intake manifold variations (FAQ) (2 Viewers)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

65swb45

65swb45

Elder Statesman
Supporting Vendor
Joined
Apr 14, 2004
Threads
1,391
Messages
35,257
Location
818-953-9230
Website
www.marksoffroad.net
The question was posed in a separate thread, but I thought it would be easier to find this info later if it was posted directly on topic in it's own thread.

58-9/66: F135 Engine [3.9 liter] 1bbl cast iron intake standard, 2bbl optional. 4 bolt attachment to exhaust manifold

9/66-9/69: F145 Engine[3.9 liter] 2bbl aluminum intake with wide runners standard. 3bolt attachment to exhaust. 4 bolt bosses on the side of the intake for oil filter bracket, which attached via an adapter plate.

10/69-1/72: F145 Engine[3.9 liter] 2bbl intake with narrow runners. 69 and 70 models had one vacuum port only, for the 4wd shifter. 71 had one port on the side for the brake booster. 72 added a second one in front of the carb for filtered manifold vacuum.

1/72-12/74: F155 Engine[ 3.9 liter] 2bbl intake with narrow runners. 74 Cali intake is distinguishable because there is a large hole in the side of the intake under the carb for the Cali-spec EGR system.

1/75-1/79: 2F [4.2 liter] 2bbl intake with 5 bolt attachement to exhaust. Port behind carb for brake booster, port under carb for PCV, port in front of carb for filtered vacuum source.

1/79-9/87 2F [4.2 liter] 2bbl aluminum intake with 5 bolt attachment to exhaust. Main distinction from earlier 2F intakes is that EGR ports into the side of the intake underneath the carb, alongside the PCV system.
 
In the F A Q



Thanks Mark man!


:beer: :beer:
 
WOW! My first FAQ on MUD. I'm somebody now!;p
 
good info Mark


thanks
 
brian said:
yes, but nobody will ever see it:D as it seems nobody uses the faq.
Click to expand...

50 points for the man with the sodium pentathol!:rolleyes:
 
I have a 66-69 with the wide runners and a 72 with the narrow runners. Both have all the vacuum ports I need.

I am running SOR headers, along with a Holley 350 carb. Is there any preference for the narrow vs wide runners for air/fuel flow on the intake side?

I've been running the intake with the wide runners for 2 years on a 77 2F engine.
 
Well, at first glance, a Holley 350 would seem to suggest that you are motivated by a need for speed!

Rather than just making the assumption, I'll offer this. The narrower runner manifolds are going to keep manifold vacuum higher at lower rpms, but become somewhat restrictive at high rpms. The wider manifold isn't gonna have quite as much vacuum at the lower rpms, but will obviously move more air for higher rpm operation.

I use the narrower manifold on my '68, which is pretty well built. I notice a little drop off in power above 4000 rpm because of the manifold. But I get in that RPM range so seldom, I can more than live with the trade off; I like the higher vacuum and torque at slow speed that the 'smaller' manifold gives.

Hth

Mark A.
 
Last edited:
I take the other side of the arguement. I feel that the gain in mid range and top end on a built engine is noticable.

For most stockish engines, this manifold won't gain you anything.

;)


Mark...
 
I've been having the same argument with myself. I actually have the Holley with a 2 stage power valve for high altitude performance, not necessarily for speed, though it does provide that also. In fact, I put in a Downey cam for more mid-range/low-range torque. I have the engine balanced, so 3,400 - 3,600 or more rpm is not a problem, but I rarely am above 3,200 rpm.

I'ts a daily driver, but also gets some serious offroad work in rough country at 10000 ft elevation when I'm hunting elk.

Based upon your observations, I think I'll try the narrow runner intake, at least for now. I've had the wide one on for two years, so I know what it does.

Thanks, Mark.
 
Thought I'd add a couple of pics. The top one is a 9/66-9/69 wide runner intake and the bottom one is, uh later, I guess? EDIT: I meant the wide runner is on the RIGHT!

Ed
Intake 001.jpg
Intake 002.jpg
Intake 003.jpg
 
Last edited:
That's cool that the wide runner has the firing order stamped into it.
 
In the first pic you can see how deep the sparation of the runners actually is. The side view shows the relative thickness of the two.


IDave.......like you need the firing order stamped on the intake. s***, that's on the wrong side of the motor! What good would that do?!?!?!?!:D
AFAIK, the firing order of all 6 cylinder motors is the same. At least the Toyota F/2F is the same as my BMW.


Ed
 
Last edited:
I ended up going back to the wide runner manifold, after I had cleaned up and prepped the narrow one. I guess it came down to "the devil you know versus the devil you don't."
 
You must log in or register to reply here.

Similar threads

calen
tips on removing 2h intake manifold?
Replies
8
Views
706
calen
calen
jbee
Can I remove these head bolts? Intake manifold gasket questions.
Replies
11
Views
920
jbee
jbee
fj40cm1980
Rust around carb base and air intake manifold rail
Replies
4
Views
799
Chilkoot
Chilkoot
C
What does this go to on the Intake Manifold?
Replies
6
Views
785
1911
1911

Users who are viewing this thread

Total: 3 (members: 0, guests: 3)

Share this page

Back
Top Bottom