(Sigh)

"MM54" (mm54mk2) 09/21/2019 at 16:00 • Filed to: '71Chevelle

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As you may recall (or not, I don’t take it personally), about a week ago I discovered the rocker studs were missing for the heads on the 383 I’m building for the Chevelle. I picked up some appropriate ARP studs from the machine shop late this week so that I could finally measure for pushrods and get to wait for those to show up.

This afternoon I mocked the head up, screwed in the studs, and...

Look closely - three imaginary bonus internet points to whoever can identify the problem before reading further.

...

They are bottoming out in the head about .075" before they even touch the guideplate. I’ve contacted the machine shop I’ve been working with (who spec’ed and provided these studs) to ask “wtf” and figure out what to do about this.

Nothing’s easy...

(Also at this point getting this car back on the road before winter this year is pretty well a pipe dream; recall it was supposed to be done late spring/early summer, then mid-summer (because b udget) but has just been one problem after another ).

AestheticsInMotion > MM54 09/21/2019 at 16:10

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Try adjusting the rebound and compression on those springs so you don't have to worry about bottoming out in the corners

MM54 > AestheticsInMotion 09/21/2019 at 16:18

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I didn’t get the double-adjustable valve springs, dang. At this point I should have just gotten bluetooth rocker arms to avoid all this trouble.

AestheticsInMotion > MM54 09/21/2019 at 16:20

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Just make sure to only use the heavy-duty rated wireless extension cord when you’re juicing those r ocker arms up each morning. Otherwise the wattage will blow the amps

7:07 > AestheticsInMotion 09/21/2019 at 16:25

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SBA Thanks You For All The Fish > MM54 09/21/2019 at 18:28

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Easy. Just run a drill bit down another half inch into those holes. No problem-0.

/s/

Seriously, though, who is the head supplier?  Because ARP has certainly built studs for THIS application before-- so I’d put my trust in them.

shop-teacher > MM54 09/21/2019 at 18:46

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I would like to claim my bonus internet’s please.

Sorry about the constant setbacks :/

MM54 > SBA Thanks You For All The Fish 09/21/2019 at 20:10

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They’re AFR heads

SBA Thanks You For All The Fish > MM54 09/21/2019 at 20:53

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Wow.  Any theories as to what’s up?

MM54 > SBA Thanks You For All The Fish 09/21/2019 at 21:53

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Best guess is that the studs you can buy from AFR fit, and it isn’t their problem if other manufacturer s’ don’t . However (according to the machine shop) the AFR studs aren’t long enough, so he spec’ed these ARP ones.

kanadanmajava1 > MM54 09/22/2019 at 05:30

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How about adding hard washers (12.9 grade or some imperial equivalent) between the studs and the guide plate? Placing the washers under the g uide plates might be even better idea if the washers would have larger contact area with the aluminum head than the guide plates.

kanadanmajava1 > MM54 09/22/2019 at 05:31

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How about adding hard washers (12.9 grade or some imperial equivalent) between the studs and the guide plate? Placing the washers under the guide plates might be even better idea if the washers would have larger contact area with the aluminum head than the guide plates.

MM54 > kanadanmajava1 09/22/2019 at 10:00

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The dimension from the pad on the head to the shoulder and top of the stud is pretty important. Spacing it out with a washer (which I couldn’t find one with the right dimensions to actually fit in there in a quick search of McMaster ) would negatively affect the geometry.

kanadanmajava1 > MM54 09/22/2019 at 11:08

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I guess shortening the threads by grinding is then the next possible solution. A belt sander and the stud rotating on a drilling machine should provide a very good shortening method.

MM54 > kanadanmajava1 09/22/2019 at 12:09

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A lathe will work well too and put less heat into it :)

Take .100 off and there’s still well over .750 of engagement on a 7/16 stud so it’ll be fine, just blow any concept of warranty from ARP out of the water