AHC: American Inline Six Engines More Widespread Post-1970s

Short of going to OHC I don't think its going to work. A pushrod V-8 isn't that much more expensive than an ohv inline six. That said from the 1960 model year on GM, Ford, Chrysler, AMC plus Kaiser all came out with new inline six cylinder engines with one shared characteristic. Oversquare bore and stroke combinations. The potential was there to produce some fairly free reving engines. But they all got saddled with crappy head designs from the performance standpoint. Non-crossflow heads were used on all of them. OK not all. The Kaiser was OHC but it was a small bore long stroke design intended to produce more torque at low rpms. Pontiac did produce an ohc version of the Chevrolet engine but it suffered from having a non crossflow head as well. Part of the reason for the port set-ups on these engines can be found in the placement of the distributor. Driven by the camshaft via two helical gears the normal placement was pretty much in the middle of the block. The distributor would then of interfered with the intake manifold. Today with electronic ignition systems it wouldn't be an issue.
Maybe if Pontiac had been able to build the Banshee things might of been different.
With cheap gas and little tax structure based on displacement/horsepower the V*8s ruled the roost.
 
Short of going to OHC I don't think its going to work.
Is there a reason we can't go to OHC for modern inline 6 engines? Today's BMW 3-series use OHC inline 6s.

I appreciate American inline 6 engines would not have the level of tech or the cost of the BMW engines, since they'd need to be built to a price.
 
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A friend of mine has a BMW K1600 motorcycle. It's an inline 6 design, and the engine is remarkably narrow due to the tiny space between each cylinder.

BMW-K1600-Engine.jpg


If this level of tight tolerances could be applied in American mid-range cars, I could see a compact inline 6 as an option where current inline 4 engines are used. However this would be more applicable to cars where the 4 pot engine is mounted fore-aft.
 

Delta Force

Banned
If this level of tight tolerances could be applied in American mid-range cars, I could see a compact inline 6 as an option where current inline 4 engines are used. However this would be more applicable to cars where the 4 pot engine is mounted fore-aft.

That probably wouldn't be a good solution for an automobile engine. It would be expensive to get those tolerances, and it would leave no room for growth. The engine probably won't have any liners, so it can't be rebuilt for heavy duty applications. Ironically, it probably wouldn't be desirable for high performance applications either, as there wouldn't be any margin for boring or forced induction.

The Volvo short six solution of making an undersquare engine would probably be better for automobile engines. It would compromise top end performance, but for traverse mounts it would be the only way to get one in the vehicle in the first place.
 
Ironically, it probably wouldn't be desirable for high performance applications either, as there wouldn't be any margin for boring or forced induction.

????1649 cc, 100 cubans, 160.5 hp, 148 mph. That is high performance. Pistons apparently are available in .5 over, at over $300 ea.

Yeah, forced induction is probably a bad idea.
 

Delta Force

Banned
????1649 cc, 100 cubans, 160.5 hp, 148 mph. That is high performance. Pistons apparently are available in .5 over, at over $300 ea.

Yeah, forced induction is probably a bad idea.

Obviously it's a high performance motorcycle engine. I was thinking more about using it in an automobile.
 
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Honda, Lancia and others use or used straight 5 pot engines with turbos in their small compacts and mid-sized cars well into the 2000s.

https://en.wikipedia.org/wiki/Straight-five_engine

Does adding another cylinder push us over the tipping point of economic or engineering feasibility?

Some fun chatter here http://jalopnik.com/the-best-inline-six-engines-of-all-time-941946955

That's only my personal opinion on turbos on non-racing privately funded vehicles. I used to repair them, and write bills. Mostly Audis.
 
How many a rear or mid-engined mass production cars were powered by an inline-6? The most common one I can think of is the BMW M1.

used-1980-bmw-m1-e26-9423-9072536-1-640.jpg


26-05-2011-017.jpg


The Tommy Kaira ZZ-II is a sweet looking car, powered by twin turbo inline 6. And then there's the fugly Lamborghini Marzal with it's half a Miura V12.
 
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