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Intake Manifold Choice
https://slantsix.org/forum/viewtopic.php?t=31166		 Page 1 of 3
Author:  DadTruck [ Wed Sep 17, 2008 7:04 pm ]
Post subject:  Intake Manifold Choice
I inherited my Dad's old pride & joy, 1983 D-150, slant 6, manual trany, no AC, power steering... but in great shape, really nice. I have been looking at the manifold updates, the Dutra Dual exhausts seems like a no brainer, question on the Intake, if I go with the super six 2bbl intake believe I can retain the stock carb/manifold heat features, does anyone have experience with the 4bbl offy intakes that can be bought new, are they compatable with the Dutra Duals, stock manifold heat... with the 4bbl intake I would adapt down to a 2bbl,other than than a cylinder head and timing chain re-new, no other major engine mods are planned.


thanks
Author:  pharmboy [ Wed Sep 17, 2008 7:38 pm ]
Post subject: 
Nice to see another Hoosier on the board. If you look around, there's a lot of info here about what works and what doesn't. As far as what's best, it'll depend a lot on your end goal. A quick search will turn up quite a few hits for any given goal. Myself, I'm working on a twin 2bbl intake that's a modified offy 5041. That and the offy 4bbl are two of the popular choices.
Author:  ceej [ Wed Sep 17, 2008 10:41 pm ]
Post subject: 
The Offy will bolt to your rear dual. Not the new casting rear, but the converted type. Not a problem.

It's getting to be more of a challenge to find a decent BBD. A consideration when building a Super Six. With the Offy you can mount some other types of carbs that are available new.

I run a Carter AFB on my Offy right now, and sometimes a Holley 600. I had a two barrel adapter on there a little bit ago. Ran a 500 Holley with that. I have a 390 Holley that I've run on there as well. Does just fine.
The Carter is growing on me. Consistent mixture control is nice after beating ones self to death with Holley's for years. Not quite as much snap at the track, but a whole lot less hassle.

Clifford offers an intake that I think is superior for drag racing applications to the Offy. For the street/strip, the Offy does pretty good.

I'm trying to get a price on one of Pierce's Manifold/Carb Kit offerings. Pretty nice stuff.
There are some other manifolds coming out of Australia that are pretty cool. I haven't run them though. By all indications, quality parts.

CJ
Author:  wvenable [ Thu Sep 18, 2008 4:57 am ]
Post subject: 
Dadtruck welcome! Both Offy set ups are a common choice. If you are interested we are putting together an Offy group buy for valve covers but intakes are discounted as well. Look on the engine thread! Pharmboy is right- nice to see someone from our neck of the woods!
Author:  SlantSixDan [ Thu Sep 18, 2008 6:11 am ]
Post subject: 
You're getting a lot of enthusiastic "Yeah! Go get a 4bbl intake!" types of responses. Perhaps I'm misreading your intent, but it sounds to me as if you're trying to get some more performance and driveability out of a street-driven truck while maintaining or improving fuel economy, not go racing. In that case, a 2bbl setup is going to work better for you (and be less costly) than a 4bbl setup. The Offy 4bbl intake is compatible with the stock or Dutra manifold heat hookup, but you'll usually be money ahead to start out with a 2bbl intake rather than buying a 4bbl intake and adapting it to a 2bbl carburetor. You can either use a factory Super Six intake or do the parallel-2bbl intake manifold mod article (pdf) to a 1bbl intake. 2bbl carburetor availability really isn't a problem (Ceej, what're you talking about? :-) ); there are lots of options for good working 2bbl carbs. You can use a factory-type BBD or a service replacement 2280 — I've got new ones in stock — or you can use any of several other non-factory 2bbls such as the Motorcraft 2100 which several people have adapted to the slant-6 with good results.

I agree with your plan to go to Dutra Duals. You may also want to look at upgrading the ignition.
Author:  wvenable [ Thu Sep 18, 2008 8:10 am ]
Post subject: 
Dadtruck, I have some super six stuff if you are interested. I also have some Dutras you can look at to get some ideas!
Author:  ceej [ Thu Sep 18, 2008 9:23 am ]
Post subject: 
You're right, of course, Dan! New is a great way to go.

