To LS7 or not
 

Hi all,

I'm just about to get things underway with my build, but I am undecided about engines. While I think that the 6.0L, Chev (dare I say it) engine has enough power etc...... I am thinking of doing a Cobra with an LS7, or 427cui engine to at least try to make it as close to original as possible.

What are your guys thoughts on this engine choice, too much power, but then right foot control come into play!!!! and what gearbox would you shove behind it. It will be a Sunday car, and maybe the odd track day.

It will have a Harrison body, as I can get an extra 4" and lowered seat, with the Factory 5 rear end in it with Commodore diff I think. (the diff may need some extra guts!)

Looking forward to joining you all with smiles from ear to ear.

Lawrence

Welcome to the "fold"...remember Shelby approached Chevrolet first and they told him to "go pluck a chook" so ford had a better idea ! ask philm .

Smithy

And from then on it was Ford all the way ....

Pluck and chook
 

Smithy,

I remember reading about Shelby approaching Chev, and perhaps the reply was that if they gave him chevy engines that he would not be able to keep up with demand, so Ford were a better option, at the time:-).

As for engines, I dont like the boss engine, too big as I need the extra space in the footwell, and thats what we have to run here in the wonderful state of Victoria, so it leaves either the Lexus or the Chev. Given that I have a Commodore V8 with the 6.0L and that has enough to get that car going, I think it will have enough for a car that weighs 2/3rds the weight. i just can't get past that LS7 engine though.

I look forward to some views, and I'm not fussed to hear from some Ford Boss people, with superchargers strapped on them, as well, as I really have no objection to them all at the moment, but I have 2 weeks to make a decision.

Lawrence.

An LS7 would be nice but an LS1, LS2 or L76 makes more power than you will know what to do with and for a lot less money too.

We need to remind people that anything much more than 400HP in a Cobra is a waste and getting dangerous. It's nice to have the bragging rights but a big HP car is a real handfull.

Cheers

Mike,

Thanks for your comments.

By the way, I love reading about your build and all the technical stuff that you are doing. I am a tech buff and love to read about little bits and pieces like your rear end (of a car variety!:LOL:!!).

Thinking 6.2L LS3 at the moment as they maybe available cheap.

Cheers

Lawrence

The LS7 is an iconic engine, a true race engine for the street. And the sound.

The LS7 will be perfectly streetable and provide great bragging rights.

Mike is right any of the Gen IV Chev/Holdens will provide plenty of mumbo for a Cobra.

Get some advice on the diff and you don't want any weak links. What gearbox are you thinking of using?

Sam's Performance in Sydney has brand new LS3 crate motors for $6950 inc GST.

02 9772 3105

Unit 9 / 78 Gibson Avenue
Padstow
NSW 2211
Australia


Glad you enjoy the build pics and stuff. I love reading about everyone's projects so I figure I may as well throw my stuff up as well.

Cheers

Are you waiting for the ex-HSV w427 LS3 engines?

Be interesting to see what the pricing is like. I expect it will be well into next year before we see good pricing when HSV seriously ramps up W427 production and offloads reasonable quantity of LS3 engines.

I'm with Mike on this one.

The 6Ltr with cam, springs, etc are getting around 400rwhp...more than enough to get most folks into trouble. It is at this 400hp point that I feel a cobra becomes "less enjoyable".

I would much prefer to spend the difference in costs on suspension/brakes etc.

Mind you...the 6.2 is appealing because of the low cost.....they can be had for about $7000.00 at the moment but may well get cheaper. see here:

http://www.ls1.com.au/forum/showthread.php?t=103566

However, that's still approx double what a L98 would cost in bare crate form.

Craig,

At the moment I am thinking 5 speed, T56 or something similar, but have to admit that I know nothing about the TKO variety of gearboxes that I see a few people have.

Will come down to what will best suit engine I think, but then I have to decide on engine, either LS7 or LS3???????

Thanks for feedback.

Does anyone know much about the Factory Five rear end that can be put into a Harrison!.

Cheers

Lawrence

Hi Lawrence,

We'll I'm clearly biased as I went through the same thought processes and chose to go with an LS7 because of the magical 427ci and I'm very pleased I did...the 1st time I heard the engine start was just amazing...

I hear the argument about too much hp and I think the argument is very valid...my stock standard LS7 crate motor produces around 440 hp at the wheels and I think that's more than enough (certainly for me!)...

