Tunnel Ram 327 - Page 3 - 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
  #31 (permalink)  
Old 07-11-2004, 02:13 PM
lluciano77's Avatar
Short changed on common sense
 
Last photo:
Join Date: Jun 2003
Location: california
Age: 37
Posts: 3,548
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
If you tune both carbs every time, before you take your car out, then the tunnel ram will make more peak power. If you get in your car on a daily basis and drive away without turning a screw, then the single carb will make more power throughout the RPMs consistently. "Consistently" being the key word.

A tunnel ram and two fours doesn't require twice the tuning of a single four. It requires at least four times the tuning.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #32 (permalink)  
Old 07-11-2004, 04:11 PM
Robbie's Avatar
Member
 

Last journal entry: nova
Last photo:
Join Date: Dec 2003
Location: Macon Georgia
Age: 46
Posts: 289
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
man you are so right!!! I just drove my car without tuning the carbs,and it didnt feel right,so i turned a screw on my dash,and boy will it fly now..Thanks for that tuning tip..keep them coming. lol lmao
Reply With Quote Quick reply to this message
  #33 (permalink)  
Old 07-11-2004, 06:29 PM
Member
 
Last photo:
Join Date: Sep 2002
Location: New Jersey
Posts: 416
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I just PM'ed 327 camaro,and we discussed this.My take on it was that the tunnel ram requires about the same amount of adjusting as a single 4 barrel on a single plane performance intake.By that I mean an "air gap" style manifold.I told him that similar to the race manifold setup,he was going to find that he needed to make seasonal changes to the carbs to get the optimum tune up.He would find that with the summer tune up the car wouldnt start up and run in the winter.Aside from having twice as many screws and jets to tune there isnt much more to setting up a tunnel ram compared to something like a 750 double pumper on an RPM airgap intake.If the fuel pressure is corect an the carbs are set properly,he shouldnt need to touch them unless there is a major weather change.I recommended that he run some kid of street type carbs with choke provisions,and run electric chokes if this is to be a regular driver.Aside from that,there is no reason to think that 2 small single pumpers would work any worse then a big double pumper,and the fact is that a street tunnel ram has longer runners then a single plane intake,and the length is similar to a dual plane intake only the runners are straight and raised.It should have a powerband more similar to a good dual plane with a cut plenum divider rather then the powerband of an open plenum single plane intake.
Either way the gain will be very minimal,but if he really wants the killer look,he wont be hurting performance to get it if he chooses his parts right.
Reply With Quote Quick reply to this message
  #34 (permalink)  
Old 07-11-2004, 07:05 PM
lluciano77's Avatar
Short changed on common sense
 
Last photo:
Join Date: Jun 2003
Location: california
Age: 37
Posts: 3,548
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
You have to reference the secondary cannisters together. The throttle positions on both carbs have to be the same. The mixture screws have to be as close as possible. It is a lot different than a 750 on an RPM Air Gap. With all multi carb setups you need to balance the carbs. That isn't easy.
Reply With Quote Quick reply to this message
  #35 (permalink)  
Old 07-11-2004, 08:04 PM
Member
 
Last photo:
Join Date: Sep 2002
Location: New Jersey
Posts: 416
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Many small tunnel ram carbs are mechanical secondary.Some have no secondary metering block or accelerator pump because the venturi are so small that 1 acclerator pump can supply enough shot for all 4 barrels just on the primary side while some had a single 4 port center squirter.That is the hot setup to use.The hardest part is getting the idles sychrononized,but in reality with a large open plenum even that isnt super critical.as long as both carbs are opening at the same rate,and the metering is the same you should have no problems uning it as if it were a single 8 barle carb.As a matter of fact you dont usually need to jet tunnel ram carbs at all when they are propely setup on a stret manifold,and that is why most tunnel ram carbs come with metering plates.But I wont get too involved with that subject.
Reply With Quote Quick reply to this message
  #36 (permalink)  
Old 09-23-2004, 03:24 PM
Registered User
 
Last photo:
Join Date: Jun 2004
Location: nebraska
Age: 35
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I know this thread is old and dead, but i just wanted to add that i ran an eldebrock tunnel ram with dual 450 holleys on the street. wasnt a daily driver but i drove it (for fun) 2 or 3 times a week. after the carbs were tuned it made serious power. especially after i upped the stall from 2500 to 3500 and got a bigger cam (244i244e, .510 lift)
Attached Thumbnails
Click image for larger version