I was referring to finding decent rebuildable cores from used sources. We've been seeing a sharp decline in available cores, as well as BBD's in poor to unusable shape around here.

That's what I meant. :roll:

Dan's carbs are an excellent way to go. Try for a SuperSix kickdown. If you have trouble finding one, Doc has posted information on fabricating such a device. Another option is to use a cable type kickdown.

As far as mileage is concerned, a well set up 390 Holley or one of the smaller Edelbrock carbs will deliver economy on a par with the BBD.

I was pulling 24 Hwy with my Tuna boat while running the 390 and the 600 Holley prior to building the Stroker. Urban cycle was very good with the 390, but suffered considerably with the 600.
Wicked/Six has been doing better than that with his 600 Holley out on the road. It is likely that a well set up 500ish Edelbrock will deliver similar results with careful attention to the advance curve and jet/metering rod selection.

CJ
Author:  SlantSixDan [ Thu Sep 18, 2008 10:04 am ]
Post subject: 
Quote:
I was referring to finding decent rebuildable cores from used sources. We've been seeing a sharp decline in available cores, as well as BBD's in poor to unusable shape around here.
Yup...with the age of these vehicles and the high price of scrap, new and used parts in good condition are getting much harder to find. :-(
Quote:
Try for a SuperSix kickdown
*cough*Manual transmission vehicle*cough* :lol:
Author:  ceej [ Thu Sep 18, 2008 10:21 am ]
Post subject: 
Well now. A kickdown won't be needed, will it? :lol:

CJ
Author:  volaredon [ Thu Sep 18, 2008 10:37 am ]
Post subject: 
DadTruck; wanna sell it? :P :twisted: :wink:
Author:  lindross [ Thu Sep 18, 2008 12:12 pm ]
Post subject: 
Welcome aboard to another slanted Hoosier.

I have two slanted cars both with 225's.

1918 Dodge Roadster - offy 4bbl intake with a holley 390. stock exhaust manifold. driven very regularly during the warmer months obviously. good driveability and pretty easy on gas.

1963 Plymouth Valiant - clifford 4bbl intake with a holley 390. clifford headers. driven daily with extremely good driveability. again, pretty easy on gas getting 18-25mpg depending on foot and how much city driving.

Both motors have mild street cams with a little shaved off the head. Both have Chrysler later model electronic ignition. They both perform very well and will keep up with the pace of life in todays world of idiots. haha :lol:
Author:  Aggressive Ted [ Thu Sep 18, 2008 2:38 pm ]
Post subject: 
Ceej,

What jet and rod combination did you get the best mileage with on the Edelbrock 500?
Author:  ceej [ Thu Sep 18, 2008 3:52 pm ]
Post subject: 
I've got a Carter 600 AFB. I haven't run with the boosters out of the 500 in there, so can't answer this. (They can be swapped out in the Carter, but not the Edelbrock IIRC.)

Jets in the 600 AFB are 98 and 95. I can't remember which Metering Rods I have in there now.

Keep in mind, I have a 248" Slant with lots of mods. This will probably be close in a 225, but as with any modified engine, there may be differences.

Mileage with the Carter so far has not been as good as with the Holley 4 bbls, but I've been fighting through some Head problems. I'll let you know how it's doing sometime next week. Following the latest patch of changes, including a half point compression boost, and more agressive intake work, I may be rejetting once again.

The 500 cfm carb I've played with is a Holley 2bbl. Mileage is hideous. Power is phenomenal. :lol:

CJ
Author:  DadTruck [ Thu Sep 18, 2008 7:07 pm ]
Post subject: 
Everyone, thanks for the info, right now I am believing I will be going the 2bbl on the 4bbl manifold route, as that leaves options for a 4bbl later.

Wvenable, Pharmboy,, I looked at the other links, the group buy on the offy intake sounds promising, but what my seem an obvious question, how does one get in, who do you pay (how much) what is delivery timing??

thanks again
Author:  runvs_826 [ Thu Sep 18, 2008 8:27 pm ]
Post subject: 
That is a great idea! I wish I would've skipped the two barrel and jumped straight to the a 390cfm guy. Plus you can get the electric choke for the 4 barrel.
Why is the clifford superior to the offy?
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