Slant 6 turbocharging- yea or nay?

I have never had a turbocharged car before now. The downside of that is that although I have read a fair amount about it, I still don't know squat.

Here are some things I think I know, but am not sure are true. Please correct me if I am wrong. Before I start, let me say this: I blindly walked into supercharging my 360 Magnum with a Vortec V-1, S-trim blower and generally have had good experiences with it, so far. It's street/strip car and picked up 16-mph and the e.t. improved 1.8 seconds at 10 pounds of boost, compared with unblown (quarter-mile times).
That seeming success means NOTHING when it comes to building a turbocharged car, I realize.

My turbocharged car, which I am building with a partner, is a slant-6 car.

Why did I go from a V8 environment to a 6-cylinder???? Good question.

Here's what I THINK to be true: As I said, please correct me if I am wrong...

BECAUSE the /6 was originally designed to be an aluminum block engine, and because aluminum is not as strong as cast iron, the main bearing webs, the top deck of the block, and just about everything else relating to design parameters that affect block strength, ended up being manufactured of cast iron, (when the plans for an aluminum block went away) without changing the specs at all. In other words, this engine should be constructed UNGODLY strong (as cast) because of the foregoing. Add to that, a forged crank (early models,) and a cylinder head that is as robust as the block. It is one rigid s.o.b., at 84 pounds!!!

There are only 4 main bearings, but they are LARGE; virtually the same size as the bearings in a 426 Hemi.

The 198 connecting rods are 7 inches long, and K-1 makes them FORGED, while Wiseco makes pistons to use this rod in a 225 application, with a thin, low-drag ring set in an 88mm size (3.465").

Due to its slim profile, laterally, there's lots of room under the hood for supercharging, headers, or turbo plumbing.

There is one one guy running 127 mph and 10.70s in a 3,000 pound car with a fairly mild turbo /6 combination... lots left in the engine.

ARP custom-made us some heavy duty head studs for this engine; 220,000 psi (garden variety are 180,000 psi.)

Big valves for the /6 head are readily available.

Over 500 HP is available from a mildly modified turbo'd engine without ever seeing the far side of 6,000 rpm.

Downsides to the /6:

Long stroke; RPM limited.

No roller cams are avilable because NOBODY makes a "blank" for it. So, ZDDP is an issue.

No aluminum head is available. The stock iron head weighs 84 pounds! My back; my back.....


High-lift (1.6:1) rocker arms and/or roller-tip rockers are hard to find.
The cylinder head was designed for a 170 cubic inch motor, with ports and valves woefully undersize for a 225. Bigger valves can be added, and I am sure there is a LOT of room for porting, if you have the patience (this head is cast iron.) Still, a really hard-running 225 normally-aspirated engine would require a LOT of headwork. A LOT!!! But, there are some out there.

Enter the turbocharger: Boost and a /6 would seem to be a marriage made in heaven!
These engines look to me to be to be an ideal candidate for 30+ pounds of boost. Their seemingly indestructible characteristics would appear to make them an ideal choice for a 500+HP street car.

You can do a lot with 500 HP if you're careful about weight.

(Your ET / MPH computed from your vehicle weight of 2600 pounds and HP of 500 is 10.09 seconds and MPH of 132.77 MPH.) from Wallace racing calculators)

That's a bad street car, where I live...

The /6 is nearly a hundred pounds lighter than a small block V8 (again, correct me if I'm wrong.)

A variety of intake manifolds is available. The /6 will bolt into nearly anything MOPAR.

Our car is a long way from completion, but we have most of the tuff stuff done..... we're just two old guys having fun...:cheers:

That's what it's all about, right?

Our /6 car is a '64 Valiant 4-door sedan with a B-Body 8.75" rear, a 904 with 2.74:1 1st gears, and a new, Auburn, limited-slip 3.55:1.

It'll have a '73 Duster disk brake setup, and a 66mm Turbonetics turbo fed by a 750 double pumper Holley with blow-thru mods by Tom Wolfe. In fact, our whole engine is a near clone of his. If not for his help and advice, we'd be stuck in the dark ages!!!

Thanks, Tom!

If anyone has any disagreements with what I've written here, please post the CORRECT info; as I said, I don't know much about these engines....

Thanks for any comments!:read2: