Tapered Cylinder Baffle Wraps
I read through this thread previously and had planned to make the baffle wrap end caps on my ECI cylinders, but really wanted to have baffle wraps that make contact with the cylinders all the way around, just like they are supposed to be. My idea is to cut off the old straight baffle wraps and rivet new ones in their place. I plan to use flush rivets, mainly because I think the nested dimples with add strength to the riveted joints, hopefully 4 1/8th" rivets on each wrap.
It took me awhile to come up with a flat pattern that would fit around the tapered cylinders. They must be curved in order to fit the slightly cone shaped cylinders. At first I tried math solutions to come up with the arc needed to come up with the curved shape. That did not work for me... So I finally just kept making cardboard templates until I had some that worked OK.
Below I will post some photos that should save others considerable work if they should want to give this a try.
Today I finally got all four of them to a close enough configuration that I had to make the big commitment and cut the old straight baffle wraps off in order to do the final tweaking of the bends on the new ones. I have not riveted them on yet so there could still be an unhappy end to this story but I think it is going to be OK.
Some notes:
Cylinder 4 baffle wrap is quite a bit longer than the other 3 cylnders so it requires more curve to make it fit. If I have any problems getting the baffle pieces back on the engine, it will be on #4. This baffle seems to be the hardest one to get in it's mounting position anyway, adding the curved baffle wrap may make it more difficult. When I get that part done, I will report back here.
Cylinder 3 and 4 baffle wraps required a difficult, double, cone shaped bend to make the offset that closes up the gap where the wrap starts, (hopefully the photos will make sense of this). At least it was difficult for me, working only with a vice and some seamers etc. I did not use a bending break which I am sure would produce much cleaner looking bends, but I think what I have made will work fine. Just not quite as pretty as I would like them to be.
Cylinders 1 and 2 have very short baffle wraps and only needed a 90 degree bend with the end cut at an angle to make them work.
It is quite easy to bend the tabs the wrong direction, I made quite a few mistakes. You have to take into account the orientation of the curve, in order to get the bend correct. Taking the flat pattern, after bending it with seamers, to the vice during bending was very helpful. The file folder material I used bent up quite nicely with the seamers to help me visualize the bends when making them, but I still bent some the wrong way
I hope this saves someone a bunch of time that would otherwise be required to figure this out. It seems to me that ECI should make some well engineered flat patterns for replacement baffle wraps, then riveting them in place of the old baffle wraps would be much simpler than making those end caps, and I think it is a much better solution to the problem.
Only time will tell how well the riveted connections hold up. I have seen photos of cracks in the original baffles where the wraps start, so I will have to keep an eye on them. Getting the bends just right should eliminate much need for tension to hold them in place and that may help keep them from cracking or breaking.
Note: The double bend on the cyl 4 wrap needs a shim where it rivets to the baffle. It just came out that way, and I could not see a reasonable solution that I could do with the crude bending equipment I am using.
Pattern above is for cylinder 4.
Number 4 cyl wrap
Cylider 4 wraps side by side, above photo and below also.
Cylinder 3 is much shorter, but requires the double bend, (although I suspect there are probably other ways to deal with that...
Cyl 3
Cyls 1 and 2 are much easier to make, just an angle cut on the end.
Like this.
Like I said above, this will not be considered a success until they get riveted in position, and then see how they do over time. They do close up the gaps to a point where putting some silicone in the remaining gaps will be a much easier to accomplish.
Randall in Sedona