LQ4, LS6 cam, 706 heads, 317 Heads, Junk Yard Dog, AND LIES

[zgeezer]

THE SET UP

 

Think major sibling rivalry here: my brother is Ford blue and good at it.  Builds only early Falcons with a preference for 4 doors.  He builds only 351C or Windsor small blocks.  He builds very strong engines, well thought out parts [He's an engineer and long ago figured out that the parts have to work together] and stuffs them into straight stock bodied Falcons.  He calls his vehicles "Dorkmobiles" and he has been a very effective predator of everything Chevrolet on grudge nights.  The dorkmobiles all run 14inch tires...radials, but not drag radials on a 3:00 9inch Ford rear end with a real locker center, think off road locker.  The 3.00 R&P is there "To kill that massive torque Ford engines are good for".  He builds Q-ships.  The last one ran two back to back runs at Sacramento of 10:8x and 128+ mph trap time.  That dorkmobile was a 426 stroker (351W block) with C6 dressed out as a 289 HiPo.  He's really good with decals, paint, and BS.  This one was also driveable with a very slight chop.

 

THE HORSEPOWER

 

Every horsepower/et./trap speed calculator I've run, using 3100# as the Falcon/driver weight, spits out something in the order of 500hp to do that deed in a Falcon.

 

THE CHALLENGE or MY SHORT BUCKET LIST

 

What GEN III combination in my Series I 240Z would it take to turn the 1/4 quicker and faster than a dorkmobile?

 

I think my Z with GEN III, me, and a 4L60E will weigh in the 2800#...maybe less range.  At 2800# computer calculators indicate I'll need 446 real horsepower.  So, 450 hp will be my design parameters...that and to be driveable at the same time.

 

HERE ARE MY PARTS

 

The Z is set up with a strong rear drive: 3:36 R200, additional clutches in the 300ZXT LSD, Racing Flag stub axles, and 300ZXT CV axles [well, one anyway, the other is a pathfinder].

 

One running 2001 LQ4 with 65000 miles and 317 heads.

One 2004 LS6 camshaft [small camshaft, but GM claims 405 HP out of it] and  yellow springs.

Eight flat top 4 inch pistons and floated rods out of a 2005 low mileage GTO.

Two sets of 5.3 truck heads, casting #706 with the small intake valve and 61.15 cc combustion chamber.

 

WHAT I DON'T HAVE

 

I don't have a truck load of money, but I do have access to a machine shop and to a large wrecking lot.

 

Some gurus have told me to pull the LQ4 crank, hang the GTO  pistons and rods on to it and balance the assembly.  This is said to push the CR to about 10.9:1  Then, buy a "real cam" and with a good tune and long tube headers, I'd put down over 500HP, easy.  I'm not too sure about that.  GTO's with LS2 are rated at 400HP and I think I'm close to creating a bastardized clone of the LS2.

 

WHAT I AM INCLINED TO DO

 

I don't like breaking the crank and pistons out of the block.  I would prefer to gain compression by reducing the size of the combustion chamber.  I don't have the cash to buy aftermarket.....and, if I can actually take on a Dorkmobile, I'd prefer to do it with all GM parts.  So here are the options I think I have.  I can keep the 317 heads and mill them for compression.  But, I'm strongly advised not to cut them more than .030 because there's not that much meat there and I would most likely incur P/V interference and misalignment issues with the intake manifold.  I'm told that milling them .030 would gain only slightly more than 10:1 CR.  The benefit to the 317 over a standard LS1 casting or the 706 5.3 truck engine is a 2.00 valve and a larger port volume.  I'm told that 317 casting is the same as the LS6 head, but with a larger combustion chamber.  They are reputed to flow better than any of the other stock cathedral port castings.

 

The other choice is to take a pair of 706 heads down to the machine shop and install a larger intake valve... opinions vary as to a simple replacement of 2.0" intake valve or something marginally larger.  I understand that the 706 castings have the same intake/exhaust port volume as LS1 heads and flow the same once the intake valve is replaced.

