The International Cessna^® 170 Association

What is the correct spark plug gap for Unison plugs in our C-O300 engines? Where would this data normally be found?

What are the various cable tension values for the different size control cables in our planes? Also, is this data readily available? Where?

Finally some questions about fuel lines/hoses. Is the fuel line from the gascolator (fuel strainer in parts catalogue)to the carburetor the only line in out engine compartment that really needs to be firesleeved?

In the 1956 C-170B parts catalogue (ipc), I don't find any reference to the fuel line from the fuel strainer to the carburetor--illustrated or listed on pages 104, 105 & 105A. In my C-172 ipc, there is a reference to a "fuel hose assy" and has two part numbers--S-1167-6-0210 w/ code U and part # S-1167-8-0210 code R. Don't find any explanation of what the difference in the two codes are. I need to get the proper length so I can order a new fuel line and have it firesleeved w/ fittings. There is most likely some minor difference in hose lengths between my C-172 and a '56 C-170B due to the difference in gascolater/fuel strainer locations (mine is more to the right hand side of the firewall). Also wondering if anyone knows a good source in the Dallas/Fort Worth area to have one of these hoses made.

170C wrote:What is the correct spark plug gap for Unison plugs in our C-O300 engines? Where would this data normally be found?

What are the various cable tension values for the different size control cables in our planes? Also, is this data readily available? Where?

Finally some questions about fuel lines/hoses. Is the fuel line from the gascolator (fuel strainer in parts catalogue)to the carburetor the only line in out engine compartment that really needs to be firesleeved?

In the 1956 C-170B parts catalogue (ipc), I don't find any reference to the fuel line from the fuel strainer to the carburetor--illustrated or listed on pages 104, 105 & 105A. In my C-172 ipc, there is a reference to a "fuel hose assy" and has two part numbers--S-1167-6-0210 w/ code U and part # S-1167-8-0210 code R. Don't find any explanation of what the difference in the two codes are. I need to get the proper length so I can order a new fuel line and have it firesleeved w/ fittings. There is most likely some minor difference in hose lengths between my C-172 and a '56 C-170B due to the difference in gascolater/fuel strainer locations (mine is more to the right hand side of the firewall). Also wondering if anyone knows a good source in the Dallas/Fort Worth area to have one of these hoses made.

The spark plug gap should be set to .016. The fuel line mentioned is probably the only one you need to firesleeve, although really picky folks might firesleeve the oil pressure hose (presuming you''ve replaced the copper tube with hose as previously discussed.) Firesleeving was not originally required on this airplane, but it's certainly a great idea to use modern methods/materials.

The "applicability codes" are defined in the Foreward of your Parts Catalog, and they will further refine which part number applies to which airplane serial number. Another method is to measure you present fuel line and give that length to the maker of your new hose. Length is measured from face-to-face of the two end fittings.

Parker Hannifin is located in Ft Worth. They are OEM for aircraft hose.

220 Robert Cut-Off Rd.
Fort Worth, TX,
76114
Phone: 817-738-6543
Fax: 817-738-9920
Website: http://www.stratoflex.com

Of course, you also know about Tex-Air Parts. 800-458-1535 located almost across the street from KFTW (that's Fort Worth Meacham for bluEldr).

Cable tensions are listed in the Owner's Manual for your early airplane. Here's the basics:
Aileron cables: 30 lbs.
Elevator cables: 30 lbs.
Rudder cables: spring tension (20 lbs is common)
Flaps: (170/170A) remove all slack. 170B:20-40 lbs.