I think if it's practicality that rules you, then any of the LS engines will make more than enough hp and they will all do a beautiful job...but there's something about the illogical and slightly extreme side of going for the 427ci that just seems to work for a Cobra....after all if practicality was everything...would we be wanting a cobra in the 1st place??

Good luck with your deliberations...

Regards.....Paul

Very interesting debate.

The 427 is appealing because I guess of its numeric link to the Cobra, but as stated, more than enough power can be sourced from the previous LSX versions with limited mods.

What is the ball park figure to source a 427 crate donk?

"Go Pluck A Chook" .. I'm still trying to catch my breath from laughing so hard on that one.:D:LOL:

OH man ! Does that hurt !! :eek::LOL:

That was good Rob.
Sorry guys but it just hit my funny ... I guess because he was a chicken farmer.
I love the LS series engines. I am impressed with the common sense approach to the horsepower delimma on this thread. Mike has it right in my opinion.

Still trying to get my composure.:JEKYLHYDE:3DSMILE:

Hersh:)

Here's my two cents. I built a Hot Rod of my own design that I raced at Run n Gun last year. I used all stock C5 suspension, brakes, wheels, tires, sway bars and the transaxle with a shortened torque tube. I bought a NEW, in the crate 405hp LS6 on ebay for $3900. I ran the stock clutch.
I have built several other cars, many that I raced at Run n Gun. The C5 Hot Rod was by far the best handling car I have ever driven. That list is pretty long. On a 1.6 mile road course I beat every car in my class by, I think, 6 seconds. I was even 4 seconds faster than my previous best time which I had 538hp for. I thought that my computer guy had screwed up as the car ran extremely rich and even fouled a set of plugs. I discovered later that I had an open vacum port that I had missed. The engine was on full rich. So, I wasn't even getting close to 405hp. The point is that our cars even with reasonable horsepower are fast! By the way I get over 30mpg on the street.
I am soooooo close to finishing a scratch built Cobra using all of the C/5 drivetrain. I designed and built a steel tubular space frame with a full backbone. I could not use the transaxle set up as it would have made the trans tunnel too wide. I had a new input shaft made along with a bearing carrier for the Vette diff. This allows me to run a driveshaft. I am using an LS6 with the T56 trans. because of the narrower track I had new rear axles made and a new steering rack made that keeps the correct geometry. I would love to use an LS7 but I ran out of money!!! Using the Vette parts gives me great suspension geometry, I believe the best off the shelf independent rear end available, great brakes and lets me run 18 or 19 inch rims.
My next project. The same chassis with roll cage, I hope an LS7, and a Daytona body! I just can't seem to stop. This is way to much fun!
I am going to run the new Cobra at this years Run n Gun. I'll know soon how it goes.
Good luck and have a great time with your project!! John

I have seen John's creations and I will vouch for the fact that they are right on for handling and looks great too. I talked to John at the last R&G and I really like his enthusiasm for his product. He's fun to watch on the track too.

Hersh:)

Yeah but Hersh........can he Pluck a Chook?. ;)

:D:D Not like Shelby could !

Hersh:)

Chevy
 

T.L.

Last week I drove my Harrison Daytona for the first time.
Stock Gen IV (L76) no tune, very restricted exhaust and I was VERY IMPRESSED. I have a 6.3 Liter FORD with heads and cam etc etc, and it
was not far off..:eek::eek::eek:

My last visit to the States I found some CNC ported heads and a smallish cam,:):) I think the 6 litre with a tune and a cam would be plenty,
the dollar was so good I got the heads aswell. Just be careful when buying the motor package, the accessories are very expensive, try to get a complete
unit with gearbox. WASP in Ballarat (Luke) can assist, they supplied the wiring harness, rocker covers, all options and the fly by wire mod. They even remapped the computer to remove the security and upped it to 307KW. They also have warranty.

STIFFY

i just finished a dyno loom for sams ls3 engine from walkinshaw afew weeks ago

was there this thhurs night testing my loom on an engine he had on the dyno

he said i can advertise his ls3s on my website or i can let people know they can get them thru me for same price which is just under 7g like others have said

ive seen ls7s complete with nearly everything u need on ebay for 17g

so depends if u can justify that

u can prob get an ls2 or l76 or ls3 then bolt a supercharger ontop for similar price