 

I have no doubt that the 706 heads will give me a higher CR.  This might be my best choice.  It would also maintain the facade of running a 4.8.

 

SEX, VIDEOTAPE, AND LIES

 

I have spent the last two years...maybe more in setting my brother up to expect a Z with a 4.8L engine.  A sad tale of paying good money for an insurance 5.3 to find flat pistons and a 4.8 in my garage.  He has been quite helpful and generous with his time: he recommended the 1998 LS1 cam over the LS6 camshaft as being more responsive for the smaller engine.

 

We will meet next year in Reno for Hot August Nights: he will be present with another Dorkmobile [This one with a late Ford V6] and my brother-in-law's  '56 Austin Healey with a dorkmobile 347 and a/t.  We will all go to the drags outside Reno to see what both Dorkmobile II and the AH can do.  I will be pushed to run my Z......  I would expect some bets of some sort will be made.... all in good nature... of course!  I want to walk away with his money, if not outright bragging rights.

 

WHAT I NEED FROM HYBRIDZ

 

I need solid advice as to how best use the parts I have and if 475HP is unlikely with the Z06 camshaft.... then give me some choices.

 

Thanks for reading this long tale.

 

g 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Daz]

I think you should go with 3.54 or higher ! I'm using a LS6 cam in my 4.8 but I'm going turbo plus its the 2004 cam(405hp opposed to the 385hp cam). If you are going all motor then I would get a more aggressive cam.

Edited May 6, 2013 by Daz

[EastTnZ]

I would recommend also consulting ls1tech with this question.  How much cash do we have to play with to get it to 475hp? 

Edited May 6, 2013 by EastTnZ

[RebekahsZ]

Throw any old POS motor together that you want and spray the crap our of it and you will win.

Edited May 6, 2013 by RebekahsZ

[EastTnZ]

/\ what he said and add an auto th400 built and your cv's might hold up

[RebekahsZ]

We forgot tires. How is your brother getting out of the hole with regular tires? Any of us going that fast without slicks/drag radials? I just sit and burn without my slicks. Got my first wheel hoping last weekend with my street tires at an autocross-sounded destructive (axles) so I got off of it. So far I've never had wheel hop at the strip on slicks.

[socorob]

He must use late falcons as the early vintage racing ones weigh less than 2500 with an all iron big block! The early 2 door small blocks in street trim were something like 2300. They were very light cars.

[zgeezer]

Throw any old POS motor together that you want and spray the crap our of it and you will win.

Oh, I like the idea and it did occur to me.  However,  The Code of The West prevails here:  we can lie, cheat, bad-mouth, misrepresent, gamble, fight, drink and hit up on your wife or sister, BUT real men build real motors.  Spraying is, how can I say this,..... simply not Manly, lower even than bolting on a hair dryer.  Besides, I can't  risk getting caught, even my sister wouldn't talk to me.

 

g

[zgeezer]

I would recommend also consulting ls1tech with this question.  How much cash do we have to play with to get it to 475hp? 

Ls1tech has a universal agreement that the LS6 cam is too puny and good only  as a support for Budweiser Beer lamp shades.  Even free, they don't like them...sort of "why bother".  But to support  the story line, I have to have a smooth 500 rpm idle and run the truck intake.

[zgeezer]

We forgot tires. How is your brother getting out of the hole with regular tires? Any of us going that fast without slicks/drag radials? I just sit and burn without my slicks. Got my first wheel hoping last weekend with my street tires at an autocross-sounded destructive (axles) so I got off of it. So far I've never had wheel hop at the strip on slicks.

He never had eye opening 60' times.  But, his solution to traction worked.  Early Falcons.  The original dorkmobile was a '62 Futura, his latest a '61 sedan.  Nine inch with 3:00 screw, his version of the old traction master link to control wheel hop.  Actually a "slapper bar", but it didn't look like one and was tucked up nice and neat.  The wheels were steel 14 inch, but wide Chrysler product.  His LSD made clicking noises whenever he turned: a detroit locker I think.  Finally, he always finished strong.

