225 slant

Who sells performance parts for this motor?

Clifford Research used to be the popular source, but I've not heard much about them of late. I did look on the web and they still have an online store.

I knew a guy years ago who drag raced a slant six. My gosh he was possessed with that engine. Spent a fortune on it. After the first handful of performance improvement add on stuff, weak links in the engine started showing up, and that's when it really go expensive.

Yeah those engines aren't designed like a BMW straight six or a Lexus straight six. I had a Lexus dual OHC straight six in a SC 300 and that was a super nice engine. 4 valves per cylinder, fuel injected, etc. That engine would purr down the road at 120 mph. The Mopar slant six was designed in a different era for a different purpose.

Try the slant 6 forum. Most power is made by 4800 even when modified. Ran one in the 70's in an altered. Lots of engine vibration over 5500. Great for boats,chipper and stock eliminator. There is some Australian stuff out there like intakes and hemi heads. There is a following down under.

The slant and the Australian engine have no parts in common.
None of the heads are any good. There has been a discussion of an aluminum head for 30 years, and nothing done.
No, the Jaguar, Toyota, blah heads do not fit.

What do you need John?

First thing you need to do with a Slant is make a reasonable plan of what you want it to do. With a little motor it is way easy to get off track and have a real turd.

The key to a Slant is getting a good head on it. When you start with postage stamp size ports and nickel and dime sized valves it's hard to make power. The best Slant head porter in the country has retired now, but I know where all his stuff went.

Torqstorm is making a reasonably priced bolt-on blower kit now. It makes 8 or 9 psi which should wake up a fairly stock motor very well. Boost is where it's at if you want to go fast.

Avoid Clifford like a plague. The clown running it now doesn't know his butt from a hole in the ground. Clifford used to make really good stuff, especially intakes and headers. Those pop up used all the time, and it is much easier than dealing with Clifford direct. Be patient and watch the for sale pages, E-bay and even Craigslist. Guys get tired and dump their new/used stuff all the time.

The Achilles Heel of the Slant is the oil pump drive gear. We went through a few years of people having the gear fail and lose motors. I had one do it. Not sure if it was ever solved, but it seemed to be more common when using Mopar Performance cams. Very seldom will you have a bottom end issue. You will hear that it's only a 4 main block, but you will never see a web crack like a big block even at 600+ horse.

www.slantsix.org is a wealth of information if you know who to listen to. There are a couple knotheads on there that will reply to every question without having a clue what they are talking about.

You are very wrong there. Many attempts have been made to get an aluminum head made. The issue is the market is so small nobody can agree on what they really want. I have been involved in 3 deals myself. 2 died because we could not get 6 people to agree on how the head should be done. 1 died because the main investor suffered a personal tragedy.

The Aussies cast alloy heads for almost anything and won't do one. That alone should tell you there is no market.

There were 7 factory aluminum heads made. Some still exist. There was no advantage to just making the head alloy.

Howard Davis had his own billet head made. Not sure how much money he spent on it, but he did it his way.

By "attempts" you mean "we talked about it, but no physical product was cast". "Done" means "here is the head, it may still need some work". It wasn't done.

The discussion you referred to is the same as every aftermarket head: the more improvements (raised ports, bigger ports, relocated intake valve, valve stem angle changed, rocker shaft moved, chamber shape change, spark plug moved), the more expensive (and slow to develop) it becomes, fewer people want it, and the more special parts it needs. As you said, just making it alloy not only does almost nothing (except save weight) for power (which many, many owners do not understand), but wayyy too expensive for a nearly stock 200 hp engine.

A cure for the pump drive with pictures can be found on the slant site - it involves tapping pressure to squirt the gears.

The Torqstorm looks good, won't need any other mods except header.

Considering the slant has had a long reputable production run in the millions across the globe, its a reliable engine, very well known, and yet the market can find the rational for building alum heads for 409's,. Ford Y blocks, AMC's, etc Other then marked red comment above, which is a huge hurdle, I don't see a market UNTIL an alum head is offered. Chicken or the egg scenario. Since the slants are still plentiful and still affordable, and its likely a turbo build will get at least equal attention as a stock Hemi at a car show. The alloy advantage is always weight. No matter what, the client base is dying off.

Slant's 12,500,000 over 22 years

409's 1965 2,828 car production ceased
1964 10,625
1963 21,267
1962 8,909
1861 142

One thing you have to remember, 99% of Slant owners are cheap bastards that cry about a $12 set of plugs. Many cry that they want an aluminum head, but most doing the crying want it ready to bolt on for $350. I've been involved in enough attempts to know. You want one? Do like Howard did and dig in your pocket and do it yourself. Then there is no arguing.


