Originally Posted by
the Wasp
yes the K&B came with a big square box muffler. I don't think the HP was made for a duct fan, it was just a performance prop engine. I read that it's older "silver" version was the must powerful 61 you could buy back then (January 1969) see my link.
Jim
HP 61R
the K&B 100 Aro w/Box Muffler
I just read the review on the K&B 100 aro engine on Septre flight. What a neat engine. That would be a good choice in a Top Flite warbird.
Yes, the PDP engines were more powerful than the std looper engines of the day.