Picked up three pipes for a song, but I am not quite sure what they are for:
This first one is 16" long and 2" wide, looks to me to be a TGA pipe for the OS91, yes?

This second one is maybe 1.75 in diameter, maybe for a 77? Definitely not for a 45, looks too big, and the exhaust header on my OS46 is much smaller....

And this third one? Big enough for a 91? Anyone recognize it?

Hi ET,
Been a while since I played with DF pipes, and I've given most of mine away so cannot compare, but my best guess is:

1) Not sure about this one. The front (header) end looks like the original JMP, made by MACS I think. There used to be aversions with 3 outlets made for an OS65 DF, but don't have the dimn's anymore.
How about asking Tom Cook - he may be able to confirm, and has been around the jet scene longer than many of us !

2) It looks very much like the pipe that Philip Avonds used to supply for OS91 with his very early F-15's, and later supllied it with the 2 stingers shortened a bit 'cos otherwise they vibrated off if the fan unit was badly balanced.
Think that MACS made them for him? Maybe shoot him an email with pic and Dimensioins and he should be abler to tell you for sure. If it is, then I can tell you it worked VERY nicely with OS91 and Ramtec fan. Would turn about 22,40 on a good day !

3) Looks really like an OPS pipe, maybe for their OPS80 (nice motor) or the 60 size boat motor. Is it baffled, or not?

Happy Landings,
Mike C

Pipe number 2 is the JHH dual outlet pipe. It is the one that avonds shows on the drawings in his F-15. I have one, so I am positive on that. I can't help you much on the other two.

I thought that one was JHH. Thanks, guys! That's good, in that I don't need anything smaller than 91.
Mike C, think the OPS80 pipe might work with a K&B82, or OS91?

ET,

I don't think the volume of the OPS80 pipe is big enough for an OS91 - never had a K&B82, so not sure. From memory it was actually a bit small for the OPS, and always a bit critical on length.

Yeah , after some thought I concur with JeffH, 2nd pipe from JHH (but still made by MACS I think ?). I was having brain-fade as it was too early in the morning when I replied!

Mike C

Been there, done that. I should never post until after I have had a few drinks, say, 9am or so!
The third pipe sort of looked a little smallish for 91 use, compared to others I have had. Maybe with a 77 or something. Like you, I have not mussed with the 82 yet, but the other two pipes should do fine for that.
How do you tell an OPS 80 from a 65? A friend of mine picked one up the other day, had a gold head and "865" cast into the webs of the front housing...