Author Topic: studs to mount intake manifold?  (Read 8809 times)

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rcodecj

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studs to mount intake manifold?
« on: January 08, 2012, 06:25:52 PM »
After having one of the threads pull out on the intake side of my Edelbrock heads I am considering using studs.
My thought is that I would double nut them before installing the intake and then after laying the intake down aligned with distributor, I would thread them in like a normal bolt and then take the top nut off.
I have found 3.5"  and 2.5" ARP studs at Summit Racing for around $70, nuts and washer would be more, pricey but I don't want to have another failure, especially on the middle ones which are extremely hard or impossible to heli-coil with the intake on.

Jay, when you did the intake comparo, how did have any problems with the multiple torquing of intake bolts on the aluminum heads?

If I go with studs would the torque setting be different?

jayb

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Re: studs to mount intake manifold?
« Reply #1 on: January 08, 2012, 07:37:05 PM »
I did indeed have problems with the intake bolt threads after multiple manifold changes, and ended up heli-coiling most of the intake bolts in my Edelbrock heads as a result.  I'm not sure what studs would buy you in this case, since you would have to remove and replace the studs with every manifold change, just like you would with bolts.  I would recommend either helicoils or EZ-Loks or Timeserts or something like that if you have a stripped thread, and using some lubricant on the bolt threads if you just want to minimize any damage from repeated R&R of the bolts.
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

afret

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Re: studs to mount intake manifold?
« Reply #2 on: January 08, 2012, 07:56:52 PM »
Yeah, decided to use studs so the threads in the head won't strip.  Just a little extra step to thread in/out the studs.  Works great.


rcodecj

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Re: studs to mount intake manifold?
« Reply #3 on: January 08, 2012, 08:00:05 PM »
Let me clarify my post, I'm not so worried about multiple intake changes as I am thinking about added strength.
I don't think a stud will pull the threads out of the heads like a bolt will, since they would not be threaded in under torque. Plus you are assured of full thread engagement.
I always thought a stud will take more torque before stripping than a bolt. Am I wrong?
I have already put a heli-coil in the stripped one. I thought about doing them all but read where someone had problems with the end ones leaking water after putting in heli-coils.
I thought they said it was a diameter issue, but not sure exactly, doesn't sound right to me.
I might at least heli-coil the other side middle one as they would be tough or impossible to do with the intake on.
I don't know if I'd want to heli-coil any of them with the intake on.
« Last Edit: January 08, 2012, 08:04:07 PM by rcodecj »

rcodecj

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Re: studs to mount intake manifold?
« Reply #4 on: January 08, 2012, 08:02:09 PM »
Yeah, decided to use studs so the threads in the head won't strip.  Just a little extra step to thread in/out the studs.  Works great.


You posted at the same time as me.
Do you remember what brand and length stud you used?
My PI intake looks like it will call for 3.5" and 2.5", unless I use the rear bolt spacers, then they could all be 3.5".
Also do you still torque the nuts to the same torque as you did the bolts, 25 ftlbs or whatever.
I realize some you cannot get a torque wrench on.
« Last Edit: January 08, 2012, 08:05:52 PM by rcodecj »

jayb

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Re: studs to mount intake manifold?
« Reply #5 on: January 08, 2012, 09:02:18 PM »
My issue with the bolts had to do with multiple manifolds where the bolts did not line up correctly with the threaded holes in the heads.  So, you had to apply some pressure to the bolts to get them to thread in.  This seemed to make them strip rather easily.  I think you would be faced with the same problems with studs, but I see your point about using studs, assuming the holes in the manifold line up with the holes in the head.  FYI, I have helicoiled quite a few end bolts, and can't recall any where I broke into the water jacket.  I didn't drill any deeper than the original hole, though.  If you did break through, a little sealer ought to do the trick.
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

rcodecj

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Re: studs to mount intake manifold?
« Reply #6 on: January 08, 2012, 09:15:50 PM »
My issue with the bolts had to do with multiple manifolds where the bolts did not line up correctly with the threaded holes in the heads.  So, you had to apply some pressure to the bolts to get them to thread in.  This seemed to make them strip rather easily.  I think you would be faced with the same problems with studs, but I see your point about using studs, assuming the holes in the manifold line up with the holes in the head.  FYI, I have helicoiled quite a few end bolts, and can't recall any where I broke into the water jacket.  I didn't drill any deeper than the original hole, though.  If you did break through, a little sealer ought to do the trick.
Yea, I understand your issue. You hit the nail on the head where some bolts thread in nicely and others there is resistance indicating a possible clearance problem.
I think when I get my manifold back I will scribe lines so I know where I want it located and then check to see if all the bolts/studs go in nicely.
If they do not then something will have to be done with the manifold hole/holes.

