DLE 35RA Muffler bolts

[Bipenut53]

Guys, I really appreciate the feedback! On my setup, I DID NOT use the gasket but went with the high temp silicone method that I have read elsewhere on forums. I used Blue Loctite on the threads but do not recall if I used a lock washers or not. If the motor came with lock washers for the muffler bolts then I used them, if it did not, then I did not add any. As for cooling, I may not have enough. The front of the cowl I think has plenty of intake openings but I may not have enough exit space to let the hot air out. Maybe I am borderline on the exit space. I have had several flights on this plane with no issues. However, yesterday was very hot and humid with little to no wind so maybe that coupled with a marginal opening caused the failure yesterday. It happened immediately following a tumble, coming out of it I noticed the change in sound and the engine didn't respond like it normally does.

I have gone both ways with the gasket and without and have not seen a difference either way. I would use red lock tight if it were me though. It will withstand a bit higher temp and if you need to get the bolts back out, then all you have to do it heat the bolt at the head with a soldering pencil until the bolt gets hot and then you can remove the bolts. It is nice to get on a thread and have an intelligent discussion about something and no one gets offended. Sorry to take over your thread wfahey415 lol.

 

[SnowDog]

My understanding is that the blue loctite will be useless in this application due to the heat. I've been told that red loctite (hi temp) is a better option for this application.

I gotta say that I love this thread! it is a perfect example of how we can all come together, share our experience, and not flame each other for having different opinions!

Way to go 3DRCF community!!!

 

[wfahey415]

I did not see it as a thread hijack. The entire conversation was relevant. I was sincere in thanking you guys for your input. I learn from these conversations.

 

[Bipenut53]

Thanks Snowdog and wfahey415, I too learn a lot on these threads and this forum has some of the best information on it and no one really seems to attack like on other forums.... I enjoy these discussions!!!

 

[AKNick]

It's a little tricky to get the right airflow with these rear exhaust engines unless you have a tunnel. I've seen people block out the forward cowl inlets to concentrate the inlet air just around the cylinder opening itself. Some have even re-directed the airflow but using small Dixie cups, and cutting them at angles directed towards the cylinder. Another way to help increase the suction at the exit area is to create an air dam, by adding about 1/2" of material in front of the exit opening. One thing I've tried is to add balsa or 1/8-1/16" sheet foam baffling to help keep the inlet air around the cooling fins. This is time consuming to say the least, it can add extra weight in the cowling as well, which in return can wear out the cowling quicker... but its great for the engine. Most people make a large opening in the exit close to 3:1 ratio, make an air dam if needed, and just fly it. If you don't like the looks of a big opening you can buy louver plates for fairly cheap and paint them to match.

 

[AKNick]

thanks snowdog and wfahey415, i too learn a lot on these threads and this forum has some of the best information on it and no one really seems to attack like on other forums.... I enjoy these discussions!!!

+1 :d

 

[Bipenut53]

It's a little tricky to get the right airflow with these rear exhaust engines unless you have a tunnel. I've seen people block out the forward cowl inlets to concentrate the inlet air just around the cylinder opening itself. Some have even re-directed the airflow but using small Dixie cups, and cutting them at angles directed towards the cylinder. Another way to help increase the suction at the exit area is to create an air dam, by adding about 1/2" of material in front of the exit opening. One thing I've tried is to add balsa or 1/8-1/16" sheet foam baffling to help keep the inlet air around the cooling fins. This is time consuming to say the least, it can add extra weight in the cowling as well, which in return can wear out the cowling quicker... but its great for the engine. Most people make a large opening in the exit close to 3:1 ratio, make an air dam if needed, and just fly it. If you don't like the looks of a big opening you can buy louver plates for fairly cheap and paint them to match.

As far as baffling, I used 1/16th inch hobby foam from like a craft store, it is easy to work with, can take CA glue and is cheap!! lol It doesn't touch the engine so heat is not an issue and you can direct the airflow where you want.

 

[wfahey415]

I have it all apart right now. But will try to get some photos posted here so you can see what I have and make recommendations. I like the idea of baffles to redirect air over the cylinder and there is a bit of an air dam built into the cowl already. I think my other option would be to increase the hole where the exhaust exits the cowl.

 

[Bipenut53]

One thing is that if the cowling has a lip just before the outlet air, try not to cut that off as it creates a low pressure at the opening and helps "suck" the air through the cowling. I have even seen people put a little deflector just in front of the exit hole to create the low pressure.....

 

[3dNater]

For muffler bolts I just have to add what I do as a non-certified and non-expert anything but this works for me. I picked it up from a 3dhs thread on rcg a few years ago and have been doing it ever since with good success. I have never had the muffler bolts come loose on my DLE35RA. The one time I thought they had it turned out to be the aluminum failed and broke around the bolts. The muffler had been through a pretty hard crash that fatigued the metal.

Anyway, I use ultra copper rtv as a gasket and in place of loctite on the bolts. It works amazingly well and guys are even getting by using it on much larger displacement without nordlocks.

Just thought I'd toss it out there as a non expert option that I have seen work for me and some others