Go Back   Infamous Nissan - Hardbody / Frontier Forums > Model Specific > Hardbody Forum (D21)

Reply
 
Thread Tools Display Modes
Old 12-14-2021, 05:04 PM   #1
jrpitdog
 
Join Date: Nov 2021
Location: Colorado
Posts: 15
Vehicle: 1994 D21
Thanks: 0
Thanked 1 Time in 1 Post
Default Exhaust manifold/studs/headers

I have been reading through old threads. Im aware of the manifold stud problem. I dont notice any manifold leak currently on my 94 4x4 v6, but I have only owned it for a few months, its has about 180k miles. It seems with how common this problem is that its just a matter of time.

Should I go ahead and replace the studs as preventative? My thoughts are, its going to be easier to replace studs that arent broke off in the head.

Anyone use ARP studs? I know they dont make a specific kit, but they do make 8mmx1.25 stainless studs, expensive as hell, but in my experience they are the absolute best you can get, just need to confirm length is good.

I know the header options are basically Pacesetter(which I dont think they actually make anymore, cant find them on their actual site, still found at suppliers), and Thorley. I would love to justify the cost of the Thorleys. My question is how well do the Thorleys fit? I read the write up on the Pacesetters and it sounds like an incredible PITA!! I know they are meant for 4x4, but I read another review I think on Summit and they said they y-pipe didnt fit on his 4x4 either, maybe thats why they dont make them anymore, lol.

Im normally a "dont fix it if its not broken" but I really dont want to be extracting broken off manifold bolts, and if Im pulling them off, maybe the extra cost of the headers is worth it
jrpitdog is offline   Reply With Quote
Old 12-14-2021, 08:39 PM   #2
rbourgeo
 
rbourgeo's Avatar
 
Join Date: Mar 2020
Location: British Columbia, Canada
Posts: 171
Vehicle: 1996 D21
Thanks: 55
Thanked 37 Times in 27 Posts
Default

In my experience the studs are fairly easy to get out of the head, even if they broke flush, but YMMV…
I personally wouldn’t worry about it until they do.

No experience with arp or headers.
rbourgeo is offline   Reply With Quote
Old 12-14-2021, 09:03 PM   #3
Deerhurst
4/86 SE-V6 2 tone 4x4 HB
 
Deerhurst's Avatar
 
Join Date: Apr 2013
Location: Oregon
Posts: 8,041
Vehicle: 1986.5 SE-V6 4WD D21, 2003 Audi A4 Avant 3.0 Quattro
Thanks: 917
Thanked 1,080 Times in 976 Posts
Default

You probably read JP's writeup with the long tubes on his 2wd. Did you read mine?



I wouldn't worry about fancy studs if you go with headers. The flange is pretty thin and will flex with the head as things get hot. You may want to snug down the bolts a few times after install and a few heat cycles but after than you shouldn't need to. I havnt touched mine in years. I just used whatever studs my local parts house hand in that thread and length.



I had one broken stud. It was an huge PITA to remove. Ended up drilling it out and putting a helicoil in.



The Y pipe on my pacesetters was too narrow and had to be cut and widened. Not a big deal.



I have not tried thorley. Basically anything you do will be a tight fit and will interfere with getting to the oil filter. In my thread I list an oil filter that works fine and doesn't get caught between header and frame. I'm now running a VG33 (with the same VG30 headers with no mods to the headers) so oil filter isn't an issue anymore.
__________________
1986.5 SE-V6 4X4 D21 Hardbody
Pacesetter Long Tube Headers
Morimoto Mini D2S HID Projectors and Hella 500s
VG33i
Deerhurst is offline   Reply With Quote
Old 12-14-2021, 09:07 PM   #4
Deerhurst
4/86 SE-V6 2 tone 4x4 HB
 
Deerhurst's Avatar
 
Join Date: Apr 2013
Location: Oregon
Posts: 8,041
Vehicle: 1986.5 SE-V6 4WD D21, 2003 Audi A4 Avant 3.0 Quattro
Thanks: 917
Thanked 1,080 Times in 976 Posts
Default

My phone is being stupid and not bringing up the keyboard when I try to edit.







Remflex gaskets. Worth it. Only gasket I have failed to blow out. I've killed fel-pro and pacesetter flange gaskets. Neither last more than a week or two. Remflex has been in there for year. It's a big thick thing. Get the one for the VG30 Z car. You will have to cut the gasket and flip one port because the car heads have a different bolt pattern on one side vs the truck.



