Rocker shaft stud kit

[Sunny Jim]

Time to do the top end. So 117 CP set at 10.8;1. Sticking with the CR460 -  Nothing too fancy, But I would like to replace the rocker shaft bolts with a stud kit or whatever.
Can anyone give me a recommendation please?

[BigT]

What's wrong with reusing the stock 12 point bolts?

[Sunny Jim]

I only want to pull it apart once and given some discussion on rocker bolt issues, I figured I would ensure all is well on assembly. That's it really.

[Durwood]

Fueling sells an ARP kit.

I have been using the stock bolts without issue, clean them and the holes up in the heads, re apply loc-tite, torque to spec.

[BigT]

I only want to pull it apart once and given some discussion on rocker bolt issues, I figured I would ensure all is well on assembly. That's it really.

I've read about a few issues with the head bolts snapping on re-use but not the rocker bolts.

[RoadGlideRob]

Time to do the top end. So 117 CP set at 10.8;1. Sticking with the CR460 -  Nothing too fancy, But I would like to replace the rocker shaft bolts with a stud kit or whatever.
Can anyone give me a recommendation please?

I used the Feuling kit, part #3037 for the rocker arms and also bought their Cam bolt kit.

[RoadGlideRob]

I only want to pull it apart once and given some discussion on rocker bolt issues, I figured I would ensure all is well on assembly. That's it really.

I've read about a few issues with the head bolts snapping on re-use but not the rocker bolts.

bolts aren't the issue,  its the rocker arm shafts that are cracking.  the stud kit spreads the torque better on that shaft with its very thin walls.  I think GMR has posted some pics on his facebook page of shafts that have cracked with the stock bolts.

[BVHOG]

In the fueling info they show the problem being the rocker support stands cracking, the fueling kit works well but is no bargain. I called ARP and bought studs and nuts separate and make it a part of every top end build. The fueling Cam bolt kits are a must IMHO

[BigT]

In the fueling info they show the problem being the rocker support stands cracking, the fueling kit works well but is no bargain. I called ARP and bought studs and nuts separate and make it a part of every top end build. The fueling Cam bolt kits are a must IMHO

Are there a ARP part numbers for the studs and nuts?

[les]

Can someone please post the specification for the studs (size, TPI each end, length)?

[PoorUB]

Can someone please post the specification for the studs (size, TPI each end, length)?

They would be grade 8, 5/16" UNC on both ends, not sure of the length, but if you have a bolt handy, add 1/2". anyone know the specs for a HD P/N 1039?

[14Frisco]

anyone know the specs for a HD P/N 1039?

SCREW, 5/16-18 x 2-1/2 hex flange hd. (Grade

[les]

Usually, double threaded studs have a course thread on one end and a fine thread on the other.  Hopefully, I'll get lucky and someone who's got a set of the Feuling on the bench will take a quick measurement and post.

The True Value Hardware store a couple of miles from my house sells fasteners, including automotive studs.  This is where I get my studs for the cam plate.  Let's see...  Each of those cam plate studs cost less than 4 bits a stud.  I'm guessing the bigger ones will be less than a buck a stud.  Hmmm...I'll let you guys put 2-n-2 together.

Once I get the measurement, I'll run down there and see if they have this size.  Until then, you can continue buying the $140 set.

[BigT]

      The screw isn't listed in my HD 2017 parts book hardware list but measures 1-1/4" long not 2-1/2".  Total length including the 12 point head looks to be 1-9/16"

[PoorUB]

      The screw isn't listed in my HD 2017 parts book hardware list but measures 1-1/4" long not 2-1/2".  Total length including the 12 point head looks to be 1-9/16"

I believe the 2-1/2" is correct, from my memory these screws are fairly long. The rocker support is probably over an inch thick, plus the screw goes through the lower rocker box and into the head.

[BigT]

      The screw isn't listed in my HD 2017 parts book hardware list but measures 1-1/4" long not 2-1/2".  Total length including the 12 point head looks to be 1-9/16"

I believe the 2-1/2" is correct, from my memory these screws are fairly long. The rocker support is probably over an inch thick, plus the screw goes through the lower rocker box and into the head.

My ruler might be a tad better than you memory. LOL My motor is apart and I listed actual measurements

[Ohio HD]

I'm sure BigT is correct as part number 1039 isn't the correct number anyway.

