Hemi 265 Straight 6

[Bruceynz]

Hi Guys,

I don't know where to post this and I am not out to start some all out argument, its just general talk about engines.

In 1966 Chrysler started development on a 245 hemi 6 to replace the slant 6. For some reason they stopped the project and Chrysler Australia picked up the project. The Aussies got it to 265 cubic inch, so where I am going with this is that I have been watching a guy throw some modern tech at these engines and he is developing 315hp to 340hp out of them at the rear wheels! With his G tech he has reeled off a 3.77s 0-60mph run I think this is truly amazing!! Watch this video and if you want to see his 3.77 fast forward to 29minutes. He has quite a few videos to watch, he is a true blue Aussie motor head! He is right up with everything with engines!

Thanks
Bruce

 

[slant6billy]

Caught one of them Aussie Mopars at Carlisle a few years ago with one of them Hemi 6 motors. Killer lines

Some

Tuff Wheel Aussie style?
And the engine:

These are truly mopars killing chevys and fords with that set up

 

[Bruceynz]

OK from memory in road trim the valiant pacer was about 220hp but with a cam and triple Webber's it was around 300hp but now this guy is getting 400+ HP out of them! At 3.77s 0-60mph you would kill most V8s, its up with a GM's show piece the Z06 corvette!!

 

[Bruceynz]

What is the hellcat 0-60mph???

 

[Bruceynz]

Imagine coming across a hemi 6 at the lights and when the lights go red to green all you see is the tail lights of a 6 cylinder!!

From memory in Aussie the gov threaten to ban these road rockets, chryser had the e38 and e49 vailant charger, ford had the xy gt ho falcon (351 v8) and gm had the holden torana that were all capable of 140mph. Because of the threats they all stopped making them.

 

[kkritsilas]

The torque curve in the first video is remarkably flat. That results in the almost straight line rise in HP. That would be a great street car; power almost everywhere.

 

[Aspen500]

Not to get too picky, it's not really a Hemi. It's more like a cross between a Hemi and wedge chamber. The valves are in line and the plug is off to one side vs a true Hemi with the valves angled toward each other and the plug in the center. Chrysler called it Hemi because they own the name and besides,,,,,it just sounds cool!
Sort of like the modern Hemi, it isn't really a hemispherical chamber but Chrysler still owns the name.

The Challenger Hellcat 0-60 is about 3.5 seconds.

 

[Bruceynz]

I think the name "hemi" was used as a sales gimmick as the 426 hemi made big impression in the day so it would of been good marketing for Chrysler.

 

[Aspen500]

I think the name "hemi" was used as a sales gimmick as the 426 hemi made big impression in the day so it would of been good marketing for Chrysler.

That's exactly the reason and there's nothing wrong with that, and because they own the trademark name "Hemi", nobody else can use it.

 

[Jack Meoff]

I want that engine in my Caravelle.

 

[Bruceynz]

Can they get that kind of power out of a slant 6?

Pretty powerful engine, would keep up with a hellcat in a 0-60mph run, how embarrassing an old 6 can keep up with the latest and greatest super charged dodge hellcat

 

[Aspen500]

One big difference is weight. The Challenger isn't exactly a lightweight at roughly 4,300 lbs. The stock Hemi-6 would be quite a bit slower than the modified one that does 0-60 in 3.77 seconds also but I know what you're saying.

 

[kkritsilas]

You could supercharge or turbocharge a /6 and get that kind of power. The Austrailain Hemi 6 probably has some pretty high flow cylinder heads to do those types of HP numbers, whereas the /6 heads are not really optimized for high flow. Forced induction (supercharge/turbocharge) gets around that by literally cramming in air and fuel. What the /6 does have is a very, very robust lower end, so high boost pressures will only create potential problems for cylinder sealing; as long as forged pistons are used, the bottom end will probably be fine.

There's a bunch of videos on YouTube, but here's a couple:

Supercharged:



Built up without a supercharger, but with 4 Barrel Intake and Exhaust header (cam as well if you read the description):

 

[Bruceynz]

What sort of power do they get out of a super charged /6 just wondering if they can get 400hp out of them like a naturally aspirated aussie hemi 6, I see one is 300hp in the video

 

[80mirada]

The Aussie hemi 6 has a better block and head for high performance. The slant is one hell of a work horse but the Aussie has more potential for power

 

[Aspen500]

Here ya go!

 

[kkritsilas]

What sort of power do they get out of a super charged /6 just wondering if they can get 400hp out of them like a naturally aspirated aussie hemi 6, I see one is 300hp in the video

The 300 HP one in the Youtube video is not supercharged, it is just a hot rodded, natural aspirated /6; no supercharger in sight if you watch the video. You can see the 4 Barrel intake and header.

I have heard of 350 HP for a supercharged /6. I tried to find a video with a dyno run for a supercharged /6, but nothing that actually showed power numbers. This all sort of depends on how much boost pressure is being applied, and at what point the pistons/bottom end break.

In the end, it is two ways to get to a particular power point/level. Six cylinder engines haven't really caught on here in North America, at least for US made cars. I don't mean to say that they can't make good power, but it is just that people jump to a V8 when they are looking for power increases. V8s are still quite plentiful, and cheap here. There have been factory hot rodded /6s, in the early 1960s (Sprint pack or something like that for the /6); Pontiac made an overhead cam version of the Chevrolet straight six (225 HP, I think), and then there were the "big 6s", I think there were 292 CI Chevy/GMCs, and a 300 CI Ford, were used for years in pickup trucks.

 

[BudW]

The engine they had looks a lot like the 4.0L Jeep engine (which ironically is 245c.i). I wonder of the Jeep 4.0L engine is the same engine as was used in in the Aussie Mopar’s?

If you take a 4.0L block and sit it beside a /6 block, you will find more similarities between engines than you will find differences. It’s a bit longer engine – which allows for bigger bores.

I’ve not played with nor owed either engine – so can’t comment any more.


I’d love to own an A-body derived El Camino/Rampage style truck. Not sure about the RHD (Right Hand Drive), though.

BudW

 

[kkritsilas]

I don't think the 4.0L Jeep and the /6 are related. I think the 4.0L Jeep engine was designed in the dying days of AMC/Renault, and is a completely different design. The engine in the video is being called out as a /6, and does appear to be leaned over, or slanted. The 4.0L Jeep is vertical, from what I remember ( I've one seen one, and briefly).

 

[80mirada]

The 4.0 is based on the rambler six from at least the 60s, may go back even further. The Aussie six is very similar but different. They both used similar layout, but they are not the same. The 4.0 was redesigned to reduce overall length with accessories installed and to add "modern" engine management.