super six horsepower ratings and specs...

[firefighter1]

Hi all,
I have a slant six with a four barrel intake manifold and headers. It's bolted to a stock 904 and 7 1/4 rear end. Do you know what the hp/ftlb this is rated at? How can I make more hp with this setup? thanks.

 

[805moparkid]

ok first off a true "super six" has a factory 2 barrel carb on it...

all the other slants are one barrel's have have sticks that say "charger 225" and what not...

but for you we have no idea... you didn't tell us what the compression is, what cam if not stock, head porting, what intake and headers, what carb...

i think you get the idea...

im all stock except the intake/header i would say no more than 120 wheel hp

 

[firefighter1]

thanks for the info. most likely i do not have a true super six. i think it is a stock slant six motor with a four barrel intake manifold and a set of headers. however, if i wanted to build a super six motor, what would the specs be?

 

[bigall]

Be around 160 horses i suppose.

 

[vynn3]

thanks for the info. most likely i do not have a true super six. i think it is a stock slant six motor with a four barrel intake manifold and a set of headers. however, if i wanted to build a super six motor, what would the specs be?

A true Super Six consists of 3 main things: A Carter BBD 2bbl carb, a 2bbl intake manifold, and a 2 1/4" headpipe (the exhaust manifold is the same as the 1bbl version). Officially, this adds 10 h.p. to the stock 100 h.p. rating.

Adding real, meaningful H.P. to a slant isn't done with bolt-ons*. It's accomplished by increasing the compression, installing larger valves, and proper head porting.

*The exception being turbocharging, but this is not for a novice. A steep learning curve and lots of research is involved.

 

[805moparkid]

Be around 160 horses i suppose.

lol... with limited port cleaning and a small cam maybe

A true Super Six consists of 3 main things: A Carter BBD 2bbl carb, a 2bbl intake manifold, and a 2 1/4" headpipe (the exhaust manifold is the same as the 1bbl version). Officially, this adds 10 h.p. to the stock 100 h.p. rating.

Adding real, meaningful H.P. to a slant isn't done with bolt-ons*. It's accomplished by increasing the compression, installing larger valves, and proper head porting.

*The exception being turbocharging, but this is not for a novice. A steep learning curve and lots of research is involved.

bingo!

 

[pishta]

Take .090 off the head, and get yourself a cam that works well with the increased compression and improved breathing that a header and a 4bbl offers. Then youll be on your way. Head porting would be next along with larger valves, then forced induction.. Make a plan early and stick to it, dont waver off your plan because a mismatched part is a "bargain" we have all done that at one time. Turbo is a leapfrog path to instant horsepower on an otherwise stock motor, but it takes a little research and a lot of fabrication. First thing you may want to try is a taller rear end. 2.76 on 140hp/215 ft/lbs torque is nothing to drag with, 3.55's would be a huge upgrade on perceived power.

 

[firefighter1]

thanks guys. i will take all of the info and put it to good use. I am going to build a 225 that will make a lot more hp and torque. One more question... what is the point of grinding off the head? I know why you port them, but don't understand why you want to make it shorter...? thanks. is this intake manifold the optimal one out there?

 

[memike]

Quote= what is the point of grinding off the head?
That is how you bring your compression up.

 

[805moparkid]

Quote= what is the point of grinding off the head?
That is how you bring your compression up.

the cheap way for sure... unless you can afford new pistons and rods...

but yes the clifford is the most performance oriented intake with bigger runners and plenum volume...

when you say alot more HP/TQ what are you looking for? fun street car or a street/strip? how fast do you want it to go at the track?

 

[firefighter1]

I mean that I want to add a lot more hp and torque in comparison to the stock motors specs. I still want to be able to daily drive the car without hurting the wallet too much at the gas pump. I would also like it to be able to make some people feel bad about being beaten off the line by a /6. haha! any suggestions? thanks.

 

[pishta]

Milling heads makes the combustion chamber smaller, the only way to increase compression without going to a longer rod, stroked crank or a taller piston. Beating someone with 6 is going to be apples to oranges if they bring a V8 to the contest. The 8 just has more HP potential and torque as there are 25% more power pulses per rotation (4 compared to 3) like comparing a 1 phase generator to a 3 phase, but not really. You can build a fast slant but HP per dollar, a V8 will win.