Another thought is since the distributor locates the intake manifold, how much can you really move the manifold front to back anyway (for port alignment between intake manifold and head) without putting the distributor into a bind condition. I would say very very little.

afret

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Re: studs to mount intake manifold?
« Reply #7 on: January 08, 2012, 10:09:50 PM »
Quote
Do you remember what brand and length stud you used?
My PI intake looks like it will call for 3.5" and 2.5", unless I use the rear bolt spacers, then they could all be 3.5".
Also do you still torque the nuts to the same torque as you did the bolts, 25 ftlbs or whatever.
I realize some you cannot get a torque wrench on.

Just got long (4 or 4 1/2 inch I think) fully threaded grade 8 cap screws and cut them to length.  You can get grade 8 threaded rod also from places like McMaster-Carr and cut it to the right length.

I reamed out the intake bolt holes so the studs would all go in easily with no interference.  I've never torqued the intake fasteners and just use a short box end wrench and tighten them down. 

66FAIRLANE

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Re: studs to mount intake manifold?
« Reply #8 on: January 09, 2012, 12:46:52 AM »
I suppose the only real advantage would be ensuring full thread engagement and preventing bottoming of bolts. Also may help with side interference as the threaded bar (stud) would be slightly smaller in diameter than the shank section of a bolt. Having said that I use stainless cap screws with Anti Seize and torque it with a calibrated wrist also.

rcodecj

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Re: studs to mount intake manifold?
« Reply #9 on: January 09, 2012, 10:07:05 AM »
The most important advantage as I see it:
From Circletrack magazine:
"Studs are also easier on the threaded holes in the block because you’re not pulling against the threads in the block to pull the stud into place. The torque isn’t applied until after the threads in both the bottom of the stud and the block are fully engaged."

http://www.circletrack.com/techarticles/ctrp_1111_high_performance_bolts_and_assembly_processes/viewall.html

cammerfe

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Re: studs to mount intake manifold?
« Reply #10 on: January 09, 2012, 02:14:35 PM »
Hardened stainless steel all-thread makes for good studs. Use anti-seize and stainless acorn nuts for a finished look. (I go back after a week or two and replace the regular nuts with acorns after everything has set up.)

KS

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Think Set Screws
« Reply #11 on: January 09, 2012, 07:33:56 PM »
You might also consider steel Set Screws.  You can install set screws with a Tee wrench instead of double nuting a stud, and most Set Screws are hardened steel  The black ones look pretty sharp with a nice shiny nut and washer on them. Just be sure to run in a bottom tap to prep hole for Set Screw and a dab of Never Seize will never hurt.  No need bottom the Set Screw hard, just touch the bottom hand tight. If you feel that the Set screw is backing out when you loosen the nut just make the adjustment with an Allen Wrench. I wouldn't change my Torque to much only because you are still pulling at the threads in the aluminum heads.   JMO

rcodecj

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Re: studs to mount intake manifold?
« Reply #12 on: January 23, 2012, 05:16:48 PM »
I ended up using ARP studs, they have an allen head so I won't have to double nut to put them in. I also used ARP nuts and washers.
It feels very much smoother when you torque the intake manifold down. Very expensive though.

For my PI intake I used:

Studs to mount PI intake (qty 8 ) 3.5”, ARP AJ350001B
Studs to mount PI intake (qty 2), 2.5”, ARP AJ2-500-1B
Flat washers to mount PI intake (qty 10) 3/8 ID, 5/8 OD, .120 thick and hardened  ARP-200-8504
Nuts to mount PI intake (qty 10) 3/8-24 ARP 200-8604, it's listed as a rod nut and has a nice shoulder.
Sometimes it's cheaper to buy a 10 pack, but I found it cheaper to buy 10 individual nuts/washers.

For the thermostat housing I used a  Spectre Performance 42513.
This is a carb stud kit so you get 4, what's nice is they have a narrowed down tip so you can start the nut easier and it can't fall off while you are putting it on.
It also has a hex on the end of the stud for turning in if needed. Nice for only $5 and I'll put the other two on my other car.
http://www.summitracing.com/parts/SPE-42513/

I also bought an ARP distributor hold down stud kit  ARP 150-1702.
This also has a necked down tip so you can start the nut easier.
« Last Edit: January 23, 2012, 05:18:51 PM by rcodecj »