Removing the cowl from O-300-D with Spinner

trake · Post by **trake** » Wed Oct 11, 2006 1:00 am

Richard,
Youre lucky to have the O300D, most of us have to 'pull the starter'. Do you have a vacuum pump? If yes was the nose bowl and baffling changed?

hilltop170 · Post by **hilltop170** » Wed Oct 11, 2006 3:16 am

Tracy- It has a vacuum pump, the original nosebowl has not been modified, and the original air box style baffling that has not been modified. Airframes, Inc in Big Lake, Alaska made a completely new set of original baffles for it using some of my parts for patterns. They now have everything on CAD so reproduction of a complete set is easy.
Richard

Dward · Post by **Dward** » Wed Oct 11, 2006 2:27 pm

Hey Hilltop, I have a question for you , if you don"t mind. Do you have the bullit spinner on your O300D? I just finished my conversion to the "D" on my 52 B model. I switched to the bullit spinner because the old skull cap won't fit the EM prop hub (and I like the looks) but now I can"t reach the front cowl screws behind the rear spinner bulkhead. I was just wondering if you had run into this. Right now I have to pull the prop to remove the cowling.

doug8082a · Post by **doug8082a** » Wed Oct 11, 2006 4:12 pm

That's a common problem when switching to the bullet-style spinner for the early cowl models. I had the same issue on my '52. I used to use a rachet wrench with a screwdriver bit to get to it. that combination provided just enough clearance under the spinner bulkhead.

jon s blocker · Post by **jon s blocker** » Wed Oct 11, 2006 5:58 pm

Dward, Sears carries screw drivers that are made at 90 Degree angles at the end that should fit between the prop and the cowl. They are 90 degrees on each end and the "blades (or cross blades of a phillips)", are 90 degrees out from each other so the driver shaft is started out at different angles. Hope that makes sense. You can also just heat and bend a long screwdriver 90 degrees at the end. Jon

swanstedt · Post by **swanstedt** » Wed Oct 11, 2006 6:09 pm

For getting at the screws behind the bullet spinner on my 170A I have to pull the bullet and there are several holes drilled into its mounting plate. These holes are spaced such that they line up with the screws in the cowl when the prop is rotated. It takes a magnet and a few tries to get the screws started but it sure beats trying to do it with an angled screwdriver.

Don't know if these holes are original or not but they work.

Scott

trake · Post by **trake** » Wed Oct 11, 2006 10:44 pm

Sorry for hijacking the C195 thread
I thought the O300D conversion required cooling changes, but I could be thinking of the belt-driven vacuum pump STC

hilltop170 · Post by **hilltop170** » Wed Oct 11, 2006 10:56 pm

Dave- Boy, that one question sure brought out some responses! To get at the screws behind the bullet spinner I cut off about 1/2" from the tip of a phillips screwdriver and silver-soldered it back on at a 90Â° angle. It is a little slow but works great. I found the pre-bent screwdrivers at Sears and other pre-made 90Â° screwdrivers to be too long to get behind the spinner. That was years ago and there may be some better choices out there now. Good luck,
Richard

Robert Eilers · Post by **Robert Eilers** » Wed Oct 11, 2006 11:55 pm

There was someone at the Kelowna Fly-in that replaced the Phillips heads behind the spinner with Hexheads and eliminated the screw driver problem. I have done the same to mine - works great.

spiro · Post by **spiro** » Thu Oct 12, 2006 1:18 am

Craftsman Offset Ratchet Screwdriver. Grind the flat-head side off flush. Then it's real thin and gives you a place for your index finger. Only have to find and engage the screw once. I don't think the ones with interchangable bits would fit as easily.

http://www.sears.com/sr/javasr/product. ... 0904116000

doug8082a · Post by **doug8082a** » Thu Oct 12, 2006 2:07 am

That's the one!

johneeb · Post by **johneeb** » Thu Oct 12, 2006 2:26 am

While installing the engine modification in my airplane I faced a similar problem. My solution was to reverse the nut plate locations, that is I mounted them on the outer cowling skin and I work the fastners from the inside out through the cooling air inlets. The nut plates do not show as they are behind the spinner (in my case it is one of those "Church Bell Sized Spinners".

n3833v · Post by **n3833v** » Thu Oct 12, 2006 11:10 am

I fabricated a special 90 degree screwdriver and when pulling the cowling, I put duct tape where the cowl will hit the spinner to protect the paint.

John

Dward · Post by **Dward** » Thu Oct 12, 2006 7:12 pm

Man! You guys are good! Thanks for all the help and I also appologize for hijacking the thread. I have the regular craftsman 90deg driver but it's too long. My clearance was tight enough that I had to leave the thin washer off the back of the prop flange, with permission (sort of), in order to use a short enough bolt to clear the cowling.

You all have given me the energy to try your ideas until I find one that works for me. That cowling mod idea is interesting

but I will probably go with one of the modified tools. I used to be a machinist.

Sorry Tracy for jumping in front of you, I'm just like that kid in school who could never keep his mouth shut.

blueldr · Post by **blueldr** » Sun Oct 15, 2006 7:14 am

There are four screws involved in the early model cowlings that are all but inaccessable behind the backing plate of a bullet spinner. The solution I used on my '52 model was to carefully drill two holes in the backing plate to just provide clearance for the shank of a #2 Phillips screwdriver. Each hole is very carefully alligned with either the inner or outer screw and the prop is rotated to allign the holes with either side. Of course, the spinner has to be removed first, but thats only an extra dozen machine screws.

The International Cessna 170 Association

Removing the cowl from O-300-D with Spinner

cowl screw problem