77 351M in a F100.


Bluf: oil pump shaft question at the bottom

So the saga begins with no ability to get consistent performance....

So this my toy. No way shape a mechanic, but i don't mind putting in the work. I could never get this engine to consistantly perform. Get it into good spot (carb adjustments) where I can come out every morning and it would fire like a new truck and then few days later it would be all over the place.
I have replaced carbs, spark plugs, cables, ​​​​ignition boxes, ect and just can never get it to stay right.

My father has always had issues with the ignition boxes so to him that was the problem. I wasnt convinced, because I had spark, fire, good volts with a voltmeter and no extra resistance (ohms) anywhere.

BUT I could NEVER adjust the distributor. It was STUCK IN PLACE.

I decided I wanted to get it out and with help from my father we tapped it out little by little without too much issue and nothing broken. Back and forth back and forth.

Now the issue

I decided (to appease my father's voice in my head), to go to an HEI style distributor. Measurements for length are all the same on the shaft, but now it will not drive the oil pump. I can prime with a socket and drill.

Is it possible the oil pump shaft 'fell' further into the oil pump. Any tricks to pulling out the top or do i have to drop the oil pan? Thoughts....i know the engine is old and worn out. I just want to drive in town. I don't need interstate, long distance or even good gas milage, I just want consistent.

Thanks for your input
Dan

 

Take a picture down the distributor hole and post it
If the oil pump drive came up with the distributor, and then fell down into the engine, you can sometimes fish them out with a strong magnet (happens)
You may need to rotate the crankshaft while pushing down on the distributor to engage the oil pump drive if it is there in the hole in place
The picture will tell us
The drive should be sitting level with the hole where the end of the distributor shaft sits
Post a pic
Good luck

 

If you can drive the oil pump with a socket and drill, there isn't anything wrong with the drive rod. They cannot go to deep into the pump. I assume the distributor was seated all the way into the block. Double check and make sure you have the correct distributor. The distributor for a 351M also fits 351C,400, 429, 460 and some other medium duty truck engines that used the 385 block
Make certain your new distributor is not for a 351W because the drive gear on the distributor is too small and will damage something.

 

Why HEI?

The stock distributor drive rod had a snap on or friction type retainer to prevent it being pulled up out of the oil pump. My distributor once seized, time and patience got it out, then I dressed the part that goes in the block. Once timing is set, unless something breaks (timing chain, etc), there's not a lot of need to be changing it like was back in the days of points with rubbing blocks wearing on a distributor cam.

I see a lot of '77s on here.

 

I have had my oil pump drive come up and out, then fall back down into the motor sideways down into the oil pan area
Bitchy to say the least, fishing it out of there with a good flexible snap-on magnet
Took about half a day
Good luck
A picture helps
Grease is your friend to help hold it into a socket for re installation

 

So in an effort to confirm a problem with the HEI distributor (the previous). I caught an original ford distributor. I'm still not getting the oil pump to read.

I can still use the drill and make 60lbs on my after market gage. But when I drop in the distributor, bump the motor to seat it fully, its not reading anything or just barely.

I'm being overly cautious. O truly do want to but a big bullet in it and buy a reman engine, just don't have the money right now. I just want to be able to move it around so the wife isn't on my back lol.

Thoughts? Thank you all for the help...

Signed
Frustrated...

 

What are you turning with a drill to get 60 psi?

Is the distributor from mounting surface to oil pump shaft socket end the same as stock, like "not shorter"?

Is the "hex" in the distributor gear a clear 5/16 hex?

By any chance, is the pin that locks the distributor gear to the distributor shaft sheared off letting the gear slip on the shaft?


My thought being .... the distributor is too short or the gear is not fully engaging the oil pump shaft.

 

It should be pretty easy to figure out with a tape measure and a piece of welding rod
I have never experienced what you are experiencing
They only make one length of shaft
You are not running two sets of intake gaskets, right?
So, your intake is sitting flat on the block?
You have to run that motor to build oil pressure
You are not going to build pressure cranking it over, it needs to be running
Alot of talk, but no pictures
We all know what the shaft looks like, installed in a 302 or 351 (well, all of us mechanics anyway)
It sits in the hole just shy of level, so you can get the shaft started in the hole, and then engage the drive as it drops down
That is what holds the distreibutor up a quarter of an inch when you drop one in, and you need to rotate the crank to get the distributor to drop in place

 

Are you absolutely ceertain you have the dizzy in all the way? It can be tricky to get the pump shaft to seat in the dizzy shaft.

 

Yeah, it's in all the way. I know sometimes you have to 'bump' it to seat it.

Someone mentioned cranking the engine to build oil pressure. Im just nervous...but I'll give it a shot. I petrified ill tear it up.

And then my temporary lawn ornament becomes a more permanent lawn kern ornament lol.

Thanks all

 

Run the engine to verify oil the pressure
Do not be terrified
Be confident in your work

 

IAre you running the engine to look for oil pressure? If you have the wrong dizzy or it's not seated you will do damage.