What would you do? Slant performance

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porterracing said:
Hey everybody I have been saving a little cash and think its time for some more POWER! I have a stock 225 slant 6 and before everybody starts on the V8 ban wagon, go ahead and hope off as this is not the right ride for you. I understand a V8 will give more power than I could get from a slant but I like the slant and don't have the required cash for that purchase... Okay back on track, I would like to get your guys ideas on a $2,000 budget. Cam what dimensions would be good, head work, intake, exhaust... It seems every time read a comment there are never specs given and there is always a comment or two that contradict the last...
I was originally looking at the dual 38 weber intake and dual exhaust from clifford, but after many saying bad things about clifford and having no experience with weber carbs I decided against it...
Basically what would you do to a slant 6 with a $2,000 budget to make the most power and torque. This is my first mopar build and am pretty lost on whats best so all the help is much appreciated! Thanks-Zach
:burnout:
Click to expand...


It MAY be possible to just add a turbo to your bone-stock slant six and get an acceptable performance upgrade IF you are careful with the "tuning." This would be a no-frills, bare-bones, turbo exercise for the street, using a complete-rebuild of the stock reciprocating assembly and changing very little, aside from the induction and exhaust system.

Let's look at the intake side, first: You'd need a Super Six intake manifold and a Holley 2bbl 350 carb (2350.) You could probably get both for $500.00 Now, you're down to $1,500.00 The stock fuel pump could be modified (by drilling and attaching a boost-pressure tube to the top of the pump, from the intake manifold, for boost-reference,) and, that would finish the mods to the fuel system. A stock distributor would need to have the timing dialed back to a total of 18 degrees, mechanical; the vacuum could stay "as is." The stock cam and valve train should work fine. You probably would need a valve job. The intake side would require that you acquire a 60mm turbo (probably off ebay,) for maybe $500.00. Now, you're down to $1,000.00.

The gaskets, rings, and rod and main bearings should run no more than $200.00, according to Summmit.

New plugs, plug wires and a distributor cap should be in the neighborhood of $50.00, leaving $750.00 at this point.

YOU CANNOT DO THIS BUILD WITHOUT A WIDEBAND, DATA-LOGGING, AIR/FUEL METER. You just cannot.

The one I have cost $350.00. Worth it at twice the price! It is a F.A.S.T.-brand.

That leaves $400.00 for an exhaust system, fluids, a tachometer, and a waste gate for boost control.
This expenditure should give you an engine that idles like a stock motor, runs on "pump premium" gasoline, probably will get better-than-stock gas mileage, and best of all, will make, probably, 200+ horsepower; enough to get your 3,200-pound A-Body into the 14's at over 90 mph.

Properly done, that's how it should run.

Good luck!! :cheers:
 
Years ago a friend built a 225 for his 66 Dart, .030 over cast rebuilder pistons, cut the head .060, bowl work stock valves. Clifford headers, 4 bbl intake, 390 Holley, the smallest of the MP cams offered at the time, 4 spd OD, 3.23 gears, 215/75x14 tires. If you stood in front of it while it was idling, it still sounded like Grandma's car, the burble from the turbo mufflers in the rear gave a different story.

This car was a blast to drive; I live in NY state not too far from Watkins Glenn International Raceway, to get there the road is 2 lane, up, down, left, right not a lot of passing zones. If you wanted to pass; in 3 gear direct at 55 mph; just pull out and drive around the car no fuss, no muss, no bother, the engine was in bottom the sweet spot of the torque curve and it pulled hard, to do that in OD, you had to be going about 70-75mph.

/6's are very receptive to bolt ons, just don't get carried away and succumb to "More's Law".

Build it, have fun.
 
Hey, that's a cool *** old Vali-wagon, don't see many of those porterracing!!
Hope you're enjoying your time w/it . Turbo power is an effective way to give your slant
a fat torque curve boost, but w/o an intercooler and using cast pistons 7-8 psi is about
the limit on pump fuel, dunno about E85 but your carb would need jetted up a bunch &
mileage will suffer. Timing and A/F are critical to prevent detonation from takin out your
head gasket or bottom end, definitely NOT cheap to learn the hard way,you've been
warned. :coffee2:
 
Nice wagon.
Free flowing 2.25" exhaust.
Rebuild carb.
Electronic ign.
New plugs, wires,cap, rotor.
Tune up.
Done.

Go to the beach.
 
Killer6 said:
Hey, that's a cool *** old Vali-wagon, don't see many of those porterracing!!
Hope you're enjoying your time w/it . Turbo power is an effective way to give your slant
a fat torque curve boost, but w/o an intercooler and using cast pistons 7-8 psi is about
the limit on pump fuel, dunno about E85 but your carb would need jetted up a bunch &
mileage will suffer. Timing and A/F are critical to prevent detonation from takin out your
head gasket or bottom end, definitely NOT cheap to learn the hard way,you've been
warned. :coffee2:
Click to expand...

