500 Hp Slant 6

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6

64cudazack

Guest
I Might Be Getting a 1965 Plymouth Barracuda With a slant 6 and 3 on the tree
Looking To Get About 500 Hp From The 6 I know it can be done
Any Suggestions
I dont want anyone saying swap an 8
i got a 64 cuda with a 340 so im trying something different
 
Keep your eye on the thread there are a few members with high hp /6's,one has a supercharger I believe and one is an 11 sec car,low 11's.8)
 
all i know is people are gonna start asking you lots of questions and telling you your crazy lol. but good luck!!

tip: ur gonna need about 10K
 
.600 lift 308*dur, big valves, 13.5-14.1 compression, flying toilet throttle body injection 900cfm, lots of head work!!!!!!, 1 5/8 primary headers-2 1/2 exhaust, custom pistons hung on 198 length h beams, lighten the crank some, oil mods or 2 and rev it about 7800rpm or so and have it live.

Then you'll need 5000 stall and 5 something gears
with the big slicks...

Or
Turbo it to death and get a manual 5-6 speed overdrive hooked up with 4.57's out back, to keep it drivable.
 
It can not be done motor only. The head will not flow enough to support that kind of number N/A, and you can't port it enough to get close.

You can get close with nitrous, but it will be a parts eating money pit.

Turbo will be easiest, and at the HP level will also be easiest on parts. Spend the money to do it right, and you can build a 500 HP street motor that will live a long and happy life, and probably with a very basic short block.

Then you just have to upgrade the rest of the drivetrain and the car to handle it.
 
I dont think ive heard of naturally aspirated slant make that sort of power...
But feel free to show me!

Turbo is another story though.
It can be done an on pump fuel too if you have the budget for it.
 
One word, "Turbo". I don't see it happening without some sort of turbo or supercharger, but I do think that it can be done with a little help. Gunna be expensive but you'll have a unique car by the time you're done, that's for sure.
 
I've heard of a naturally aspirated six getting 1hp per cubic inch plus with a long run ram manifold. Here's a link to the article.
http://www.moparmusclemagazine.com/...1962_plymouth_valiant_slant_six/photo_01.html

There's also an article on fuel injecting a slant six on slantsix.org, but that recycles components (electronic control unit, mostly) from a GM V6 that has the same displacement. So it probably won't have nearly enough performance.

Keep us all posted, I love the idea of a high performance modernized slant six in a lightweight early A body.
 
I agree with most of the replies here, you`re going to have to force feed it to make that kind of power.....turbocharging would probably be your best bang for the buck.
 
if ur force feeding it go to

http://www.aussiespeed.com/details/?page_id=110

they have a blower manifold for the 6. if ur going to do that call ersons cams and talk to john 1-800-641-7920 he has done cams for me and my friends and there great! the thing thaat is keeping me from making real power are my rockers tho... the are like 1.3-1.4 stock...
 
if ur force feeding it go to

http://www.aussiespeed.com/details/?page_id=110

they have a blower manifold for the 6. if ur going to do that call ersons cams and talk to john 1-800-641-7920 he has done cams for me and my friends and there great! the thing thaat is keeping me from making real power are my rockers tho... the are like 1.3-1.4 stock...

That's funny, I've seen Mike Jeffrey run in the 11's with stock rockers.
 
yea he also has alot of tricks that i have yet had time to impicate into my motor... and mine isn't a race only motor, but im still gonna be in the 12's with mine and i drive mine every day!
 
I had a video of my buddy's 292 stovebolt 6. Runs high nines ina race chassis Studebaker. That is a 100% filled factory block, massively lightened factory crank, aluminum rods, custom pistons, two DART V8 chevy heads cut and welded together, the deck of the block filled and re-drilled to fit, custom cam, custom manifold, single turbo, on methanol. I really can't see why you would want to just to prove a point.. But.. i was looking into doing a stroked 225 for my '65. There is a lot of room to make some serious power. it will not be cheap but I'm pretty sure you can do it or come very close NA on methanol and 290 inches.

edit - heres the link to the engine build page http://www.cdpautomachine.com/leo/assembly.html
 
I have seen people refer to 5 or 6 speed transmissions for slant 6 but did not think that was possible. Any info you have would be great!
 
A long time ago people did a lot with a lil, just took some $$$$ and a lot of thought.


1974 was the year...
cricket modified 225 slant triple induction intake ports bored out and tubes brazed in [mega flow]/chevy trans what ever for the rear.

Here's a quote from the magazine on the cylinder head work and camshaft used, good stuff!

cars magazine writes..

''What's so hot about the slant 6?
Until last year, for instance, it powered a lil Anglia pannel truck and ran in E/altered, gernerally well under the record. Now, in the Criket it's running in L/Gas, still well under the record. Since L/ Gas has a 10-pound-per-cube weight break, a couple of hundred pounds was added to the Criket, all of it in the right place-over the rear wheels.''

Probably the most striking single improvement and modification on the engine would be the cylinder head. the slant 6 starts out with a long ram manifold but Jim Witt definitely does it one better by transforming the cylinder head into a full independent runner head and manifold. For a good start, the intake passages were milled out to achieve a more straight line approach to the port/'valve' , cutting right through the water jacket and part of the valve cover rail. Tubes made up of 18 gauge exhaust pipe were form a snug fit at the head and extend well past the orig intake flange to create a new int flange. A transition manifold, in turn, provides the change in spacing from cylinder head ports to carburetor mounting flanges and also allows the carburetor to sit vertically. Tying the tubing and the cylinder head was something of a space work project. Both the head and the tube were copper plated prior to their being furnaced brazed in a neutral atmosphere . Vac-Hyd in detroit gets gets credit for this elaborate brazing procedure.''

''Jim Watt built his own flow bench and did an extensive amount of flow work to get the most out of this head. Part of the hump in the intake port was cut away to help the flow re-attach , and the back wall was carved out out on the intake side. The exhaust ports were enlarged and smoothed out. Also the exhaust valve guide projection and part of the hump and floor in the exh port were cut back. Jim Witt & Bob Brown section a few heads to find where they could and couldn't go.
The hump area [SHORT TURN] in the intake port is too critical to blindly grind on so don't.The stock 1.60 valves were swapped for 1.72's and the 1.36's were swapped to 1.50.The change was accomplished by use of early '61 corvette F.I valves w/ 11/32 stems.''

''During flow work Jim found that using the head of a pencil to create a disturbance at the valve seat near the valve head increased flow. This led him to try valve with a thick margin=,ore material between the seat and the head of the valve. This is easily done by cutting down a larger valve '' .

''The cam is a 'chrysler express' .675 lift solid, General Kenetics aluminum retainers, spring diameter increased to 1 9/16, Stock rockers that are plenty strong [folded steel] 'but with lock nuts'
Carbs are nascar 4500 1 11/16 straight bore from venturi down, each venturi feeds one cylinder, no balance pipe.=63 main jets & use of stacks to keep fog captured
fog=reversed pulse coming back to the carburetor, common with IR setups, you can use this if you keep it captured by say a stack on top like Jim Witt did.
The intake pipes are 13.5 inches from the top of the venturi to the top of the intake valve=perfect I.R length.
compression is 12.5 w/ 30cc chambers, 7'' rod was used with a 4.12 stroke bored+.100 over=238.
they used a mopar slant windage tray by means of 340 main cap bolts.
They changed dampeners and crank assembly's often do to torsional vibrations=torsioning.
aluminum oils pump would explode at the bearing so TRW cast iron or melling unit is used.
super T-10 trans and 6.17 gears are used''

In a nutshell
end.
I didn't wanna sit here and type the whole damn thing, don't have that much time..

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A turbo seems the way to go. It's going to have to be a stout motor NA to make that kind of HP with so few cubes even with forced induction. Be sure to upgrade the brakes and if you take it to the track don't be surprised if they ask you not to come back with out a bar or cage. My calculator shows 10's with 500 HP and 2800 race weight if you can hook it up.
 
I am shooting for a simple 10:02 driver myself:cheers: in the 1/8 mile though:-D
 
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