LSX block VS LS3

[Rumbumbees$ponsor]

Looking at the following 440 with 4.185 bore in the LSX with 4.00 stroke or the LS3 4.065/4.070 bore and the 4.00 stroke.. 416/417 both use the 6.125 rods..

question is will the extra torque/HP worth the added weight of the Iron Block?

1. I figure 90 to 100 lbs more is this correct?

2. Keeping variable the same how much HP/torque is needed to over come 100 lbs difference?


I figuring 10:1 or 10.5:1 compression on either Cube motor..

NOT CONCERNED WITH ONE BLOCK IS STRONGER THAN ONE ANOTHER!

Kinda want to know the HP difference.. given the same Cam used and a set GMHP CNC LS3 heads.

[BullF-16]

Stick with ls3 for your goals

[Unreal]

ls3 block will take more than an eforce can ever put out. Cubes aren't going to limit power, the power adder will.

[smokum]

Deciding where you going in the end is the biggest decision to make 1st. Do it once and do it right.

[Livernois Motorsports]

Originally Posted by Rumbumbees$ponsor

Looking at the following 440 with 4.185 bore in the LSX with 4.00 stroke or the LS3 4.065/4.070 bore and the 4.00 stroke.. 416/417 both use the 6.125 rods..

question is will the extra torque/HP worth the added weight of the Iron Block?

1. I figure 90 to 100 lbs more is this correct?

2. Keeping variable the same how much HP/torque is needed to over come 100 lbs difference?


I figuring 10:1 or 10.5:1 compression on either Cube motor..

NOT CONCERNED WITH ONE BLOCK IS STRONGER THAN ONE ANOTHER!

Kinda want to know the HP difference.. given the same Cam used and a set GMHP CNC LS3 heads.

On either of these previously mentioned combos the LS3 heads you listed will be a bottleneck.

The GM head is designed for smaller cube builds Like others mentioned the restriction will then be the power adder.
A LSA casting would be a good starting point boost level dependent. The thicker castings offer many advantages over the LS3/L92's on a power adder car.

A properly prepped LS3 block will be just fine for your project.
We rate our Pro Series engines to 1000 flywheel HP and have custom engines for the customer looking for more than that.

With good parts selection this can be a fun and drive able package for you to enjoy.

Here is a sample of a build we just completed along the lines of what your asking for.

The supercharger you selected will be out of steam with a 416 build so going with a 440 on the same package will run out sooner.

[Bo White]

I agree. I was going to say a 416 would be limited by the blower much less a 440. No need in going past a 416. If you get beat with a blown 416 then you either messed up or you jumped on the wrong car lol.

[Rumbumbees$ponsor]

Thanks..

I guess I asked the question wrong..

I'm asking if the extra cubes makes up for the 80lb heavier block? not counting power adders(YET) waiting to see what happens..

The camaros weight is all ready heavy but getting the extra cubes makes up for it or not? Is the torque and HP worth the 80lb disadvantage? (Straight line not road track)

Power will not be a problem, longevity not worried about either just will the stroke over come the 80lbs .. I want to know is the extra Cubes worth the 80lb of extra weight? Will the stroke over come the weight disadvantage by hp or torque to get down a drag strip or passing someone on the road.

Question 2:

I do have plans to possibly sell the blower and get the AGP kit. If I didn't want to take a loss on the blower... like 2500.00 loss

You can't tell me that if I keep the compression 10.5:1 to 11:1 the blower is useless? and will not make more power than being NA.

Could always do a shot of NOS when I come to the wrong car!

If I had my choice I would do the 427 with MAST back labels and a AGP kit.. but I'm trying to think this out and be practical..


If you go to certain websites a 417 is worth 600 HP average @ 11:1 and a 440 is worth 700HP on average @ 11:5.1

So 100 hp and average of 40lbs of torque worth the weight?

[Rumbumbees$ponsor]

Originally Posted by Bo White

I agree. I was going to say a 416 would be limited by the blower much less a 440. No need in going past a 416. If you get beat with a blown 416 then you either messed up or you jumped on the wrong car lol.

Help me understand,

Are you saying if I start with a motor like the 440 that makes 100 Hp and 40 lbs of torque over the 416/7 with no power adders that when the blower is installed the 416/7 will make more power and over come the loss?

The 440 was a Stock LS7 head that Flowed 365 @650 lift which is the same as the CNC LS3

[LTRS777]

I think theyre saying you can change a pulley before needing to change a block (and then need a bigger blower to take advantage of the cubes).

[Unreal]

Cubes barely matter in Power adder applications when it comes to power. No the extra cubes won't make up for the weight.

You can make 1100rwhp with twins on a stock 376, 416, or 440, just the bigger motors may get into power sooner but all will make a good power band for racing with the correct sized turbos.

