250 cam bolt question

[Anonymous]

Hi guys, newby here. I have assembled many engines in my time but this is my first 250 I-6. I am trying to teach my nephew to be patient and make sure everything fits together well without forcing anything. We chased all the threads in the block and cleaned all bolts before reassembly. Well I may have messed up.

I noticed that the cam sprocket bolt went in rather tightly so we used a die on the bolt and cleaned the threads up. Now when I tighten the bolt up it clamps the cam gear on the thrust plate and nothing will rotate. I am now thinking that the cam bolt was designed to tighten up like it did and allow for some thrust plate clearance. Can someone here please enlighten me as to what I am missing? Thanks

Greg

 

[MustangSix]

Is this a new cam?

ON the nose of the cam there is a locating dowel. Behind that dowel there should be a spacer that looks like a thick washer. New cams don't come with this. You have to take i from the old cam.

Without the spacer, the cam gear will tighten down and clamp the retainer between the gear and the camshaft.

 

[Anonymous]

Now we're getting somewhere. Thank you fo the reply. Yes we are trying to put a new cam in there. We have the old cam. I must have missed it. I'll have to take a look for that spacer. Thanks again.

 

[MustangSix]

No problemo. Just pull the dowel with a pair of vise grips and the spacer should just slide off.

 

[Anonymous]

Runum,

just did a cam swap on my 170 and noticed that the cam bolt was unusually hard to turn. Upon closer inspection, realized it was a special
type of thread(class 5) I believe. It's kind of semi-finished to reduce the likelyhood of loosening up. Ford uses that alot on exhaust manifold studs.
If it's not too late, you might want to find another factory bolt or a grade 8 bolt of equal dimensions, I always worry about die cut threads on critical engine fasteners !


Best wishes,

Ron.


p.s. Comp 260H is "almost" too big for a 170, but I'll get over it! HA HA.