Name:	i-6.jpg
Views:	130
Size:	28.7 KB
ID:	2648  
Reply With Quote Quick reply to this message
  #37 (permalink)  
Old 09-23-2004, 08:02 PM
Lonestar's Avatar
"May the Schwartz be with you"
 
Last wiki edit: How to rebuild an engine
Last journal entry: Finally getting going...
Last photo:
Join Date: Aug 2004
Location: United States
Age: 44
Posts: 1,054
Wiki Edits: 1

Thanks: 0
Thanked 0 Times in 0 Posts
I have a 327 with a single 4 tunnel ram, the engine used to be in my S10 and I ran a best of high 9's.

Have fun tuning it!!
Reply With Quote Quick reply to this message
  #38 (permalink)  
Old 09-24-2004, 08:44 AM
Odium's Avatar
Member
 
Join Date: Jul 2004
Location: NJ
Age: 37
Posts: 150
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The one thang that may not have been mentioned is that a tunnel ram is best suited for higher rpm use. Since it's going on a 327, its a great match because the chevy 327s were high reving motors. I have a Weiand mini ram on a sbc 406 and I love it. You can buy carbs that are pre-setup for tunnel ram use in matched pairs. It may require tuning, but it sure as hell beats a quad Weber or mech fuel injection setup.
Reply With Quote Quick reply to this message
  #39 (permalink)  
Old 09-24-2004, 09:03 AM
willys36@aol.com's Avatar
Hotrodders.com Moderator
 
Last wiki edit: How to rebuild a Rochester Quadrajet 4MV carbureto...
Last journal entry: How to change auto shift timing on 200R4
Last photo:
Join Date: May 2002
Location: Bakersfield
Posts: 8,393
Wiki Edits: 21

Thanks: 1
Thanked 8 Times in 8 Posts
Any induction system can be made to run on the street. I know a guy in LA who has gotten a 4-hole Hilborn blower injector to idle, do low and high range etc., sitting on top of a 671 blower on the street. If you want that look, then it can be done but don't expect it to ever do things it was never intended to do. Tunnel rams were designed for a very specific purpose. They have short, equal length runners that open into a quite large plenum chamber. This divorces the organ pipe waves from confusion in the bores of a carburetor which results in much better top end performance at high rpm. The short runners tune the organ pipe pressure waves to do their supercharging at quite high rpm. The big plenum smooths out the vacuum signal to the carb(s) and, at high rpm, draws air and gasoline much more uniformly form the carb bores which improves the charge going to each cylinder at high rpm.

The thing is specifically designed for a high rpm range. Sorry, but them's the facts. The price you pay to get that look on the street in a grocery getter is that bottom end performance is severely compromised. The divorce of the flow signal from the cylinder to the carb bore, so beneficial at high rpm, results in sluggish response off throttle. That monster plenum, again a great benefit @ WOT, high rpm, results in gas condensation, puddling, and poor air/fuel ratio distribution at the bottom end.

That's why Edelbrock, Weiand, Holley, etc., all offer so many manifold options for a given engine. Each is best suited for a specific and limited type of engine performance.

But, as a guy running a 950cfm Holley 3-bbl on a 354, "It's so much better to look good than to run good!"
Reply With Quote Quick reply to this message
  #40 (permalink)  
Old 09-24-2004, 09:29 AM
Lonestar's Avatar
"May the Schwartz be with you"
 
Last wiki edit: How to rebuild an engine
Last journal entry: Finally getting going...
Last photo:
Join Date: Aug 2004
Location: United States
Age: 44
Posts: 1,054
Wiki Edits: 1

Thanks: 0
Thanked 0 Times in 0 Posts
How right you are willys36. When I had mine in my S10, I tried to drive it on the street. 4:56 gears and an 8" converter got me close. Idle at 1500 or so. The thing would still foul plugs at idle, sitting in traffic. The gas pedal was either all the way up or all the way down for it to run right. Part throttle cruise sucked, it would buck and jump...really got the attention of the local lawmen!
Reply With Quote Quick reply to this message
  #41 (permalink)  
Old 09-24-2004, 10:41 AM
willys36@aol.com's Avatar
Hotrodders.com Moderator
 