Same with the blower, the blower will limit power. The larger cubes may give you slightly more low end torque, but not a huge difference. Either way you will probably max out around 750rwhp if you push it as hard as you can and keep IATs under control, but for what you would spend on doing that you could easily make up the $2500 you lose selling it.

[Rumbumbees$ponsor]

Originally Posted by Unreal

Cubes barely matter in Power adder applications when it comes to power. No the extra cubes won't make up for the weight.

You can make 1100rwhp with twins on a stock 376, 416, or 440, just the bigger motors may get into power sooner but all will make a good power band for racing with the correct sized turbos.

Same with the blower, the blower will limit power. The larger cubes may give you slightly more low end torque, but not a huge difference. Either way you will probably max out around 750rwhp if you push it as hard as you can and keep IATs under control, but for what you would spend on doing that you could easily make up the $2500 you lose selling it.

Thank you Unreal..

do you know of a calculator out there that is setup for a 5th gen that says for every 100lbs you need X amount of HP and X amount of torque to overcome the added weight?

That's probably the only way to get the answer for sure..

I have to disagree with the Cubes not being a factor..

Another member here started with the 454LSX and put a tv2300 on it no meth was at 803 RWHP no meth.. with 10 to 12 psi.. personally I think the 4.125 crank is to big for blowers and to big for LS or LSX blocks

I couldn't get 803 from a 376 if wanted apples to apples not a turbo on a 376...

[Unreal]

You can make it on a 376. Won't be the same boost, but boost doesn't mean anything but the restriction. A 427 will flow more and have better heads/cams typically so you can make 800rwhp on 12psi, while it maybe 16psi on a 376. Either way you can go until the blower is tapped out. Car doesn't care what the boost is, fuel system doesn't care, just the power and airflow. X amount of air will support Y amount of power, doesn't matter the cubes.

Don't forget iron blocks run hotter, and will mess with suspension/handling. Straight line speed wise it would probably take ~50-60hp to make up the difference, but like I said multiple times, your power adder will limit that, not the size of the motor.

[smokum]

If it's 700,800,900,1000rwhp that you are truly looking for makes a big factor. If your looking 750-800 rwhp i would build a pd 417/427. Over that turbos would make more power up top. But if you want to compare say 750rwhp pd vs 750rwhp turbo in a drag race. No question it will outrun it in a quarter mile. Because 700rwtq at 2900rpm pulls these turds out of the hole a lot faster.

[Livernois Motorsports]

Originally Posted by Rumbumbees$ponsor

Thanks..

I guess I asked the question wrong..

I'm asking if the extra cubes makes up for the 80lb heavier block? not counting power adders(YET) waiting to see what happens..

The camaros weight is all ready heavy but getting the extra cubes makes up for it or not? Is the torque and HP worth the 80lb disadvantage? (Straight line not road track)

Power will not be a problem, longevity not worried about either just will the stroke over come the 80lbs .. I want to know is the extra Cubes worth the 80lb of extra weight? Will the stroke over come the weight disadvantage by hp or torque to get down a drag strip or passing someone on the road.

Question 2:

I do have plans to possibly sell the blower and get the AGP kit. If I didn't want to take a loss on the blower... like 2500.00 loss

You can't tell me that if I keep the compression 10.5:1 to 11:1 the blower is useless? and will not make more power than being NA.

Could always do a shot of NOS when I come to the wrong car!

If I had my choice I would do the 427 with MAST back labels and a AGP kit.. but I'm trying to think this out and be practical..


If you go to certain websites a 417 is worth 600 HP average @ 11:1 and a 440 is worth 700HP on average @ 11:5.1

So 100 hp and average of 40lbs of torque worth the weight?

The extra cubes we are talking about here is something that needs to be discussed. For a dedicated power adder build we would not get an aftermarket block and take it out to max or close to max bore. We would leave the liners as thick as reasonable for the combo. Keep in mind we are always after a durable engine you can enjoy for a long time. This means we would always choose a 427 for an aftermarket block build to keep everything as durable as possible. Plus, this gains you access to running a big valve head, like our LSX-LS7 head, or LSX-DR head that a smaller bore wouldn't have.


as far as the weight thing goes, you already are adding weight by installing the blower(or what sounds like could be something else), so what's a little more weight if it opens doors that would normally be closed.

Just about every new production engine has higher "street" compression
10.8:1-11+ and we install blowers on pump fuel every day. Don't worry about that one bit.

If we were starting from scratch to optimize your combo using the blower you have we would recommend a LS3 416 with our stage 3 LSA heads and this will net you a fantastic street combo.

If you are looking to go with a bigger blower, or turbo, and really wanted to turn up the combo past ~15# then we definitely would move to the LSX block, not only for durability, but for the ability to have a far greater choice in cylinder head technology.