Slant *        6        Forum
Home Home Home
The Place to Go for Slant Six Info!
Click here to help support the Slant Six Forum!
It is currently Tue Dec 23, 2025 1:59 pm

All times are UTC-08:00




Post new topic  Reply to topic  [ 48 posts ]  Go to page 1 2 3 4 Next
Author Message
PostPosted: Thu Apr 26, 2007 8:35 pm 
Offline
EFI Slant 6
User avatar

Joined: Sat Nov 08, 2003 8:14 pm
Posts: 299
Location: West Covina, CA
Car Model: 1968 A108 225/3 on the tree
i'm collecting parts to upgrade my A108 from a holley 1bbl, to a carter 2bbl. i have the intake, carb, and air cleaner.
my dilemma is over using headers or duals.
i read lots of opinions leaning to either one or the other.
is there somewhere that i can find factual data on the capabilities of each system?

my ego just wants to run out and get headers. my common sense wants to get the best performance value.

i'm not really conserned about the carb heat. i'm in Los Angeles.

where can i get raw data?

D~~~!


Top
   
 Post subject:
PostPosted: Thu Apr 26, 2007 8:38 pm 
Offline
Board Sponsor & Contributor

Joined: Thu Oct 31, 2002 5:39 pm
Posts: 24800
Location: North America
Car Model:
There aren't any raw data; if you want 'em, you'll have to buy both systems and run a bunch of dyno pulls to generate the data. If you don't want to go to that expense, go get the Dutra Duals and save yourself a bunch of hassles with noise, leaks, and excessive heat in the engine bay.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Image


Top
   
 Post subject:
PostPosted: Thu Apr 26, 2007 8:39 pm 
Offline
Board Sponsor & Moderator
User avatar

Joined: Thu Oct 17, 2002 7:27 pm
Posts: 14766
Location: Park Forest, Illinoisy
Car Model: 68 Valiant
Right now I have a pair of Dutra Duals (both castings, not the modified stock back half) and performance seems to be very close to what I had with Clifford headers. :shock:

_________________
Official Cookie and Mater Tormentor.


Top
   
 Post subject: Harold ?
PostPosted: Fri Apr 27, 2007 3:59 am 
Offline
Board Sponsor & SL6 Racer

Joined: Wed Oct 23, 2002 7:57 pm
Posts: 9104
Location: Waynesboro, Pa.
Car Model: 65 Valiant 2Dr Post
Slantzilla,

Have you heard anything from Harold on the new headers recently?

Rick


Top
   
 Post subject: Re: Harold ?
PostPosted: Fri Apr 27, 2007 5:35 am 
Offline
Board Sponsor & Moderator
User avatar

Joined: Thu Oct 17, 2002 7:27 pm
Posts: 14766
Location: Park Forest, Illinoisy
Car Model: 68 Valiant
Quote:
Slantzilla,

Have you heard anything from Harold on the new headers recently?

Rick
Haven't heard anything for a month. :?

_________________
Official Cookie and Mater Tormentor.


Top
   
 Post subject: Ok. . . . .
PostPosted: Fri Apr 27, 2007 6:26 am 
Offline
EFI Slant 6
User avatar

Joined: Sat Nov 08, 2003 8:14 pm
Posts: 299
Location: West Covina, CA
Car Model: 1968 A108 225/3 on the tree
Right now I have a pair of Dutra Duals (both castings, not the modified stock back half) and performance seems to be very close to what I had with Clifford headers.

what differences have u noticed?
torque?
HP?
noise?
heat?

do u have the 2 casting set up or the cut rear manifold?

did u change the rest of the exhaust system when u went to the Dutra's?

did your experience with each system involve the same /6, or r u dealing with different vehicles? if different, were the engines set up the same internally?

was the same intake used?


thx,

DT


Top
   
 Post subject:
PostPosted: Fri Apr 27, 2007 1:36 pm 
Offline
Turbo EFI
User avatar

Joined: Mon Jul 14, 2003 10:02 am
Posts: 1817
Location: Southeastern Pennsylvania
Car Model:
Doc posted a while ago that headers are worth about a tenth in the 1/4 over dual duals. Not a big gain per se but every little bit helps on a race engine.

_________________
ImageImage


Top
   
 Post subject:
PostPosted: Fri Apr 27, 2007 2:37 pm 
Offline
Turbo EFI
User avatar

Joined: Tue Feb 22, 2005 5:35 pm
Posts: 1044
Location: Maine
Car Model:
I would think that with the engine sharing the passenger compartment in an A-108, the heat issue would be pretty important.

Headers would really warm up that doghouse.

The Dutra dual option would be much preferred over headers.

