I posted in the guest section with a request to see if people had any older model cowls available which are supposed to fit the bigger O-470 engine. I did not get any responses and ran into some threads mentioning that has lead me to believe I'll need both halves of an older cowl to get it to work. I haven't found much in my search on the internet so I'm going to see if we can modify the cowl.

We have 1961 Skylark that previously had the GO-300 and we are currently putting in the 0-470-J. The cowl on the 1961 has
the hump in the nose and I want to see what has been done to modifying the cowl. I've read on a few threads dicussing modifying cowls but not sure how to best accomplish it. I don't know much about aircraft body work but my guess is that this is done by cutting out a section near the bulging spark plugs and add essentially a bubbling piece of aluminum and pop rivet the new piece in. Alternatively use an english wheel to bend the aluminum and flatten the now unnecessary hump where the gear was needed and bend a bubble for the plugs are but I'm concerned about the weakening of the cowl with this method. Does anyone have information on this or can tell me if any of these ideas are out there? We haven't yet discussed this with our A&P since he is still putting the motor together but this will be on our plate sooner than later.

Thanks.

I used to own a 1961 Cessna 175 (N8002T) that has an O-470-S and McCauley constant speed propeller installed. If you like, you should reply to me directly using my e-mail address listed below, and I will send you some photos of the aircraft, as well as the current owner's contact information. You can also order the FAA documents on CD and look at the 337 that is on file for the aircraft that shows the cowling alterations. It's really not that big of a deal to take the hump out of the top cowling, and it can be made to look really good with not a whole lot of effort.

Stan Bearup
American Falls, Idaho
bearup@ida.net

I have mine replaced by 58-59 cowls to accomodate the larger engine IO-360 i will post the picture on my gallery to see the difference since mine were 1960 cowls

HERE IS THE DIFFERENCE

Thanks for the information. I'll see how far we'll get with the modifications and go from there.