 

[805moparkid]

Milling heads makes the combustion chamber smaller, the only way to increase compression without going to a longer rod, stroked crank or a taller piston. Beating someone with 6 is going to be apples to oranges if they bring a V8 to the contest. The 8 just has more HP potential and torque as there are 25% more power pulses per rotation (4 compared to 3) like comparing a 1 phase generator to a 3 phase, but not really. You can build a fast slant but HP per dollar, a V8 will win.

unless a turbo slant but as said that takes alot of fab time....

dont plan on beating every v8 out there because you wont be to happy with your results... but do some research and ask around you can get into the 15's or even 14's on pump gas very easily...

 

[firefighter1]

I am realistic. I don't want to be a hero, just want to earn the respect that /6 engine deserve that's all. Is it true that earlier year stock 225 engines had more hp? I saw a diagram of hp/torque ratings and the hp dramatically decreased after '70 or '71 i think...? it was from about 145hp to 108 or something like that. thanks.

 

[furz4]

The HP ratings went down because they went from flywheel HP to as installed net HP.

 

[805moparkid]

I am realistic. I don't want to be a hero, just want to earn the respect that /6 engine deserve that's all. Is it true that earlier year stock 225 engines had more hp? I saw a diagram of hp/torque ratings and the hp dramatically decreased after '70 or '71 i think...? it was from about 145hp to 108 or something like that. thanks.

they also lowered the compression even more...

so what kinda times are you looking to run?

 

[firefighter1]

well with that in mind, would you guys recommend getting an earlier year 225 motor? just wondering if there are any distinct advantages of doing this? thanks.

 

[805moparkid]

well with that in mind, would you guys recommend getting an earlier year 225 motor? just wondering if there are any distinct advantages of doing this? thanks.

depends... what kinda times do you want to run and what year is the engine?

 

[firefighter1]

there are two that i am looking at; a '67 and a '74. i am looking to run mid to high 14's. thanks.

 

[805moparkid]

there are two that i am looking at; a '67 and a '74. i am looking to run mid to high 14's. thanks.

the 67 has the better head of the to.. but if you engine is pre 75 then you can just get a head and have it worked over...

for 14's your gonna need some time picking out a good combo...

what kinda car is it? weight if you know it....

 

[firefighter1]

1971 dodge dart coupe stock. Weight is is 2,920 lbs. What kind of head will work well for the 225 block? Another thing... if i am to get the power to the wheels in the most efficient way possible, will i need to replace my stock auto 904 trans and 7 1/4 rear end? or maybe change the gears? thanks.

 

[805moparkid]

1971 dodge dart coupe stock. Weight is is 2,920 lbs. What kind of head will work well for the 225 block? Another thing... if i am to get the power to the wheels in the most efficient way possible, will i need to replace my stock auto 904 trans and 7 1/4 rear end? or maybe change the gears? thanks.

if your 7.25 has a suregrip (posi) in it then no... it will ive but if it is a one legger then you should get a 8.25 (cheaper and plenty strong for a built 6) and put gears and a posi in it...

the 904 trans is a great trans! just take it to a very good mopar trans guy and he will know what to do for your setup... probably can use stock style bands and clutches but he will set all the clearances just right to make the trans live... also a manual valve body helps to...

as for the head if you have never done one it is best to find a 6 guy to help you/port it... mike jefferies in i think it was nebraska is a really big slant six guy... so is doug dutra in the frisco bay area (which ever is closer)

 

[805moparkid]

P.S. this is 14'ss with a six... should be 13's but i have alot of bugs and not enough bug killer!

[ame="http://www.youtube.com/watch?v=PZstyQMWmWU"]YouTube - ‪6k shift‬‏[/ame]

 

[firefighter1]

cool car. nice race! thanks for all your help. I am in California, bay area, therefore doug dutra in SF bay area is obviously way closer for me. I'll get in touch with him. thanks again. i'll also start looking for an 8 1/4 rear end. thanks.

 

[805moparkid]

cool car. nice race! thanks for all your help. I am in California, bay area, therefore doug dutra in SF bay area is obviously way closer for me. I'll get in touch with him. thanks again. i'll also start looking for an 8 1/4 rear end. thanks.

yea if your not familiar go check out slantsix.org... they can be real A-holes sometimes but all these sites have them... lol