LSX 454

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Discussion

Pascal Mertens

Original Poster:

25 posts

114 months

Monday 12th October 2015
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After weeks of doubt I've decided on the SBC replacement. I'm putting in an order for a 454 LSX. It is heavier than the LS7 but the experts convinced me it will be a much stronger base for a trackday vehicle and future upgrades. It will be fuel-injected and power should be around 580 hp/flywheel in standard NA condition.

Did I make the right choice ???

Edited by Pascal Mertens on Monday 12th October 13:02

The Italian

136 posts

121 months

Monday 12th October 2015
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How about the crankshaft flange? the bolt pattern is 8 vs 6 ? An adapter? This may raise issues

chuntington101

5,733 posts

235 months

Monday 12th October 2015
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The block is stronger because its the iron version. Did you get the standard or Tall deck? if its the standard deck you are going to be using an pretty long throw crank and you run the risk of increased piston wear. If its the tall deck you should be fine.

Pascal Mertens

Original Poster:

25 posts

114 months

Monday 12th October 2015
quotequote all
chuntington101 said:
The block is stronger because its the iron version. Did you get the standard or Tall deck? if its the standard deck you are going to be using an pretty long throw crank and you run the risk of increased piston wear. If its the tall deck you should be fine.
It will be a tall deck. The last time I checked with my engine guy he told me that I wouldn't need the adapter because it should fit the one I now have.

ROWDYRENAULT

1,270 posts

213 months

Monday 12th October 2015
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You asked a question "did I make the wrong choice" Answer yes, I live in Southern California, there are lots of talented people here because of the enormous "motorhead community that they can sell to. The LS motor is the go to motor for many projects and folks like Dutwieler, Castillo Motor Sports, Nelson racing engines ........... will whip up a a big inch alloy LS motor that will make north of 700 H.P. all day long. For the really serious projects they usually start with a billet RHS block and a Callies crank shaft a set of Carrilo rods some All Pro heads, top it off with a 8 stack injector manage it with a Motec. Two instances that might call for a LSX block if they are putting it in a 69 Impala that's going to weigh 4000lbs and mostly cruise or if its going to be a highly boosted motor that lives 1/4 of a mile at a time or is trailered to shows with a sign that brags about how much power they generated on a dyno one time on 125 octane fuel. If you have the talent to fully use more than 650 hp in this car on the street or on a track then I tip my hat. Lee

Pascal Mertens

Original Poster:

25 posts

114 months

Monday 12th October 2015
quotequote all
So, what I understand from your answer is an LSX is more than needed or is it to heavy ?
I quite like the LSX because it will be strictly track only and I'm looking for a troublefree engine.
I know it will be 50kg extra but then again the car has zero unnecessary stuff so I still will be around the 1000kg mark.

Storer

5,024 posts

214 months

Monday 12th October 2015
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For track use all you need is added lightness (as Colin Chapman said).

The more weight you have the slower it will corner, so the extra power will not give a faster lap.

My standard LS7 with custom exhaust and air box produces 575hp. On the track it goes like a rocket but could stop and go round corners faster.

Spend the money getting it to corner faster and you will be a 'driving god'.

Also, if like me you could weigh a bit less, that would help too......


Paul

F.C.

3,896 posts

207 months

Monday 12th October 2015
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I run a smaller (383) boosted LSX iron bloc.
If you want BIG numbers then it is a good place to start they will handle well in excess of 2000 BHP.
In an Ultima I'd suggest overkill, I run mine with 1-2 lb boost at around 525-550 BHP at the contact patch and it is enough for me on road.
I have plans to run a variable dual boost system (purely for high speed runs) and fully expect to see 900 + BHP on the rollers.

I wouldn't worry too much about weight, the nature of a build on these (normally) is you will be using a lightweight crank, rods, top end components and so there is little difference in the finished car compared to a crate engined one.
If you do the same to a alloy block you will see a weight advantage.
Given the need to fit a new engine into mine I would use an LS3 base and build it up with boost in mind but with a ceiling of about 600 BHP.

R8VXF

6,788 posts

114 months

Tuesday 13th October 2015
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Why not use an LSA base as it is basically an LS3 base with built in oil cooling jets for the pistons and a few other bits and already built for boost? LS( id Titanium forged bottom end for even better results.

