For those that have experience on baffling engines in general, take a look at these pics.
Would it be enough ? or should I enlarge the cowl air inlets?
I reinforced the balsa sheeting by applying CF clothing, in addition, there is plenty of specie behind the engine mounting to allow air circulation through the piston fins. The cowl not shown here already fixed with a large opening.
This is a Hangar 9 Edge 33%, BME 110.

The inlets on the cowl are plenty big enough. No issues there at all. The front baffle you have built is a very good start. There are two things that I would do to assure good cooling. One would be to construct and install an upper baffle, or top if you will, that extends over the engine from the forward baffle and angle it downward after clearing the head to get the air flowing the direction I wanted it to go, which is down and out. A big open area behind the baffle and in front of the firewall creates a lot of turbulence. In not being directed anywhere it's entering the front of the baffle and slamming into the firewall, creating a big "roil" in there and not going out as quickly as it should. The other thing I would do is assure that I had a large exit area for the hot air to exit. That area can be reduced some whith the addition of an air dam at the bottom of the cowl, forward of the opening but they can be a pain to do at times.

Dick Hanson posted a picture in this forum a couple of weeks back that well depicted an upper baffle and the way it would direct air. It would not have to be done as well as his but something along similar lines would make the good start you already have into an excellent finished product.

Looks good to me, and better than what I have done on my plane. The only other thing you "might" do would be to slightly block the top to not let the air run over the cylinders, but through.

The baffle for my BME 110 completely surrounds the engine and an additional piece of wood behind the engine conforms with the top of the cowl to ensure all the air going into the cowl is forced between the fins. The following link has a picture of the baffling Chip Hyde uses on his Ultimate.

http://www.scaleaerobatics.com/gallery.aspx

Silversurfer/RTK

Thanks for the reply, I kind of see what you mean, just let me make sure that I got it right, would it be like a sort of "giant ventury "effect by accomodating the baffling plates inside the cowl like this:

I can see where I may have been confusing. Delete your lines at the inlet side. Picture a wall at a downward angle from the top of the engine/cowl downwards toward the rear of the engine. Doesn't need to be full as in an arc, but enough to start the moving and direct the air down and out from the back side of the engine.-----\ Best I could do, with the angle at the lupper eft being against the top rear of the engine and the bottom right of the angle relative to the lower rear of the engine. Figure the bottom of the firewall to be at the same place or close to it. Dashed lines are just above the top of the cylinder heads.

I made a power point drawing of what SS was trying to say, but it will not upload. Sometimes first attempts are failures.

I think you forgot the new lines

Dang, I hate these damn computers when they refuse to do what I tell them

You did not tell it in a way it understood. The computer is mentally retarded and only understands the one and only way it was taught. Anything else will be rejected because it is too dumb to understand. Remember your Dads' empoyees? Same thing

Oh well, I think the RCU server needs to be reseted or perhaps my ISP vpn. The text is OK, some pictures that should be part of the HTML file, are not uploaded, I just got [x]. Same thing if I log onto a different PC.

I will check the RTK PP later or tomorrow.

Anyhow, I believe I know what you guys mean.

To get the best cooling, it should look like this. Both RTK and Silversurfer already pointed that out.
\The air exit is just as, or even more important than the air entry, which needs not be very large. To create a low pressure zone at the air exit point is most important. Air guiding around the fins is important too.

pe reivers

I go it, make sens.
Ops, something else, the rear baffling plates are easy to built and install on split cowl, mine is a single piece cowl, perhaps still doable, however as far as I can picture inserting and removing the single piece cowl might be a little bit tricky. I'll see what I can do in my shop. I may be back with more questions by then.

Thanks amigos !

Pe's picture drawing shows my actual setup .

A couple of other things -- the uppermost line should be in contact with entire top of cowling - use sponge rubber or light bendable 1/64 plywood
Also--don't visualize the airflow as "blowing " thru the cowl -- it is actually just following the easiest path to a low pressure point In the case of a EXTRA or the EDGE -at a lower aft hole.
If you have other holes up front in the cowl -the air will bypass the intended flow
In some cases overly long in cowl exhaust pipe slots will flow more easily than the intend path thru the engine

If I were doing a YAK (and there is no chance of that ) --I would open all the louvers at rear of cowl all around - and make straight parallel paths over top and lower engine--with engine shoved as far forward as possible .
My upcoming Cassut --will simply flow thru the cheek cowls. straight back n out.
I looke at the pics of Chips bipe - strange --that is not how Dave Johnson told me the setup used looked
On the four banger - there was a cross flow dam as well as inlet flow direction plates.

Dick.

I looked at the same pics of Chips plane you did and was quite curious why it had been arranged that way. Perhaps there was something I failed to see, but simply splitting the cylinders as it appeared would not be beneficial.

That was my initial impression also and I didn't understand how it worked. On closer examination this appears to be a very good setup. The baffle surrounding the cylinder heads is attached to the front and sides of the cowl so there are no air leaks. The plate behind the cylinders is conformed to the top of the cowl. All the air entering through the cowl intakes is forced through the fins from top to bottom, none of the air is allowed to exit the cowl without first cooling the engine. An allowance should be made for cool air to enter the carb below the baffle.

Chip used this setup during the last TOC and I copied it for my airplanes. I never had any engine overheat problems during the hot Vegas summers.

The inlet air follows a path down thru the fins - yes - I remember that
As I remember tho -- there was a center vertical piece to divide each side
I was Line Chief at last TOC

No need to. Look at the horizontal white line just behind the spark plug which closes off any by-pass possibility. This makes it easy to mount the baffles fixed to the fuselage without all the cowl fitting. The top between baffle and cowl is now free to provide fresh air for the carb.

How do you guys get all this baffling inside the cowl and have it so the cowl goes on the plane.
I haven't see how to get tangent surfaces to stick and to know how long to make the baffle so that you can get the cowl on.

It's a lot of time, trial and error. That's why making them out of cardboard first is a good way to start. Attaching as much of one or the other baffle to the aircraft structure helps a lot with the cowl on/off sequence. It can all be quite a p.i.t.a., but sitting there looking at things for awhile often comes up with a workable solution. Being perfect is not a requirement, just getting close goes a long way to improving the cooling situation.

just add the pieces that will work and dont add anything that wont.
Have a cold beer - lean back -close yer eyes and think of smoke coming into the front of the cowl - then imagine how you would add a little vacuum at rear of the cowl to pull the smoke thru the engine fins .
Re member-------
The air pressure in the cowl must always be lower than the pressure outside the cowl
If'n not ----- then there is no airflow.

Good Lord, Dick[X(] we agree on something!!

Breaking new ground here

This was the exact thread that I was looking for... so thanks guys for the great input.. I am in the process of baffling my Edge 540, and searching for some guidance.

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