bigtommy
old school power
i want to put a 4bbl intake on my STOCK slant six. but people i have talked to said it will blow it up without doing engine work and other people say it wont hurt. what do you guys think?
4bbl intake question
- Thread starter bigtommy
- Start date
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2 Darts
A-body Addicted
BS. If you want to put a 4 bbl on a /6, do it. The Mopar Six Cylinder book has recommendations for a 390 cfm Holley on an Offenhauser manifold for street use in the Slant Six section. The recommendations are for carb set up primarily. They also recommend the 72 and later stock cam.
The thing that the book does not address is the issue of kickdown linkages if you're using an automatic. Lokkar and Buchillon Performance make kits that address this issue.
Mo' par to ya!
dustoff440
Well-Known Member
If you use a carb like a 390 cfm Holley with a vacuum secondary and tune it to the engine it should work ok especially if you do some exhaust mods. I have seen hot slant 6 engines that ran a 750 cfm thermoquad very sucessfully. It all depends on how much you want to spend and how fast you want to go. Check out slantsix.org and google slant six there is a wealth of info out there. The resident guru slant six dan is a walking encyclopedia on the slant 6. I believe that by saying if you keep your stock slant 6 below 4500 you should be ok if you put a 4 barrel on it. If you arent going to do any other mods I would consider a factory Super Six setup with a factory 2 barrel and freer flowing exhaust manifold AND very importantly the kickdown linkage you will need. I have seen complete setups carb, manifold, linkage, and air cleaner for between 150-300 bucks. If you install the 4 barrel you have the high frig factor of fabricating a kickdown system which you must have or will eventually wind up lunching the trans. Last time I saw the price on the Lokar kickdown cable for your application it was 80 bucks. Price everything out before you go for it. Slant 6 stuff isnt like small block chevy you will be paying a pretty stiff price for new /6 stuff.
66340SEDAN
FABO Member #3649
Let me guess...your friends drive Chevelles and Mustangs? LOL! I put a 390 double pumper race carb on a bone stock 69 225 slant six with a Offy intake and headers, ran pretty good. You will be fine :toothy10:
bigtommy
old school power
no. the people at autozone told me that it would blow the engine lol.
slant6/4speed
Well-Known Member
Same people that could not find a rebuild carb kit in their books. Tried to tell me that my sixpack set up must be after market. Chrysler never offered it factory. And look at you funny when you ask if they have a group 2 or 27 battery. Then they ask "What vehicle does it fit" What does it matter? I want a group 2 battery!
Barry Moore
New Member
I have a 390 Holly with a clifford intake, headers and dual exhaust. It works, but there is a lag between the time you kick down the peddle and when the engine picks up.
slantsixdan
=..=
It won't blow it up, no, but it also won't be the most effective use of your money, time, and effort on a stock slant-6. What is your goal? I don't mean "To have a 4bbl carburetor" (unless all you want to do with the car is point under the hood and say "Lookit my 4bbl carburetor!"), I mean what do you want the car to do that it doesn't do now? Those are the terms to think in. Picking actual parts is the last step before buying and installing…not the first step.
bigtommy
old school power
i want a 9 second slant six lol
I hope you are talking 1/8 mile, I removed my one barrel carb and did this to my little 170/6 and It likes the hwy speeds and I am running all stock little 170 cu /6 and can get a 11.90 1/8 mile. To get where you are wanting you will need allot of port work on your head and shave at least 100k of the head to bring your compression up and larger valves and stronger springs and then a good header so it can breath. Dan is one of our great /6 gurus and he keeps me strait :happy10: and No a four barrel will not blow up a /6.....
Me, I picked up an easy 8 to 10 miles to the gallon and she jumps in and out of traffic as good as a 273 I think. I built this as a daily driver and love the extra hp, it don't take mush to push 2.700 car. and yes , I like opening my hood and see my system I have.
Me, I picked up an easy 8 to 10 miles to the gallon and she jumps in and out of traffic as good as a 273 I think. I built this as a daily driver and love the extra hp, it don't take mush to push 2.700 car. and yes , I like opening my hood and see my system I have.
