I have a 351W in my 1972 F-100 that has an issue. I'm not exactly sure what year the engine is. I bought the truck from a family of a deceased gentleman who owned it, and they didn't know too many details to share with me. I assumed that the engine was relatively close to the same year as the truck, but I found out that the spark plugs were the smaller diameter size. I've had this truck for a little over a year, and it has never offered to give any trouble.

Now for the problem. One morning recently, I tried to start it, and the engine would not turn. It was trying, but something was keeping the engine from turning. I have been nursing a leaking power steering system, so I immediately suspected that the pump had locked up and was binding the engine. My wife was leaving for work at about that same time, so I didn't even raise the hood, I just rode with her. That same evening, I raised the hood and tried starting it again. It fired up and ran, so I checked out a few things and couldn't really find anything. So I hoped that it was OK. I cranked it and drove it to work the next morning. It ran a little rough at first, but smoothed out after just a minute or two, and seemed to be OK. After a 10-mile trip down the Interstate highway, when i got off at my exit, I noticed it was puffing some smoke out the right-side exhaust. The smoke was white-ish, and did not smell like oil to me. I thought I smelled a little antifreeze, but afterward, I wasn't 100% sure. I let the truck set until today and I tried to crank it again. It repeated the same deal of not wanting to turn over when I turned the key. I rocked the truck back and forth a little and tried again, and it started and ran, still puffing a little white smoke out the right-side exhaust. I really didn't smell any antifreeze this time but I can detect a slight missing sound, both under the hood, and at the exhaust pipe, on that side. I'm looking at pulling that head off and replacing the gasket, but I want to get some thoughts an ideas from some folks who might know a little bit more than I do. What say ye?

(Sorry for the long post!! )

 

Yeah kind of sounds like it. Coolant, or "antifreeze", is going to produce acrid, white smoke. Not necessarily from a head gasket, but that's a good bet.

 

OK, so is it feasible for me to replace just the one head gasket? I had visions of rebuilding this engine one day, maybe even with some Cleveland heads eventually, but I wasn't necessarily wanting to have to do all that right now.

 

Do yourself a favor and replace the pair. Also, check the heads for burnt valves, etc. Cheap insurance in the long run. The reason the motor would not crank is that the coolant does not compress and locked the motor. When you got back hours later, the coolant had leaked into the oil pan and now it had no 'obstruction.' Does you oil look like chocolate milk?
Check your plugs for a clean one - or two. This is where the leak is. Next time yank the plug(s) on that (those) cylinders and see if you don't have a geyser coming from the spark plug hole.

 

No, actually the oil looks like it should. I meant to mention that in my original post.

I should have a chance to tear into it Monday evening. We'll see what we can find. THANKS for the input!!

 

Welp, I decided to take the plugs out to take a look at them. #1 looked ok. When I took out #2, water came out with it. So, I just slowly turned around and went after the tool box....

 

OK, time for an update. I decided to take the plunge and yank the motor out of the truck so I can get to everything better, and I'm going to clean up the engine bay and fix a few other issues while I'm at it. Currently I have the entire front end taken off the truck and I am six or eight bolts away from having the engine cut loose from the truck.

This promises to be an adventure and I'm sure have some questions along the way....

 

First question. I discovered this aluminum bracket/spacer between the alternator and the front of the head was broken. What's it for and can I easily replace it?

 

Wondering if that isn't likely a "junkyard only" part at this point, though maybe ND can scare up a diagram and find a part # and at least do a search from the usual suspects.

 

I actually found a few for sale online. $20 and up....

 

That's an accessory spacer used to compensate for the deck height differences between the 302 and 351W so that Ford could use the same brackets on both engines. I've seen at least 4 different versions (aluminum or iron and driver's or passenger side head)

 

Update #2....I've got the engine out of the truck and it's ready to go onto the stand. My intention is to try and re-do the top end, and leave the bottom end, if possible. A small amount of water came out when I drained the oil. If I get the heads off and there's more trouble, I may start leaning toward finding another motor and going that route. We shall see what happens....

 

I got the right side head off this morning. It's pretty obvious where the gasket issue is. But, I also have another problem. Looks like I have a crack at the exhaust valve seat in that same cylinder. Here are some pictures:












So now I really am looking for another engine, or at least some different heads. Gotta get the rest of the engine torn apart before I make that final decision.

 

Those are E7TE heads, they're a dime a dozen in the J'yards. If you need a single head I'll ship you a "good-un" if you pay the freight.

 

Thanks for the offer, bad dad!! Got some sources here in NC that I am going to check out first, though.