The International Cessna^® 170 Association

I've got a 170A with the original rounded hub spinner. I'm looking for an upgrade to help with aero and cooling. Anybody out there know where I can get a used pointy one that will fit the 8 hole Cont 145hp? I would need the backing plate also.

I've got the prop off right now during an annual and I'm having it re-pitched from 76-50 to 76-48. Anybody know if that's a typical pitch for a 170A for better climb performance? At 500ft MSL, my static runup RPM has only been 2250-2275. I'm hoping for something closer to 2300.

Bob

How "pointy" are we talking here? Later model C-172 kind of "pointy" or the "bullet" style from the C-170/early 172 days? The Bullet ones are available from Spruce/Univair.

Thanks for the reply Doug. I'm looking for the "bullet" type, preferably a used one. I guess "pointy" would not be the best discripton.

Bob

The spinner is not likely your cooling problem. The probable cause is 1-indicator error, 2-cooling baffle condition/leaks.
With the current prop, a static rpm that low indicates an erroneous/inaccurate tachometer at that rpm. The "standard" climb prop was a 7651.

gahorn wrote:The spinner is not likely your cooling problem. The probable cause is 1-indicator error, 2-cooling baffle condition/leaks.
With the current prop, a static rpm that low indicates an erroneous/inaccurate tachometer at that rpm. The "standard" climb prop was a 7651.

and Float prop was 76/49

I just bought a 6 bolt unit for my O300D from Al the spinner man at Desert Aircraft. I think he had an ad in TAP. I don't know if I can talk about prices here but it was way cheaper than the other place mentioned and still had the Cessna stickers inside. Also he is nice to deal with.

Sure. Tell us the price.

One of the members with a "bullet" spinner contacted me and I'm going to get it from him. Thanks everyone for the terrific responses.

Bob -- N1320D

Thanks George. Al the spinner man sold me a complete unit, dome and both bulkheads, for $125.00. Univar wanted $200 and $300 respectively for the bulkheads and $350 for the dome. It should be noted that the Univar parts were new and the dome was aluminum.

Desert Aircraft was very pleasent to deal with and Al took a lot of time trying to help me.

Bob, I'm glad you found what you were looking for.

I've dealt with Al and he's another classic, good guy.

Does someone have a phone number or e-mail or website for "Al the Spinnerman"?

TIA

Rich

ksaccounts wrote:I've got a 170A with the original rounded hub spinner. I'm looking for an upgrade to help with aero and cooling. ...
Bob

Sorry to be so late in noticing Bob's stated purpose in "upgrade" to a "pointy" spinner...

I wouldn't consider a spinner from a later airplane (different model) to be an "upgrade." It's simply a part from a different model aircraft, and would therefore need a basis of approval for installation on a 170. The 170 was test-flown and it's engine was approved with the cooling airflow developed by the original bullet-spinner. While the later 172 may have used a different spinner, it also used a different cowl and different engine baffling system. Therefore the use of a later spinner on an engine utilizing the original cowl/baffles would not likely have been tested for cooling airflow.
Some engine/cowl/baffle combinations are very sensitive to specific spinners and changing that item (or any item in the group) might adversely effect engine cooling, and would require a basis of approval to be considered legal.

(Having posted that msg, ... I'd like to express a personal opinion that I doubt Cessna changed to the pointy spinner for "aero and cooling" anyway. I imagine they did it as a cost-saving move (the pointy spinner is easier/cheaper to make.) The use of a spinner frequently improves engine cooling when compared to non-spinner-equipped aircraft because it calms the "storm" of turbulent air near the prop-hub and directs the relative wind outward toward the cylinder cooling fins. So-called "skull-caps" are likely merely cosmetic in that regard.)

Tap has his ad under the FREE section (sorry my Scotish came out of me for a second) as 800-537-7494 or also listed 506-746-2477

I am showing my ignorance: what is "Tap"?

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