Tunnel Ram I designed - 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> General Rodding Tech
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 08-27-2011, 08:10 PM
Registered User
 
Last photo:
Join Date: Jan 2005
Location: Colorado
Posts: 30
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Tunnel Ram I designed

I designed a new type of tunnel ram. I call it the Real Street Ram. In my dyno testing, it makes more torque than a dual-plane from right off idle. I've attached a graph of the torque curve vs. a dual plane on a stock Goodwrench 350 engine.

The biggest difference from a regular tunnel ram is that instead of having one huge plenum it has four small separate plenums. Only two runners connect to each plenum. I had to do a lot of work to get fuel distribution to be even between the cylinders. We used vacuum secondary 580CFM carburetors, so you can slam the throttle open even at <1500RPM.

Testing so far has been terrific. ****************

Hoping to get some technical discussion going.
Attached Thumbnails
Click image for larger version

Name:	torque gif.gif
Views:	176
Size:	58.8 KB
ID:	57844  

Last edited by 68NovaSS; 08-27-2011 at 08:36 PM. Reason: Other.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-27-2011, 08:37 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: Tri-Cities, Washington
Age: 67
Posts: 5,152
Wiki Edits: 9

Thanks: 86
Thanked 122 Times in 114 Posts
This post is borderline classified ad, feel free to use the classifieds here, they're free.
__________________
Boost adds dignity to what would otherwise be a vulgar brawl...

Midnight Sun Street Rod Association

Last edited by 68NovaSS; 08-27-2011 at 08:44 PM.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-27-2011, 09:04 PM
B.A.M.F
 
Last photo:
Join Date: Feb 2010
Location: New York
Age: 27
Posts: 252
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
yeah lets bring this post in a better direction lol pics? describe the process you used to actually create such an intake. did you use a tunnel ram thats in production and modify it or was this a ground up design? what are the specs on the engine you used as a test subject?
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-27-2011, 09:18 PM
Registered User
 
Last photo:
Join Date: Jan 2005
Location: Colorado
Posts: 30
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
I used a Weiand base and designed custom tops for it. Attempting to attach a picture.

OK, that worked.
From the picture you can see how the plenum area is divided into four plenums.
Attached Thumbnails
Click image for larger version

Name:	view down into both.jpg
Views:	622
Size:	1.32 MB
ID:	57845  

Last edited by L79vette; 08-27-2011 at 09:19 PM. Reason: adding more text
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-27-2011, 09:24 PM
Registered User
 
Last photo:
Join Date: Jan 2005
Location: Colorado
Posts: 30
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
So I had the idea to divide things up to get better venturi velocity at low RPM. I have a friend who is a hardcore engine builder and has a dyno. We tried a bunch of different schemes to get the fuel distribution right, and then had to do a bunch of carburetor customization to get the carbs to deal with the uneven firing in each plenum.

Tested on a bone stock Goodwrench 350, an 11:1 compression engine with ported L98 heads and a .570 lift roller cam, and the history-unknown-but-appears-to-be-stock-except-for-headers 350 in my 1971 El Camino. The torque graph is off the Goodwrench engine.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-27-2011, 10:17 PM
NEW INTERIORS's Avatar
Believe in yourself !!!!!!
 

Last journal entry: 41 WILLYS FRAME
Last photo:
Join Date: Jul 2007
Location: In My Shop..
Age: 48
Posts: 9,811
Wiki Edits: 0

Thanks: 994
Thanked 429 Times in 326 Posts
Quote:
Originally Posted by L79vette
I used a Weiand base and designed custom tops for it. Attempting to attach a picture.

OK, that worked.
From the picture you can see how the plenum area is divided into four plenums.


Look's like two plenum to me...

Front and back makes two..
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-27-2011, 10:33 PM
Registered User
 
Last photo:
Join Date: Jan 2005
Location: Colorado
Posts: 30
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Each top is completely divided in half. There are two tops, each of which has completely separated right and left plenums. So there are four plenums all together. Using small-block Chevy cyinder numbering, there is one plenum for #1 & #3, one for #2 & #4, one for #5 & #7, and one for #6 & #8.

When you start thinking about the firing order, you quickly see a big problem we had to engineer around. #5 and #7 fire right next to each other in the firing order. The other pairs have a pattern like bang-rest-rest-bang-rest-rest-rest-rest (for #1 & #3). So you get this weird induction, rest-two-cycles, induction, rest-four-cycles pattern. For some pairs the cylinder under the primary venturi goes after four rest cycles, while for the #6 & #8 pair it is the cylinder under the secondary. So we had to do some major work on the carburetors to get even fueling everywhere. We have screw-in air bleeds, and each venturi has jetting and air bleeds tuned separately. We have 8 wide-band oxygen sensors on the dyno so we can graph what each cylinder is seeing for air-fuel all the way through the pull.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-27-2011, 10:53 PM
NEW INTERIORS's Avatar
Believe in yourself !!!!!!
 