All good advice, I think. Jim Burch said in a previous note, " /6's are very receptive to bolt ons." I think That's basically true up tp a point, but the cylinder head is so restrictive, (and there's in a limited amount that can be done about it,) that they are ham-strung in the power they can make, naturally-aspirated, and it's far below the limit of forced induction engines. For example, there was FABO member who built a '68 Dart, with a naturally-aspirated 225 /6 that he spent a lot of time and money on, finally getting into what I would call "full-race" status with a ported head, big valves, a 4bbl carb, headers, a milled head, aftermarket ignition, and a radical cam. He had it geared for the quarter-mile and slicks on it. He was a car guy and obviously knew what he was doing.

His best e.t. was just over 14-flat.

Another poster, here on FABO, took a bone stock, 100.000-mile slant six in a '70 Dart, added a 4bbl and a Buick turbo (no other modifications) and ran 12.95-seconds at 104mph. And, yes, he was running the engine at a boost-level far above where it could live very long, but that just shows what these engines need. They can't BREATHE (naturally-aspirated,) with the only head we have to work with. Here's a video of that stock motor+ 4bbl/turbo run...

[ame="https://www.youtube.com/watch?v=pPe_vHwZsF4"]Slant Six Turbo 1970 Dodge Dart 1/4 Mile pass - YouTube[/ame]

You can add a 4bbl and headers to a stock motor and get the e.t. down into the 16s, or maybe the high 15's with a cam and a milled head, but, it will never be the torque motor that it will with a turbo.

You pays your money and you takes your choice! :cheers:
 
While the stock slanty head is restrictive,it can be made to flow,but it takes O/S
valves and KNOWLEDGEABLE porting to do it. It is not some home project for a beginner
w/o a flowbench, that said, they can flow in the low 200's. I have personally gotten 193
cfm out of an external plug casting using a 1.88 max wedge exh. valve in a 3.5" bore,but
that is really too large a valve for the bowl size of the head.That was about 21 yrs. ago,
and I'm about to take another run at that with a smaller 1.81 valve this time.
Lets say we could open up the bore by .850" min., and install 2.08 intakes,wouldn't
that be great? Oh yeah, then we would have this;

http://www.hotrod.com/how-to/engine/5115-cylinder-heads/#photo-04

:coffee2:
 
2 words and 2 names: "Tur" and "bo", "Bill" and "Dedman". He's done it and is willing to talk about the good and the bad. And you can get a turbo for far less than $500 on Ebay, thats just more money to spend on your tune. You can blow 5-6 psi and not even change your timing or fuel delivery, But the wideband IS almost mandatory.
 
Don't listen to anybody and do just what you want. There will always be Yes,No, and Maybe out there. Have fun doin' it too. Gotta love them Slants !!!
 
Wow - it's like that parable of the prodigal son - but Triple R and the Kid both come back in the same thread on the same day?

Good to see y'all back!
 
pishta said:
2 words and 2 names: "Tur" and "bo", "Bill" and "Dedman". He's done it and is willing to talk about the good and the bad. And you can get a turbo for far less than $500 on Ebay, thats just more money to spend on your tune. You can blow 5-6 psi and not even change your timing or fuel delivery, But the wideband IS almost mandatory.
Click to expand...


PISHTA, you give me too much credit.... But, thanks for the kind words. My experience in turbocharging a slant six is pretty much limited to one car (mine,) but it was an education, of sorts....

Look back at note#26 in this thread for what information that might be useful.

And, thanks for the advice on turbo prices. I never researched that issue, since the turbo on my car was a gift, and just happened to be the right size.:prayer::prayer::prayer:
 
I built a 225 shot peened crank truck motor with a .125 milled off block and head combined. 9.5 compression. Runs on 93 perfectly. Manley pro flow valves, .464 cam 276* 340 springs
Ported head, lightened and balanced crank by 20 lbs. Originally 87lbs
Had to bore 60 over , room for more believe it or not. Lots of meat on the blocks
The lower end is pretty much stock, except ARP studs everywhere, head included
Hyperpack manifold, eddy 600, shorty headers, electronic ignition, 32* total timing
2.5'' dual exhaust down to 2.25 tails
274 hp at flywheel 4800 rpm on dyno
Torque 290 a little earlier on
150 hp at 2000 rpm
Running 3.23 and low gear '65 a833 tranny
Msd 6al
Small lock fuel pump with adapted / arm
Blast to drive in a 2600 lb lancer
Light and handles awesomely
$5000 with all including clutch
$3000 in parts
It ain't cheap.
BTW it sounds like my 69 340S cuda
 
Johnny Dart said:
Congrats...Your now in the 16's. Lol
Click to expand...

