The International Cessna^® 170 Association

can you use copper pipe to make up the primer line??G

I did at the direction of a respected local IA.

I know that copper primer lines have been in use for the last 50 years.
However, be careful, do not use aluminum fittings against copper tubing. Brass or steel fitting and copper are compatable. Copper/aluminum contact will cause electrolisis.

Ralph

For those of you that deal with an IA who is comfortable with replacing stock parts with those that qualify as "equal to or better than", the following information might be of interest. This information does not specifically pertain to primer lines, but primer lines could be replaced in a similiar manner. A possible replacement for the old copper oil pressure lines would be two teflon stainless steel braid covered lines ( P/N 124001RRA-0200-C ). These are -3 lines with special -2 fittings ( 20" long ) which most hose fabricators do not stock. A possible replacement for the main fuel supply to the carb would be an teflon stainless braid hose ( P/N AE3660000G0180) ( 18" long ).

I wonder if those aircraft had a restrictor in the oil line. If you're getting immediate oil pressure indicationcould that be a sign that the expensive( for what it is) restrictor has been replaced with a normal an 45 elbow ?

n4517c,
Good suggestion...can you also provide a source for those part numbers?? Probably showing my ignorance, but don't know where to shop. Thanks, Chuck

P/N 124001RRA-0200-C came from Precision Hose Technology, 2702-D North Sheridan Road Tulsa, OK 74115 800-331-5946

P/N AE3660000G0180 came Herbert Aircraft Service, Inc, 1401 East Franklin Avenue, El Sequndo, Ca 90245-1875 310-322-9575

I've been reading up on the links for older posts on the fuel primer lines but was a bit confused on the part numbers for the fittings from the firewall out to the manifold and from the fuel strainer to the firewall. The only exception listed seems to be the nipple on the strainer - p/n AN816-2D. I know the lines themselves have listed part numbers, but the rest of the fittings are not in the IPC (or I'm just not seeing them).

Can anyone assist in filling in the blanks ? Thanks in advance.

Kyle T.

Kyle, what you need (AN fittings) can be found on the following pages.
http://www.aircraft-spruce.com/menus/ha/an.html


Originally AN817 sleeve-nuts were common but it's cheaper and more modern to use AN818/AN819 combinations.
You will need AN818 "nuts" and AN819 "couplings/sleeves" and perhaps unions in the appropriate sizes.

Keep in mind that most primer lines were made (in 170s at least) out of 1/8" copper tubing which requires double-flares at the ends if you use the AN817 stuff and that can be an expensive tool to buy for such a small job. I recommend you use the AN818/AN819 combinations and ordinary 37-degree flaring tool.

You can use aluminum tubing also, if you prefer.

Hope that helps.

George, many thanks - this helps....

A really effective mod for better starting in severe winter weather is to install a six cylinder "Primer Spider" off of a C-182. Than remove the 1/8" pipe plugs on the intake ports of your O-300 cylinders and replace them with primer orifice fittings, hook 'em up to the spider and be able to prime all six cylinders at one time. Beats hell out of trying to prime three cylinders at a time from the lower end of the left bank intake pipe.

blueldr wrote:A really effective mod for better starting in severe winter weather is to install a six cylinder "Primer Spider" off of a C-182. Than remove the 1/8" pipe plugs on the intake ports of your O-300 cylinders and replace them with primer orifice fittings, hook 'em up to the spider and be able to prime all six cylinders at one time. Beats hell out of trying to prime three cylinders at a time from the lower end of the left bank intake pipe.

Better yet , don't live where there is severe winter weather.....I tried it a couple times and did not like it..