Slants are pretty indestructible, and you would definitely see a difference over the stock one barrel on a stock motor after you got past the tuning headaches. Super Six setup with split exhaust would probably be more satisfying on a totally stock motor, particularly if you're running an automatic.
Different ballgame cammed up with oversized valves and a little head work, especially if you rework the bottom end with a zero deck and/or overbore, and add tuned headers into the mix. In that case a four barrel, three twos, F I, and/or a power added would be warranted.
Time to put in a little time over at /6.org. Time on that site should answer just about all the slant related questions you can dream up.
Different ballgame cammed up with oversized valves and a little head work, especially if you rework the bottom end with a zero deck and/or overbore, and add tuned headers into the mix. In that case a four barrel, three twos, F I, and/or a power added would be warranted.
Time to put in a little time over at /6.org. Time on that site should answer just about all the slant related questions you can dream up.
65Val
Average Length Member
Stop asking the AutoZone droids for advice. Most of these cars were built before they were born.
2 Darts
A-body Addicted
You're going to need a lot more than a 4-bbl to get this to happen. Naturally aspirated, with no power adders, Mopar has packages that will put an A-body in the 12 second bracket. Among other things, you'll need a 4.10 SG rear, 10" wide slicks, car diet to 2350 lbs, 12.5:1 compression ratio, roll bars, and frame connectors. By the time you get finished, the car will not be streetable.
nqkjw
Well-Known Member
I run a 600vac holley with headers on my stock slant six.
Been that way for 4 years now and it hasn't hurt anything.
Goes well too with good mileage.
Been that way for 4 years now and it hasn't hurt anything.
Goes well too with good mileage.
Why not upgrade to the Super Six system? It will probably be much more efficient on a stock engine. You'll still need to upgrade the exhaust to see the full benefits. Just a thought.
bigtommy
old school power
yea that is true. my car is like 25 yrs older then me though too lol
bigtommy
old school power
no im think 1/4 mile lol. is that doable?
I run in the 12's w/ my slant....You want 9's, you better have some deep pockets.
I have given my build before, but just a quick note: 12:1,bored, long forged rods,MP cam,roller rockers,750 carb....3200 stahl,4:10 gears w/ spool.
Its a great car......but I want to be able to run w/ Mark,we are fairly close, but Mark is still about a full second faster.
Andrew/Kidd
I have given my build before, but just a quick note: 12:1,bored, long forged rods,MP cam,roller rockers,750 carb....3200 stahl,4:10 gears w/ spool.
Its a great car......but I want to be able to run w/ Mark,we are fairly close, but Mark is still about a full second faster.
Andrew/Kidd
bigtommy
old school power
dont have deep pocket yet lol. how much houseppower does your have? i think i would be happy with alittle over 400. i know its not 9second but 400 is better then 160hp mine is now ):I run in the 12's w/ my slant....You want 9's, you better have some deep pockets.
I have given my build before, but just a quick note: 12:1,bored, long forged rods,MP cam,roller rockers,750 carb....3200 stahl,4:10 gears w/ spool.
Its a great car......but I want to be able to run w/ Mark,we are fairly close, but Mark is still about a full second faster.
Andrew/Kidd
I recommend forced induction.
bigtommy. It looks like you may be new to slants 6. and by the number of post you are fairly new to this site. I would say look around and learn about the slants. what you are asking (400hp) would cost you a ton of money on the slant, if even doable. How are you going to use the car? Street only, Strip only, or both?
I have a 390 holley and Offy 4bbl intake on a stock 225. It has not hurt the motor.
Mike, I will never get too much of your setup. I just love your car ****.
I have a 390 holley and Offy 4bbl intake on a stock 225. It has not hurt the motor.
Mike, I will never get too much of your setup. I just love your car ****.
Bigtommy,
I suspect you have a 225, not a 170. The head used on a 225, which is just a stroked 170, is the same as the one on a 170. It doesn’t breath as well as it could on the larger displacement 225.
Best bang for the buck would be increasing compression to 9-9.2 from stock 7.9-8.1., and a distributor re-curve so it will run on mid grade fuel.