Below is what I think is needed.


10200503 - SCREW 5/16-18 X 1-1/4 12 PT. HEAD GRADE 8

[PoorUB]

I forgot where I was at. I was thinking Twin Cam.

[Billy]

I forgot where I was at. I was thinking Twin Cam.

Haha. I was just getting ready to post this.

I believe you're thinking about a Twin Cam.

The M8 has raised bosses on the cyl heads which cradle the rocker shafts and secures them with bolts in the ends. The lower rocker boxes can be removed with the rocker arms in place providing there is enough backbone clearance.

[les]

I'm sure BigT is correct as part number 1039 isn't the correct number anyway.

Below is what I think is needed.


10200503 - SCREW 5/16-18 X 1-1/4 12 PT. HEAD GRADE 8

Yes, that is the part number.  So, if the bolts are 1 1/4" long, I'll look to see if True Value has studs in the 2" length range.

[les]

So, I just ran down to the hardware store and bought this automotive stud.  It is $2.34 including tax.

5/16"x18x24x2"

The course end has about .525" of usable thread depth.  The fine end has a good 1" of usable thread depth.

Now, we need to get someone on here to perform some measurements on a real M8 rocker assembly to verify that the .525" depth of the stud's course thread (18 TPI) is enough completely ground out at the bottom of the bolt hole, the 2" stud is an appropriate length to cap off with the 5/16"x24 ARP nut, etc.


[attach=1,msg1274084]

[les]

A 10-piece set of ARP nuts from Summit Racing is about $15.  A set of eight 2" studs is about $20.

If these studs work, the entire kit comes in under $35.

[BigT]

The stock 1-1/4" bolt protrudes 3/4" thru the rocker shaft. I was able to thread in just over that (. into the head rocker boss. The 1st 1/2" of the head rocker boss is machined out to clear the rocker and has thinner walls around the threads. Having a full 3/4" of thread engagement would optimal.   The rocker shaft takes up  a 1/2".   A 2" stud seems like it's going to be too long.

[les]

The stock 1-1/4" bolt protrudes 3/4" thru the rocker shaft. I was able to thread in just over that (. into the head rocker boss. The 1st 1/2" of the head rocker boss is machined out to clear the rocker and has thinner walls around the threads. Having a full 3/4" of thread engagement would optimal.   The rocker shaft takes up  a 1/2".   A 2" stud seems like it's going to be too long.

The 2" length being too long is not a problem.  Pre-threading a thread chaser and a cutoff wheel solves that problem.  When you say a full 3/4" of thread engagement would be optimal, are you saying that the .525" available thread on the stud is about a quarter inch not enough?

[BigT]

Just saying that the last 1/4" is in the thickest part of the casting.

[les]

Could someone please measure this?  It's the bolt hole depth, from the bottom of the shaft journal to the bottom of the bolt hole.

[attach=1,msg1274281]

[BigT]

 [attach=0]

Could someone please measure this?  It's the bolt hole depth, from the bottom of the shaft journal to the bottom of the bolt hole.

1.065

[BigT]

I was able to tread a long ALLEN bolt in .9" to each of the holes before it bound up. The boss for the bolt next to the valve spring is so thin part of it is exposed where is was milled out to clear the spring
[attach=0,msg1274347]   [attach=1,msg1274347]

[les]

Thank you, BigT.  So, since the studs I got only have about a half inch of 18 pitch threads, I think the approach would be to load them up with red Loctite and screw them in just snug until the 18 pitch threads come to an end at the top of the bolt hole threads, and not attempt to ground the base of the stud against the base of the bolt hole.

The treaded bolt hole is much deeper than I expected. 

I appreciate the information.  Next M8 I do, I will take a closer look at this rocker area.

[BigT]

The more I look at this design I can see why using a stronger stud would be a good idea. I personally wouldn't use a stud that only engages a 1/2" but there doesn't seem much else available.  I wonder how deep the Fueling ARP studs thread in?

[Ohio HD]

When needing answers, start at the resellers web site.

Rocker arm studs - 5/16-24 x 1.700"


http://www.feulingparts.com/products/Fasteners/Internal%20Engine/3047

[FSG]

    hard to miss

[Ohio HD]

From the photo, I would say the 0.900" on the 5/16-18 end of the stud is good. They should bottom and be loctited in place per Feuling.


