CJ love

[turbohunter]

Like all the pictures especially the journal pics. Will use that soon.

That’s the beauty of this medium. How much of a chance would you or I have without the help we get from here. Take your bearing thread. The builders have been more than gracious with the info they are giving. And it’s up to us hobbyists to pass on information that may seem obvious to them but we have no idea. Like FM being renamed Speed Pro.
I think we all owe Mr. Brown a big thank you for keeping this forum on point and to the builders for their generous contributions.
FEs have become “a thing” again.
My dad’s pinging old 352 would be proud.

[WConley]

I think Jay will be along to deliver a flogging!   

Seriously, that's a good way to get 'er done without risking damage to the timing set.

[turbohunter]

Thanks Bill. I think so too. It’s just to tight to chance it.

[jayb]

I've done worse than that LOL!  I've also left the dowel pin a little proud of the gear and just let the washer bend when I tightened the bolt.  Not a hardened washer of course, just something to keep the pin from coming out.  Never had a problem...

[Barry_R]

Effective if not elegant solution to the problem.

I do not often disagree with Jay, but personally I would not recommend bending a washer.  The retention of the cam sprocket is actually the result of fastener clamp load, much more so than the dowel itself, which should primarily be a location item.  That's why we recommend a high quality (ARP or similar) fastener along with a very thick washer and a comparatively high torque value.  I have put a partial depth "dot" in a thick washer to accommodate an overly long dowel.  I have seen several cases where a hardware store quality washer deformed under clamp load, allowing the fastener to come loose and valvetrain havoc to follow.

[blykins]

Effective if not elegant solution to the problem.

I do not often disagree with Jay, but personally I would not recommend bending a washer.  The retention of the cam sprocket is actually the result of fastener clamp load, much more so than the dowel itself, which should primarily be a location item.  That's why we recommend a high quality (ARP or similar) fastener along with a very thick washer and a comparatively high torque value.  I have put a partial depth "dot" in a thick washer to accommodate an overly long dowel.  I have seen several cases where a hardware store quality washer deformed under clamp load, allowing the fastener to come loose and valvetrain havoc to follow.

I agree, Barry.

A washer that's not thick or not hardened will lose tension over time. 

I had a batch of Pond aluminum heads that were not heat treated correctly.  When I would torque the head stud, it would not hold torque because the aluminum was deforming underneath. 

Same deal with a washer that has bent, is thin, or isn't hard enough.  It will eventually lose clamping force on the timing gear and cam.   The cam washers I use are probably 3/16"-1/4" thick and are hardened.  Cam bolt gets torqued at 70 lb-ft. 

[blykins]

On another note, I would add that everyone doing this at home should check for adequate fastener length.  Not only do the cam cores come in different thread pitch styles (7/16-14 and 7/16-20) but the depth is also different.  Sometimes I will use a 2" UHL and sometimes I use a 1.750" UHL.  One of my assembly steps is to mock up the timing gear and eccentric and see how much thread engagement I get into the cam. 

[frnkeore]

If the thread is 7/16 x 20, the torque should be 78 lb-ft.

[blykins]

If the thread is 7/16 x 20, the torque should be 78 lb-ft.

This has worked for me for the past 15 years. 

FWIW, ARP doesn't change the torque spec of their fasteners depending on thread pitch.  They only change it depending on the material.  For instance, a 180ksi fastener such as a Ford 302 main bolt gets 70 lb-ft and a 200ksi fastener such as a Ford 302 main stud gets 80. 

[frnkeore]

Brent, did you intentionally leave this out of the chart?

Torque, strength and yield, are all based on the Stress Area of the bolt. That is .1063 for a 7/16x14 and .1187 for 7/16x20. ARP recommends, their bolts be loaded to 75% of yield. You can not yield both 7/16x14 and 7/16x20 to 75% at the same torque or stretch. 

[turbohunter]

70+ seems like a lot of torque for a bolt that doesn’t seem to need it.
I would’ve thought 45 or 50 lbs would be enough.

[Barry_R]

The SAE torque values (and all torque values) are friction measurements only, and are highly dependent upon the lubricant being used for assembly, and on the surface quality of the threaded members.  They also preclude any design variations such as the undercut shaft common to some high strength fasteners - which focus stretch loads into the smooth shaft rather than the rolled or cut thread minor diameters.  If you really feel the need to be accurate another method of measurement is required - torque angle is best in the case of a blind hole fastener where stretch cannot be measured.

[jayb]

Hey, I didn't say that letting the washer bend was the right way to do it.  I just said that I did it 

[blykins]

Brent, did you intentionally leave this out of the chart?

Torque, strength and yield, are all based on the Stress Area of the bolt. That is .1063 for a 7/16x14 and .1187 for 7/16x20. ARP recommends, their bolts be loaded to 75% of yield. You can not yield both 7/16x14 and 7/16x20 to 75% at the same torque or stretch.

No Frank, I didn't intentionally leave anything out, because that addendum was not listed on the page that I copied and pasted.

But I'm glad that you brought that up, because it highlights something very important:

"The torque values represented here are intended for general information only and bulk fasteners, not for specific installations." 

The cam bolts I buy are "bulk fasteners".  I buy them in bulk in different lengths and different thread pitches.  In addition, each installation is different:  it could be a cast iron cam, it could be a billet core cam, the thread lubricant could be different, etc, etc.

In addition to that, it's listed that they are "general torque instructions". 

I will still stand by my additional comment in that I have never seen ARP vary torque specs based on thread pitch only, but only based on material.  Even in "specific kit instructions", I have never seen a different spec for a fine threaded bolt.

One more thing...

I don't like at all that you inferred that I intentionally left something out to skew/mislead a point.   

[frnkeore]

Here we go again............

Brent, I know that you can't be wrong and you never are. But, with all do respect, you just are!

Finer threads have a larger CSA, just like a larger bolt has a larger CSA. There is no difference. It makes no difference what material the bolt is made of. It can be aluminum or 240K steel, the CSA never changes. A 1" aluminum bolt is weaker with a 8 pitch as opposed to a 1" bolt, with a 16 pitch and the 16 pitch. The 1x16 bolt will require a higher torque value, to attain 75% yield. Replace the word aluminum with 240k alloy steel and it will always be the same. The thread depth, is what makes the difference, alloys being the same. A 16 pitch thread has a depth of approx .0406 and a 8 pith, .0813. Therefore, it makes the root smaller along with the CSA.

As a graduate engineer, I'm surprised you would argue this point, it's simple mechanics. I'm posting a torque chart to demo what I'm talking about.

What I posted above, is the header to what you posted and the torque that ARP gives, is with engine oil. They don't recommend anything else.