Author Topic: Flooding 251 engine  (Read 569 times)

Offline the old trucker

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Flooding 251 engine
« on: March 22, 2013, 03:34:33 pm »

  My friend Mike,(57 rebuild) has a 1957 C18 Bombardier that is close to ready to plow through some snow. He had the original engine out to clean up, install new seals & gaskets & make her purddy looking. He put in a new carb kit & new electric fuel pump that puts out 5-8 PSI. It starts first click of the key & sounds good but when he gives it a shot of gas she will give out a noticeable puff of black smoke. His question is this; Is it ok to run the electric pump or should he go back to the original manual pump or would it be carb problems ?

OT.
after covering a few acres of prime real estate.

Offline Walrus

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Re: Flooding 251 engine
« Reply #1 on: March 23, 2013, 02:45:44 pm »

  My friend Mike,(57 rebuild) has a 1957 C18 Bombardier that is close to ready to plow through some snow. He had the original engine out to clean up, install new seals & gaskets & make her purddy looking. He put in a new carb kit & new electric fuel pump that puts out 5-8 PSI. It starts first click of the key & sounds good but when he gives it a shot of gas she will give out a noticeable puff of black smoke. His question is this; Is it ok to run the electric pump or should he go back to the original manual pump or would it be carb problems ?

OT.

Electric fuel pump should be fine at that pressure, float in carb may not be set right. Does it bog down when he gives it the gas? One thing to remember this isn't a new car with precise metering of the gas, carbs dump fuel in there and hope it burns  ;D

Offline Cranman

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Re: Flooding 251 engine
« Reply #2 on: March 24, 2013, 11:14:06 am »
I'm assuming a new needle and seat went in with the carb rebuild. I agree the float may be set a bit high too. I run my flow through 12v bendix  fuel pump at the fuel tank on the way to the mechanical pump. The electric is switched and is on for a few seconds at start up and the stock fuel pump usually handles the needs except for a few times each year in hot weather I have to turn it on when enough heat builds at the pump to cause vacumn lock. I have a fitting tie wrapped to the line at the carb to allow me to run on the electric alone should I have diaphram failure in the mechanical. That would be rare but could happen..

Offline Averyman

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Re: Flooding 251 engine
« Reply #3 on: March 24, 2013, 11:36:59 am »
The automatic choke on these engines seems a little slow in coming off choke (at least on mine) so it runs pretty rich until warmed up. There is an accelerator pump in the carb that gives it a shot of fuel when you tramp it hard, the linkage to it can be adjusted I believe by bending the rod that activates the plunger to reduce the amount of fuel delivered on each stroke.