I have a 88 ford f250 with a 7.3l non turbo diesel that i think needs some valve seals replaced. I have a top end gasket set for another one of my pickups which is a ford f250 with a 6.9l diesel. the question is,Will the valve seals and the little plastic oil shields in that kit fit my 7.3L ? Also i read somewhere that it's a good idea to put umbrella seals on the exhaust valves? thanks in advance

 

My guess is that yes the kit will work on either or.. however dont quote me on that, i know there were differences in the seals from the factory between 6.9 and 7.3. The 6.9 let more oil through to lube the valve stems, but ford had complaints of hazy exhaust at idle so on the 7.3 they went with tighter clearences.

That was an obscure article i read one night, at least what i remember of it. But as far as i know the valves, rockers, seats / seals all should interchange.

 

Is that why the 6.9 uses so much more oil then the 7.3L? I'm always filling the 6.9 and the 7.3 dosen't seem to use any between changes.

Chet

 

it's just the opposite with me. My 6.9l doesn't use much at all, but the 7.3L can really go through it. When i start it up, it doesn't really smoke. when i leave my house, i have to go a couple of miles down a dirt road so i go pretty slow. When i turn out on the paved road and get into it a little bit it smokes for about 5 seconds. I hope the valve seals fix it. It's got about 170,000 miles on it

 

to be honest from what i read and real world experience, i doubt there is a noticable difference between the two to the operator, but your guides will thank you. One of the main reasons you dont want to let a 7.3 idle, they dont oil well on the top end, at least thats what ive been told. I think its tied in with the 7.3 having harder exhaust valves and better rockers, to compensate.

 

thanks for all the good info. I took an old glow plug today and broke the bottom and the top part off and drilled out the center. Then i took a air coupling fitting out of a nail gun and welded it to the glow plug, this i'll be able to connect the air line to when i do my seals tomorrow. But one more question, I;ll have to go to the parts house and get the umbrella seals for the exhaust valve, but if they didn,t put them on there from the factory, What do i ask for? do they make some for just the exhaust valves?

 

If the seals for the 7.3 fit, Clay at Riffraff Diesel has the seals for the 7.3 . Just use them. They look great and are what your looking for.

Chet

 

I started replacing the valve seals this morning on the drivers side of the engine. everything was going good until i got to the rear cylinder, There wasn't enough room to get my valve spring compressor in there. I've got one of the overhead type with the wheel that you turn on the top. any idea what kind of compressor i can get to get into that tight space at the back?

 

Can you rock the motor by removing a motor mount or bolt?

Chet

 

Well, i guess it's possible,but id have to take the motor mount completely off to get it to go down on that side enough to get my valve compressor in there.I hope i don't have to do that much work. I'm trying to figure out how to make another compressor that will fit into that space

 

Are the 7.3 and 6.9 seals the same? I remember someone talking about it, just wondered if it was for sure.

Chet

 

well, they looked the same. The guy at the parts house looked up the FEL-PRO number and he said they would work. I went to a automotive machine shop yesterday and got the umbrella seals for the exhaust valves.The seals on my truck must have been replaced before because there were umbrella seals on the exhaust valves, and they were crispy. Anyway, i got 3 cylinders done on one side, i put it all back together because i needed to use the truck. I'll have to look around for a compressor that will work back there. If i took the motor mount off of one side, i'd probably have to take it off the other side too. Don't want to do that much extra work

 

I know on the powerstroke they have to take the mount off or loose and rock the motor. Clay has a real good looking set of seals. They are umbrella that look like a pc seal all in one. I'd use them on both sides if able.

Chet

 

is it normal to see some oil on valve stems when looking in exhaust manifold ports on the heads of a older 7.3 engine? only a couple of them were wet with oil