LS engines education

[Dragsinger]

I am an experienced and successful racer, but my experience is with the SBC 23* engine.

We are beginning a new project and plan to build an LS engine that will produce around 800 horsepower with a carburetor on methanol. We are completely capable of accurately building the engine, but I need to tap into this forum's experience.

NOTE: This is a trailered, dedicated drag race package in a purpose-built car.

The main question I have are:

*Is an Aluminum block a good choice? If so, which block? Or other block choices?
*With my 23* builds, I mostly install Calles Compstar crank and rods. Is that a good choice for the LS?
*Which heads with attain my 800 horse goal?
*Which intake will accomplish the goal?
*What is required for the six-bolt head, or is that necessary for a NA 800 horse build?
*I expect to install a mechanical roller with the proper valve train.
*Which oil pump, pickup tube, and pan are acceptable?

Beyond those basic questions, I expect to be able to complete the build.

What are your suggestions?

Larry & Jeff Woodfin - owners
Woodfin Automotive
319 Omaha St
Kilgore, TX 75647
903-985-1162
woodfinlarry@gmail.com

[mt-engines]

Aluminum block for weight savings and some Brodix STS BR 7 BS 273 heads

[Walter R. Malik]

double post ...

[Walter R. Malik]

I am an experienced and successful racer, but my experience is with the SBC 23* engine.

We are beginning a new project and plan to build an LS engine that will produce around 800 horsepower with a carburetor on methanol. We are completely capable of accurately building the engine, but I need to tap into this forum's experience.

NOTE: This is a trailered, dedicated drag race package in a purpose-built car.

The main question I have are:

*Is an Aluminum block a good choice? If so, which block? Or other block choices?
*With my 23* builds, I mostly install Calles Compstar crank and rods. Is that a good choice for the LS?
*Which heads with attain my 800 horse goal?
*Which intake will accomplish the goal?
*What is required for the six-bolt head, or is that necessary for a NA 800 horse build?
*I expect to install a mechanical roller with the proper valve train.
*Which oil pump, pickup tube, and pan are acceptable?

Beyond those basic questions, I expect to be able to complete the build.

What are your suggestions?

Larry & Jeff Woodfin - owners
Woodfin Automotive
319 Omaha St
Kilgore, TX 75647
903-985-1162
woodfinlarry@gmail.com

What cubic inch is this engine going to be ...? What RPM level are you looking to obtain ...?
With alcohol I would use a Dart Iron block unless you absolutely NEED the weight savings.

[Dragsinger]

Walter, I have in mind a 4.125 bore x 4.00 stroke. I expect the operating range to be around 6200 - 7800 RPM—one Methanol carb. Even 775 horses would accomplish my performance goal.

[Racer71]

I would avoid the oem alum block for those power levels. The oem iron block would be fine. If you’re wanting to go 6 bolt then aftermarket it will have to be. I *think* naturally aspirated the 6 bolt may not be necessary but there are others here I would trust their advice over mine. The aforementioned heads or maybe check out Frankenstein or all-pro offerings as well

[mt-engines]

I was referring to an OEM aluminum block.
6 bolt heads fit on a 4 bolt block.

if aftermarket block, like Walter mentioned the Dart block is great.

If you want purely OEM LS7 Block and heads. The heads will need to be fully ported new guides etc.

The BR7 heads will support a lot of power NA. 900+ with a mildly aggressive cam

If you want to be cheap. Ported Proheader LS7 heads and a 6.2 or 6.0 block, 408-420" rotating assembly cam in the high 270s@.050 will get you in that 800hp range. Peak power in the 7500-7800 rpm range

There is nothing wrong with an aluminum block. 100lbs off the front of the car is still 100lbs off the car.

[jed]

The only real practical way to get a 4.125 bore block is to get a Darton sleves 5.3 stock block. As I understand the LS7 (4.125 bore) GM block is no longer avaible and are hard to find and expensive. A Dart alumin block is the best choice.
The Comp Star rods and crankshaft will serve you well. Just be sure you order a 8
counter weighted crankshaft. You will have less main bearing distress.
As mt said the Brodix STS BR7 BS 273 will give you 800 hp easy.

[Walter R. Malik]

Walter, I have in mind a 4.125 bore x 4.00 stroke. I expect the operating range to be around 6200 - 7800 RPM—one Methanol carb. Even 775 horses would accomplish my performance goal.

Making 775/800 horsepower with a 427 cubic inch LS engine should be fairly straightforward.
Several different brand cylinder heads with get you there but, I would definitely use a CID intake manifold, matching whatever head you use.
For that power level, I like the "retro" LS7 heads available from Bob Williams at "All-Pro".

Probably a "distributor" front cover from "All Star" with a good single coil ignition.
I would use the standard Melling 10295 oil pump.
A General Motors windage tray for that stroke.
The oil pan would really depend upon the chassis needs.

[skinny z]

Probably a "distributor" front cover from "All Star" with a good single coil ignition.

I find that a curious statement. Care to elaborate?
I can't say I like the appearance of the coil on plug whatever it's benefits might be.

[rustbucket79]

I see zero benefit going back to a distributor, buy the MSD LS ignition box and you can raid the auto wreckers for the coils, harnesss and plug wires. Who wouldn’t want a fully programable ignition system for minimal dollars?

[Walter R. Malik]

Probably a "distributor" front cover from "All Star" with a good single coil ignition.

I find that a curious statement. Care to elaborate?
I can't say I like the appearance of the coil on plug whatever it's benefits might be.

"Coil near plug" has power benefits on a true race engine ...? What ones are those ?
No computer necessary and fewer High RPM mishaps. Simplicity.
Use a "mag" and you don't even need to carry a charged battery.

Use whatever you want ...

[skinny z]

Simplicity.

That's the part that appeals to me.
I'm no stranger to component wiring (it's my job) so there's no fear in that regard.
This is appearance driven.
I do like the tunability that comes with the electronics though. The stand alone ignition controller is great for tuning as opposed to weights, springs, slots, vacuum cans, etc. Makes me want to invest in an electronic distributor for the old Gen 1.
To each their own.

[Walter R. Malik]

Simplicity.

That's the part that appeals to me.
I'm no stranger to component wiring (it's my job) so there's no fear in that regard.
This is appearance driven.
I do like the tunability that comes with the electronics though. The stand alone ignition controller is great for tuning as opposed to weights, springs, slots, vacuum cans, etc. Makes me want to invest in an electronic distributor for the old Gen 1.
To each their own.

You can still use a "Programable" ignition box with a crank trigger and "locked" distributor; if you like.