Rebuilding the heads on a '93 351

[KJEfting]

Well guys, I'm going tackle the task of rebuilding my heads next weekend. I'm starting to get some oil passing through the crankcase ventilator and up into the airbox and I hear some valve rap in there, so I think it might finally be time for an overhaul. Thankfully I've got good compression and I don't use any oil, so I figure I'm good to go from the rings down. This will be the biggest job I've done on a vehicle yet. I've got a Haynes manual, but I haven't looked into the topic too much yet. I've also got a full shop and all the necessary special tools at my disposal. Unfortunately, I don't have a back-up vehicle right now, so I'll have to try and knock this out over the weekend. Just a few questions I hope to get answers for first.

What parts should I expect to replace and which should I re-use?

Should I count on getting the head milled?

Any reccomendations on which brand name parts I should use?

Any good tips you guys would like to share to help make this easier would be appreciated. Thanks a ton!

-Ken

 

[Seabronc]

It's a little late now, but maybe you should put it off a week and go to a local book store and get a book on rebuilding small block Fords. There are a lot of good suggestions in them.

Don't panic when you take the valve cover off, if you find tons of crud, it has a tendency to collect there /emoticons/[email protected] 2x" width="20" height="20" /> .

Depending on what parts you are going to reuse, but be sure to keep things that you are reusing in order and know who's who in the zoo. When removing parts that are to be reused, keep them in order so you can put them back in the same location they came out of. Make a space on a bench and lay them out in the same order that they come out of the head. If you are not replacing the valves, no need to do that if they are in good shape, then do the springs, lifters, seals, and stem caps. Use a prelube on the parts so you don't have a dry start when it is re installed. I'm sure you are aware of by buying the parts, but just in case, note that the springs for the exhaust and intake valves are different. There is no lifter adjustment other than tightening the nuts to the proper torque. Clean out all threads in the bolt holes and use new bolts to reassemble it or at least clean all bolt threads. Be sure to torque according to the book numbers and pattern and recheck the torque on all bolts before starting it . Recheck the torque after you have run it for a while.

You can replace the upper components without removing the heads since the compression is good which means the rings and valves are good. The advantage to this is that the heads don't need to be removed along with the associated replacement procedure and it does not require removing all the push rods at once, just one at a time for cleaning, again do one at a time and put it back where it came from. This method requires a compressor with a fitting on the end to ***** into the spark plug, with 80 to 100 lbs of pressure to hold the valve in place while changing the upper components on the stem. Simply remove all spark plugs bring the cylinder that is being worked on to TDC to prevent the accidental dropping of a valve into the cylinder in case the seal of the valve to head is accidentally lost. If the cylinder is not at TDC the valve would drop too far to recover without removing the head. If the cylinder is at TDC you can just pull it back into position. This method requires using a spring compressor that simply grabs the spring and compresses it, available at most parts stores. The whole job takes about 4 to 6 hours.

Check the book this is not an exhaustive commentary Just what comes off the top of my head at the moment.

Good luck,

>-

 

[KJEfting]

Thanks for the info. Great post! I will try to track down a book. I have seen them online; maybe I can hunt one down at a bookstore in the local area here.

Also, I suspect I have a failing head gasket, so I am going to go ahead and pull the heads. I apologize for not mentioning that in the first post.

 

[Bully Bob]

Another thought is;

Ogden should have a "good" head shop....& they may just have your heads there ready to go..! (re-built swap)

-OR-

He may be able to schedule you for quick turnaround.

-reason-

They re-build to spec.

Local library will have your books as well...