Why am I even contemplating this?

SlantSixSullivan

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Right off the bat, most people will say this idea is stupid. I might even be one of those people, but hear me out. After owning three slant six cars, I've developed a strange love for the 225. Now, I know that I'll never make the power of a small block with a slant six (which is why I am building a 360 this summer). If you've ever driven a slant six, you're aware its no powerhouse. But it seems to me that when I'm at full throttle, I know there's more power available. You just have to find it. Firstly, the heads used on all slants were designed to flow for 170ci. Fine, for 170ci but not for 225ci. And they are HEAVY. For under $1000 I want to challenge myself to build the best slant I can build. This means a complete tear down, stock rods, crank, pistons, etc. I just want to see what a four barrel manifold and carb will do, along with a shaved, ported and polished head. There's a lot of meat that can be taken off those heads, and it'd help compression a bit. There's also a small selection of cams to choose from, but I don't know about all that yet. Anyway, let me know what you think. I'm bored in my hotel and I need something to think about.
 

jasperjacko

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You need to find a slantaholics group and get some therapy
 

rcmaniac791

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I mean, an engine is just an air pump in reality. If you can make it breath properly with lots of air (and fuel) flow while still being drive-able, then it's not crazy at all. So in theory, any engine can be a performance engine, it just depends how much time you want to spend and how quickly you want to empty your pockets. ;)
 

Joe12459

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Why do any of us do the thinks we do? Because we love our cars. A healthy slant six should make a fun car to drive, and somewhat unique, or at least rare. Sounds like a great project!
 

lowbudget

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Slantsix.org has a lot of info. The Direct Connection slant six book is out there with a free download somewhere.

Doc Dutra designed some cams with Elgin that they had a group buy over at Org there which is probably over now. I bought one but forget which one. I also heard good things about Racer Brown cams for the slant.

You can get 4 bbl. intakes through Offy or Clifford. I don't know if Doc Dutra is still doing the hyper pac manifold. I think an Aussie Company still is along with Clifford also. The Aussies have lots of parts just do your research as there is one shady character out there. I know from experience. The Super Six set up is still availble through e bay or the classifieds.

As far as exhaust Clifford headers or another brand if you can find them or Dutra duals.

engnbldr on Ebay had the big stainless valves. I don't know if he's still selling them or not.

Campbell enterprises has hi comp pistons and such.

Do your research on Clifford before ordering. The have a rep. for being slow.

Yes I have a war chest of slant six stuff. I just need the time to put it all together for my Valiant
 

BudW

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There are two ideas I have on the /6 that I might do – if I ever get one.

Naturally aspirated and make (not sure how yet) a twin/tri-runner (and switchable) intake system with fuel injection.
Or
Turbo (or twin turbo) and fuel injection.

Back in the early ‘60’s Chrysler had come up with the long ram intake system.
Ram Theory
A variation of that was the short ram intake – which at first appearance looks like a long ram.
61 300G engine.jpg

ramshortcrease2.jpg

Then the cross ram used on the race Hemi’s came out (another variation).
crossram-offy-tops.jpg

Not a Mopar but to give an example of shorter runner length.

Pretty much all cars in last twenty years use a tuned length intake or variable length intake runner system – and most of them are plastic.
Variable-length intake manifold - Wikipedia

A /6 intake – um, not so much (tuned).

In my mind, I want to use a 3-D printer (or something) to make a couple of intake designs.
First is the long ram intake. I already have a set of aluminum long rams and would really love to install in my big block 5th Ave – but suspect it won’t fit.

What I would like to do is make a set close to it that will have a pair of throttle body’s on it (one per side) and 8 fuel injectors (one per runner).
Those intakes have four pairs of runners.

The difference between the long ram and short ram is the internal divider length (about ½ the distance at 15”).
ramshortcrease2.jpg

The long rams - the tubes went the whole distance. These stop mid way - which you can see.

My thought is to make a plastic version of same intake and have 2 plates in it per tube pair (8 total). Already cast into the plastic is a 7½” (to middle of intake valve). Have a 7½” plate that either rotates or pops up to have a 15” runner – then the last plate, which will be 15” long) that will either rotate or pop up to create a 30” runner for low end power.
As RPM rise, at roughly 3,100 RPM, the longer plate would pop up (or rotate out of the way). At roughly 4,000 RPM the shorter plate would pop up (or rotate) so I could maximize air induction.

A more or less straight intake without any heat source close by “should be” fairly simple to make.

- - - -
I would like to do the same to a /6 intake as well – but not sure what to do about the heat source (exhaust manifold/header) or how to get that long of an intake stuffed under the hood.

- - - -
The Magnum engines with beer keg intake are using the 15” runners. The new Hemi’s (and most other Chrysler engines) use a variable runner intake (7½” and 15”). The 3.5L engine uses 7½” and 30” runners.

No matter what, getting rid of the un-equal length /6 intake and adding fuel injection (either throttle body or port fuel injection) should help a /6 a lot.
Turbos – even more so.

My thoughts on the matter,
BudW
 

BudW

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Yes they are – but a fixed length.

I'm talking a variable runner length intake.
 
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