What's new
Van's Air Force

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

How far to trim the forward baffles?

bruceh

bruceh

Well Known Member
I need to get the remaining clips for the connection between the center and forward baffle sections fabricated and riveted in place. The instructions are pretty vague about where to trim the center section pieces with respect to the cowling. Do I line up the forward part of the center section with the cowling inlet and cut on the blue line? I know to leave some room for the baffle gap seal material on the side. I don't have the upper fiberglass inlet ramps glued on to the top cowling yet, so I know there is still some trimming down the road.
IMG_3224-M.jpg


I had to notch the lower inlet ramp on the left side of the photo here to clear the starter ring gear and alternator belt pully. Is there any reason to leave this much floor here, or can it be trimmed back to the vertical center baffle pieces?
IMG_3225-M.jpg
 
rv9av8tr said:
It just takes LOTS of patience....
Click to expand...

Exactly......
Its a doggone iterative process where every dimension is interelated with some other undefined dimension. I think my baffles and cowl came on and off more than any other part of the plane during fabrication.

Bruce,
Can tell you that there is ZERO overlap of cowl and baffle, so... sure you can cut on the blue line. But thats not the final cut. You need a gap for flexing the baffle seal material for engine motion but more importantly..installation of the cowl. So...do you cut the aluminum baffle or do you cut the fiberglass inlet to make the gap... um ....yes..both...maybe.. er ...maybe not. :rolleyes:

Good luck grasshopper. Sorry, I can't be more definitive. :(
 
Hope this photo might help:
On mine, the front edges of the baffles line up to the aft edges of the lower cowl inlets. I don't think there is any overlap.
0a79abfa039b40f1a65658dceffad2ca25304_photo.JPG
 
Lower cowl lift tool

Bruce,

If you haven't seen it, check out Clive Whittfield's lower cowl lifting tool in the general discussion posted 1-21-12. It saved me a lot time and head aches.

John
 
This post kind of goes along with my Dam air dams again post a couple of weeks ago. I did trim the air dams on both sides and reduced the CHT's on # 3 by 35 degrees during climb and got # 2 and 4 CHT's closer to the same temps although # 4 is still the coolest. # 3 is still my hottest cylinder.Now upon further inspection I see that the remaining air dam on # 2-4 is flush to the cylinder head with no gaps, while the dam on # 1-3 has about a 1/4 inch gap between the baffle and the front cylinder all across the bottom of the baffle.. That doesn't seem right. Time for some r-temp filler in there or is there a better way?

John Morgan
 
follow up pictures

Thanks everyone for the links and suggestions. Here is what I ended up trimming (still not completely done, but very close).

I took the front edge back quite a bit. It still overlaps the cowling just a bit.
I was able to line up the center baffle sections on the upper cowling to see just what is going on there for my trims next to the upper inlet ramps.
IMG_3240-M.jpg


Made some rough marks on each side to transistion the inlet up to the top of the cowling.
IMG_3242-M.jpg


After some trimming, I ended up with something more like it should look.
IMG_3245-M.jpg


Still lots of fine tuning to go, but now I'm confident I can get the baffle seal material on the baffles and have them seal up the gaps on the inlets.

I may still close up the inlet ramps with some fiberglass or foam along the sides. The fiberglass ramps are not bonded in yet and the fit of these in the inlets is less than perfect (not wide enough).

More photos and gory details of fitting the baffles on my web pages.
 
You must log in or register to reply here.
Back
Top