Dodge Slant-6 Engine.

[Incommando]

Mopar made outstanding engines including the various slant sixes but either of the three CID's would be a giant step backward from the 4.0. Why adapt F.I. & go through the swap hassle when the factory engine is good for 250,000 miles easy? What a waste of time & money.  In actuality the 170, 198, & 225 slant sixes as well as the 277, 318, 340, 360, 361, 383, 400, 413, both 426's, and the 440 V8's were pretty awesome motors. For you kids who only know of the FWD era here is Mopar that has what must be a junk engine, the 440. The engine retains the factory block, heads, stroke, etc...   With just a basic rebuild and aftermarket cam, pistons, intake, carbs., and distributor the 440 in that Road Runner makes 550 hp/550 lbs. Dollar for dollar the 440 will deliver more HP than the vaunted SBC of the same era. With the exception of the roll cage only the engine and torque convertor have been modified. The rest of the car is 100% stock and it is 100% driveable on the street. All of the lights, windows, alt. etc... are in place and functioning. Even the hood is steel with a glass scoop molded onto it. At 4,300# with me in it the car will run 11.30's all day. In a Duster body this would be a low 10-second street car on pump gas. That suspension is the original '71 springs, torsion bars, everything but the shocks which have been replaced ( it is 40 years old after all). It does pull the front wheels off the ground with that well used stock suspension.

 

Added a pic to show the tires and wheel openings at static height

[big66440]

That is an awesome RR,my oldest brother had one right out of high school,383,air grabber,pistol grip 4 speed I used to get butterflies in my stomach riding in it, it was fun but scary :yes:

[a1awind]

 

Funny thing... I was just thinking about the slant six in my buddies '83 D150 today... I know an internet search would show me this, but the one thing I never knew was the liter/CI of it... Since the topic is here, anyone know off hand?

 

Rob

 

It came in three different sizes, with the 225 cid being the most notable since it was the best one.  I'd love to do a swap like this, convert it to MPFI and use the Renix ECM to run the whole set up.  Only problem that I have seen in my little research finding a suitable transmission to run behind it... AX15 is out of the question without heavy modification/custom adapters and anything 4x4 would be a ton of work.  But, with a 2bbl carb, I've heard people were getting 30 mpg back 40 years ago on some of these.  I imagine with some level of EFI, you could get at least the upper 20's for mpg for sure.

I had an 83 d100 royale long bed 2wd.

 

  it was a 225ci six with a 727TF behind it.  1 barrel carb. rated at 90hp (seemed like a hell of a lot  more...i  never was really wanting for more power with that truck) i drove a mixed cycle at that time 24 miles each way  i averaged 25 mpg.  even though it was a beat up old farm truck....it still ooozed cool.  i had it the same time as my 98 s10 2wd 4 cyl. the s10 got the same mpg across my commute as the full size dodge!!!!

 

to be fair the little chevy got 33mpg straight hwy... so it was the go to for road trips.

[onlyinajeep726]

I want that Ram!

[azdiesel]

As a suggestion, look for a 225 aluminum block & save some weight. I used to drag race a valiant Hyper-pak. 4 barrel afb carter on a long ram manifold cam, cast exhaust headers. Any knowledgable engine remanufacturer will tell you it is one of the best engines ever built. Build yourself a Mega-squirt EFI system/ignition and you would have a sweet package. In the earily 60s there was a compact car race at daytona,  Valiant---driven by Lee Petty,  Ford Falcon & Corvair.  The Valiant was a hyper -pak and won the race with I believe was 37 laps ahead of the Falcon .  The Corvair DNFt.  (didn't finish)

[johnj92131]

As a suggestion, look for a 225 aluminum block & save some weight. I used to drag race a valiant Hyper-pak. 4 barrel afb carter on a long ram manifold cam, cast exhaust headers. Any knowledgable engine remanufacturer will tell you it is one of the best engines ever built. Build yourself a Mega-squirt EFI system/ignition and you would have a sweet package. In the earily 60s there was a compact car race at daytona,  Valiant---driven by Lee Petty,  Ford Falcon & Corvair.  The Valiant was a hyper -pak and won the race with I believe was 37 laps ahead of the Falcon .  The Corvair DNFt.  (didn't finish)

 

Those early 60's (61-62) aluminum blocks did not last in production or in real life.  I have never seen either the slant 6 block or the AMC block in a scrap yard.  But you are correct about the hyper-pak power.

[Incommando]

As a suggestion, look for a 225 aluminum block & save some weight. I used to drag race a valiant Hyper-pak. 4 barrel afb carter on a long ram manifold cam, cast exhaust headers. Any knowledgable engine remanufacturer will tell you it is one of the best engines ever built. Build yourself a Mega-squirt EFI system/ignition and you would have a sweet package. In the earily 60s there was a compact car race at daytona,  Valiant---driven by Lee Petty,  Ford Falcon & Corvair.  The Valiant was a hyper -pak and won the race with I believe was 37 laps ahead of the Falcon .  The Corvair DNFt.  (didn't finish)

If you were to find those parts what would that mega-squirt custom rebuilt 225 cost, what would the output be, and at what RPM? Those blocks are nearly non-existent and those that can be found often have issues. Weight in the flyweight MJ isn't really the enemy, anyway.  The Hyper-Pak 170 produced a whopping 150 +/- gross horsepower according to what I have seen. They would probably garner around 120 +/- horsepower net. I have an econo-box that gets 40 MPG that has 140 net HP. Installing this package on a 225 would get you around 150 +/- hp net. You could have a very capable LA for less than a 225 build ( MUCH less than a hyper-pak clone) and the adage remains true:  there is no replacement for displacement. Many modern V6's get 250-300 HP while V8's get a lot more especially if we add in torque. Compare this to an oft-mentioned internet "slant six hero" who built a very heavily modified 225 that, when compared to the hyper-pak, uses a bigger cam, different pistons, milled head, bigger carb and real headers plus a 150-hp Nitrous system to get....350 horsepower. WITH the nitrous. Nitrous is not daily driver nor Jeep friendly. The hyper-pak kit had a ridiculous price tag at the MSRP of $450 in '61...about 25% of the cost of the average new car and about twice the cost of building a hot V8 in 1961. That 25% figure would make it $7,500 today...for a cam, intake, carb, and cast exhaust and 50 extra horsepower. Um, no thanks. There was a reason this set-up only lasted a couple of years 50 years ago. The power band was set way too high for a Jeep as well. They were reported to be dogs until high in the RPM range and most considered them unsuitable for the street. They could not be used with an automatic tranny for this reason. BTW: that race mentioned was in a special class that NASCAR experimented with but dumped after half a dozen races and a large investment loss. The V8 cars dusted their times.  Another good adage: Just because you CAN doesn't mean you SHOULD.

[Eagle]

When I was crewing on short-track stock cars, several drivers ran in the 'Sportsman's" class with in-line sixes. The only engines we ever saw in that class were the AMC I-6 and a GM I-6 truck engine (and my friend's Hudson Hornet). The ONLY street-derived I-6 to have ever been run in the Indianapolis 500 was Barney Navarro's AMC-powered car.

 

The Mopar slant six was a good engine, but IMHO anyone who claims it was in any way superior to the AMC I-6 is on some kind of mind-altering chemical substance.

[hmurray]

I just installed a 1974 225 slant 6 in my 1954 Willys wagon.  So far so good.  I love it.

[Pete M]

38 minutes ago, hmurray said:

I just installed a 1974 225 slant 6 in my 1954 Willys wagon.  So far so good.  I love it.

 

be sure to start a build thread about that wagon   we need way more details!  

[Jeep Driver]