Catalina engine replacement

[flywise 169]

I made a quick trip to the hangar this morning and made a more careful measurement now that everything is tighten up and in final location and my centerline of prop to fuselage is a little over 37 inches. The info in my manual says" preliminary" 912 engine installation. But I think the fact that our measurements are the same indicates some change was made. I will send you a copy of what I have if you want it. I am a retired engineer and and an A&P. I am very aware of the importance of keeping the weight down. I put just enough Polyfiber spray, the silver coats on the wings, to block the light and eliminated a coat of the sprayed on Polybrush. the finish stills looks good. Today there are very light batteries, 4 lbs,, and digital instruments. I will probably initially fly with airspeed, compass and altimeter for flight instruments and a hand held radio. I have a water rudder that will not initially be installed. I have the forward retracting gear which helps with the C.G. I have the after market fuel tanks, two in each wing. I did use the plywood covers that came with then but I am sure that installation is heavier than the original set up. This kit came with a very a heavy galvanized steel fire wall. I changed it out for thinner aluminum. The fire wall made no sense to me. The Searey does not use one. Again I appreciate your input.

Hey, yessss I'd love a copy of the 912 install. Also I want to share my thoughts about 3 bladed vs 2 bladed prop on the catalina. I had the opportunity to try out the same propeller (koolprop/Nrprop scimitar blade shape carbon fibre) in both configurations (2 bladed/70inch and 3 bladed 69inch). On my catalina, the 3 bladed propeller does not allow the wings to be folded...not enough space between the flaperons for the 3rd blade.

Performance wise I found the inflight numbers to be VERY close/equal. There was a little gain on initial acceleration for take-off for the 3 bladed / 1/2 to 1 second shorter take off run.

I chose the 2 bladed option because:

1. less weight

2. less propeller moment of inertia 

3. very small performance difference versus 3 bladed

4. much nicer sound

5. need to fold my wings for storage

6. cheaper

Remember, the catalina with a 100Hp is a lot of power for it's weight (750Lbs) & big wings (36ft). Propeller does not make the big change...HP does...and it only needs 28Hp to stay in flight not loosing any altitude!!!

Also note that the catalina hits an aerodynamic wall reaching 100Mph no matter how much Hp it's being fed. More Hp equals higher rate of climb and shorter t/off. To give an idea, 4800rpm=86Mph / 5200rpm=92Mph / max power 5700rpm=97Mph flying straight and level

[jbmaridon 0]

Flywise, I just found page 2. My email is: jbmaridon@centurylink.net. If you give me contact info I will send you what I have on the engine installation. Also I have some questions that you can probably answer easy by email rather than through the forum. I had to trim some of the rubber bushings for the engine mount to clear some tubing and I did not find any steel bushings that would go through the rubber bushings that are called out in the manual. I made short bushings for the large dia. mounts, 1/2 inch O.D. and 3/8 inch I.D,. and the 3/8 dia. bolt fills the hole in the small dia. rubbers when they are installed.

Your pictures have been very helpful but I am struggling with how and where to mount the ignition modules.  Also how do you check the engine oil level? Did you add an access door to the cowling? Any thoughts on the firewall?

That is an interesting discussion on the propeller. I have no problem going with a two blade as long as I can get off the water and it sounds like you have confirmed that is not an issue.

I am excited about this airplane . It is well along with the engine installation and related controls the major remaining project.

Again thanks for the help.

[flywise 169]

Flywise, I just found page 2. My email is: jbmaridon@centurylink.net. If you give me contact info I will send you what I have on the engine installation. Also I have some questions that you can probably answer easy by email rather than through the forum. I had to trim some of the rubber bushings for the engine mount to clear some tubing and I did not find any steel bushings that would go through the rubber bushings that are called out in the manual. I made short bushings for the large dia. mounts, 1/2 inch O.D. and 3/8 inch I.D,. and the 3/8 dia. bolt fills the hole in the small dia. rubbers when they are installed.

Your pictures have been very helpful but I am struggling with how and where to mount the ignition modules.  Also how do you check the engine oil level? Did you add an access door to the cowling? Any thoughts on the firewall?

That is an interesting discussion on the propeller. I have no problem going with a two blade as long as I can get off the water and it sounds like you have confirmed that is not an issue.

I am excited about this airplane . It is well along with the engine installation and related controls the major remaining project.

Again thanks for the help.

I also made bushings (aluminum) but they go full length inside the rubbers so as to use  1/2in bolts. My rubbers were designed for 5/8 inch...

I also had to grind some rubber to make them fit in the engine mount. 

I have a question for you..is there anything about thrust line/angle for the 912 install???

Keep going, it's a great project you have :)....& send us pictures of your work

[jbmaridon 0]

Flywise, there is no information in the manual about thrust line. The engine mount that bolts to the engine appears to put the engine at a slight angle with the nose end of the engine down.

The main issue that  i have now is where to mount the ignition control boxes.

I have made changes to the engine mount bolts and rubber discs that at least get the engine mounted. My bolts are 3/8, AN6, as called out in the instructions. At least this will all be out in the open for easy inspection on every flight. As I have said before the manual leaves a lot to be desired.

I have been taking pictures and will make an effort to post some. I think I should start a new subject if I do that. Joe

 

[flywise 169]

Flywise, there is no information in the manual about thrust line. The engine mount that bolts to the engine appears to put the engine at a slight angle with the nose end of the engine down.

The main issue that  i have now is where to mount the ignition control boxes.

I have made changes to the engine mount bolts and rubber discs that at least get the engine mounted. My bolts are 3/8, AN6, as called out in the instructions. At least this will all be out in the open for easy inspection on every flight. As I have said before the manual leaves a lot to be desired.

I have been taking pictures and will make an effort to post some. I think I should start a new subject if I do that. Joe

 

I will take close-up pictures of my ignition module install. Most important is that they don't get too hot from engine or radiators..I also mounted them on rubber vibration mounts .

I am surprised there is no info about the angles the engine has to have. My engine has a 1.5deg to the right as viewed from the rear. My catalina has a tendency to turn left (yaw) proportional with power. It flies perfectly straight without power at the same speeds. I did try a tab on the rudder but that did not help 

[jbmaridon 0]

Flywise, The manual I have also  does not include any weight and balance info, no control travel limits or rigging. Probably a lot more as I go. I tried to attach some pictures but the system says upload failed. Maybe the files are too large and with this new computer I can not find  how to reduce the file size. I could send them by email. My email is jbmaridon@centurylink.net. Looking forward to your ignition module install pictures.