[zgeezer]

He must use late falcons as the early vintage racing ones weigh less than 2500 with an all iron big block! The early 2 door small blocks in street trim were something like 2300. They were very light cars.

 

He must use late falcons as the early vintage racing ones weigh less than 2500 with an all iron big block! The early 2 door small blocks in street trim were something like 2300. They were very light cars.

Well, can you imagine that, he lied to me about the weight.  It also means that his 426 stroker wasn't as strong as I thought.  Hey, I just might carry this off.

 

g

[EastTnZ]

Well if you had a spare $3k this gets you 475hp and 460 ftlbs TQ N/A from a 6.0 with a free flowing exhaust... long tubes, cam, tune, springs, etc...

 

http://www.tpis.com/parts/view/149

[Slow_Old_Car]

Mill the crap out of the heads for a higher static C:R, switch it over to E85, invest some real time and $$$ into a GOOD longtube header setup for the car vs. any of the standard fair shorty huggers commonly seen (or roll the dice on the holley LS swap cast iron units that claim to support 450-500hp and see if backpressure chokes you). Get a smaller cam and a looser convertor in that 4L60.

 

Last but not least, get someone to tune it who know's their stuff on E85, ramp some timing in, and go fast, no hodge podge swap master tuner who bricks all the settings to where the car will pull stumps then nose over on the big end cause the tunes all flat up top.

[RebekahsZ]

What chassis you putting this in?  You better strip it, that means no interior at all, a lawnmower battery, dump the swaybars, light weight driver seat only, quit drinking beer and eat salads, 5 gallon fuel cell; cut everything out that you can.  Put helium in the tires.  Sub-11s isn't as easy as it looks.

Edited May 6, 2013 by RebekahsZ

[geno51]

5.3 single turbo, 14psi ,cam & springs, z06 intake, E85 good tune,  Slicks = Game over 

 

I plan on doing a similar setup in my Z but going 6 speed cause I love rowing the gears too much

 

My buddy parish/jim and the guys from Omaha put this together years ago to be on pinks but it never happened. It was the fastest at the time of the video not anymore though  

 

Speaking of witch SunnyZ tell kyle I said hi,, And nice job smoking his Z06

Edited May 6, 2013 by geno51

[mattd428]

Port the 5.3 heads yourself mill them down go with a big nasty cam with springs and push rods ls6 intake and call it good.

[zgeezer]

What chassis you putting this in?  You better strip it, that means no interior at all, a lawnmower battery, dump the swaybars, light weight driver seat only, quit drinking beer and eat salads, 5 gallon fuel cell; cut everything out that you can.  Put helium in the tires.  Sub-11s isn't as easy as it looks.

1970 240Z, lightest of the light,  with additional weight from R200 and associated improvements.  Current LM7 in chassis courtesy of JCI in Texas.  I'm guessing around 25-2600 without stripping anything other than the spare tire and jack.

[zgeezer]

Port the 5.3 heads yourself mill them down go with a big nasty cam with springs and push rods ls6 intake and call it good.

Or the ls3 rectangular port heads, matching intake, small cam, and good long tubes is reputed to do the job also.  A common recommendation are stage 2.5 TEA modified 5.3 heads also. 

 

G

[mattd428]

Or the ls3 rectangular port heads, matching intake, small cam, and good long tubes is reputed to do the job also.  A common recommendation are stage 2.5 TEA modified 5.3 heads also. 

 

G

ls3 heads will hurt a 5.3 way too big.

[The Infidel]

What year was the 5.3? At one point GM went to flat tops in both the 4.8 and the 5.3, if you dont have the year of the block you can check the crank part number. You might have the LM7 H/O.

 

Stay away from 706 heads, some of the early ones have a bad casting that cause them to crack and leak coolant.

 

317s are comparable to 243/799s but with lower cr. If you mill 243s past .030 you need your intake milled to match, any competent shop can do that. I do not know what cr an lq4 and 243s make off the top of my head, but if you have access to a large wrecking yard sell off your lq4 and pick up an lq9. Same displacement but with flat top pistons.