This is all in my thread. I'll see if I can find a link.
__________________
1986.5 SE-V6 4X4 D21 Hardbody
Pacesetter Long Tube Headers
Morimoto Mini D2S HID Projectors and Hella 500s
VG33i
Deerhurst is offline   Reply With Quote
Old 12-14-2021, 09:55 PM   #5
jrpitdog
 
Join Date: Nov 2021
Location: Colorado
Posts: 15
Vehicle: 1994 D21
Thanks: 0
Thanked 1 Time in 1 Post
Default

Good to know. Im hoping my truck being a 94 4x4, the fitment should be a bit better. And if I have to cut and weld on the y-pipe...I guess thats why I have a welder.
jrpitdog is offline   Reply With Quote
Old 12-14-2021, 10:02 PM   #6
jp2code
Software Developer
 
jp2code's Avatar
 
Join Date: Dec 2011
Location: Longview, TX [USA]
Age: 52
Posts: 11,119
Vehicle: 94 LB 2x4 Manual VG33e
Thanks: 1,824
Thanked 1,777 Times in 1,551 Posts
Default

The problem with expensive studs is they could still break. Then you have hardened steel studs that you can't drill out.
__________________
Joe (not a mechanic!) Don't have an account? EMAIL ME
Factory Service Manuals: https://www.nicoclub.com/FSM/Hardbody/
Walk-through: Checking Nissan Trouble Codes
1994 VG30E to VG33E with H256 Cams

jp2code is offline   Reply With Quote
Old 12-15-2021, 02:40 AM   #7
Deerhurst
4/86 SE-V6 2 tone 4x4 HB
 
Deerhurst's Avatar
 
Join Date: Apr 2013
Location: Oregon
Posts: 8,041
Vehicle: 1986.5 SE-V6 4WD D21, 2003 Audi A4 Avant 3.0 Quattro
Thanks: 917
Thanked 1,080 Times in 976 Posts
Default

The VG30 from 86.5-95 is the same. Hell, theVG33 is the same as far as the exhaust routing goes for headers.



I can almost gurantee you will have to cut and weld.
__________________
1986.5 SE-V6 4X4 D21 Hardbody
Pacesetter Long Tube Headers
Morimoto Mini D2S HID Projectors and Hella 500s
VG33i
Deerhurst is offline   Reply With Quote
Old 12-15-2021, 03:32 AM   #8
SBJ
Total Buzzkill
 
Join Date: Nov 2016
Location: OR
Posts: 3,108
Vehicle: '90 D21 4cyl 5spd 2wd
Thanks: 347
Thanked 593 Times in 527 Posts
Default

I'd agree with JP, hardened studs will be a pain if any of them ever break off flush with the head. It would be a lot like if you broke off a tap or an easy out in there. I did this job on a pathfinder recently (not headers, just the gaskets and manifold studs) and I just bought a couple of exhaust stud kits for a Ford 4.6/5.4 engine. They are the same thread pitch, M8x1.25. The side that threads into the head is a little long, but if you cut them down to match the factory studs it'll be fine. I also used some generic GM exhaust manifold studs for the flange at the downpipe and cut them to match the originals. They are M10x1.5, IIRC.



SBJ is offline   Reply With Quote
Old 12-15-2021, 11:30 AM   #9
Foul_Mouth
Pounding Rox Truck
 
Foul_Mouth's Avatar
 
Join Date: Mar 2010
Location: Western NY
Posts: 4,842
Vehicle: Too Many to List Here
Thanks: 592
Thanked 879 Times in 685 Posts
Default

I went with ARP bolts, not studs.
__________________
*1992 Supercharged and Body Swapped WD21 Pathfinder
*1995 D21 Regular Cab 2wd
*(2)1991 D21 Regular Cab
*1990 WD21 Pathfinder Frame
*2004 Xterra
*2010 Infiniti G37x

Nissan Truck Videos (Builds-Racing-Shows-Tech)
https://www.youtube.com/c/NissanTruckguy
IG@ rainmaker_d21









Foul_Mouth is offline   Reply With Quote
Old 12-15-2021, 01:19 PM   #10
Cusser
 
Cusser's Avatar
 
Join Date: Aug 2016
Location: Hot Arizona
Posts: 789
Vehicle: 2004 Frontier
Thanks: 0
Thanked 144 Times in 127 Posts
Default

Use never-seize lubricant.
__________________
2004 Frontier King Cab (2WD, 5-speed, 4-cylinder, 105K), 1998 Frontier regular cab (2WD, 5-speed, 4-cylinder 253K), 1988 Mazda B2200 (2WD, 5-speed, 4-cylinder, 220K), 1971 VW Convertible (140K), 2005 Yukon (215K), 1970 VW (260+K)
Cusser is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 02:20 PM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.