What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Pulling tight lower cylinder baffles

Daida

Well Known Member
Hi folks......

Just recently i saw a post where saftey wire was used to pull the lower cylinder baffles tight around the tappered portion of the cylinder.

So far i used threaded rod, but they failed on me twice. I want to try saftey wire now and already have an idea how to.

Just to get even better ideas or my idea backed up, would you please post pics and/or explain/describe how you use saftey wire to tighten the lower cylinder baffles around the tappered portion of your cylinders......

Or help me find the thread i am talking about at the beginning......

Thanks in advance!
 
google site:vansairforce.com danh lower baffle

Here's the thread. Look for Dan's picture.

https://vansairforce.com/community/showthread.php?t=172830

I did something similar, although not as clean as Dan's, and it seems to work pretty well (so far, < 50 hours).

And another thread.

https://vansairforce.com/community/showthread.php?p=745889

You can kind of see mine here:

http://www.rv8.ch/wp-content/uploads/2020/08/IMG_1640.png

Also, the tapered cylinder baffles were discussed here: https://vansairforce.com/community/showthread.php?p=1477956
 
Last edited:
Hi folks......

Just recently i saw a post where saftey wire was used to pull the lower cylinder baffles tight around the tappered portion of the cylinder.

So far i used threaded rod, but they failed on me twice. I want to try saftey wire now and already have an idea how to.

Just to get even better ideas or my idea backed up, would you please post pics and/or explain/describe how you use saftey wire to tighten the lower cylinder baffles around the tappered portion of your cylinders......

Or help me find the thread i am talking about at the beginning......

Thanks in advance!

Just to be sure - - Your cylinder fins are shorter at the base than the head?
 
Bolts

Here is what I do:

1. Strengthen ends flanges with 0.063 alum. I extend them down a little bit as well to create slightly bigger flanges

2. Drill #12 holes in flanges

3. Use drilled bolts (AN3-x) installed with metal nuts

4. Run 0.040" safety wire through drilled holes in bolts to pull flanges tight to each other. I also run thick pitot tube material around the wire to prevent scratching
 
They hold up much better if you hand form the baffles to fit tight to the cylinders before you apply the safety wire or rods. The safety wire or rods should be there to prevent dynamic pressure from forcing the baffles out of their “normal” position, not to pull them into position.
 
I bought some 1/8" stainless rod at the local hardware store, cut it into lengths equal to the width of the baffle folded tab.

Drilled a couple of #40 holes for safety wire to go around the SS rod.

The purpose of the SS rod is to distribute the load over the entire width of the baffle flange.

I also used a bit of high temp RTV to bed in the rod so it would not cut into the alum baffle from vibration

baffle ties.jpg

Also shown is the SS tube that the safety wire runs through to keep it from eating into the inter cylinder baffles.
 
YES!!!

Thank you all for your response.

rv8ch: Exactly what i was looking for. Your memory (or search pattern) is obviously better than mine!

BillL: Yes, they are.

sjhurlbut: also a good solution, maybe next time.

Kyle Boatright: good point, will try as good as i can.

Mike S: This is what i will do

all said!!!

Great Forum this is!!!! 4 more days till the next RVeekend!!


Cheers!!!
 
I use stainless rod for model aircraft flight controls from the hoppy shop, thread the ends, double lock the aftend , use a compression spring and then washer and nut on the front, works great!

gary
 
When I swapped over to the the Titan 370 I added an extra safety wire tensioner to the IB side of the inner baffle so I have 2 sets of safety wires pulling the inner baffle into position on the taper part of the barrel.
So far so good and CHT's are great.
 
Back
Top