Question relating to Hemi/other.

[Removed user as requested]

Hello,

Outside of the whole Hemi > everything and how Hemi Cudas > Chevelles > basically everything unless its a smaller/lighter Mopar also with a Hemi....

Is 700 Horsepower, 700 horsepower regardless whether it is a "Hemi" or LS design or whatever?

The way I have read things (the way they are made out) it is like Hemi is the most 'feared' name in engines, thus Mopars are the street kings, while cars like Chevelles, even the SS 454 LS6 sucks compare to a "Hemi Cuda" in terms of performance.

Now perhaps in 'stock form' some were better than the others, but what im wanting to know is, does an engine being a HEMI some how mean a "Hemi at 700HP" is different to a "Wedge at 700HP" and thus 700HP is not 700HP?

From another angle, I have seen manufacturers offer Hemispherical heads for LS motors. Thus a Chev can be a "Hemi" powered car. If 700 HP is the goal, is it even worth spending all the extra $$$ for it to be a "Hemi 700HP" vs the standard "LS 700HP" motor or as said, 700 hp is 700hp hemi or not is irrelevant...

If it is irrelevant, what is the point to a hemi then? To make MORE power than you would get from other designs or what?

The other question is related to Gearboxes, again people say the Hurst 4 speeds are the gearboxes even chev owners want over the 'cheaper' muncies that were no where near as good.

Then I hear in differentials, that chev sucks at that to. I mean, why would someone want a Chev diff when Dana 60 or Ford 9" is the way to go.

Is this all true so far to say 'original' but now days, with all the parts available etc, all of that is false?

So I would like clarification on these 3 points.
Thanks guys!

[dontlifttoshift]

Buick > Mopar

Big Blocks are boat anchors

200 LS horsepower is equivalent to 400 horsepower in anything else....yes LS motors are that good.

Hemi heads are great to run nitro with and I think that is what you should do.

I have never seen a Hurst transmission.

Chevy differentials are bulletproof, but only in reverse.

Congrats on another great thread!

[Removed user as requested]

Buick > Mopar

Big Blocks are boat anchors

200 LS horsepower is equivalent to 400 horsepower in anything else....yes LS motors are that good.

Hemi heads are great to run nitro with and I think that is what you should do.

I have never seen a Hurst transmission.

Chevy differentials are bulletproof, but only in reverse.

Congrats on another great thread!

I was being serious. I wanted to know whats up with that. Sorry for hurst gearbox, the A833 etc that mopar use over the gearboxes chevy uses.

This is not a brand bash, i just wanted to know some answers on 3 of the points.

[J-440]

700HP is 700HP whether it's coming from a blown HEMI, an LS modded motor, or a Honda 6 banger with a turbo. Horsepower is a unit of measurement and there is a formula for it that goes way back. One of the reasons the HEMI was and is still a good motor (only in a straight line for the original 426) was it's heads. It breathes really well. Older big blocks are cool and can make a ton of HP, but with today's technology, you can get the same power from a modern small block.
The rule of thumb for rear ends: Ford 9", then a Dana 60, then the Chevy 12 bolt. Compare those 3 with lightness and strength, the Ford wins every time.
As far as tranny's go, the M-22 known as "the rock crusher", a Jericho, a Mopar 727, and Ford's C6? (Forgive me if I screwed up Ford gurus) are some strong ass transmissions. I'm sure I've missed a few, but reading all kinds of magazines/blogs, those are mentioned quite a bit. Hope this helps.

[dontlifttoshift]

I was being serious. .


So was I. Did that read sarcastic?

[WallaceMFG]

Horsepower is horsepower, what can be different is the way power gets delivered. Big blocks like to make power down low, but LS motors tend to make more power the faster they spin in most cases. They could have the same HP rating but feel completely different.

[Removed user as requested]

When one is straying from stock (aka pro-touring), then whether its mopar or chevy or ford or whatever, Hemi or not Hemi (dealing with a 502ci Chev motor vs a Hemi), Tremec gearboxes, or Richmonds (or something else) then the comparable aspect is gone altogether as all this stuff is aftermarket and all can make the same power, and thus hemi or not it's the same difference, gearboxes wouldn't use stock boxes for pro-touring anyway, so that then become irrelevant as well and differentials... well.... Should I assume Ford 9" diffs are the ones used in serious pro-touring cars (non-ford) or is something altogether different here used as well making even the differential irrelevant?

If that what I just said is basically right, then, it only matters when dealing with stock-stock car not a completely re-made car as pro-touring.

Thank you for helping me understand.

[BMR Sales]

I wish I could understand what you just asked!

[benno505]

yeh, maybe re word the quesion.

Hemi is and still is the most feared motor for drag racing, i think the fastest nitro car uses a hemi. i probably wouldnt use one in pro touring unless it was a world full aluminium block
alot of people prefer wedge engines to them cause there not the easiest to run. Plus a LS is 1/100th of the price of a hemi i spose chebbie gear is cheap and plentiful.

A833, mopar box was one of the strongest 4 speeds ever built. dana 60 uses a larger pinion and IMO stronger gear than a ford 9" except the ford 9" is half the price of a dana 60 as it is cheap and plentiful.

[Removed user as requested]

What i was saying/asking is, do these differences matter in pro-touring or not because in pro-touring people dont use the 'stock' gear anyway. Therefore the differences only perhaps matter in stock cars only?

[Nicks67GTO]

Its 100% all about the tq curve making the hp and its intended use

[HellPhish89]

i think ii get your question.

while hp is hp, how you put it to the ground matters. stall, gear ratios, tire size all matter. the other thing that matters is the power curve itself. you can have a 700hp supra but it will make all that power in a tiny rpm range. a 6.0L engine will make it in a much broader range than that 3.0L. power under the curve matters (aka avg power). the bore and stroke can affect the power band as well with a higher stroke generally having more low end to low- mid range power while a bigger bore will have more higher-mid to top end power. it really comes down to the combination. you can have a 700hp dog and a 700hp monster that runs like a chimp ripping someones face off.

[mmosley]

Its 100% all about the tq curve making the hp and its intended use

Bingo. That is why in a street race a 440 6-pack could out run a Hemi; and a 340 4 speed in a Dart could make either look silly on street tires.

OK. Regardless of everything else, you need heads to make power. I will put a conservative estimated peak power number next to each assuming all benches measured the same, all displace 7.0L (426ci or 427ci) and all engines use a 0.600" cam just for reference.

Hemi:
Stock unported street Hemi [email protected] lift; [email protected] lift; [email protected] lift 609hp
Race aluminum Hemi Head [email protected] lift; [email protected] lift; [email protected] lift; 802hp

My ported Edelbrock 440 Wedge Heads (pretty close flow to a stock street hemi head):
[email protected] lift; [email protected] lift; [email protected] lift 620hp


Another set of numbers (different source, different bench, etc.)

Edelbrock E-CNC LS1/LS2
[email protected] lift; [email protected] lift 540hp

Edelbrock E-CNC Rectangular Port BB Chevy
[email protected] lift; [email protected] lift; [email protected] lift; 671hp

Edelbrock 405cc Victor BB Chevy Heads (Monster spread bore race)
[email protected] lift; [email protected] lift; [email protected] lift; 787hp

Now those are peak numbers, what is going to matter, especially on a street car is the shape of the torque curve. I will give you an example. My car with the previous engine combo made over 500lb-ft from somewhere around 3000rpm to about 6000rpm. Shifted about 6500rpm. I think peak power was about 550hp. Car weighed about 3000lbs. My friend had a turbo Civic that put 590hp to the front wheels on the chassis dyno. We raced. I won. Easily. His torque was probably half mine at 3000rpm. By the time he hit peak power and started to make up ground I was a few cars out and he would have to shift, and I would gain a little more ground, and so on... even at a 60mph roll I smoked him. Acceleration is a direct result of torque. Horsepower is a function of torque, it is power output which is torque x speed.

[mmosley]

Hurst made shifters.

The 833 is a very strong transmission, yes better than the M21 / M22 cousins. The Muncie M21/M22 & BW T10/Super T-10 design started out as a 3 speed. The reverse gear was added outside the case in the back to make room to add another gear for the four speed design.

9" is a larger ring gear than a 12 bolt @ 8.875". Dana 60 is 9.75" ring gear. But the bigger issue of the GM axles are the C-clips.

[Removed user as requested]

Ok that makes sense. For a street car, tq lower = better.

By design though, is not a hemispherical design simply more efficient because it can compress more etc?

I have seen LS6 and someone offering LS6 with hemispherical alloy heads for the chev motors. Is that worth getting to add to a chev block... that way its not a boat anchor Hemi dodge make but it is efficient based on hemi heads....?

[mmosley]

Ok that makes sense. For a street car, tq lower = better.

By design though, is not a hemispherical design simply more efficient because it can compress more etc?

I have seen LS6 and someone offering LS6 with hemispherical alloy heads for the chev motors. Is that worth getting to add to a chev block... that way its not a boat anchor Hemi dodge make but it is efficient based on hemi heads....?

They are all air pumps, all have engineering compromises. The new 3rd Gen Dodge Hemi engines are actually pretty good for a pushrod engine. The Hemi head gains because of the straight shot short run from the intake to the valve, the taller the port, the less curve, the better the angle the valve, it all plays in. The hemispherical head design tilts the valves over and creates a less restrictive path for the air to go in and out. Has a few downsides also in the chamber size and lack of quench, some of the newer designs squeeze the sides to try to help that. The next big thing though is starting to come out now. Direct injection! You will see a step increase in the power per cubic inch with this change. I am curious what limitations this technology will have.

[Removed user as requested]

They are all air pumps, all have engineering compromises. The new 3rd Gen Dodge Hemi engines are actually pretty good for a pushrod engine. The Hemi head gains because of the straight shot short run from the intake to the valve, the taller the port, the less curve, the better the angle the valve, it all plays in. The hemispherical head design tilts the valves over and creates a less restrictive path for the air to go in and out. Has a few downsides also in the chamber size and lack of quench, some of the newer designs squeeze the sides to try to help that. The next big thing though is starting to come out now. Direct injection! You will see a step increase in the power per cubic inch with this change. I am curious what limitations this technology will have.

How is this new technology when ferraris, lamborghinis etc make roughly 1.8, 1.9 horsepower per ci while all the american stuff makes like 1.2 if that HP per ci. I dont get what the deal is. A 454ci would make 900HP if it was european.

Can someone explain that? Is it a physical problem with American technology or is it just a decision not to do it.

[Schwartz Performance]

Why is it that a Corvette ZR1 6.2L supercharged gas guzzler gets 50% better MPG than a sleek lightweight 6.5L naturally aspirated Lamborghini Aventador?

Relating back to the power curves.. Look at a lambo dyno sheet. No power down low.. Max power is at 8200rpm which is 1000rpm higher than what a stock LS spins, due to the Lambo having dual overhead cams and less valve train parts aka no pushrods.

By the way the Aventador is around 1.6-1.7 hp per CI.

Oh and pricing... Look what you're paying for.. Can you get a lambo crate engine for $6500? Don't think so! :)

-Dale

[WallaceMFG]

How is this new technology when ferraris, lamborghinis etc make roughly 1.8, 1.9 horsepower per ci while all the american stuff makes like 1.2 if that HP per ci. I dont get what the deal is. A 454ci would make 900HP if it was european.

Can someone explain that? Is it a physical problem with American technology or is it just a decision not to do it.

As mentioned above, the Euro engines spin faster to make power. Just look at the Ferrari 458. 4.5L V8 makes about 560 HP, but has a redline of 9500. It has to spin like mad to make that power. Its like comparing a F1 engine to a NASCAR engine. The NASCAR V8 and F1 V8 (not around anymore) made similar power, but the F1 engine had to spin 18,000 RPM while the NASCAR engine spins 8,000-9,000 RPM.

[Motorcitydak]

Wallace is 100% right on that. Exotic cars spin to very high RPM to make that kind of HP and have much shorter strokes VS american engines. If you want to compare apples to apples with any engines, you need to look at TQ maps on a dyno chart since that is the only number that really exists. HP is just a calculation of how well an engine can maintain its torque curve, HP=(TQxRPM)/5250

So, take the 458's 560hp at 9500rpm the 458 makes just over 300ft/lb at that rpm. If an american v8 can spin faster, their power potential is HUGE. Just look at the 426 Hemi used in drag racing that guys are spinning to 10k

[Removed user as requested]

So i take from that that the new technology may show increase in HP per ci for american stuff at the rate they spin now. So basically same power band, curve, same rpms but more hp gotten out of it than currently?

[HellPhish89]

So i take from that that the new technology may show increase in HP per ci for american stuff at the rate they spin now. So basically same power band, curve, same rpms but more hp gotten out of it than currently?

hp per ci or hp per liter is ricer math. its not really useful for anything other than advertising. besides that, the general rule is that as the engine size increases...power density drops (until you boost things at which point my original points become more valid). i think what you are talking about/wanting to know is brake specific fuel consumption.