#1  
Old 09-09-2021, 04:36 PM
Joer Joer is offline
Junior Member
 
Join Date: Sep 2021
Posts: 2
Default Offenhauser

Need help!! I am putting a Offenhauser duel quad 360 on my 75 455. It is hitting the valley pan. Has anyone ever heard of this and what would be the correct valley pan to use???
Thanks Joe.

  #2  
Old 09-09-2021, 05:22 PM
tom s tom s is online now
Ultimate Warrior
 
Join Date: Jan 2000
Location: long beach ca usa
Posts: 18,764
Default

Yes,some valley pans have a raised part kind of in the middle that can interfere with 2-4s and 3-2s.Tom

  #3  
Old 09-09-2021, 05:25 PM
Joer Joer is offline
Junior Member
 
Join Date: Sep 2021
Posts: 2
Default

Thanks Tom, do you know which valley was used? I was thinking an early tri power valley pan? I just did not want to get order it and get stuck with it.
Thanks again,
Joe

  #4  
Old 09-09-2021, 05:32 PM
Half-Inch Stud's Avatar
Half-Inch Stud Half-Inch Stud is offline
Ultimate Warrior
 
Join Date: Jul 2000
Location: BlueBell, PA or AL U.S.A.
Posts: 18,457
Default

Some designs clear, and others need convincing.

The Following User Says Thank You to Half-Inch Stud For This Useful Post:
  #5  
Old 09-09-2021, 10:01 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,294
Default

Some need a lot of convincing.

If the car is not driven in the winter, I would switch to a All Pontiac Aluminum valley pan (Lots of clearance but no PCV
system in the aluminum pan) and then use the 74 455 SD PCV system: Fresh air from the air cleaner into one valve cover
and a PCV Valve (installed in the other valve cover) with hoses going to the intake manifold or the nipples at the rear of the carbs.

Tom V.

__________________
"Engineers do stuff for reasons" Tom Vaught

Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward.
  #6  
Old 09-09-2021, 10:24 PM
tom s tom s is online now
Ultimate Warrior
 
Join Date: Jan 2000
Location: long beach ca usa
Posts: 18,764
Default

I would believe ANY 66 or earlier will clear your Offy.Tom

The Following User Says Thank You to tom s For This Useful Post:
  #7  
Old 09-10-2021, 06:02 AM
steve25's Avatar
steve25 steve25 is offline
Ultimate Warrior
 
Join Date: May 2008
Location: Westchester NY
Posts: 14,633
Default

You need a Ames performance N178WK valley pan if you can't find a early used one.

__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs!
And he was not talking about 1/8 or 1/4 mile ETs!

1) 1940s 100% silver 4 cup tea server set.

Two dry rotted 14 x 10 Micky Thompson slicks.

1) un-mailed in gift coupon from a 1972 box of corn flakes.
Two pairs of brown leather flip flops, never seen more then 2 mph.

Education is what your left with once you forget things!
  #8  
Old 09-11-2021, 03:25 PM
Bill Eveland's Avatar
Bill Eveland Bill Eveland is offline
Ultimate Warrior
 
Join Date: Apr 2004
Location: Glasford Il
Posts: 3,650
Default

If you need a pcv, BOP engineering valley pan has a stand tube for a pcv valve

__________________
Illinois Outlaw Gassers

6.27@107
9.97@131
  #9  
Old 09-11-2021, 04:12 PM
tom s tom s is online now
Ultimate Warrior
 
Join Date: Jan 2000
Location: long beach ca usa
Posts: 18,764
Default

A aftermarket is not necessary!I have run 2-4s for close to 60 years now and have never used one.Tom

  #10  
Old 09-11-2021, 04:38 PM
"QUICK-SILVER" "QUICK-SILVER" is offline
Ultimate Warrior
 
Join Date: Feb 2008
Location: LaFayette Georgia
Posts: 5,512
Default

Someone needs to ask exactly where this intake is touching.

Around the edges is trim and grind.

75 EGR should be sunk deep in the middle.

Clay

  #11  
Old 09-11-2021, 05:57 PM
61-63's Avatar
61-63 61-63 is offline
Ultimate Warrior
 
Join Date: Jun 2001
Location: Sour Lake, Texas
Posts: 2,394
Default

Tom S. is correct. You need one of the earlier pans which has the down draft tube/pcv port at the rear of the pan on the passenger's side. I'm not sure when they stopped making them that way but '66 as Tom said is about right. Those pans have a wide dip from front to rear and the offy will clear it. The later pans with the pcv port at the front of the pan have a much narrower dip front to rear and the intake will not clear. What is hitting is the heat cross over in the center of the pan under the plenum that runs between the two carb bosses. I have an offy on my test stand engine which has a '61 pan on it and it clears. Then my '65 GTO which has a ?? 72 400 engine in it and the correct pan for that engine will not accept an offy 2x4 intake.

  #12  
Old 09-11-2021, 06:13 PM
b-man's Avatar
b-man b-man is offline
Moderator
 
Join Date: Sep 2002
Location: Sunny So Cal
Posts: 16,411
Default

You want a ‘65 - ‘67 valley pan. They’re easy to identify with the rear PCV location along with four notches at the sides for each of the four pairs of intake runners.

‘64 and earlier are slightly wider due to the higher intake port location and will interfere unless trimmed on both sides. These ones don’t have the notches to clear the runners on the bottom of intake manifold.

__________________
1964 Tempest Coupe LS3/4L70E/3.42
1964 Le Mans Convertible 421 HO/TH350/2.56
2002 WS6 Convertible LS1/4L60E/3.23
  #13  
Old 09-11-2021, 06:37 PM
tom s tom s is online now
Ultimate Warrior
 
Join Date: Jan 2000
Location: long beach ca usa
Posts: 18,764
Default

I think Butler sells new ones.Tom

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 -4. The time now is 10:20 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017