5w-40 recommendation for 392 HEMI

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Originally Posted By: A_Harman
Yes, Chrysler's small-block Hemi isn't a true hemi, but neither was the 426 or the 392 (331, 354, 392) family that preceded it. None of them had combustion chambers that were half of a sphere. The big advantage of a Hemi is the ability to put large valves in it, thereby enhancing high-speed breathing ability. The dual spark plug, twin squish combustion chamber of a new Hemi gives a lot faster burn than old single-plug quiescent chambers.



Actually, the first-generation "Whale" Hemi's did have true hemispherical chambers. The 426 *almost* did, the big deviation was that the whole chamber was canted so that the valve angles weren't symmetric around the cylinder centerline. That was done to help make the heads narrower, the first-gen Hemi is a good bit wider than the true big-block 426 even though the block itself is more closely related to the Chrysler smallblock. The modern Hemi is more of a hemi-ellipse. ;-)

There's nothing magical about the hemispherical shape in and of itself, the magic is in the valve angles and the fact that the entire circumference of the valve becomes unshrouded when the valve lifts, unlike a wedge head where a part of the airflow bangs straight on into the cylinder wall at right angles, or even a multi-valve head where the flows from adjacent intake valves interfere with each other. The hemi shape does help smoothly bend the flow into the cylinder, too.
 
Originally Posted By: A_Harman
Originally Posted By: LineArrayNut
Originally Posted By: A_Harman
For Chrysler's 6.4 Hemi:
470 hp / 392 cubic inches = 1.20 hp/cid

For Chevy's 7.0 LS7:
505 hp / 427 cubic inches = 1.18 hp/cid

Come on Chrysler, do whatever you need to do to bore and stroke the Hemi to 426!


theta II 2.0T 122 CI 274 hp : 2.25 hp/cid lol

That's a turbocharged 4 vpc engine. We're talking about naturally aspirated 2vpc engines with about 500hp. Try again if you want to make a relevant contribution to the discussion.


If you belong to the old "there's no substitute for cubic inches" school of thought, the current Hemi is pretty good.
If you prefer power in a lighter package, the turbo Hyundai is what you want.
WRT specific output, no pushrod V-8 in emissions legal form can touch a good turbo four cylinder for specific output, nor even a strong normally aspirated four cylinder.
 
Baloney.

Power isn't just horsepower. Did you forget torque? Then there's noise, vibration, and harshness.

You must have missed the ZR1 corvette, over 600 hp and tractable as anything. Even the Caddy CTS-V detuned version (550+ hp) is a spectacular pushrod V8, smooth and quiet in a way that no 180 degree 4 banger can match because of the primary imbalances.

These days the whole pushrods vs OHC thing is being greatly mitigated by technology. Lightweight valvetrain components and other esoteric tech are still advancing the ole pushrod V8.
 
Originally Posted By: Drew2000
Originally Posted By: artificialist
What I don't understand is why the Hemi doesn't produce a significantly higher HP/L even though Chrysler went through the trouble to build a hemi style head, whereas the Chevy has a much simpler wedge head.


FWIW, "Hemi" has been just a marketing term for years. Hemisperical combuston chambers have problems meeting emmission limits and have been pretty much phased out since the '70's.

What I'm trying to say is the Hemi style ports are supposed to be superior to the ports of a Wedge style cylinder head.

I'm sorry that I didn't clarify that earlier.
 
I'm all about torque. Or maybe area under the curve. I rode inline fours for 20 years until I tried my twin... and I like my V-8's ;-) I'd have got a CTS-V if I made twice as much on my paycheck. Try a theta II 2.0T GDI in either flavor, you may be as favorably impressed as I at the torque...



Originally Posted By: SteveSRT8
Baloney.

Power isn't just horsepower. Did you forget torque? Then there's noise, vibration, and harshness.

You must have missed the ZR1 corvette, over 600 hp and tractable as anything. Even the Caddy CTS-V detuned version (550+ hp) is a spectacular pushrod V8, smooth and quiet in a way that no 180 degree 4 banger can match because of the primary imbalances.

These days the whole pushrods vs OHC thing is being greatly mitigated by technology. Lightweight valvetrain components and other esoteric tech are still advancing the ole pushrod V8.
 
Originally Posted By: fdcg27
Originally Posted By: A_Harman
Originally Posted By: LineArrayNut
Originally Posted By: A_Harman
For Chrysler's 6.4 Hemi:
470 hp / 392 cubic inches = 1.20 hp/cid

For Chevy's 7.0 LS7:
505 hp / 427 cubic inches = 1.18 hp/cid

Come on Chrysler, do whatever you need to do to bore and stroke the Hemi to 426!


theta II 2.0T 122 CI 274 hp : 2.25 hp/cid lol

That's a turbocharged 4 vpc engine. We're talking about naturally aspirated 2vpc engines with about 500hp. Try again if you want to make a relevant contribution to the discussion.


If you belong to the old "there's no substitute for cubic inches" school of thought, the current Hemi is pretty good.
If you prefer power in a lighter package, the turbo Hyundai is what you want.
WRT specific output, no pushrod V-8 in emissions legal form can touch a good turbo four cylinder for specific output, nor even a strong normally aspirated four cylinder.


If the objective is to build a 500-hp engine with specific output of 2.25hp/cid, you would need 222 cubic inches. Something like a 3.6-liter 24-valve V6 with twin turbo's, and all the complication associated with the extra machinery. At the end of the exercise, the total weight of the engine and all the turbos, intercooler's, etc would be about the same. You'll pay more for such an engine than you will for the "old-tech" 16-valve NA pushrod V8. Remember, we're not racing here, and money IS an object.
 
Merk....you may be right on your call for Valvoline. When I looked at some of the forums from Europe, the consensus of opinion from drivers of German auto's was that they preferred to use the Valvoline 5w-40 rather than the Mobil 1, 0w-40. Their preference for the Valvoline over Mobil 1 had nothing to do with the add packs of the oils. Instead, they noticed that in their extended OCI, Mobil 1 would have to be topped off quite frequently. It seems that they did not have the same issue with Valvoline.

IMO....all we can do is wait for some UOA results to be posted for Valvoline, MST, Euro Blend, 5w-40 oils before we can make any decision. However, I had noticed an excellent UOA posted from someone using Amsol "low saps" oil for over 6K miles and it started with a very low TBN, lower than Valvoline MST, and had plenty of TBN left in the sump. He did use the car for racing, towing and other severe duty and still had great results. He planned on keeping that fill in the vehicle for another 2K rather than changing it out.

So...we'll have to wait to see some UOA results for the Valvoline MST before any decisions are made on this "Mid Saps" Euro Blend oil.

Originally Posted By: Merkava_4
Originally Posted By: Quattro Pete

Why would you want to use this mid-SAPs, weak add pack, weak TBN oil if you can have M1 0w-40 for about the same price?


I believe that Synpower 5W-40 is superior to Mobil 1 0W-40.
 
Agreed.
You can build a big displacement engine that makes big horsepower, and torque, pretty cheaply.
You can also end up with an engine that will be pretty durable without very careful machining and build as well as very exacting maintenance.
I don't mean to discount the current pushrod Chevy and Chrysler V-8s as a class.
They are pretty rudimentary devices that make awesome power, and in the case of the Corvette, at least, also deliver remarkable fuel economy.
These engines are easily better than anything actually offered during the fabled muscle car era.
They make more power, they last longer and they even deliver decent fuel economy.
Not my kind of engines in cars I wouldn't own, but impressive nonetheless.
 
Originally Posted By: A_Harman




If the objective is to build a 500-hp engine with specific output of 2.25hp/cid, you would need 222 cubic inches. Something like a 3.6-liter 24-valve V6 with twin turbo's, and all the complication associated with the extra machinery. At the end of the exercise, the total weight of the engine and all the turbos, intercooler's, etc would be about the same.


I looked HARD at the ecoboost in both truck and sedan; both the mileage penalty was too great. And I'd run either for kicks, lol! Dusted a 2000 Mustang GT from a 60 roll to 141 and was still able to stay at 28 mpg on the comp screen lol!
 
Mobil 1 5W-40 TDT is a very robust oil. Regardless of the rating on the bottle (people often mistake newer for better) , it has a great add pack, high TBN, high ZDDP and HTHS.

UOA and real world results consistently put this oil at the very top of the heap. It's that good. No reason to avoid it.
 
Originally Posted By: SteveSRT8
Originally Posted By: A_Harman
For Chrysler's 6.4 Hemi:
470 hp / 392 cubic inches = 1.20 hp/cid

For Chevy's 7.0 LS7:
505 hp / 427 cubic inches = 1.18 hp/cid

Come on Chrysler, do whatever you need to do to bore and stroke the Hemi to 426!


It's awesome how much gitty up she's got..

Numbers do not tell the tale here. Peak hp is better, but at low rpm that Hemi is making WAY more torque than the LS7.

That's what makes this thing a monster on the street. No waiting for it to wind up, it's always there.
 
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