QQ Python MTW RE2 Pipe Install

[crhammond]

I'm posting the MTW pipe install since no one else has yet. It seems fairly straight forward thus far.

The mounts are a little tight being 2 1/8" when the pipes are 2". The trick will be getting the pipes in without being too tight.

To get the pipes in either the bottom lip of the motor box or the bottom of the LG plate will need to be relieved.

If the mounts work it's an easy install. If not it is a bot more work requiring a new mount or something like an RC Showcase style mount.

QQ just emailed me that the Greve mounts are in the supplies too ... so I'll check them out but I think Greve are a little smaller.

Chris.

[Extra nuts]

Where are we supposed to plumb a smoke line on tuned pipes. I run mtw 75's with my da 100. I dont know wher to put the smoke line at on the pipes. Any ideas or help. Thanks.

[crhammond]

The smoke lines should be run on the header after the flex section just like with cans. Not so close to the engine that it will suck in the oil but not so far away that it is too cold to make good smoke. My 2c anyway.

[crhammond]

Okay - it is a VERY easy install (so far.) The primary problem is that the pipes can't get into the fuse uder the gear mount due to the lip on the firewall. I made two 2" x 1/4" slots in the lower lip of the firewall. This allows the pipes to slide in easily but does not reduce the strength of the firewall as you're just removing a small amount of material. The tri-stock is still beefy and there is plenty of meat supporting the motor.

The next issue might be the "ring" where the pipes are welded together. Depending on the header length this might be back by the mounts... but again I am optimistic.

The 2 1/8" built-in mounts are a perfect size.

[crhammond]

I'm pleased to report it works perfectly. The weld passes through the 2 1/8" opening with light pressure. The mount is fairly far forward but the pipes are held just fine.

More pictures tomorrow of the finished install.

[crhammond]

The engine is in and the pipes are mounted.

I ended up adding a support near the rear made with a DA mount for MTW cans. I had to modify it quite a bit to fit but it worked out well. It's not 100% necessary - but should the pipes move around they will be supported by the silicone buffers. I wanted to be sure that the teflon couplers were not taking too much load as they get quite flexy when hot...

The only part that didn't work out 100% is the exhaust stinger on the left pipe comes up a bit short and is 1/2 covered by a support. I might be able to move the pipe back (depends on tuning) or I may just make a slight cut-out.

I plan to make a nice louvered cover for the pipe tunnel and I will add an exhaust exit ramp closer to the end of the pipes.

All in all they fit quite well with a small amount of work.

[Uncle Brett]

Chris, do you think it would be possible to use a tube bender and bend the left stinger out a little so it clears the support? Or do both stingers have to be equal angles?

[newshoundaussie]

What about a new cross member ahead of that one and remove the original, also put a new balsa defector plate behind the pipe stingers. Looks good Chris

[crhammond]

	Quote: Originally Posted by heydick
	Chris, do you think it would be possible to use a tube bender and bend the left stinger out a little so it clears the support? Or do both stingers have to be equal angles?

I'm not sure about bending the stinger... these pipes are muffled but they are still pipes so it might have some small effect on back-pressure? I'm not sure. I've had to repair MTW stingers before and they bend easily if you use a rounded off wooden dowel and work them slowly.

	Quote: Originally Posted by newshoudaussie
	What about a new cross member ahead of that one and remove the original, also put a new balsa defector plate behind the pipe stingers.

The cross member runs through the tunnel sides and I think it might be part of a former (I'll look today.) Not a good idea to cut it I will be adding a new deflector plate for sure. I am also going to add a little structure other than just the cross members. I often pick my planes up from the bottom - and I hang them from pulleys in the garage... I want to make sure the bottom can take a small amount of abuse.

The easy fix is to add 1/4" to the header length. I need to measure anyway as the recommended length is 11"... normally the headers from DA are only 10 1/2". I have a 1/4" gap right now. The main issue with making it 1/2" is that the couplers might melt.

On the plus side these pipes are definately workable