[attach=0]

[BigT]

I see the studs in the kit have a longer course thread section than fine thread which is opposite of what seems to be available for other sources.  Looks like I'll be biting the bullet and getting the kit. In the process of installing a 124" set up with the lower end at Darkhorse getting blueprinted. Another $200+ to the ongoing list.....

[rigidthumper]

The ARP stud looks like it uses .875" coarse thread, .15" gap, and .675" fine thread.

[les]

Thanks, Ohio.  So, you're saying that the 18 pitch threads on the Feuling studs are .9" long, or that it would be optimal if they were .9" long?

BigT, when you get your stud kit, would you mind posting exact measurements?  Especially, the length of the course threads on the studs.  Overall length is not that critical because the fine thread side can be cut down and thread chased.  If these are custom made studs, that could explain the expense from Feuling.

[Ohio HD]

I would go by the dimensions Rigidthumper posted. Sounds like he's measured them. It totals the 1.700" as advertised.

[les]

I would go by the dimensions Rigidthumper posted. Sounds like he's measured them. It totals the 1.700" as advertised.

Got it.  Thank you.  Final answer is the local cheap studs won't work for this application.  The only way to get the advantage of the stud's support is to be able to sink it in the ~.9" into the rocker support.

[Ohio HD]

I could have them made in our plant in Italy, they make all sorts of grade 8 specialty shoulder bolts and studs with non standard lengths. Probably charge me about $50.00 each.     

[les]

I could have them made in our plant in Italy, they make all sorts of grade 8 specialty shoulder bolts and studs with non standard lengths. Probably charge me about $50.00 each.     

Yes, I've seen what custom studs can cost.  So, the Feuling price appears to be right in line, now that I've been educated on the exact dimensions.  I won't feel bad about spending the $140 for the kit.

[HD/Wrench]

I posted that you could not use the cheap stud way back when  this first started . .  I had ARP make us kit as well .  ARP will make the studs for anyone no big deal ,

[BigT]

Fueling stud

[les]

Thank you!

[les]

So, looks like:

.75", .125", .8125" for the course threads that sink into the head.

[Ohio HD]

0.8125" with a steel rule? man you got good eyes.

[PoorUB]

0.8125" with a steel rule? man you got good eyes.

Years back I worked at a shop and we machined a few large flywheels with a large counter bore, something like 24". We didn't have anything to measure them with except a good quality rule with very fine graduations, plus a magnifier. Tolerance was something like +.010/-.000. We did them and never got any rejected but the customer probably couldn't measure them either!

[Swoop76]

I reached out to Alloy Boltz and the have rocker stud kit fo $72 half the fueling price.  It's ARP grade 8 stainless, so question is there any issues going with stainless?

[Ohio HD]

Not knowing the specs of the studs you speak of, I would say most likely they're weaker than grade 8 steel.

[PoorUB]

ARP stainless has a tensile strength of 180,000 pounds. The will be fine, better than regular Grade 8.

[Swoop76]

Thanks I just looked at ARP site here is the information.  I've sent them a mail asking for a kit directly from them and will update when here back.

ARP manufactures a variety of premium grade bolt and stud kits to facilitate installation of exhaust headers including the popular stainless stud kit with 12-point nuts. The Stainless 300 material is not affected by corrosion or extreme heat, making it ideal for the application. What's more, the compact 12-point nut lets you easily slip a socket close to the pipe. Each ARP accessory stud or bolt kit includes the specific number of parts for your application, plus premium-quality washers and hex or 12-point nuts, as required. Studs are manufactured with a unique nut-starter nose that helps prevent cross-threading. Studs and bolts come either black oxide chrome moly or Stainless 300. Both are nominally rated at 170,000 psi tensile strength; substantially stronger than Grade 8 hardware.

Available for a wide selection of Chevrolet, Chrysler and Ford engines, plus many "universal" kits that can be matched by dimension.

[les]

0.8125" with a steel rule? man you got good eyes.

Lol.  I machined the cases for my 124" using this.   

[Ohio HD]

0.8125" with a steel rule? man you got good eyes.

Lol.  I machined the cases for my 124" using this.   

I have vernier calipers. They're not a steel ruler.....     

[rigidthumper]

0.8125" with a steel rule? man you got good eyes.

