NAMBA rule book with the list of approved motors.
Note: CD does have some discretion to add motors. See verbiage under the motor list in the rule book.

[zooma]

I see that the official rule book has not changed, and that it can be the CD's decision at a particular club's event. This motor fits the recently discussed 36 x 61 size limits, that seem to be "agreed upon" on this forum but without formal NAMBA recognition. So if it's a really good motor in that price range I'd like to use it and know that I can show up at most meets and compete. Also, I'd like to get my home club to accept it, even though we don't host open meets anyway. So I guess that I am just searching for some info that demonstrates club acceptance.

[rol243]

Looks like you guys get a good variety of motor sizes for your P limited class . over yonder in Australia we only get 1 motor size which is a 1500 kv max size plus a 50 amp esc both of a certain brand name.

[dethow]

I see that the official rule book has not changed, and that it can be the CD's decision at a particular club's event. This motor fits the recently discussed 36 x 61 size limits, that seem to be "agreed upon" on this forum but without formal NAMBA recognition. So if it's a really good motor in that price range I'd like to use it and know that I can show up at most meets and compete. Also, I'd like to get my home club to accept it, even though we don't host open meets anyway. So I guess that I am just searching for some info that demonstrates club acceptance.

- No, the official rule book has not changed.
- The CD does have some discretion to add motors, but I don't believe that's ever been done at a NAMBA nationals event.
- A club doesn't need a CD's discretion for particular club events. A club can run whatever motors they want. You'd most likely just need a club vote depending on your club's structure.
- There are some clubs running any motor that fits within size limits of 37mm diameter x 62mm long. That's probably the most widely "agreed upon".
- Some may have added a weight limit to that. Weight limit being run at the IMPBA FE Nationals is 268 grams.
- There has been some talk by a couple/few NAMBA members of going with around a 36.3mm x 60.0mm size limit with no weight limit for a new NAMBA rule proposal. Nothing official there, just some talk. And I wouldn't say that's widely "agreed upon". Just talk by some that feel 37mm x 62mm is too big and don't like the weight limit idea.
- The reason for the slightly increased size (37mm x 62mm) is to allow for manufacturing tolerances. It's been seen that some motors which may spec at 60mm long are sometimes manufactured slightly over 60mm. TP3630 motors are a prime example of variations. There are even ranging specs listed, let alone what's actual made and shipped. tppower.com says they are 58mm long, tppowerusa.com has specs ranging 58mm to 65mm long (depending on where you are looking on their site), and OSE says they are 61mm long.

- As far as your search for some info that demonstrates club acceptance... There really isn't. Clubs are just trying some things out and waiting on leadership from both organizations to provide some opinions/guidance on what direction they feel would be an acceptable rule set for limited/spec classes. Most are hoping the two (NAMBA and IMPBA) will end up with similar rule sets so that there can be ease of cross over for national events put on by both organizations. Clubs will most likely adopt the final rule set so that their members will be running motors which can go to national events.

- For now, I'd start with your club and see what other members want to do and are are willing to set as a club rule. If you guys are trying to get the Dynamite 3650 and the Leopard 3660 involved I'd think your club could probably start with the 36.3mm x 60mm size limit. That would allow those motors along with many other new choices. And then wait out any future changes in the official NAMBA rule book. I don't foresee any rule proposal (if one occurs) going smaller then that. But only time will tell on that subject.

An FYI... another good motor option is the SSS 3656 2030kv 6-Pole.
You can get the ProMarine version with a cooling jacket included for $80.

https://www.promarinerc.com/online-store/PMRC-3656-2030kv-Motor-w-Cooling-Jacket-p97411655

Or you can get the direct from SSS version without a cooling jacket for $65.

https://www.ebay.com/itm/SSS-3656-2030KV-Brushless-Motor-6-Poles-For-RC-Marine-Fast-Electric-Boats/282701449194?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649