dbarrym

My Feedback: (47)

While installing the Tam's bifurcated pipe in my Skymaster F-18, a sharp edge on a former caught on an overlapping seam of the outer pipe skin and bent/wrinkled it a bit. To make matters worse, the entire outer segment came loose while pulling the pipe out and is now retained by basically just a friction fit.

Tam is in China for the next week or so and I am trying to get this Bug ready to test fly before the GSW rally in a couple weeks. Otherwise I'd pack it up and send it on to him for repair.

Can the pipe be used as is? It looks like there were only four small spot welds retaining the outer sleeve on, and the wrinkles (after straightening as best I could) seem superficial. I've had a seriously bad run of jet luck lately and have no desire to add to the tally anytime soon...

Thanks,

Barry

PS - Other SM F-18 owners...The rear of the pipe (spread between both outlets) seems about 1/4-1/2" too wide. Is your pipe the same fit as mine? See pic below.

yeahbaby

My Feedback: (21)

hey bro'

take a good look at the hot section of the pipe. if the hot sections is ok I would think you can get away with just the friction fit. it's just bypassing cool air over the setup anyway.

look at all the pipes out there that are single walled.

buuuuuuuuuuuuttttttttttt.....why risk it?? just wait 'til Tam comes back and have a chat with him.

in the meantime, start gearing it up. BTW, I know someone who has one that won't be used for a little while. maybe you can borrow it until yours gets repaired.

hasta

buck

did you check out the pix of the SM Hawk??? I wonder how far along the Tiger II is.

wojtek

My Feedback: (73)

use a few small nuts and bolts to hold it together for peace of mind .. like the ones used to hold the bellmouth on .. as long as the inner part is ok, the outer wall is just for cooling ...


Wojtek

HotelSierra

My Feedback: (9)

Barrry,

I have the same snug fit with my Tam bifurcated pipe in the SM F-18. When installing or removing the pipe, I use the fingers of my right hand from the rear of the plane to squeeze together the pipe at the rear while using my left hand to pull the pipe out from the main hatch. It is a snug fit, but it does fit. Also try keeping the pipe near the top of the fuse where the opening on the rear formers is the largest. Consider using Tam's pipe. The SM bifurcated F-18 pipe has an easier fit, but their design priority was for installation ease rather than thrust performance. There is a significant difference in performance of the Tam pipe over the SM pipe in this particular airplane. Like mentioned before, the seam separation is on the outer cooling wall, so it is not as critical. However, Tam is the authority here so it is best to call him. By the way, will we see you with the F-18 at Fresno Jets?

dbarrym

My Feedback: (47)

Thanks...Yeah Buck, I am installing servo extensions and air plumbing tonight.

I thought it'd be OK but best to ask.

HotelSierra, I'd like to go to Fresno and that is my backup plan if i don't get it done in time for GSW. Trim scheme and paint details won't be complete but at least it'll be in the air.... also, do your pipes extend past the rearmost formers (in the tailcones)? Mine seem to be about 1/4" short, and I'd like to keep the P120 as far forward as I can for CG purposes.

I had to grind away quite a bit of the double internal formers at the stab mounts, until the width of the inside edge of the formers (just above the stab mount block) is only 1/8". Even then, I have to squeeze the pipes (as you mentioned).

Barry

seanreit

My Feedback: (60)

I think your pipe is ok, and I'm the most paranoid pipe man in this game!!

On my F-15 tams pipe, the last outer sleeve of the exhaust, both sides of the bifurcated, the welds gave during INSTALL!! They litterally will slide off.

I just added some aluminum tape and have been flying it with no problems. I was thinking quality control could be a new issue, but then last week I received the pipe for a Euro I'm building, and this thing is the nicest Tam's pipe I've ever seen!!

Wocketman might be interested to know that this pipe is heavier duty than what I had in my last isobar. Very interesting.

Nick Yuhasz

My Feedback: (11)

Well, I too have a problem. A one inch tear on the outer pipe at the same location on Tam's pipe as yours. And yes, I was squeezing it to remove it, but it caught the edge and tore the outer pipe.

I'll try to have it repaired locally, but there is a problem with the fit. At least they are all consistant in size; a lot of folks are having the same problem!

Nick

wojtek

My Feedback: (73)

the skymaster pipe fits perfectly, and has no performance issues, look at the SM f-18 on the flodida jets video from SKS, (or if you were there ) ... that plane had great performance on a p-120 and the skymaster pipe ..



Wojtek

mr_matt

My Feedback: (10)

If it is the outer pipe only, can't you just use some aluminum tape over the tear?

dbarrym

My Feedback: (47)

Thanks Matt and Sean, I just taped over the seam with aluminum joint tape, all is OK. Still think the pipe should be about 3/8" narrower at the rear and about 1/2" longer, but I feel better about using it now.

Barry