I just happened to be talking with a BMW owner about engines, and I mentioned the Slant Six was a classic engine design with a great reputation. He responded that BMW I-6 engines are at a 30 degree slant.

Which got me wondering, is there any link between these two designs in the idea of using a "slant?" Who was there first, Chrysler or BMW with this idea?

Just wondering how unique the slant six design really was/is...

I'd have to say that the /6 was first. It was being designed in the mid 1950's. The BMW 6 is based on their 4 cyl designs, which I don't believe were in the works until the early 1960's. The concept is the same though.....incline engine 30degrees=lower hoodline=lower wind resistance=more performance/better fuel economy.

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"That thing gotta HEMI in it??"

The 4.0 liter inline six in my 95 Jag XJ6 is also slanted to the right by about 30 degrees for packaging reasons.

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Jack Collins
66 Mustang 250 EFI
Lotus Seven Replica (Under Construction)
<img border="2" src="http://fordsix.com/locost/locostsig.jpg" width="275" height="118" >

I'd heard of the rumor before, but got really curious after an article on the BMW Bavaria appeared in Grassroots Motorsports. They stated that the engine these cars originally came with was not only an inline six tilted 30 degrees to the right, but the bore and stroke were within under 1 mm of the dimensions on a 170. On the other hand, the combustion chamber design and cylinder head are totally different.

I'd chalk it up to a case of parallel evolution. On the other hand, if the bore spacing is close enough, I have to wonder if you could get a BMW M3 cylinder head to go on a slant six block...

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

Be kinda tough to fit an M3 head onto a Slant......if I remember my Bimmers right, the M3 is a 4cyl....might be a little short....
Now an M5 head....that Might be interesting, as its a 6 cyl....

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"That thing gotta HEMI in it??"

Some diesel railcars came with a 60 deg. tilted Detroit Diesel inline six...

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

Ah, A railfan I see. Every once in a while the gang and I like to take trips up north country to Canada to watch/photograph/railfan the CN and CP lines. The only thing we have down here in NH is Guilford Rail (the old MaineCentral and B&M railroads) and Amtrak on its way up to Portland, ME.

Hmmm.....I wonder.....think one of those Detroit Diesels will fit in place of the Slant in my Ram? Or better yet.......A few Hyperpack slants in the railcars......yeah thats it.......

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"That thing gotta HEMI in it??"

Wow this thread has it all slants and railfanning! I like to take a peak every now and again at what is happening on the RR. The first year I took my Dart (340) to Carlisle I ended up driving home through some really nice NS/Conrail yards along the eastern edge of PA.

But back to the BWM all I have to contribute is that the M3 is a definately six and the M5 is a hell of an 8. I love the equal length runner intakes on some of those BMW sixes. clever plumbing.

I know there are many manufacturers who have used the slant inline for many years but I can't say I know who the first was.

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It is easier to REACT,
than it is to THINK!

Middy.

Well, I suppose it depends on the year M3 and M5 we are talking about. The original M3 was a 4cyl and the original M5 was a 6 cyl.

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"That thing gotta HEMI in it??"

The first M3 was the E30, made from '88 (I think) to '91. This one had a high revving four banger. The later M3's were all inline six designs, with the newest (E46) having variable valve timing.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

Whoops thanks for the update. I stand corrected.

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It is easier to REACT,
than it is to THINK!

Middy.

I believe BMW had design influence at Buick, the 215 allow V8. I'm sure that engineers borrow ideas. The Datsun L series is closed modeled upon a BMW series, lots of ideas get copied. Some old Toyota sixes look like Chevy inline sixes, and used them until well into the 1980s, maybe even later.

What is the bore spacing of the Chrysler Slant? I'd estimate 3.875" bore to bore, but its never been reported, to my knowledge. It's not a siameshed engine. In Australia, people put 100 thou over 3.5" pistons in these engines with ease.

I understand it is built on similar tooling to the 1.8/2.0/2.2/2.5 L4 ohc Chrysler. Same bore spacings.

The 1962 BMW's 1.6/1.8/2.0 OHC cross-flow four spawned the cross-flow OHC 2.8/3.0/3.2/3.5 slant sixes. Wonderfull engines with a treatening reputation which ultimately crushed Fords wild Essex and Cologne V6 engines in the European Touring Car Challenge during the 70's. In the 80's, the mid engined Lamborghini/BMW built M1 (non-slant EFI with 270 hp), and 635 based M6 got twin cam variants which were a four valve per cylinder set up. Mighty cars!

The new six cylinder 320/323 engines in 1977 were siamesed bore, non-cross flow engines with much shorter bore spacings than the classic strain of long sixes. I don't know the bore spacings, but the realted M3's were bore out to over 97mm, which puts the spacings centre to centre at about 105 mm, or 4.13" or so

The early M3's were based on the six cylinder 2.8/3.0/3.2/3.5 engines, but were cut down to 4-cyl. There was a school of thought that the high winding circuit racer would be unblanced with the longer six, and wouldn't handle 7500 rpm or more with the little 1.77" crank pins the 323 sixes had.


Any ways, the little sixes were siameshed in the cylinders...they had no water jacket between cylinders. I'd say the bore spacings are about 92 mm, or 3.62".

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A FordSix.Com refugee. Former Aussie 225 AP5 owner. Non-violent, and totally aware of Slanted Chry-Power.

I have heard the same about the slant having same bore spacing as the 2.2/2.5 engines. If I remember correctly, they were produced in the same plants, and I have heard it was done to be able to use some of the same tooling/machines to save development/production costs. After all Ma Mopar was on the verge of bankruptcy in those years......

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"That thing gotta HEMI in it??"

A friend of mine drives an old BMW 6, If you've got any questions - I'm sure he would be glad to take a peek under his hood or even make some photo's of it for you guys. here's his email adress

maurice_aex@hotmail.com

Just tell him you got it from me

Job

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1965 Barreiros Dodge Dart. 225 / 4 speed.