Lol.  I machined the cases for my 124" using this.   

That is not a proper cutting tool

[Helmwurst]

Thanks I just looked at ARP site here is the information.  I've sent them a mail asking for a kit directly from them and will update when here back.

ARP manufactures a variety of premium grade bolt and stud kits to facilitate installation of exhaust headers including the popular stainless stud kit with 12-point nuts. The Stainless 300 material is not affected by corrosion or extreme heat, making it ideal for the application. What's more, the compact 12-point nut lets you easily slip a socket close to the pipe. Each ARP accessory stud or bolt kit includes the specific number of parts for your application, plus premium-quality washers and hex or 12-point nuts, as required. Studs are manufactured with a unique nut-starter nose that helps prevent cross-threading. Studs and bolts come either black oxide chrome moly or Stainless 300. Both are nominally rated at 170,000 psi tensile strength; substantially stronger than Grade 8 hardware.

Available for a wide selection of Chevrolet, Chrysler and Ford engines, plus many "universal" kits that can be matched by dimension.

So, does ARP have a kit number available for the M8 Rocker studs and nuts? If anyone knows it, do you mind posting it?

[les]

I reached out the ARP to ask them if they made studs according to the dimensions that are in the Feuling kit.  They said no.

[Txwezl]

So, does ARP have a kit number available for the M8 Rocker studs and nuts? If anyone knows it, do you mind posting it?


It's kit #3037 you can find it on Ebay cheaper than ordering direct from Fueling

[Swoop76]

I never heard back from ARP but Alloy Boltz has the kit in stainless so hit them up

[Helmwurst]

So, does ARP have a kit number available for the M8 Rocker studs and nuts? If anyone knows it, do you mind posting it?


It's kit #3037 you can find it on Ebay cheaper than ordering direct from Fueling

Not finding that part number anywhere.

[Ohio HD]

How many do you want?


https://goo.gl/tJgsGD

http://www.feulingparts.com/products/Fasteners/Internal%20Engine/3037

https://goo.gl/8CUyvh

[Helmwurst]

Thanks for the information and links. I am not sure why my search did not bring anything up !!

[Billy]

Exhaust stud HD 10900015A ($0.51 ea.) on left, Feuling stud on right.

ARP 12 point nuts from Summit $13.99 for 10.

[attach=0]

[BigT]

Exhaust stud HD 10900015A ($0.51 ea.) on left, Feuling stud on right.

ARP 12 point nuts from Summit $13.99 for 10.

[attach=0,msg1280321]

Close but no cigar.  The nut is flush with the top of the Fueling stud once installed. The exhaust stud looks to be short

[Billy]

Exhaust stud HD 10900015A ($0.51 ea.) on left, Feuling stud on right.

ARP 12 point nuts from Summit $13.99 for 10.

[attach=0,msg1280321]

Close but no cigar.  The nut is flush with the top of the Fueling stud once installed. The exhaust stud looks to be short

Yeah, it may be. I don't have the heads back to mock it up. Thanks

[BigT]

The only way it will work is if you don't thread the course part of the stud in all the way...

[Swoop76]

The only way it will work is if you don't thread the course part of the stud in all the way...

Finally heard back from ARP

At this time we do not offer a stud specifically to replace the head rocker bolts.


Here are a couple of studs to choose from:

Stud # AG1.750-5B
1.750" OAL
5/16-24 X 5/16-24
.375" X 1.000" thread length
(no guide)
$  3.95  each
Offered in four-pack # 100-3204
(includes hex nuts & washers)
And/or
Offered in four-pack # 100-3219
(includes 12 point nuts & washers)


Stud # AG1.700-5G
1.700" OAL
5/16-18 X 5/16-24
.500" X .200" guide +.800" thread length
$  3.83  each
Offered in four-pack # 200-2401
(includes hex nuts & washers)

[Malazan]

Would these work for the studs?

http://www.hillcofasteners.com/prod/ARP-High-Strength-Stainless-Steel-Stud-516x1700__ARP3101700.aspx

[Nedmorpower]

Could anyone explain why we could not use feulings exhaust studs instead? Everything looks to be the same as far as threads pitch and thread length other than the obvious one is black oxide finish and the other is stainless. Reason im asking is i find the exhaust studs on ebay for $40. so x 2 = $80 versus $130 to $140 depending on where you get them from.