You get it, Johnny.... Naturally-aspirated, these things are just too much of an uphill battle to make it worth all that effort. Conventional hop-up methods don't pay off very well, for N/A slants; it's been proven, time and again.

There is only one way I am aware of, to get resonable performance out of a slant six (because the poor-flowing cylinder head defeats all you can do,) and that's forced induction.

Turbocharging, or supercharging a slant six isn't easy nor is it cheap, but it will put one of these motors in an early A Body, well into the tens at almost 130 mph, and that is pretty fast for an old Mopar... Hellcats need slicks, just to keep up...

If less speed is needed, it can be a lot cheaper and easier, using lots of stock components, such as stock pistons, rods cam and valve trains... but, that M.O., along with less boost will result is a lot less horsepower... but, not everyone wants to go 125mph+ in the quarter...

You pays your money and you takes your choice... :)
 
Johnny Dart said:
Congrats...Your now in the 16's. Lol
Click to expand...

What? Estimating an as raced wt. of 2770#, and a rough est of 220hp@the wheels puts
that thing in the low 13's @ 100mph. I guess all those 240hp 5.0'stang's turning mid 13's
in the '90's w/3.73's and hoosier DOTquicktimes were secretly using mag-propulsion?
 
Killer6 said:
What? Estimating an as raced wt. of 2770#, and a rough est of 220hp@the wheels putsthat thing in the low 13's @ 100mph. I guess all those 240hp 5.0'stang's turning mid 13's in the '90's w/3.73's and hoosier DOTquicktimes were secretly using mag-propulsion?
Click to expand...

Case in point: Back in 1962, I had a friend who had a '60 Valiant 225 (cast iron block) that he played around with. The modifications he had made included the addition of some second-hand HyperPak parts he had acquired that included a HyperPak intake manifold and the Carter AFB that the factory recommended for that application, a pair of the cast iron HyperPak exhaust "headers," the hyper pack cam and lifters, and a head that was milled .100", plus some stronger valve springs.

He usually ran it without mufflers. It was equipped with a 3.91 and a three-on-the-tree, manual transmission. I remember something about his having up-graded the clutch, at one time.

Over a three-year period of trying to get the most out of it, it finally ran a best e.t. of 15-flat at 92+mph.

One of the current FABO members (Mopar305kid?) purpose-built a naturally-aspirated 225-powered 1968 Dart for the expressed-purpose of seeing how fast/quick it would go, He didn't use any "heroic measures" but it pretty-much had all the usual bells and whistles such as a 4bbl carb, headers, a deep-geared, limited-slip rear end, a "full-race" cam and valve-train, modified ignition, a ported, milled head, with big valves, a high-stall converter in the 904, racing shocks, and drag slicks.

His best-ever e.t. after much experimentation, was 14-flat at something less than 100 MPH.

The car weighed approximately 2,900 pounds...

Mad Max (on FABO) has gone a lot faster and quicker than that, but, he has an unusual-performing car that has been the recipient of some serious weight-reduction over a period of time... I think his car weighs somewhere around 2,300-pounds... and, it HOOKS!

Anybody can take weight out of a car, but the Mad Max car has taken it to a whole, new level...:cheers:

I think that Johnny Dart is not too far off the mark. We had a '62 Lancer in '63 that had a 225 with a HyperPak manifold and carb, with a .100" milled head a 3:55 gear and a HyperPak cam, running through a stock 225 exhaust system, and it ran 15.88 at 88 MPH. The cast iron HyperPak manifolds had serious interference problems (wouldn't work) with the 904 starter solenoid...

That isn't very fast, but remember, these cars usually start out in the mid 18-second range.

Knock 2 1/2-seconds off any car's quarter-mile time and it won't "feel" like the same car...
 
Killer6 said:
What? Estimating an as raced wt. of 2770#, and a rough est of 220hp@the wheels puts
that thing in the low 13's @ 100mph. I guess all those 240hp 5.0'stang's turning mid 13's
in the '90's w/3.73's and hoosier DOTquicktimes were secretly using mag-propulsion?
Click to expand...

Doug Dutra Build Hot Rog mag 2000
70 Duster
Gutted interior 22 pound A-100 seat
Clifford cam
Hyper pack intake
Clifford headers
Trick pistons
Oversize valves
Shaved/Ported head
Demon 4bbl
Holley blue pump
Weber/Mcleod race clutch
Race built 833
MP Drag shocks rear
Competition Engeniring front
MT slicks (13psi)
8 3/4 Sure Grip
4.30.1 gear set.
Race fuel
Etc Ect Ect Ect Ect Ect Ect Ect

Add Dougs life long knowledge of the motor, with all his techniques & tricks
The best it did was 14.926/78.83
Your math doesnt jive. Nice try though.

But then you know much more about the slant than Dutra right ? :-k











?
 
