SB VALVETRAIN SHAFT HOLDOWNS -- STUDS VS BOLTS
#2513117
06/25/18 05:42 PM
06/25/18 05:42 PM
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Joined: Jan 2010
Posts: 1,442 NW Chicago suburban area
Mopar Mitch
OP
pro stock
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OP
pro stock
Joined: Jan 2010
Posts: 1,442
NW Chicago suburban area
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Helping assemble a friend's road race 340 with EDDY aluminum heads, and using Hughes rocker 1.6 arms and their valvetrain hold-downs that uses studs. We kept experiencing the studs would unload (despite being tightened into the head very securely, in our opinion) and turn out of the heads. Can anyone suggest a better hold-down method than the studs? Factory bolts? The Hughes complete valvetrain setup appears to be top quality, however, the studs could be longer so to allow grabbing the cap nut, as you first have to progressively work down the shaft without the shaft retainer because it's fairly thick... and then progressively change to the retainer with the washer and nut when there's finally enough threading to grab.
This same engine recently had one shaft snap/break due to the studs coming loose (we'believe that's what happened).
Any suggestions would be appreciated. (Hughes is being contacted also by the engine owner for his suggestions.)
This car will be racing at Road America Vintage weekend, July 20-22... come and see it.. awesome! (and the Posey and Gurney cars will also be racing there that wknd). 1967 B'Cuda fastback #48 (Gurney Blue).
Last edited by Mopar Mitch; 06/25/18 05:44 PM.
Mopar Mitch
"Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers!
Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!
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Re: SB VALVETRAIN SHAFT HOLDOWNS -- STUDS VS BOLTS
[Re: Mopar Mitch]
#2513184
06/25/18 08:00 PM
06/25/18 08:00 PM
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Joined: Aug 2003
Posts: 43,116 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,116
Bend,OR USA
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Did the instructions say to install the studs finger tight only, not to torque them If so by torqueing them your probably asking for problems like you have The studs need to basically almost float in the heads or blocks so the all threads can touch and be tighten against the threads in the block or heads, not tighten or torqued What torque are you using on the retaining nuts?
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: SB VALVETRAIN SHAFT HOLDOWNS -- STUDS VS BOLTS
[Re: Mopar Mitch]
#2513264
06/25/18 10:37 PM
06/25/18 10:37 PM
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Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,206
New York
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This^^^ Finger tight on the studs, all torque on the nuts.
Boffin Emeritus
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Re: SB VALVETRAIN SHAFT HOLDOWNS -- STUDS VS BOLTS
[Re: Mopar Mitch]
#2513538
06/26/18 04:16 PM
06/26/18 04:16 PM
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Joined: Jan 2010
Posts: 1,442 NW Chicago suburban area
Mopar Mitch
OP
pro stock
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OP
pro stock
Joined: Jan 2010
Posts: 1,442
NW Chicago suburban area
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Thanks for the responses. the nuts were torqued to 30 #ft. My buddy has ordered ARP studs (perhaps longer and having center hex) and we'll redo it in a cpl days.... let you all know! T/Anks!
Mopar Mitch
"Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers!
Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!
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Re: SB VALVETRAIN SHAFT HOLDOWNS -- STUDS VS BOLTS
[Re: merpar]
#2513742
06/27/18 12:49 AM
06/27/18 12:49 AM
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Joined: Aug 2003
Posts: 43,116 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,116
Bend,OR USA
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Double nut to torque studs down. The ARP kit instructions do not say to torque the stud Finger tight only and then torque the nuts to 30 Lbs. on the BB Mopar kit
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: SB VALVETRAIN SHAFT HOLDOWNS -- STUDS VS BOLTS
[Re: Mopar Mitch]
#2514468
06/28/18 02:31 PM
06/28/18 02:31 PM
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Joined: Jan 2010
Posts: 1,442 NW Chicago suburban area
Mopar Mitch
OP
pro stock
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OP
pro stock
Joined: Jan 2010
Posts: 1,442
NW Chicago suburban area
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Well, after getting new ARP Rocker Arm stud kit #144-7201 (Mopar Small Block), these studs are too short!... they will be returned... package indicates "318-360 Magnum"... so, the web-sites need to clarify this... as they will not work with the LA engines, (especially not with the Hughes shaft assembly). We are ordering from another supplier studs that are 1/2" longer than the Hughes studs, and with center hex.
Will let you know again with an update.
Mopar Mitch
"Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers!
Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!
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