The biggest limiting factor is the tiny bore size. A big port head is not much use when you have the cylinder shrouding the valves.

Before this derails anymore, I am going to guess John isn't wanting an all out race car anyway, more of a nice, peppy driver.

Much like our Hemi 6 engines over here, they can be a money pit if you're not careful. Aussie Speed do a little bit for them.

http://www.aussiespeedshop.com/product-category/slant-6-chrysler

Hello Guys, the slant kit we offer is a great way to bolt on a bunch of power. If you have any questions about it feel free to ask.

Thanks
Jeff

Here's an article in Mopar Muscle about a \6 build. A lot of work and coin for stock 318 power.


spoiler alert



The rare alum block popped the head gasket on the dyno.

"One thing you have to remember, 99% of Slant owners are cheap bastards that cry about a $12 set of plugs. "

And that is one of their better qualities.

Slant problem: the cars don't auction for $80,000 like the 1968 Camaros.
People with $5,000 cars don't spend $4,000 on the engine.

You could call Sharadon Performance in Hugo, MN. They were running a slant 6 Duster at BIR a few years back that ran pretty good, upper 10’s IIRC.

Doug Dutra is the Slant 6 guy.

The four main engine has a number of disadvantages but one of the worst is that the bore spacing is uneven. It's 0.020" more between 2 and 3, 4 and 5.

The engine layout just BEGS for a turbo. All that room plus exhaust right into the open space. But the engine is only 225 cubic inches. It has a 4+ inch stroke already, so there is no easy way to increase engine displacement. If you are bound and determined to do this, look up Dutra online.

The head is a bottleneck. Ported you may see 200/150 cfm intake/exhaust.

Fuel distribution is a problem, port fuel injection solves that problem nicely.

The problem is money. You may have $3,000 to $5,000 tied up in a 300hp engine.

R.

You may want to look into a 170 Chrysler made a ton of power with them and they were stable/ reliable at speeds over 6K. I had a slant 6 Duster and won plenty of times with it years ago

I recall there being something about a guy cutting up some 5.7 Hemi heads and modifying it to fit the /6.

https://www.jalopyjournal.com/forum/threads/home-brew-hemi-head-slant-six.372471/

Don't know if it was BS or not though. The pictures were hosted on photobucket, so those are gone.

I made /6 parts for awhile. During that time I met one guy who was willing to spend money to buy good stuff.

It was a hoax. A really good one, but crap just the same.

And, as I said at the time:
"I wonder how many cut-n-shuts he did to the original head(s)?
Slant bore spacing is alternately 3.98" and 4.00".
The 5.7 is 4.46", just like the LA.
This means if you start at the front, the #2 cylinder is .46" too far back, the #3 is .92", #4 is 1.38", #5 is 1.84", and #6 is 2.3"... hanging off the back of the block.
Even cutting each head in halves (2 chambers each), each pair of chambers (if centered) is off by .23".

Lot of welding."

Has anyone ever found a head with the same (at least similar) bore spacing? Yes, I know it alternates .020" but really a non alternating one would be fine

4.6 Ford is close.

I'm tired. Let someone else do this.

Whatever

Already been done almost 50 years ago. A guy who worked for Ford used a combination of SOHC 427 and Pinto parts to make an OHC 170. He made cam stands on the head, had a cam ground, modified SOHC followers, and used a Pinto style belt driven off a sprocket between the crank and flywheel. He also made a spacer for between the block and bellhousing. IIRC, it was in a '63 Valiant.

The motor came up for sale a few years ago. I thought Lou Madsen bought it, but it went somewhere else.

FWIW, my good motor has made real close to 300 n/a and 375 on a little spray for waaaaayyyyyy less than $10K.

I have a faint memory of a slanty race group maybe in Michigan with some of them tapping in the 10's.I haven't bought a mag in years so I'm not up on the latest.
I do have a friend that built an AWB Dodge,put a turbo on it with a big stuff 3 setup.

That pic he still is blowing through a carb.Have pic's in my archives,,,,,,,somewhere.Having over 10k images,it's getting harder to find stuff PLUS,,,,,,I have CRS!

Shades of Luke Duke.

Thanks for all the input guys. Lots to mul over. Ya, not lookin to run mid 10's. Just want to [censored] it up a bit. With the inherent limiting factors mentioned, sounds like puffing it might be one way to go. My other option might be to just do a little home port work on the existing cast iron head, up the C.R. a bit, intake, headers, cam and call it done. If I could squeeze 200 HP out of it (normally aspirated) that would be great. Ether way, I'm sure just dumping a stock SB in to it would result in more HP with a lot less $. This is my first /6 endeavor, so I'm on a learning curve at this point. On the plus side, at 112 HP, my tinker toy drive line should last for ever.