Rochester 2GC help needed Tri-Power - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 12-01-2013, 01:04 PM
Registered User
 
Join Date: Dec 2013
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Rochester 2GC help needed Tri-Power

I am planning on a 3x2 set up using my present Rochester 2GC small base for the center carb.What fittings,size, NPT?,do I need for the large threaded hole in the rear of the throttle body which I have read is for a PCV valve.Do most hot rodders keep the PCV valve?I saw photos of one Tri-Power carbs and manifold for sale and the center carb had a 90 degree elbow coming off the back of the throttle body leading to a hose barb,but the barb was capped.Does a hose lead to the PCV valve mounted off the engine?Obviously this is my first build so any information will be appreciated and will be more than I already know on this subject.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 12-01-2013, 09:23 PM
68NovaSS's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Working with chromed bolts
Last journal entry: New to me T-Bucket
Last photo:
Join Date: Sep 2002
Location: Nine Mile Falls/Suncrest, WA
Posts: 5,285
Wiki Edits: 9

Thanks: 113
Thanked 139 Times in 130 Posts
Why not just take the carb down to Home Depot, Lowes or the parts store and trial fit their fittings?
__________________
Boost adds dignity to what would otherwise be a vulgar brawl...

Midnight Sun Street Rod Association
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 12-02-2013, 06:32 AM
Registered User
 
Join Date: Jun 2010
Location: TX
Posts: 1,259
Wiki Edits: 0

Thanks: 0
Thanked 110 Times in 101 Posts
The threaded port in the rear of the center carb base is a vacuum source for the heater door actuator and the distributor vacuum advance. It takes a special T-fitting and most people plug it. The tri-power manifolds were only interchangable on cylinder heads from 1957-1960, 1961-1964, and 1965 - 1966. A PCV port was not required on factory tri-power intake manifolds until 1963. The 1963-1966 389/421 tri-power manifolds had a twin-port vacuum source for a dual plane manifold for the PCV. The ports are located between the center and rear carb. A 1961-1962 389 CI tri-power had a PCV provision but it was piped to a special spacer under the center carb. There are no PCV ports in the 1961-1962 manifolds. The special fiber spacer with the PCV pipe is a very rare item because most of them have been tossed in the trash.

IMO.... a Pontiac tri-power is only for the "WOW" effect when you pop the hood and should only be used by restorers. For performance, a Pontiac Rochester tri-power is a expensive way to only get 660 CFM at WOT. A 1962-1966 Carter AFB 4-barrel carb is rated at 625 CFM at WOT and is less troublesome.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 12-02-2013, 06:33 AM
Banned
 
Last photo:
Join Date: Nov 2012
Location: Florida
Posts: 2,442
Wiki Edits: 0

Thanks: 195
Thanked 461 Times in 410 Posts
check through this link.

https://www.google.com/search?q=+Roc...-US%3Aofficial
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 12-02-2013, 08:18 PM
Registered User
 
Join Date: Nov 2008
Location: South Jersey
Posts: 66
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
is this carb setup going on smallblock chevy? or are you restoring something that came with the tri power? if you are intending on using the 3 arb setup for nostalgic purposes, its a great way to revive some nostalgia. if you want simple, trouble free power, the 4 barrel is a far better answer. (as stated in an earlier post) Since this is your first build, I am going to assume it is going to be a small block with a non-factory setup. Be advised that the 3x2 set up takes a lot more precision than a single 4 barrel setup. (They don't call them triple trouble for nothing) I have a setup on my SBC that is in my '31 hi boy. until I got it right, I drove around with secondary carbs blocked off and unhooked. I had originally gotten carbs rebuilt by a guy in Florida. He did not do a very good job. I then got a hold of Charlie Price of Vintage Speed. Amen the whole setup works flawlessly. I also reccomend a HEI distributor. I rebuilt my distributor with the pertronix kit, but you can also buy the distributor that is the same size as old points style distributor. just be sure that you have clearance between distributor and firewall. Sorry to ramble on, but I wish that I had this info before I started my project. BTW when you crack the throttle and all 3 carbs open up... the sound is priceless.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 12-03-2013, 06:49 AM
Registered User
 
Join Date: Dec 2013
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks, the carb is off a 1963 Chevrolet which is about all I know,since its ID tag was gone.Thanks for all the information.Its for nostalgia in part, for a small block Chevy someday.Tulsa Edison high class of 1959 reporting for duty,so you see where I am headed on nostalgia road.I had a red 1958 Delray "synchromesh" a word no one ever used with the big block 348 with a four barrel.Very few could beat me for a city block and half but one guy with the same car with 3x2 edged me out at block two and I have never gotten over it.I think he had done some other "improvements" too.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 12-03-2013, 09:38 AM
Registered User
 
