http://www.geocities.com/gotnitro2003/
Take a 1971 Dodge Dart GT Body Thats Beat To Death, And Cut As Much Weight Out As You Can, And Yank The 225/6 Out Grab An Old School Chrysler Engineer And Get Him In The Machine Shop And Build One Radical All Motor Hyper-Pak Take The A-904 Get It Built With A 3,500 Stall
Full Manuel Valve Body And Put A Set Of 4:30 Gears Out Back And When That Ford Or Chevy Pulls Up Next To You And Laughs Throw It Into 1st Gear And When The Light Turns Green Mash The Pedal And Watch As The Paint Gets Sucked Off Of The Ford Or Chevy.

Jerry Engle " Brinkly's Auto Machine "
Specializing In Hyper-Pak Engines
Landover,Maryland

http://www.geocities.com/gotnitro2003/

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Being Schooled By A Chrysler Engineer From The 1960-70's Who Worked On The Team That Designed And Built The Original Hyper-Pak.
Carrying On The Hyper-Pak Tradition!

What's the deal with the "heater hoses" (that's what they look like to me), running to something underneath the carb? Anyone?

Nick

duster idiot has a custom heater of some sort on his hp, the gas was puddling up in the runners if i recall correctly...

My guess would be to the same reasoning behind the exhaust manifold connecting to the intake on a stocker, the /6 needs some heat to provide a better fuel dispersement

The slant six with a 4bbl carb (and probably the big 2bbls too) will run better at low RPMs with intake manifold heat. If you are using headers, the intake will be much colder than it would be than with the stock exhaust manifold.

When the throttle valve open wide, the manifold vacuum drops to the point where fuel condenses out of the air onto the intake manifold floor. It's the exact same principle that causes water to boil at a lower temperature at the top of a mountain compared with sea level. The heat keeps the fuel mixed with the air and prevents a bog at low RPMs.

If you check the Clifford Performance web site (http://cliffordperformanceshop.com/) and look up their 4bbl intake manifold (PN 45-4500WH), you can see that they recommend hooking the water jackets for street use.

Offenhauser manifolds are made so that you can attach the stock exhaust manifold. If you are using headers with this manifold (or even stock 1bbl & 2bbl manifolds), you can fabricate a water jacket to give you intake manifold heat.

I am currently working on having an slant six intake manifold water jacket fabricated now. I should have it commercially available soon.

Frank

With the Hyper-Pak Intake and living in The Colder Climates It Is Well Worth Opening UpThe Stock Exhaust Manifold Outlet To 2-1/2 Outlet And Then Doing Some porting Work As Well.
If You Live In A Warmer Climate Then Headers Are The Way To Go, But For A Daily Driver In The Colder Places You Will See A Big Difference Between Headers And The Stock Exhaust Manifolds As Far As Heat For The Carb & Intake.
I Ran Both For Awhile And The Headers Were Hurting The Performance Due To Lack Of Heat For The Carb Intake.
With The Stock Manifold It Performs Alot Better Then The Headers And It Is Now My Daily Driver All Year Round.
The 500cfm Edelbrock Performs Excellent Right Out Of The Box And I Can
Light Up The Rear Skins With Ease And Break Them Loose Through Each Gear Change All With A Stock Exhaust Manifold That Been Gutted.
If You Gut The Manifold The Chances Of It Ever Cracking Are Very Slim Because The Heat No Longer Builds Up, And You Can Add A 2-1/2 Single Exhaust With A Flowmaster And Get The Same Performance As A Header.

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Being Schooled By A Chrysler Engineer From The 1960-70's Who Worked On The Team That Designed And Built The Original Hyper-Pak.
Carrying On The Hyper-Pak Tradition!

Huh?

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If it ain't broke, fix it!

He may mean that with a bigger headpipe/exhaust, there is less heat dropped in the manifold due to the gases not being able to expand in the more restrictive stock setup. It's a balancing act, I expect.