Last journal entry: 41 WILLYS FRAME
Last photo:
Join Date: Jul 2007
Location: In My Shop..
Age: 48
Posts: 9,811
Wiki Edits: 0

Thanks: 994
Thanked 429 Times in 326 Posts
Quote:
Originally Posted by L79vette
Each top is completely divided in half. There are two tops, each of which has completely separated right and left plenums. So there are four plenums all together. Using small-block Chevy cyinder numbering, there is one plenum for #1 & #3, one for #2 & #4, one for #5 & #7, and one for #6 & #8.

When you start thinking about the firing order, you quickly see a big problem we had to engineer around. #5 and #7 fire right next to each other in the firing order. The other pairs have a pattern like bang-rest-rest-bang-rest-rest-rest-rest (for #1 & #3). So you get this weird induction, rest-two-cycles, induction, rest-four-cycles pattern. For some pairs the cylinder under the primary venturi goes after four rest cycles, while for the #6 & #8 pair it is the cylinder under the secondary. So we had to do some major work on the carburetors to get even fueling everywhere. We have screw-in air bleeds, and each venturi has jetting and air bleeds tuned separately. We have 8 wide-band oxygen sensors on the dyno so we can graph what each cylinder is seeing for air-fuel all the way through the pull.

I see them now.... I guess I was in the sun to long today..
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 08-28-2011, 03:15 AM
B.A.M.F
 
Last photo:
Join Date: Feb 2010
Location: New York
Age: 27
Posts: 252
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
Wow keep us up to date more pics wish i had the resources to do things like that
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 08-28-2011, 03:19 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,182
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
Interesting. Looks like it is air flow limited s the torque at 5000rpm is equal. So it likely does not make any more peak horsepower than the stock manifold even thou it makes more low-mid power.

How does your manifold compare to a out of the box weiand tunnel ram?
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 08-28-2011, 07:01 AM
Registered User
 
Last wiki edit: General Motors transmissions Last photo:
Join Date: Mar 2006
Location: near Yellowstone park
Posts: 4,038
Wiki Edits: 27

Thanks: 10
Thanked 208 Times in 195 Posts
spider leg manifold.

A few years ago i built a corvair engine for my dune buggy They have intregal intake as part of the head. I machined the manifold part down, added mounting flanges then welded up steel tubing like a set of headers to a box and used a 2 barrel holly truck carb. It would pull the wheels up in second gear.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 08-28-2011, 10:07 AM
Registered User
 
Last photo:
Join Date: Jan 2005
Location: Colorado
Posts: 30
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by F-BIRD'88
Interesting. Looks like it is air flow limited s the torque at 5000rpm is equal. So it likely does not make any more peak horsepower than the stock manifold even thou it makes more low-mid power.

How does your manifold compare to a out of the box weiand tunnel ram?
We're not airflow limited on that engine.
Horsepower peak with the Street Ram was 286, vs. 274 with the Performer.
Where we did get into limitation is on the 350-inch 11:1 roller motor we ran. There the RPM air-gap style intake made 460HP peak vs. 440HP for our setup. We made more power everywhere below 4000RPM. So I'm thinking 450HP is about the limit of engines it makes sense to put this on.

We ran the regular Weiand top with a pair of 390CFM vacuum secondary carbs to give it the best possible chance on the mild engine. Those carbs are over $700 for a pair, so way more expensive than anything you get in the combo kits from Summit or Jegs. Our setup made 42lb-ft more torque at 1500RPM, 23lb-ft more at 2000, and keep making more up to 4000RPM where they crossed over. The regular top made more top-end power, but was mushy down low even with the small vacuum secondary carbs. If you put on the 450CFM mechanical secondary carbs you get in the kits, it would be terrible down low because the venturi velocity would be so bad.

This setup is so eager and responsive on the street. If you coudn't see the dual carbs you would swear it was a single four on a dual-plane.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 08-28-2011, 11:47 AM
B.A.M.F
 
Last photo:
Join Date: Feb 2010
Location: New York
Age: 27
Posts: 252
Wiki Edits: 0

Thanks: 2
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by L79vette

This setup is so eager and responsive on the street. If you coudn't see the dual carbs you would swear it was a single four on a dual-plane.

that being said wouldn't it be easier and more economical to just run the single carb dual plain and save the $$???
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 08-28-2011, 12:05 PM
Registered User
 
Last photo:
Join Date: Mar 2007
Location: Corinth, MS
Posts: 580
Wiki Edits: 0

Thanks: 0
Thanked 23 Times in 22 Posts
Keep up the good work! Too cool!
ssmonty
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 08-28-2011, 03:04 PM
Registered User
 
Last photo:
Join Date: Jan 2005
Location: Colorado
Posts: 30
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by UPandComing
that being said wouldn't it be easier and more economical to just run the single carb dual plain and save the $$???
For sure! But then you don't get the eye candy.
The point of this project was to build eye candy that works well on the street.
Reply With Quote Quick reply to this message

Recent General Rodding Tech 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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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
Carb designed for zz4 zz71s Engine 0 05-12-2008 06:54 PM
a cam that i designed what do you think? kuhn-77 Engine 2 11-25-2006 10:49 PM
Designed 2 New CarBoards! check 'em out :) Tony_D Hot Rod Art 2 03-30-2006 09:40 PM
Custom Designed door panels HELP radcliffkennels.com Interior 26 08-24-2004 05:10 PM


All times are GMT -6. The time now is 02:11 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.