-Mac


Top
   
 Post subject: exaust
PostPosted: Fri Apr 27, 2007 3:28 pm 
Offline
EFI Slant 6
User avatar

Joined: Fri Jan 05, 2007 2:57 pm
Posts: 355
Location: Florida
Car Model:
This is just for info,almost stock motor little head work :wink: full body 72 Duster with power steering, 225 stock exhaust manifold -ET 16.21, header 15.97 both with the same 2'' duel exhaust. This header went on with out removing the starter, boxed end wrench on all nuts, is available with stock exhaust hook up :) and up to 3" output. :lol: Or turbo flange. :twisted: !!!Hope this helps. Don

_________________
'72 Image Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page


Top
   
 Post subject:
PostPosted: Fri Apr 27, 2007 4:10 pm 
Offline
4 BBL ''Hyper-Pak''
User avatar

Joined: Sat May 14, 2005 10:31 am
Posts: 46
Location: Florida
Car Model:
And you didn't have to use a header gasket. Thought I'd never quit hearing about that. :lol:

I might add that it sounds pretty good, too. Good job!

_________________
Image


Top
   
 Post subject: Dual Dutra Duals
PostPosted: Fri Apr 27, 2007 6:44 pm 
Offline
TBI Slant 6

Joined: Tue Mar 02, 2004 6:30 pm
Posts: 118
Car Model:
I have engine work, cam, shaved heads, ported, decked block, 1.6 roller rockers, Eddie 500cfm 4 bl, and dual dutra duals in my '62 Valiant signet, turning15's @ 90 or better with 3.55 detroit locker and 15" street radials. My car dynoes 250 h.p. with this setup. This is fast enough for me. It'll get good gas mileage IF I keep my foot all of the secondaries, and it'll pass most other cars on the road. The cast iron Dutra's don't leak, but stay pretty cool compared with steel headers.

_________________
Restored '62 Signet, 229 4bl, Offy intake, auto, Dual Dutra exhausts, shaved head and block, high stall converter, 1.6 roller rockers, etc.


Top
   
 Post subject:
PostPosted: Fri Apr 27, 2007 7:22 pm 
Offline
SSRN National Champion
User avatar

Joined: Thu Oct 31, 2002 3:56 pm
Posts: 1967
Location: Dalton, GA
Car Model:
Bingo if it is not a all out race car ie full open headers strip or roadcourse . I would have Dutras duals. Done deal listen to the force. :D Thanks Ron Parker :D










Bagel Doint Know Where He Is I Know Where Im Going


Top
   
 Post subject:
PostPosted: Fri Apr 27, 2007 7:28 pm 
Offline
Turbo EFI
User avatar

Joined: Mon Jul 14, 2003 10:02 am
Posts: 1817
Location: Southeastern Pennsylvania
Car Model:
Headers only leak if you use poor quality gaskets. I haven't had a leak in over 2 years.

_________________
ImageImage


Top
   
 Post subject:
PostPosted: Sat Apr 28, 2007 5:44 am 
Offline
Board Sponsor & Moderator
User avatar

Joined: Thu Oct 17, 2002 7:27 pm
Posts: 14766
Location: Park Forest, Illinoisy
Car Model: 68 Valiant
Right now I have the Dutra castings on both ends. Initially they were a pain in the ass to install, until I figured out that you need to leave all the nuts completely loose until you have them all on. The castings are so thick that space is limited in getting my big hands into put the retainers and nuts on without moving the manifolds around a lot. It also helped to take the carb off the intake for space. I also have a mini starter and it clears the back casting well. This would not be an issue with the cut stock rear. I have no exhaust on the car other than a pair of 1-7/8" down tubes that Jeff Long bent up for me.

As far as performance goes, this motor went 16:20's@80 in really good air with Clifford headers. Last weekend at RT66 it went 16:62@79 in marginal air. Same stock '80 Volare motor, same Offy intake, and same 390 Holley carb. The only difference in the car is that it is lighter. We will get the car out next weekend and test again.

_________________
Official Cookie and Mater Tormentor.


Top
   
 Post subject:
PostPosted: Sat Apr 28, 2007 11:25 am 
Offline
4 BBL ''Hyper-Pak''
User avatar

Joined: Sat May 14, 2005 10:31 am
Posts: 46
Location: Florida
Car Model:
Thank you Dodge Girl.Trying to make it sound as good as your car :) nothing like post under dodge girls name.I will check next time. Don back to work!!!

_________________
Image


Last edited by DodgeGirl on Sat Apr 28, 2007 11:32 am, edited 2 times in total.

Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 48 posts ]  Go to page 1 2 3 4 Next

All times are UTC-08:00


Who is online

Users browsing this forum: Bing [Bot] and 10 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited