Intake/exhaust question
Thread Starter
|
New User
Joined: Apr 2013
Posts: 1
Likes: 0
Intake/exhaust question
I'm replacing the intake/exhaust manifold in a 1983 f150 300 straight six. Is there a specific bolt sequence on the bolt down? I know it's 20ft/lbs on the intake and 27 on the exhaust.
Postmaster
Joined: Feb 2011
Posts: 3,560
Likes: 1
since the intake and exhaust manifolds share bolts, they cannot have different torque specs.
as for sequence, do it much like torquing down a head, working from the center outward. but also include the 3 bolts that connect the intake to the exhaust in your sequence. if i remember right, its best to start with those 3 bolts a little more than finger-tight, then put all the rest of the bolts to just snug, in sequence, then tighten the 3 bolts to maybe 10 ft-lbs, then do the same on the rest of them, then go up to the proper spec and repeat the same sequence.
if in doubt, work in smaller steps, maybe only 5 ft-lbs at a time.
and if something really jumps when torquing it to the head, don't be afraid to loosen the 3 bolts, retighten them, and then do the same with the bolts holding it all to the head.
the goal is to have no weird forces on the manifolds, so everything has to settle into its comfortable home.
as for sequence, do it much like torquing down a head, working from the center outward. but also include the 3 bolts that connect the intake to the exhaust in your sequence. if i remember right, its best to start with those 3 bolts a little more than finger-tight, then put all the rest of the bolts to just snug, in sequence, then tighten the 3 bolts to maybe 10 ft-lbs, then do the same on the rest of them, then go up to the proper spec and repeat the same sequence.
if in doubt, work in smaller steps, maybe only 5 ft-lbs at a time.
and if something really jumps when torquing it to the head, don't be afraid to loosen the 3 bolts, retighten them, and then do the same with the bolts holding it all to the head.
the goal is to have no weird forces on the manifolds, so everything has to settle into its comfortable home.
Thread
Thread Starter
Forum
Replies
Last Post
hillcountryflt
Ford Inline Six, 200, 250, 4.9L / 300
15
Oct 13, 2020 10:57 AM
scottddove
Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)
2
Nov 9, 2007 09:59 PM
PaulzF150
Ford Inline Six, 200, 250, 4.9L / 300
5
Mar 4, 2006 03:18 PM
