# F21-8w

### Help Support The Rocketry Forum:

#### horsefish

##### Member
Found some F21-8W Econoject motors cheap (13.99 for a 2 pack) at the local Hobby Lobby. I know these are older motors, but will they still be good? Also picked up a pack of Aerotech igniters for $3.00 and some igniter clips for$2.30. I basically bought them out of their remaining Aerotech stock. I think the F21-8W would be good in my wifes Mustang, but don't want to use them on it if they may be bad and possibly cato or have a bad ejection. Let me know your thoughts.

Bob

#### Ryan S.

##### Well-Known Member
those motors are great and there is no reason they should be bad, I have some F21s from a while back and the ones I used were fine. AP motors will only oxidize over time making them harder to light, but this will not cause a CATO

BTW they will give the mustang an awesome ride

#### n3tjm

##### Papa Elf
The eight second delay may be a bit long for the Mustang, especially since Aerotech delays tend to burn on the long side... The F21-8W is great for rockets like the Estes Eliminator .

#### Ryan S.

##### Well-Known Member
maybe a little long but I think it would be okay

I plan to fly my eliminator on that motor....bye bye

#### firemanup

##### Well-Known Member
I too think you'll be ok with the 8 sec with that bird, it will be a little long, but the 6 is a little early according to WRASP...

Either way it's a tough bird and the stock shock cord is wide enough i think you'll be ok with a little bit of a high speed deployment..

I looked over the flight logs on EMRR and found plenty of flights with this bird on F20-7's and F22-7's and they look to work fine.

The only flight with an F21-8 was mine and it worked fine being a second or so late but no damage..

#### Stones

##### Well-Known Member
I've flown my 'Stang on 8's plenty of times with no ill effects. It's sturdy enough to handle some speed, if ejection is late, being a fairly light rocket.

#### Ryan S.

##### Well-Known Member
True, the shockcord is wide, and the body tube is tough so this should take the shock....we wanna see some pics of the flight though

#### horsefish

##### Member
I figured the F21-8w would be OK for the Mustang since they seem to be pretty tuff and it recommends an F20-7w. If nothing else, I will fly them on some other rocket, as I can't pass up a bargain. I have a 7oz. scratch built that is just itching for a bigger motor than an Estes E9-8. It was built out of scrap parts, so no big deal if it is lost or trashed.

Bob