Increasing carburetion is unnecessary unless you have improved the stock engines breathing. A stock engine just can’t take full advantage of a carburetor much larger than the one barrel it came with from the factory. It can only suck in just so much air, and push it out the tail pipe. A carburetor that has a higher cfm rating than what an engine can move is over sized, won’t improve performance, and in some cases if it is a lot bigger, it will hurt performance.
You will need to increase air flow through the engine, a project that can be expensive. One needs to increase compression, install over sized valves, bowl port, valve relive, gasket match, upgrade intake to a 2v or 4v manifold.
Exhaust enlargement is next; to get more air in, one has to get more air out of the engine. Dutra Duals or Headers, into a “Y” pipe, single 2 ¼” or 2 ½” back to axel to a free flowing muffler, and out to the bumper with a slightly smaller tail 2” pipe.
Now that you have the engine breathing a lot better, a larger cam with more overlap is needed, and still more static compression added, because with more cam overlap, dynamic compression drops. Compression drops, performance drops along with it. So one needs to hit the online engine calculators to figure out what has to be done.
Now you can plop on a 4V carburetor and get some performance out of it.
As for connecting kick down & throttle cables; there are several ways to easily accomplish it. I took the Bouchillon Performance rout with a Holley 390.
Now you have the engine pulling real good, the drive train has to be upgraded with higher stall torque converter, and 3.55 - 4.11 rear gears… It goes on and on… $$$$$$$$$
So set a goal, take advantage of online calculators and make a plan that works for you, and let the fun begin. Also take a look over at slantsix.org.
I suspect you have a 225, not a 170. The head used on a 225, which is just a stroked 170, is the same as the one on a 170. It doesn’t breath as well as it could on the larger displacement 225.
Best bang for the buck would be increasing compression to 9-9.2 from stock 7.9-8.1., and a distributor re-curve so it will run on mid grade fuel.
Increasing carburetion is unnecessary unless you have improved the stock engines breathing. A stock engine just can’t take full advantage of a carburetor much larger than the one barrel it came with from the factory. It can only suck in just so much air, and push it out the tail pipe. A carburetor that has a higher cfm rating than what an engine can move is over sized, won’t improve performance, and in some cases if it is a lot bigger, it will hurt performance.
You will need to increase air flow through the engine, a project that can be expensive. One needs to increase compression, install over sized valves, bowl port, valve relive, gasket match, upgrade intake to a 2v or 4v manifold.
Exhaust enlargement is next; to get more air in, one has to get more air out of the engine. Dutra Duals or Headers, into a “Y” pipe, single 2 ¼” or 2 ½” back to axel to a free flowing muffler, and out to the bumper with a slightly smaller tail 2” pipe.
Now that you have the engine breathing a lot better, a larger cam with more overlap is needed, and still more static compression added, because with more cam overlap, dynamic compression drops. Compression drops, performance drops along with it. So one needs to hit the online engine calculators to figure out what has to be done.
Now you can plop on a 4V carburetor and get some performance out of it.
As for connecting kick down & throttle cables; there are several ways to easily accomplish it. I took the Bouchillon Performance rout with a Holley 390.
Now you have the engine pulling real good, the drive train has to be upgraded with higher stall torque converter, and 3.55 - 4.11 rear gears… It goes on and on… $$$$$$$$$
So set a goal, take advantage of online calculators and make a plan that works for you, and let the fun begin. Also take a look over at slantsix.org.
madmax/6
Well-Known Member
Stock they are not close to 160 rwhp,and getting over 300 rwhp is very very hard unless you turbo,supercharge it,spray it or run alky.Trust me,IF there was a way to build a slant,all motor on gas and get over 320 rwhp I would bee building it.Guzzi Mark
If you get an early A body and build a slightly warm slant....or even a stock Super Six you could stick a 4 speed OD trans in it with 3.91 gears and have a blast and still get great mileage doin it. Your final drive ratio with the .73 OD would be 2.8543:1. That would turn like 2200 RPM at 55 MPH. BUT, the fun is in the 3.09 first gear. Couple that with the 3.91 gearset and you have 12.08:1 which would set your eyeballs back in your head off the line. And all in an Early A body that weighs around 2500 pounds. Even with the 67-76 cars that would be a barrel of monkeys to drive.
Ain't that the truth?
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