Ok,.. here is some real math;

My car in 1992; "72 swinger loaded iron a/c comp. etc,plus 8 3/4,plus wooden console I
fabbed, plus nice short cut pile carpet on console sides& over the ugly "cardboard" headliner
and package shelf that matched the Olds radiant green stripes on my car. Wt. w/me 3200#
w/a full tank as raced FACT.
Trans; bone stock 904, no shift kit, no stall converter, dexronII,no bullshit, FACT.
Engine; '69 slant from my 1st car, .060" over,9.37:1 comp.,lite 2 pc. alum. Supersix int.,
OE 2245 holley [email protected]"Hg depression modified/rejetted, stock fuel
pump,purpleshaft 276/.490 solid- actual net lift .450" and [email protected],6 into1
Mopar header,2.5" all the way out back,1.74/1.41 valves w/only the port entry&
bowls opened,red 340 hp springs/dampner,shortened crane crmoly pushrods.
Rear; '71 8.75 from duster w/4.10's
It should be obvious this car is under carb'd,over geared,needed a stall TC,
a shift kit etc etc etc etc, yet ran 16.0@88mph anyway,so your math doesn't
jive. My math is Mopars bracket racing math,and it has been accurate for any project
I've done,Olds.Chebby.Furd,whatever. and my car did 3/10's better than the "stock"
drivetrain math, but far short of the optimized number of 14.8 for that mph.
Captproblems ride is definitely not "in the 16's" that is all :glasses7: P.S. rear skins were 235/60HR14 Delta Road Max
 
Johnny Dart said:
Doug Dutra Build Hot Rog mag 2000
70 Duster
Gutted interior 22 pound A-100 seat
Clifford cam
Hyper pack intake
Clifford headers
Trick pistons
Oversize valves
Shaved/Ported head
Demon 4bbl
Holley blue pump
Weber/Mcleod race clutch
Race built 833
MP Drag shocks rear
Competition Engeniring front
MT slicks (13psi)
8 3/4 Sure Grip
4.30.1 gear set.
Race fuel
Etc Ect Ect Ect Ect Ect Ect Ect

Add Dougs life long knowledge of the motor, with all his techniques & tricks
The best it did was 14.926/78.83
Your math doesnt jive. Nice try though.

But then you know much more about the slant than Dutra right ? :-k
Click to expand...

Doug Dutra has forgotten more than most of us will ever know about slant sixes, but, in this particular drag strip test, the MPH at the finish line doesn't match the elapsed time. Any car that will run the quarter mile in less than 15 seconds will be going well over 78 mph. Could have been a typo , (maybe eighty-eight MPH) I dunno, but even the Wallace online calculator lists the probable times for a car running an e.t. of 14.9; it says that car should be going eighty-eight+ MPH at the finish line.

Something's not right with this finish line MPH.

But, regardless of that, we'll assume that the 14.9 number is correct for this hopped-up slant. A 14.9 is just not very quick for a car with that (considerable) amount of modifications. It just points up, once again, the fact that slant sixes don't respond very well to bolt-on speed equipment, even when applied by an expert, which Doug Dutra certainly is.

It's the strangulated, asthmatic, cylinder head. It will defeat the best efforts at moving air through this motor... I'm talking conventional mods, like Doug added to this motor. They just don't work very well, here...

What DOES work well, and there us plenty of evidence to support this, is forced induction; turbo or supercharging (or, possibly, nitorus oxide, though I haven't seen it tried.)

My own car, a turbo'd 225-powered '64 Valiant has only been to the drag strip twice, but at 15 pounds of boost, and a weight of 3,000 pounds (driver and passenger included) the time slip for its last run in the eighth-mile said 91.5 MPH and an e.t. of 7.6 seconds. That computes to a quarter-mile e.t. of 12 second, flat, at 112 MPH.

And my car is really S-L-O-W compared to Tom Wolfe's turbo slant (11-flat at 120 mph, weighing 3200 pounds, and Ryan Peterson's, similar 1966 Valiant which has gone 10.67 at 127+ in the quarter, about 400 pounds lighter than Tom's '70 Dart.)

Those two cars are running 28 pounds of boost to get those numbers. They don't seem to incur engine damage at those levels; slants are built VERY tough and can withstand this kind of boost, unlike a lot of V8 cars.

THAT is the way to performance from a slant six.

I wouldn't say that building a slant motor like the one Doug built, was a waste of time and money, but, the results are quite different...

My motor makes, according to that Wallace online calculator, about 357 horsepower at 15 pounds of boost, which is a little more than you could expect from a full-race slant, and it idles like a stocker.

And, I haven't tried 20 pounds of boost, yet, nor 25... As I said, it's only been to the drag strip, twice so far.

Stay tuned; I may blow this thing up, yet... LOL!:banghead:
 
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