Jump to content
NotStock

What would be your "perfect" LS sand car motor?

Recommended Posts

I'm having a new car built and trying to decide what road to go down. I'm going to be using an existing Dart Next LS7 6 bolt 427 stroker motor that I just had built which currently has a pair of 66mm ball bearing Bullseye turbos and made 1375 hp and 1200 ft lb at the crank. Not to say I'm unhappy with it by any means but I'm strongly considering switching over to a 4.5L Whipple when its put in the new car.  The car will never be the fastest out there nor do I want it to be.  I want something that rips in all areas, duning and drags and is as reliable as possible. What's y'alls thoughts on which road I should go down? 

Edited by NotStock

Share this post


Link to post
Share on other sites

I’d say what you have now would be my ideal set up. 

Share this post


Link to post
Share on other sites

Same motor I had built the last time. The best motor I could afford that gave me the most reliable and best performance using pump gas. 

Share this post


Link to post
Share on other sites

Just my opinion. But I have an LS3 425 with a 4.0 Whipple. 825 to 850hp. 625 to 650hp to the wheels. I'm a duner and this motor is awesome. My buddy has an LS7 440 with a 4.5 Whipple, I think 850+ to the wheels, and to me it is to much power for duning. Front end is hard to keep down. If you want the drags its fine, but we usually just go down the drags and park.

Both are on the edge of using pump gas. A little octane boost is recommended for both our cars.

 

I think an LS7, stroked or not, with a 4.0 would also be really great controllable power.

 

Duner = blown

Drags = turbos.

 

Good luck.

Share this post


Link to post
Share on other sites

Here is my existing configuration. 

49898.jpeg

Share this post


Link to post
Share on other sites

My builder just finished an almost identical 4.5L Whipple motor besides the fact I'm running e85 and this was on 91.  Were thinking we could get even a little more out of mine if I stayed on E85. I'm thinking the instant response of the Whipple and nearly identical hp would make the Whipple platform the best of both worlds for me

49899.jpeg

Edited by NotStock

Share this post


Link to post
Share on other sites

For me it depends on your driving style, expectations (dune or drag) and lots of factors.

I am a fan of usable HP rather than nice Dyno HP in an RPM range I regularly don't use.

For me

Rule 1 – There is no replacement for displacement

Rule 2 –  I would rather be blown

Rule 3 – You don't drive the Dyno

LS engines are so reliable and robust that you can just about have it all with the right build and cost can be contained "pretty well"

Here is the combo I did in the past that is still my goto (assuming I have cash and the car to handle it)

RHS tall deck  502cu in,   KB 4.7L Liquid cooled SC on E85 solid 1400RWHP and 1200ft TQ all day long.  Pulls like a rocket from just above idle to 6000 with a nearly flat TQ curve. Never need to dump the clutch or rev it like you hate it...  Way more power left there - but built like this, it will last forever - run on 91 and take away 280HP and 340Ft Lb TQ.

Where most Dyno runs "start" at 4000 RPM because they are hiding the low end ramp (saying you never really are under 4000 in the dunes is nuts  - a well designed blown engine can cruise at 2500 RPM and when you stomp it, its a rocketsled from there..), The power under the normal driving curve with this combo is amazing, start the Dyno run at 2000 RPM and see a flat curve through the redline (6000) - that is real bragging rights IMO. Its hard to beat the "two Stroke" feel of a Twin Turbo car in a limited RPM range, but the constant pull of a well built blown car has to be experienced.

Little details in build make it a super reliable runner like the right cam thats easy on the valve train for reliability yet has enough power, its a fairly basic build since it never needs to spin past 6000RPM  9.5:1 comp, no exotic head port work  needed.  A combo like that runs forever, just change the oil.    I put this one in a 1968 Camaro

 

 

Edited by fullthrottleguy

Share this post


Link to post
Share on other sites

That's an awesome and informative post Fullthrottle! Thank you! Starting from scratch I'd go that route in a second. I am however confined to my current long block. But some solid points I will give thought to. Thank you!

Share this post


Link to post
Share on other sites
29 minutes ago, NotStock said:

That's an awesome and informative post Fullthrottle! Thank you! Starting from scratch I'd go that route in a second. I am however confined to my current long block. But some solid points I will give thought to. Thank you!

Your starting point is excellent already  the LS Next is a very good platform -  You did not say what heads you are running, but the ramp on an SC cam will be a bit steeper than on a Turbo so might require a spring change.. A small cam and spring change and bolt on the Supercharger and you will make incredible power.   SC cams like a bit of overlap where turbos hate it - You can run a 110 or 112 LSA and that will get your TQ curve moved down a lot compared to the 114 or 116+4 or higher you probably have on the Turbo cam, and you can increase duration a bit and run an 8-10 degree split duration  and still have great drivability. With the 427 I personal would go smaller on the SC to reduce the parastolic loss and make the engine super responsive. A 3.2 or 3.6 will get you 10Lbs on Pump and 16-18 on 110 or E85 and save that 40-50HP loss at low RPM the Whipple 4.0 or 4.5 takes to turn - thats all wasted HP and TQ - Bigger is definitely Not better when it comes the SC's  Thats probably mistake number one - but its done in the sand so much because the Whipple 2.9 is well lets just say - not the best choice... so most people get talked out of it and into a big wasteful 4.0 I like the Kenne Bells because they generally take far less HP to turn Liter to liter (due to inlet efficiency and rotor Lobe dimensions) per Lb of Boost and they have the Liquid cooled gear set that lets you pump 1-2 Lbs more boost in before detonation - they made me a believer only after I tried it.

Thats my 2 cents...FWIW

Share this post


Link to post
Share on other sites

My original plans were a set of All Pro heads but the turbo company actually talked me out of them and recommended the AFR heads that it was built with. He had said the lower flowing head would spool the turbos faster and make the original 1300 hp goal better. Which they certainly did but I feel the All Pros are a superior head that I wish I had gone with. 

Edited by NotStock

Share this post


Link to post
Share on other sites

What's your thoughts Kenne Bell to Whipple or others? 

Share this post


Link to post
Share on other sites

The "perfect" LS engine is all relative. I built my L76 for not much cash at all and it does everything I need it to, the gas pedal seems bottomless at times so I need nothing more. A buddy of mine threw a rod out the side of his block a month ago,  and with a crank and rods I gave him plus the block and pistons he had to buy I think he's into the replacement for less than a grand. We were out at Gordon's this weekend and his new engine rocks.  So for us common folks these would be the "perfect" LS engines.

I do like the sound of a big dog with a lot of compression and a healthy cam though. 

Share this post


Link to post
Share on other sites

I have a 425cu in Ls3 with a 4.0 whipple and mostly dune but always want more. It is supposed to be a 750+ hp package, but in my 3500lb pre runner I would like a couple hundred more hp.  That being said, I want no part of race gas and duning. Burn way too much to justify the increase cost. 91 is where its at.

So for my car the perfect engine would likely be about 1000hp and pump gas. Whatever it takes to do that.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

More Links

©2001 GlamisDunes.com.
All rights reserved.

×

Important Information

By using this site, you agree to our Terms of Use.