Last wiki edit: How to rebuild a Rochester Quadrajet 4MV carbureto...
Last journal entry: How to change auto shift timing on 200R4
Last photo:
Join Date: May 2002
Location: Bakersfield
Posts: 8,393
Wiki Edits: 21

Thanks: 1
Thanked 8 Times in 8 Posts
Quote:
Originally posted by Lonestar
How right you are willys36. When I had mine in my S10, I tried to drive it on the street. 4:56 gears and an 8" converter got me close. Idle at 1500 or so. The thing would still foul plugs at idle, sitting in traffic. The gas pedal was either all the way up or all the way down for it to run right. Part throttle cruise sucked, it would buck and jump...really got the attention of the local lawmen!
I have written several chapters in that book!
Reply With Quote Quick reply to this message
  #42 (permalink)  
Old 09-24-2004, 11:00 PM
Member
 
Join Date: Jan 2003
Location: Louisiana
Posts: 188
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
tunnel rams

Ive ran Offenhauser, Edelbrock and Wiend on the street :; 283s and 350s , 11 to 1 engines mostly but some less. 488 gears , Muncies ( never an auto.) They looked good and ran good , I dont see all this fuss about low end power etc. When I released the clutch they all drove smooth and good . My main problem was gas milage . Id fill up cruise up town head home later near empty . Most were in a couple 55 Chevys and they were not my everyday drivers : as Im older now I wish I still had one of them again , and yes I would tame them down and probably run a single or maybe a tri-power so I could go on longer cruises . But in those days the cars served their purpose well . I just dont see all the belittle ing of tunnel rams .
Reply With Quote Quick reply to this message
  #43 (permalink)  
Old 09-25-2004, 12:21 AM
willys36@aol.com's Avatar
Hotrodders.com Moderator
 
Last wiki edit: How to rebuild a Rochester Quadrajet 4MV carbureto...
Last journal entry: How to change auto shift timing on 200R4
Last photo:
Join Date: May 2002
Location: Bakersfield
Posts: 8,393
Wiki Edits: 21

Thanks: 1
Thanked 8 Times in 8 Posts
Like I have said many times it just depends on what spins your prop. Sure you can use them on the street but that isn't what they are intended for and you will pay a price for doing so, in your case it was gas mileage because you made up for the bad low end mixture problems by over jetting. Good solution to get some responsiveness and protect from burned valves but costs $$ in extra gasoline use. With gasoline over the $2 hurdle permanently and probably heading higher (eat your hearts out over there in the old country - you haven't seen gas that low in decades!), most of us need to seriously consider the cost of looking good over running good.
Reply With Quote Quick reply to this message
  #44 (permalink)  
Old 09-25-2004, 10:18 AM
Lonestar's Avatar
"May the Schwartz be with you"
 
Last wiki edit: How to rebuild an engine
Last journal entry: Finally getting going...
Last photo:
Join Date: Aug 2004
Location: United States
Age: 44
Posts: 1,054
Wiki Edits: 1

Thanks: 0
Thanked 0 Times in 0 Posts
Your so right willys36, over jet to get an idle...hence why my plugs were always fouling.

Definately is a fun ride above 4 grand, but the public doesn't care much for that!!

I am in the process of trying to make my '85 Bird street legal again, it has a single 4 tunnel ram on it. I have to go out and run the thing to 7,500 to clean the plugs!
Reply With Quote Quick reply to this message
  #45 (permalink)  
Old 09-25-2004, 11:07 PM
Member
 
Join Date: Jan 2003
Location: Louisiana
Posts: 188
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
tunnel rams

We all realize that a 2 fours tunnel is not going to be an everyday driver . I Mean if I were a rich person , could afford to replace plugs real often and gas was no issue I could enjoy driving one . As for a vehicle driven around on say weekends to cruise a little up town : no problem , thats what most of us do with our hotrods anyway. I have an 82 Chevy truck Im driving tonight just during the weekend : it feels pretty good tonight coming to my girlfriends : another Chevy truck came zipping around me ;;when we came to the light , he just sat there. He could hear the cam rocking my truck. All week I drive my other one with a v6 . Ive also got a Samurai with a mild 350, 63 Chevy 2 convertible in the works 283 to be a cruiser in the spring. It all depends on the purpose of the vehicle.
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



All times are GMT -6. The time now is 02:05 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.