K&B 7.5 ducted fan

[dhal22]

I have several high rpm nitro engines that will probably never run as they're all nib. I got the itch to make some noise so I picked up this used K&B. I'm going to go through it first then make some noise.

 

[dhal22]

Interesting mounting bracket assembly. Homemade I guess.

 

[pawnshopmike]

What are you putting this in?

 

[dhal22]

No idea. A delta is an option.

 

[Snoopy1]

Interesting never played with a KB. How does that intake work is it a rotary disc or a reed valve. Need a tune-pipe for that engine to make a little noise. Need to make a video of it when it runs love hear it and the nitro smell if you can do that.

 

[jbeech]

That engine is used for a ducted fan, and really needs a pipe. It's equipped with a rotary valve instead of a reed. I've still got several and ran them in RK40 fans and on pylon models. It's timed similarly to a pylon engine to turn in the 20K range. Appropriate prop will be in the range of 8-1/2 to 8-3/4" diameter. Terry Prather offers many, many, many variations. I'd buy them by the box (as would everybody else) as we sought the 'world beater'. Fuel-wise, begin with helicopter 30% nitro and go up from there to as much as 65% (boat guys use this). Otherwise, you're just making noise instead of power and you'll be greatly disappointed. And without a pipe it'll be loud 'and' obnoxious and sans protection damaging to your hearing (and of those around you). Damage, by the way, which is both cumulative and permanent.

 

[Snoopy1]

Wow a 75 at 60% nitro and turning 20k now that is impressive. That will make a stupid amount of hp at that rpm. I just have to see and hear that run. Ok fuel consumption is going to be impressive. I have run YS 60 at 30% and at 16k rpm but this engine takes the cake.

 

[Snoopy1]

That engine is used for a ducted fan, and really needs a pipe. It's equipped with a rotary valve instead of a reed. I've still got several and ran them in RK40 fans and on pylon models. It's timed similarly to a pylon engine to turn in the 20K range. Appropriate prop will be in the range of 8-1/2 to 8-3/4" diameter. Terry Prather offers many, many, many variations. I'd buy them by the box (as would everybody else) as we sought the 'world beater'. Fuel-wise, begin with helicopter 30% nitro and go up from there to as much as 65% (boat guys use this). Otherwise, you're just making noise instead of power and you'll be greatly disappointed. And without a pipe it'll be loud 'and' obnoxious and sans protection damaging to your hearing (and of those around you). Damage, by the way, which is both cumulative and permanent.

Do you have video of one running that would be nice to see and hear.

 

[dhal22]

That engine is used for a ducted fan, and really needs a pipe. It's equipped with a rotary valve instead of a reed. I've still got several and ran them in RK40 fans and on pylon models. It's timed similarly to a pylon engine to turn in the 20K range. Appropriate prop will be in the range of 8-1/2 to 8-3/4" diameter. Terry Prather offers many, many, many variations. I'd buy them by the box (as would everybody else) as we sought the 'world beater'. Fuel-wise, begin with helicopter 30% nitro and go up from there to as much as 65% (boat guys use this). Otherwise, you're just making noise instead of power and you'll be greatly disappointed. And without a pipe it'll be loud 'and' obnoxious and sans protection damaging to your hearing (and of those around you). Damage, by the way, which is both cumulative and permanent.

I have a pipe. Macs 7.5 cc pipe, photo later today. I abhor/loathe mufflers, in fact I don't own any. Tuned pipes only on 2 cycle glow and tuned pipes/canisters only on gas.

Actually the little OS 40LA that will power my son's trainer has a muffler so I correct myself.

 

[dhal22]

Interesting never played with a KB. How does that intake work is it a rotary disc or a reed valve. Need a tune-pipe for that engine to make a little noise. Need to make a video of it when it runs love hear it and the nitro smell if you can do that.

Dang right I'll post a video. Can't include the wonderful smell though........