640 VALVE GUIDES

[Blindhawg]

My 134ci head seems to have replacable valve guides on the intake, but integral,non-replaceable guides on the exhaust. Both have ringed grooves inside. I'd like to replace both with the usual 3/4 x 2-1/2" valve guides bought from this site and others, but don't see where the belong.

 

[trucker40]

ok Im not an expert on gas Ford motors,but I have replaced valve guides on diesel motors and I saw where nobody has answered yet so I will try.Looks to me like somebody put a different type of valve guide in there.An insert inside of the real valve guide.Also I saw where you posted before and the ones in your picture looked to be the wrong ones.Now I remember that a bunch of Ford motors had replaceable valve guides.As you described in your first post they had a ring to stop them.I think you need those kind.If you have those kind of guides,you take a air hammer,and you could have to make a tool or buy a tool for the air hammer and drive them out from the bottom,make sure the head is clean and drive in new ones.Thats what replaceable valve guides mean to me,I could be wrong.I also remember that there is a way to put brass valve guides in(which is what I think that insert is inside of your valve guide that you are talking about.These I think are screwed in and maybe are replaceable too.Another thing that was done was called knurlizing which was kind of like running a tap through the guides and cutting a sort of thread which raised the inside diameter and tightened the valve stem up in the hole.This was the cheap way out and worked for a while.Most people that have something like that break down and want it fixed yesterday.So there is no telling what was done to it.The right way is what you asked about before,I think you need ones like came out.I think it would last a long time if you did it that way.

 

[trucker40]

Also after thinking about it,as somebody said before you need to measure how far they stick up above the surface where the spring sets.It needs to be accurate measurement.Since its been 20 years ago,I forgot how to do that.I think maybe there is a measureing device just for that.Maybe.It would make it easier if you can just drive them in.Somebody on here will maybe know better than me.You might be able to press them out and back in too.

 

[Blindhawg]

You may have hit on something. The guide bores are knurled or grooved. I guess I could find a reputable machine shop take a look at it.

Thanks.

 

[Blindhawg]

You may have hit on something. The guide bores are knurled or grooved. I guess I could find a reputable machine shop take a look at it.

Thanks.

 

[Dick L]

So your thinking they could sand cast valve guides into the head and machine the valve guides inside the ports as well as on top? What does it look like down in the ports?

 

[Blindhawg]

Bingo! Its a 172 ci head. Cast into the head is EAF. 134's are EAE.

 

[Blindhawg]

Exhaust guide bore, knurled
Intake pressed insert, also knurled.

 

[Blindhawg]

Update: took the head to an automotive machine shop Friday. I was told that inserts that I bought wouldn't work, bores need to be drilled out and new inserts pressed in. $85 plus parts.
Note that all the intake guides had an insert installed at some time. I assumed the the exhaust guides had be left alone other than knurling as were the intakes. What confused me in the beginning was the flat top intake ends and the pointed (like the new inserts)exhaust guides. I'm thinking now that the pointed end of the intake guides were machined off when the inserts were added. This leads me to believe that all have inserts 3/4 x 2-1/2" exactly like the ones I bought. I going to try to pound them out with a driver and hammer as instructed in the shop manual. We'll see!!

 

[Blindhawg]

As I thought!!! Just had to pound out the inserts. Case solved. Thanks for the input.