Lou

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Home of Slant6-powered fun machines since 1988

Thats Exactly What I was Saying Lou.
Alot Less Heat And The Exhaust Gases Don't Get Built Up Inside The Maniflod Creating Extreme Heat Which Is The Reason Why So Many Of Them Crack Is Due To The Heat Built Up Inside, Thats Why If You Take The Time To Open Up The Stock Manifold And Enlarge The Dump Outlet To 2-1/2 Inches You Will Have A Great Free Flowing Exhaust.
Living Next Door To A Chrysler Engineer I was given alot Of Manuels On The Slant Six Hyper-Pak That Are Dated From 1961 All The Way To 1973.
With All Of This Information I Started Putting Together Some Tech Articles So That Other Slant Six People Can benefit As I Did.

_________________
Being Schooled By A Chrysler Engineer From The 1960-70's Who Worked On The Team That Designed And Built The Original Hyper-Pak.
Carrying On The Hyper-Pak Tradition!

I like all the holes in the inner fender panels. I think Homer Simpson called them "speed holes."

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'66 Cuda 225/4spd
'66 Dart GT convertible 225/auto
'64 Dart GT 340/4spd

ok, everybody says dump the stock exhaust and go header or dutra dual. now we can keep the stocker and "modify it"??? must work, you are running 13's !!!!!

That's quite an impressive engine you've built, Jerry. I am curious how you made the exhaust manifold work with the HyperPak intake. My understanding of the design of the HyperPak intake is that it had no provision for intake manifold heat from the exhaust manifold. Did you just blank-off the top of the exhaust manifold or did you have to do something more radical?

I have been reading up on headers and exhaust manifolds and it appears that engines are relatively insensitive to tuned exhaust pipes (or headers). Tuned intake pipes have a much greater effect on engine power. So the key for making more power on the exhaust side is simply to have as low a backpressure as possible. It looks like your engine is proof to the theory.

BTW, the one advantage to having headers or Dutra Duals is that running exhaust pipes to the back of the car is easier pipe fabrication. Obviously, the smaller the diameter pipe, the easier it is to bend. For example, on turbocharged engines, a 3" exhaust pipe is recommended but you can run dual 2½" pipes which have a greater flow area (and less backpressure). Dutra Duals allow you to run 2½" pipes from each manifold without any modifications and I think it is impossible for them to crack.

I have been doing "Dutra Duals" for 15 years now, we have casted hundreds of them and never had one crack.
Over that time, I had one returned because one of the outlet flange "ears" broke right through the tapped hole. (I replaced it even though it looked like it had been dropped) At that point the outlet flange size got larger to put more metal around the threaded holes. (go ahead, try breaking one now! )

The biggest advantage of a "3 & 3" exhaust system is that the firing order allows more time between exhaust pulses, the next "shot" is always in the other manifold. This really helps reduce back pressure at high RPMs.
DD

In durability, it's hard to beat a good design in "Detroit Wonder Metal"!

SlantValiant thanks for the reply you are defenitly right on about the Detroit Iron and it's dependability nothing like the factory engineering.
I see alot of people on here were talking about the stock manifold being famous for cracking and i'm sure some have cracked over time.
But with alittle work they can perform very well .
The original Hyper-Pak that was tested in dyno cell 13 at Chrysler in 1960 was fitted with a stock manifold and the cast shorty manifolds for testing purposes. The race version that powered the Hyper-paks for the sanctioned NASCAR compact race were cast iron shorty manifolds and were used for the race only version.
The parts program for the street version Hyper-Paks gave you the choice to use your stock manifolds or the cast iron shorty manifolds.
The Hyper-Pak package was sold as a package or you could just buy certain parts from the package.

_________________
Being Schooled By A Chrysler Engineer From The 1960-70's Who Worked On The Team That Designed And Built The Original Hyper-Pak.
Carrying On The Hyper-Pak Tradition!