windage tray studs

[Chuck R.]

I test fitted the windage tray studs into the block and am puzzled at just how the stud tightens into the block.

The olny way I figure they will work is if I double nut the stud and wind it in until it snugs up and then back the nuts off.

This way I have only threads showing above the main caps and I'll know that I'm pulling down completely on the caps.

If and only if I'm half way correct on this, would using thread locker (say blue) be advisable?

Instuctions are cloudy to say the least.

Milodon tray and reccomended stud set.

Be gentle on me now

Chuck

[Joe L.]

Re: windage tray studs

Chuck-----

I'm not very familiar with the Milodon studs. The Chevrolet studs for use with windage tray have a hex head flange which seats on the main cap and an extension with seperate, 3/8"-16 studs at the top for windage tray retention.

With most true studs (as the Milodon variety probably are), the studs are installed by simply screwing the stud into the block as far as it will go by hand. Use assembly lube on the studs and they will screw in quite easily and completely. If necessary, you can "double nut" them for installation purposes, but this is usually not necessary if the threads are properly lubed and CLEAN.

[Michael H.]

Re: windage tray studs

Chuck,

Many engine builders that use main cap studs instead of bolts do use loctite to secure the stud, although it's not absolutely necessary. If you install the studs the way you describe using the double nut system, it will get the job done.

Hopefully, because this is a quality stud kit, it includes very important specific instructions about reducing the torque value of these studs down from the factory specs IF SAE/FINE THREAD is used on the cap end of the stud. The fine thread increases the applied clamping force for any given torque value by about 15%. In other words, if the original GM specs call for. say, 65 lbs/ft, using standard coarse thread, the computed value for the same fastener with SAE/fine thread would be somewhere arounf 48 lbs/ft.

[Chuck R.]

Re: It's interesting

These are bare studs with both 7/16" nuts for the bearing caps and 3/8" nuts for either side of the tray for adjustment.

They say to torque the 7/16" cap nuts to 65 ft/lbs "with oil" My shop manual for stock main caps spec 80 ft/lbs Why the 15 ft/lb difference?

The studs come with lock washers vs. the original studs, could this be it?

I'm tempted to pull them down to the original 80 ft/lb

Thanks for the response Joe,

Chuck

[Chuck R.]

Re: You answered the questions while I was typing

Ok, now that makes sense.

Many thanks Mike and Joe, I'm all through hyper ventilating now

[Michael H.]

Re: You answered the questions while I was typing

Yup, it's all in the angle of the thread. As the angle increases, the load, or clamping force decreases per rotational torque value. (coarse to fine thread) In this case, we're going the opposite way, high angle to low, so the torque required to achieve the same load, or clamping force, decreases. There's a formula for this and if I find it in all this rubble, I'll scan and post.

There is a much simpler method though. If you divide the old thread (14) by the new thread (20), then multiply the original torque value by the results, you will have the new correct torque spec. 14/20=.7. 80lb times .7=56lb/ft.

[Michael H.]

The Formula

Found the formula for converting std thread to SAE thread torque load equivalant. (upper right formula) I think you'll find that the long complicated formula comes out the same as the short one I posted earlier.

[Chuck R.]

Re: Excellent!

Already down loaded, laminated and taped to the tool box lid.

Hey Mike I have another question..( thought I was just going to go away huh?)

The way that the tray is setup, I received six studs but can only use five. I was told by a Milodon rep. that 400s take six so it's a boiler plate package

If I follow the pattern and use all the studs, the sixth stud will be running up through the cut out on the tray for the dip stick.

Now.... Will I be getting into trouble mixing torques with a stud on one side of the cap and a regular bolt on the other? I was thinking of clipping off the 3/8" tray portion of the stud and using the remaining 7/16" fine thread portion to keep the torques consistent.

Does it really matter as long as I follow the torque requirements for each bolt/stud application?

Thanks for sharing the grey matter and the chart.

Your newest best (pest) pal,

Chuck

[Michael H.]

Re: Excellent!

Morning Chuck,

You can use either method that you describe. Since the "applied force" is all that is important, and either bolt or stud (std/SAE) method applies the same force, (after the reduction in torque for SAE thread) either will work.

I would probably feel most comfortible clipping off the extension of the stud in question and using it instead of mixing bolt/studs on the same cap.

I always wondered why the companies that make stud kits, especially for cyl heads, don't just use the same standard thread to eliminate all the confusion? Even the GM big block stud kit that was available many years ago came packaged with NO instructions for converting the torque value.

[Chuck R.]

Re: You would think

With the potential risk of engine bearing failures I would think that companies would do as you suggest by standardizing the thread applications, especially with my "unique" situation.

These outfits can really tank practical ideology with the grey areas they create getting "cute" with components can't they.

Well this turned out to be quite an educational experience Mike.

Both Mr. 350 and I thank you for your help.

Chuck

[Chuck R.]

Re: Windage tray stud conclusion

Hi Mike,

Just thought I'd let know that t******* the excess stud off did the trick and everything including the dip stick clears with no isues.

I DO feel a whole lot better having all six studs in place torqued equally vs. having the odd bolt opposite the stud on that lone cap.

Thanks again for your help,

Chuck