F.C.

3,896 posts

207 months

Tuesday 13th October 2015
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R8VXF said:
Why not use an LSA base as it is basically an LS3 base with built in oil cooling jets for the pistons and a few other bits and already built for boost? LS( id Titanium forged bottom end for even better results.
I wouldn't because it is a torque monster and a lightweight car like the Ultima Just doesn't need it especially low down the rev range, I prefer the delivery of a centrifugal charger, that said could always dump the twin screw set up, could be a good base to start from.
depends on cost I suppose, definitely worth a look.

ETS a quick google reveals the LSA in crate form is about $11000 or half that of the LS9!
There are a few differences of course, notably crank, rods and pistons, so worth checking what you would change and the cost to do so.

Edited by F.C. on Tuesday 13th October 09:21

Boosted LS1

21,167 posts

259 months

Tuesday 13th October 2015
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Or how about a Darton dry lined 427 alloy LS, callies crank, eagle rods, custom JE pistons, ls9 heads and valvetrain, trunnion kit and lots more, ati damper, ls7 dry sump, ls3 intake and injectors ;-)

Storer

5,024 posts

214 months

Tuesday 13th October 2015
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Pascal has said that this will be a track car with little road use.

The focus should be totally different to one used on the road.
To get the best round a track you want slick tyres. This will require stronger wishbones, wheel bearings and rose joint suspension. Anti-roll bars too. I would also opt for the longer wishbones to enable wider front tyres with a slight reduction in steering effort. Make the steering wheel come closer to the driver to reduce steering effort.

I would mount the engine oil cooler at the front for better airflow.

Single fuel tank behind the seats (additional bulkhead for driver protection) with in tank pumps. This would give plenty of air flow into the engine bay which would then allow a flat floor to the rear of the car.
Air for the induction would be from the outside of the clam and sealed against under clam heat.
Sequential shift gearbox with LSD.

Larger brake discs, and higher performance callipers if you can get them inside the wheels. 19 or 20" wheels possibly.

Large front splitter with the car lowered but retaining the 2" difference front to rear.
Open up the top of all four wheel arches.

Remove/do not install anything unnecessary. If something can be lighter then make it so.



Or buy a Radical

Paul



Pascal Mertens

Original Poster:

25 posts

114 months

Tuesday 13th October 2015
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Hi Paul,


I understand what you're saying but getting the car to the level you're talking about is beyond my budget. I want a quick trackday-car not a top of the line competition-monster such as our Mac G-friends have... Well, to be honest I want that also but don't have the euro's to do so smilesmilesmilesmile.

ROWDYRENAULT

1,270 posts

213 months

Tuesday 13th October 2015
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To much or to heavy? Both. lee

deadscoob

2,263 posts

259 months

Tuesday 13th October 2015
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Why 19 or 20" wheels Paul? Otherwise sounds good!

R8VXF

6,788 posts

114 months

Tuesday 13th October 2015
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deadscoob said:
Why 19 or 20" wheels Paul? Otherwise sounds good!
For REALLY big brakes smile

Pascal Mertens

Original Poster:

25 posts

114 months

Tuesday 13th October 2015
quotequote all
ROWDYRENAULT said:
To much or to heavy? Both. lee
That leaves to heavy then... smile

I believe I know roughly what to expect from a 600 hp Ultima since I've done a few 1000 track-miles
with a 515 hp at the wheels-one. However I'm far from a driving God, I think that will be fine...



Edited by Pascal Mertens on Tuesday 13th October 16:39

F.C.

3,896 posts

207 months

Tuesday 13th October 2015
quotequote all
R8VXF said:
For REALLY big brakes smile
I run 360mm discs on my car and TBH they are overkill and then there's also the un-sprung weight penalty of going large.
I think the factory have the standard AP brakes bang on.

I know Mac G use larger still (378mm I think) but still in 18" wheels and they are racing theirs.

Pascal Mertens

Original Poster:

25 posts

114 months

Monday 19th October 2015
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So guys, I've listened to all the advice and I'm waiting for a new custom-build LS3-engine wich will be ready within 8 weeks.

Storer

5,024 posts

214 months

Monday 19th October 2015
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Probably a bit late as you have placed your order but watch the video link I posted on LS engines.



Paul