Started to pull the motor on my 81 f250. Its a 351m with 4 speed 4wd. I have everything disconnected and ready to pull. I have my picker hooked up and when i start to lift the tranny wants to come with. Its starting to separate but wont give. Am i missing something? Is the clutch still locked in or what how do i go about getting this motor out !!

 

You have something to support the trany?
Recheck you have ALL the motor to trany bolts out.
IIRC there are 2 or 3 small bolts in the lower motor plate to trany that have to be removed.


If you jack up the trany a little and the motor so the motor mount bolts clear you should be able to pull the motor forward and shake the motor from the trany.
Dave ----

 

Yes i have everything off i triple checked haha !
but ill give that tranny a lift and hopefully that works!

 

Sometimes they can be a pain, hey they have not been apart in how long?
as said shake up down and side to side and it will break free.
Get mad at it!
Dave ----

 

You have to support the tranny as high as it will go, till it hits the firewall. Then that will let you lift the engine up just enough to clear the motor mounts, and slide it forward.

 

Aha okay ill keep yall updated. I was pretty happy with myself i got as far as i did without help. This is the first v8 ive done

 

So a little update, I have the motor pulled thanks to all of you !! So thanks for that.
Now im at the tear down stage. My questions now are about the "essential" parts which in my mind are Heads, block and crank. With the block I was just gonna do a super good clean, hone it myself the a ball type hone. is that good enough? Then with the crank is it really worth getting balanced? A buddy of mine had said just getting a better harmonic balancer should be good. And last the heads... Ive looked into the machine shop, and what ive thought about doing is hot tank cleaning, valve job, milling and porting. Now ive heard both sides of porting, its good or bad for the cost. Now I was thinking about milling to increase compression. So opinions pleaseeeee

 

Good to hear you got it pulled out.


Now for the rebuild part.
First I have to ask why do you need to or want to rebuild it? What will the motor be used for?


What you posted on the block of quick hone and wash may or may not work.
What ridge lip do you have at the top? What is the taper of the cly? Any scuff marks in the cly?
If the lip is too much you will break rings when pulling pistons if you could even get them out. With out tools to measure the cly you will not know if the taper or bore is with in spec.


Same kind of goes for the crank but I have used dial caliper to get a size to order bearings on a junk yard rebuild, kind of what you want with the block, it did not have a ridge lip.


Now you want to go cheap on the block but spend $$ on the heads? That does not make sense to me.
You can pull the motor apart take the block, crank & heads to the machine shop and have them hot tank them and measure them.
With that information you will know if just a hone job and new rings will work or bore the block for new pistons.
Do you want the block mains line bored.


Will the crank just need a polish or be turned? If you need new pistons some are made "lower in the hole" so if you have the crank stroked it will get the piston back up to deck level.
Or the block could be decked but to get the pistons back up but not the best way to do this.


Heads would also need to be looked at to see if parts are needed. For street motor I would not spend money for port work. I think a multi angle valve job would do better for you.
Remember port work is all labor and it is not cheap so do you really need it? Maybe a quick clean up but that would be it.


Also know if you do port the heads so they flow better what are you doing on the air in side and air out side?
If you do one thing it changes what the other things need to do and may not be up to it.


So you need to think out this whole rebuild.
Dave ----

 

I agree - think out the whole build before you do anything. If you want the engine to live for 100k miles you really need to have the proper machining done, including boring to get the cylinders round, turning the crank, and resizing the rods. But don't worry about balancing it.

Now on the heads, lay them beside some Windsor heads and you'll realize why we think the W stands for Wheezer. The ports on the 335 Series engines, meaning 351C/351M/400, are huge in comparison to W heads. So, unless you are building a serious engine that will put out more than 350 HP don't bother porting the heads. But, do have the valves ground, guides and seals replaced, etc. Oh, and have the heads and block checked for cracks. Especially the block because the 335 Series blocks do crack.

And, thinking of building a 351M for performance, don't. No one makes pistons that will give you anything more than 8:1, and you can't get much power out of 8:1. However, if you will change the crank out that will make it a 400 and Tim Meyer has pistons for a 400 that will give good compression.

So, develop your plan and bounce it off of us.

 

My main purpose for the truck is daily driver/off road toy. I suspect the rings were bad due to blue smoke. And also white smoke so either head gasket or rich fuel



mo

 

Rich on fuel gives black smoke. The only thing that gives white smoke is coolant. Again, make sure you have the block checked for cracking before having machine work done on it.

 

i have an ultra sonic cleaner at work. So i can definitely throw my heads in there for a good day. But block might be too big. How heavy is the block if anyone has a ruff estimate

 

You need to find a good machine shop that you want to work with, the ones that are going to do your heads. You can't do them yourself, too much specialized equipment. When you take your heads, take your block and crankshaft. If you are paying them to do your heads, they will usually check out the block for you for free, and quickly check the crank. They do this everyday and can quickly tell you what is good and what is not.

The cranks don't usually wear, but the thrust surfaces sometimes do, they will check that. If it's bad they will have to spray it up, which can cost. Or you can check on a crankshaft kit the store sells and compare prices. The kit usually comes with the crank, bearings, etc.

The better the block is, the more power you will have and the longer it will last before it starts using oil again. .006 inch wear is considered the top limit for bore wear, and still have a engine that will last a little while and not burn oil.

I would have a serious look around in everyone's back yard, there is usually a old LTD or something sitting back there, and some of them had 400's. The late 70's truck and Broncos had 400's also. If you can't find one ok, go with what you have. But if you could find one I think I would convert it like Gary said. If you are doing it you might as well go for it. If you need a crank kit, maybe you can do the 400 thing then.

 

so what exactly is the 400 swap? Crank , pistons and bored block ?

 

I have never done it, but wait till Gary comes along or go down to the 351c/351m/400 engine forum and look around down there. Or do a google search. I don't think it's very hard to do, and you will have a very good running engine in the end. You will only be 60 cubic inches less than a 460.