Join Date: Jun 2010
Location: TX
Posts: 1,259
Wiki Edits: 0

Thanks: 0
Thanked 110 Times in 101 Posts
Nostalgia:

In 1965, I purchased a Edelbrock 3-2 bbl intake manifold for the SB Chevy engine in my 1959 Chevrolet Impala. I purchase all new 1966 Pontiac GTO Rochester tri-power carbs from Holley Chevrolet dealership. The counterman and I closely examined the Master Parts Catalog diagram and we ordered all the parts I needed, including the factory linkage, air cleaners and foam filter elements.

The dealership bolted the tri-power set up on a new 1965 327 CI, 365 HP Chevrolet short block in my 1959 Impala. The engine started instantly and ran perfect with only a minor adjustment to the center carburator idle mixture and idle speed. I topped off the engine with a rebuilt pair of 1964 double-hump FI heads and a new pair of Corvette valve covers.

Holley Chevrolet was one that specialized in Chevrolet high performance parts and vehicles. The Holley Chevrolet dealership was one that was chosen to sell a 1969 Chevrolet Camaro COPO with a aluminum 427 ZL1 engine. The Cortez Silver Camaro was #6 of 69 1969 Camaros made with a 427 ZL1 engine and was ordered and sent to Fred Gibb in La Harpe ILL and re-sold Holley Chevrolet. The #6 ZL1 Camaro was finally sold to Jim Hall Racing and they installed the 427 engine in the last Jim Hall Chaparal race car.

.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 12-03-2013, 03:58 PM
Carter Carb Shop, parts & serv
 
Last photo:
Join Date: Dec 2009
Location: Virginia
Posts: 144
Wiki Edits: 0

Thanks: 5
Thanked 11 Times in 9 Posts
I seem to remember the original triple two barrels having a hollow carb stud for vacuum, there wasn't much room and none had pcv - maybe the later corvette & chevelle, but they had holley carbs.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 12-04-2013, 06:20 AM
Registered User
 
Join Date: Jun 2010
Location: TX
Posts: 1,259
Wiki Edits: 0

Thanks: 0
Thanked 110 Times in 101 Posts
Pontiac first used a PCV on the 1962 tripower engines. All 1955 -1962 GM engines with a 2-bbl , 4-bbl and 2-4 bbl did not have a PCV and used draft tubes to evacuate the crank case. . The 1957-1962 Pontiac tri-power intake manifolds did not have a provision for a PCV. However, the 1962 tri-power engines had a PCV system by using a 3/8" fiber spacer under the base plate of each carb. The spacer under the center carb was equiped with a PCV nipple with a hose to the PCV in the rear of the valley cover. Starting in 1963, all GM engines and intake manifolds had PCV provisions in each plane of the dual-plane intake manifold. If you want a 1963-1964 Pontiac engine without PCV, use a 1961-62 2-bbl, 4-bbl or 3-2 bbl intake manifold.

The hollow carb stud was usually capped and not used for anything.

Last edited by MouseFink; 12-04-2013 at 06:26 AM.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 12-05-2013, 11:18 AM
Registered User
 
Join Date: Dec 2013
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I decided to plug the "pcv"threaded hole at rear of throttle block.Does anyone know what size male plug and is it NPT?I would rather not have to take the carb into a auto parts store.Carb in from 1963 Chevy 283 and is Rochester 2GC small base.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 12-05-2013, 03:28 PM
Registered User
 
Join Date: Apr 2012
Location: washington state
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
66 was the last year for Pontiac tri power, also they used the larger flowing 2gc carbs in the end positions giving a larger total air flow than the 4 barrel of the same year. my 65 has the 3 small carbs . the tri power on my 66 has the bigger end carbs.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Rochester 2 barrel 2GC Float Settings. JoshuaRhine27 Hotrodding Basics 1 11-02-2011 10:12 PM
Rochester 2gc 2 bbl. problems... turbotbucket Engine 4 07-14-2011 08:21 AM
what Rochester carbs for tri-power new_rat_rodder Engine 7 09-05-2007 05:14 PM
rochester tri power ollie horton Engine 3 12-19-2005 06:16 PM
rochester 2gc in 3.8 buick alford Engine 1 04-02-2003 04:39 AM


All times are GMT -6. The time now is 10:57 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.