Regarding street use:

At what compression ratio, does the slant start to become more of a HP motor?

What lift/duration becomes the tipping point?

How much can the stock 1bbl manifold support? And a modified stock manifold? Can a 4BBL manifold work well on a Torque motor?

So if I was to try and design a Slant 6 build that is a torque motor, and wanted to have it be at the max V/E at about2700- 3300 RPM.. (cruse speed)

I doubt I will ever need or want to spin it over 4500. It Will spend time a 1500-2000 RPM..

It is better to ask: When does a street engine become a "race" engine?

I have built many "High Performance" street engines and race engines.
What it comes down to is what fuel you need to run.

A basic street engine will run, with-out "fuss", (no spark knock or run-on) using any available pump gas.
An HP street engine needs to run high quality pump gas.

The same thinking applies to race only engines. A "no fuss" race engine can run on high quality pump gas and/or other blends of pump & other fuels / fuel additives.

Here is the key point: Set your goals in terms of engine operation and fuel, review your budget & then select a cam to support your goals.

Next, measure the engine's deck, head cc, bore size & find the intake valve closing point on the selected cam so you can calculate the engine's Dynamic Compression Ratio. (DCR)

Once you know the current DCR, do the needed machining so you get to a 8 to 1 DCR. (up to 8.3 to 1, for HP street engines)

The process above get you the basic engine "foundation" for a high performance (high VE) engine but you will also have to do a lot of other little efficiency "tricks" during the build process and do lots of tuning work, in order to maximize the combo.
DD

Thanks D.D. for sharing your clarity and experience. Your blueprint clarify's what this is Not. That makes decisions easier to understand, and arrive at.

I do not want a race engine....

I need to define my budget next before proceeding.

At this instant I can say it will be an 87 octane engine. (in a heavy truck)

Operating range 1000-4500, Cruse RPM 2700-3300RPM

Horsepower and torque are equal at 5252 RPM. So, mathematically it's a HP engine over 5252 RPM.

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Joshua

Darn, you beat me to it!

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If it was easy, everybody would be doing it.

max TQ > max HP = TQ engine

max HP > max TQ = HP engine

max TQ = max HP = it's confused

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes