The International Cessna^® 170 Association

We just purchased a 0-300B that is going to go on our 170B project. The engine came off of a 170. The engine has a external fuel pump at the front R/H side (aft looking FWD). Why would there be a mechanical fuel pump on a carburated engine?

Normally the gravity fed engine such as the 170 would not have a mechanical fuel pump. Low wing planes would. The TC allows for an automotive type pump.

'48 170s are required to have a full pump. Probably because of the way the fuel lines are routed.

A and B model 170 fuel lines routes where changed and the pump was dropped. You don't need it on your B model project and might depending on it's condition be able to sell it to someone with a '48 who does.

I believe that fuel line size also had something to do with the fuel pump requirement on the C-170. I've been told that they increased the size of the fuel lines on the C-170A and subsequent airplanes.

Those automotive style aircraft fuel pumps are VERY pricey in comparison to their cousins on automobiles and homebuilt airplanes.

Insufficient head-pressure exists in the straight C-170 due to fuel line size and routing under certain flight conditions and fuel tank levels. For that reason a fuel pump is REQUIRED equipment on that installation. (Cessna borrowed certain components from the C-140 for the C-170 and they are inadequate for the larger engine's fuel flows. It was addressed in later 170 A/B models with larger tanks/lines/routing.)
Installing this engine on a C-170A or B would not be a problem, simply obtain the correct "blanking cover" for the engine and delete the pump.

If I read the post correctly it stated an O-300B engine with a fuel pump had been purchased to go into a 170-B. Is this correct? If so, it is the first "B" O300 I have heard of with a fuel pump. All I have seen didn't have provisions for a fuel pump on the right hand side of the case. Am I remembering this correctly--only earlier O300's had the fuel pump pad?? Maybe I am confused (that kind of goes without saying ) but I just can't picture the fuel pump pad on my "B" engine. Maybe its because I have been spending all my time at the rear of the engine these past few months

All of the C=145/O-300 engines I'm familiar with have had blanking pads on the fuel pump drive pad. They require a fuel pump on low wing installations too.

170C wrote:If I read the post correctly it stated an O-300B engine with a fuel pump had been purchased to go into a 170-B. Is this correct? If so, it is the first "B" O300 I have heard of with a fuel pump. All I have seen didn't have provisions for a fuel pump on the right hand side of the case. Am I remembering this correctly--only earlier O300's had the fuel pump pad?? Maybe I am confused (that kind of goes without saying ) but I just can't picture the fuel pump pad on my "B" engine. Maybe its because I have been spending all my time at the rear of the engine these past few months

Look on the right side, close to to breather tube it will be where the cam is internally to the engine. It will kinda look like a diamond with I beleive two nuts holding it on. Even though I don't know what airplanes the 0-300 goes on except for the 170/172 I'm sure there are others that may have been low wings. (or 170's that requried a fuel pump)

A large number of stock Swifts are flying with C-145/O-300's and they use the mechanical fuel pump. The GC-1B's were originally produced with the C-125, which also uses this same pump, but almost all have been converted to either the C-145/O-300 or the IO-360 Cont. An old mechanic once told me that a C-145 was a "stroked" 125. A spare fuel pump is a prized possession for those guys with the 145s.

I have the O 300c installed on my 48, the the fuel pump was installed to meet the tc for the 48 fuel feed requirements.

you can see it in this picture: