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#416732 - 06/25/08 07:05 AM Re: Big Block replacement in a small package [Re: D-Rod]
WaterMutt Offline
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What about the 500ftlbs statement? Still beyond the 496?
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#416743 - 06/25/08 07:30 AM Re: Big Block replacement in a small package [Re: WaterMutt]
seabuddy Offline
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Just ahead to my understanding, but not enough to call it that way. I would rather say, they are about equal to a 375 Hp. version of the 496 production engine at 3,000 rpm and ahead of the 420-425 Hp version at 3,000 rpm and as that continues to climb up to a peak troque reading into the middle 4,000 - 5,000 rpm range, unlike the 375 Hp. (different cams), the Raylar beats the torque of the 420 - 425 Hp version of the 496 also, with its (Raylar's) peak torque up around 565 if I remember right.
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#416746 - 06/25/08 07:35 AM Re: Big Block replacement in a small package [Re: seabuddy]
seabuddy Offline
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Let's not compare a production engine to much to a GOFASTBELOUD engine too much, though. I do not think this is a replacement engine for a stock, regular Merc or Volvo 496 offering.
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#416750 - 06/25/08 07:42 AM Re: Big Block replacement in a small package [Re: seabuddy]
seabuddy Offline
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My conjecture (check my spelling please) is the variable cam idea that D-Rod has been liking for many a month is perhaps the reason for the excelllent torque numbers for a 550 Hp engine of around 7 liters displacement. But, that is a guess, not a known fact.
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#416751 - 06/25/08 07:43 AM Re: Big Block replacement in a small package [Re: seabuddy]
WaterMutt Offline
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Sorry, the title was misleading to me.
So this engine is a limited market GFBL powerplant. How does it provide any benefits over what is being offered now? That would be the biggest question when attempting to get the fast crowd to switch from thier tried and proven engines.
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#416793 - 06/25/08 09:09 AM Re: Big Block replacement in a small package [Re: WaterMutt]
Bankonit27 Offline
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Raylar has many excellent offerings, and I think something like this will become more common, as the 496 goes away. Many GFBL use custom motors, but many also come stock with 496 HOs. Many recently have upgraded via a Raylar package, as it is somewhat inexpensive and reliable power. As the 496 is phased out and the LSx phased in, you will see boats getting this upgrade.

My opinion, bang for the buck it is good. Not to mention lighter and not as much torque down low (Good for drives).

YOu could build a strip monster, but not reliable for marine use. JMO.


Edited by Bankonit27 (06/25/08 09:10 AM)
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#416798 - 06/25/08 09:25 AM Re: Big Block replacement in a small package [Re: Bankonit27]
WaterMutt Offline
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So, you would consider this as a replacement/upgrade to the stock 496?

I am trying to see where this engine falls into place.

And I would agree with you on a slingshot engine, not really useful for marine use.
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#416803 - 06/25/08 09:37 AM Re: Big Block replacement in a small package [Re: WaterMutt]
Bankonit27 Offline
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Yes I see the LSx small blocks being the replacement for the 496. It is already starting to happen with ski boat manufacturers.
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#416851 - 06/25/08 11:14 AM Re: Big Block replacement in a small package [Re: Bankonit27]
seabuddy Offline
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I think that a 502 will be the popular power of choice for now. This 434 cu. in. engine is big news as its the first with the weighter weight, small block, variable cam timing, and coming from a marine engine builder.

Raylar makes alot of stuff for the 496 series engines right now. I would think that is where their bread and butter will be coming from for awhile.

Merc and others in the marine field have stuff for the 502 size engines.

Both of these should be a cheaper way to go for now.

How much does one want to lead the market?

How much will one spend to do so?

These are the questions that focus on this engine,IMO.

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#416896 - 06/25/08 01:08 PM Re: Big Block replacement in a small package [Re: seabuddy]
seabuddy Offline
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I think most know that the 496 is going out of production and then the 502 will also taking that path.
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#416903 - 06/25/08 01:25 PM Re: Big Block replacement in a small package [Re: seabuddy]
D-Rod Offline
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Originally Posted By: seabuddy
My conjecture (check my spelling please) is the variable cam idea that D-Rod has been liking for many a month is perhaps the reason for the excelllent torque numbers for a 550 Hp engine of around 7 liters displacement. But, that is a guess, not a known fact.


Have you seen a power chart for this engine? I noticed earlier you said it compared favorably with the base 496 at 3,000 rpms.

One thing VVT engines are good at is deception. At times, VVT engines can feel more powerful then static cam engines.

Why you might ask?

A good example is the marine 5.7L. It has plenty of low-end grunt for hole shot. It feels like a freightrain launching out of the hole. Once on plane, it fall "dead". It no longer feels are powerful as it slowly creeps through the upper range of its limit.

The engine does make more power at higher rpms, which is what continues to increase the speed of the vessel, ablieut, slowly. However, the rate of power increase decreases. From a mathematical standpoint, it has a negative concavity or negative 2nd derivative. It is this tapering-off of power increase that we feel, which is what yields the "dead" feeling.

VVT engines prevent this from happening. Infact, in many instances, VVT can increase the rate of power increase. It's this rate increase, or positive concavity, that feels "powerful".

The 5.7L has a HUGE rate of increase in power initially, which gives the strong hole-shot feeling. However, it then quickly falls.

A 5.7L with VVT (this is hypothetical because to my knowledge one not made) could start with the same HUGE rate of increase and then continue to build power at an ever increasing accelerated rate.

In this particular hypothetical instance, the VVT 5.7 would make substantially more power at WOT then the static 5.7. Obviously the more powerful engine is going to feel more powerful.

A better example would be to compare a 5.7L set to make peak HP instead of peak torque.

Hypothetically, assume you have two 375hp 5.7L engines. One is set with a static cam and the other is variable.

The static cam is going to feel dead coming out of the hole. However, as it approach max power, it's going to "come alive". We all have felt the "come alive" feeling with different engines.

The variable cam engine is going to feel MUCH stronger coming out of the hole. Most people will assume it's a more powerful engine. However, we know that is not the case. They're both 375hp.

Here's the fun part (and difficult part to follow). The static engine is going to feel more powerful in the last powerburst than the VVT engine is. Let's assume that from 4,000-5,000 RPMS, both engines have identical power curves. However, because the VVT engine pulled stronger leading UP TO 4,000 rpms, it's not going to feel AS powerful a the non-VVT engine is through that range. The reason is because of the rate of power increase. The static cam engine is going to go from a relatively low power output to a high output quickly. This makes the rate of change of power larger. Because the static VVT engine has a faster rate change increase, it's going to feel more powerful than it is. The actual fact is both boats accelerate at the same rate. However, because the static cam engine has a higher rate of change, it will feel more powerful.

This second example is the opposite of what happens with the first explanation. Don't worry...I haven't lost my head yet. It's important to grasp both extremes first. Most static cam marine engines are adjusted for peak power just below the midrange point. The 5.7 is an exception. It's actually adjusted for low-range power. The 5.0 is a good example of a midrange setup.

If you compare a VVT engine with a midrange static cam engine, it will most definitely feel more powerful. It will launch of the hole quicker. It will have a greater rate of power increase at the top end, even if both engines make the same amount of power (engine displacement is the dependent variable).

Example: A 350hp VVT 5.7L engine should feel more powerful than 350hp 6.2L engine. In theory at least, for the reasons stated. On the clock, they should have similar numbers. Feel of the pants, VVT should win.

Wow. That's a long preface.

My point in case: I think this new proposed engine will feel more powerful to GFBL crowds than a similar power-creating competitor. It deals with the rate changes and the physics in which it plays with your body. We actually have to examine 3rd derivatives to understand the mechanics/physics of WHY this happens, but I don't have the time to appropriately explain.

A couple of additional thoughts:

VVT engines are more capable of controlling emissions. This is a solid approach to meet CA upcoming emission regulations. Feel of the pants matters more to most than actual numbers.

D
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#416912 - 06/25/08 01:46 PM Re: Big Block replacement in a small package [Re: D-Rod]
WaterMutt Offline
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It might be as easily stated that as the slope of the hp/torque curve decreases, that perceived power also decreases. And vise versa.

Isn't the Toyota truck engine a 5.7 with VVT?

With CVT transmissions, do you feel VVT is still needed?
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#416918 - 06/25/08 02:25 PM Re: Big Block replacement in a small package [Re: WaterMutt]
D-Rod Offline
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Registered: 06/25/05
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I don't like CVT's. They're energy wasting junk pits. I'm a bigger fan of 6/7/8 speed transmissions in the automobile industry. That's for a different thread.

The Toyota 5.7L is a dual VVT engine DOHC engine. Not one single component on the Toyota engine is comparable to the SBC 5.7, as i'm sure you already knew. smile

And good summary. More simplified version. smile
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#416927 - 06/25/08 03:01 PM Re: Big Block replacement in a small package [Re: D-Rod]
seabuddy Offline
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Registered: 12/15/02
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Back to the water. No, I was told the torque figures at 3,000 and in the mid-4,000 rpm ranges.
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#416928 - 06/25/08 03:03 PM Re: Big Block replacement in a small package [Re: D-Rod]
WaterMutt Offline
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I have not confirmed it, but was told the bore X stroke of the toyota is quite similar to the sbc. If true, you could somewhat compare the two engines in your analysis as they *should* be about equal in the performance due to engine dimensionals. But that is where similarities end. That's the reason I brought it up.

This thread has jumped around too much for me this afternoon, have a bit of a headache. The engine isn't for comparison to the available big blocks of today, but then it is discussed as a possible replacement for them, but only in GFBL's, but how much should one invest to make this engine or a family member of it the replacement of the big blocks of today. IDK.....
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