Sadly, I may not be able to post here anymore...

[occupant]

The 351M is OUT of my car and sitting on a shop floor. The 351CJ is set in place and should be hooked up and running tomorrow.

No longer will you people get to hear about me and my freight train tendencies. I will no longer make references to "miles per gallon of oil" or "go ahead and run your wipers, tailgater, smear it, smear it good", or the ever-popular "it's not worth changing my oil because I burn so much". I will not be adding several quarts of oil per week. I will not be wondering how many MMO soaks it might take to make it stop. And I will certainly not refrain from driving my car due to ozone alerts anymore.

Just wanted to say that and ask a mechanical/maintenance question. This is a 1972 model engine, and it has 2V heads date coded to 1974. This was the last year before catalytic converters, and might not have hardened valve seats. I will not be racing, towing, or driving in mountains. Worry about this or ignore it? Should I use a lead substitute, MMO, or something else? Or should I just not add anything?

 

[Chris142]

Ya those heads probly have pretty soft seats. Some 351C/M heads won't take a replacement hard seat W/O hitting water. If it comes to needing the valves ground someday your machinest will know if he can do em up or not.

 

[rshunter]

ROFL!

 

[mechanicx]

I don't know about those specific cylinder heads and engine but generally most '72 and newer had lower compression and induction heat treatment harden exhaust seats to be compatible with unleaded fuel. I would bet a '74 cylinder head would be low compression, harden exhaust seats.

 

[Herz]

I got a good laugh out of this.

 

[addyguy]

You don't think you'll have 'issues' with a 38-year old V-8???

Especially oil-burining issues???

Are you nuts?

 

[Kestas]

My 71 Cutlass came with hardened valve seats from the factory. The owners manual states that it can burn unleaded gasoline.

If you need verification, I suggest going to a Ford-specific web site and ask guys who may be more intimately acquainted with these engines.

 

[flanso]

Originally Posted By: mechanicx
I don't know about those specific cylinder heads and engine but generally most '72 and newer had lower compression and induction heat treatment harden exhaust seats to be compatible with unleaded fuel. I would bet a '74 cylinder head would be low compression, harden exhaust seats.


+1

 

[Chris142]

Originally Posted By: mechanicx
I don't know about those specific cylinder heads and engine but generally most '72 and newer had lower compression and induction heat treatment harden exhaust seats to be compatible with unleaded fuel. I would bet a '74 cylinder head would be low compression, harden exhaust seats.
But the hardning is very thin. Once a machine shop recuts the seats the hardning may be gone.

 

[TooManyWheels]

I faced this problem about twenty years ago. As I recall, the recommendations I read about and received from machine shops said that the solution was stainless exhaust valves, rather than hardened seat inserts.

 

[Shannow]

Oz transitioned to Unleaded in 1987.

The solution was hardened inserts, removal of valve rotators, and some fuel additives carrying sodium(?).

There's still a fair few from pre that era out there running OK. And plenty that recessed the exhaust valves into the head until they stopped starting.

Occupant...you meant that there's another half a dozen hours cut out of your year doing oil changes moving into the future ?

 

[Merkava_4]

Isn't the 351C already rebuilt with the hardened valve seats already installed?

 

[Kestas]

Originally Posted By: Chris142
But the hardning is very thin. Once a machine shop recuts the seats the hardning may be gone.

It's not that thin.

 

[Thermo1223]

Post the rebuild on Automay!!!

I still have the "Mirage story" in the back of my mind when I see your name.

 

[occupant]

Originally Posted By: addyguy
You don't think you'll have 'issues' with a 38-year old V-8???

Especially oil-burining issues???

Are you nuts?


Issues on a 10K mile rebuild? Nope. I do not think I will have issues. I do not expect it to burn or leak oil nearly as significantly as the 351M did. I do not consider a car to "burn" oil unless I can see or smell the smoke or until it gets to a point where I have to add oil more often than every 500-600 miles (2 tanks of fuel).

Am I nuts? Yes.

Originally Posted By: Thermo1223
Post the rebuild on Automay!!!

I still have the "Mirage story" in the back of my mind when I see your name.


I have finally confirmed through stealth detective work, that the car I assumed hit my car, did not. She had dropped it off at a shop in Hillsboro and I checked it out one Sunday afternoon while it sat outside and no one was looking. The damage as seen from 20 feet is consistent with hitting my car. The damage as seen from 2 feet is not even close to what it would look like had she hit the left rear of my car with the right front of hers. Her damage goes all the way across. It has damage too low, too.

I should be able to pick it up Friday. I'll have to get out on the road with it this weekend and take some video or something. The passenger manifold from the 351M wouldn't fit, starter was in the way. So it has the truck manifold on it and it doesn't quite seal against the pipe right.

I do not know the specifics of the rebuild. It could be a line of [censored]. But it's DEFINITELY got an RV cam in it, burbles so nice.