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Carb'd LS2 - 240Z on the way!


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Might have lost my mind, but finally got off the fence and started ordering parts. Lots of very expensive parts. The big parts are as follows:

 

LS2 364/440 crate motor. 440 HP with a single plane carb intake

LS7 clutch and flywheel

 

TKO600 5 speed, GM street strip version, 0.64 OD fifth

Keisler engineering LS style bell housing

Keisler’s hydraulic throw out bearing

 

JTR radiator and ceramic coated headers

 

Mallory Comp 110 fuel pump and return style regulator. Will use ½†feed and return lines.

 

Carb is TBD, but most likely Holley 750 DP with mechanical secondaries and manual choke.

 

VISA is impressed.

 

All going into my 1970 240. Due to the TKO being shorter than a T56 will pattern mounts after Mark Ickard’s write up. This should give me some flexibility positioning the shifter.

 

Got to use my neighbor the car salesman’s employee discount for the engine, clutch and flywheel. Just under $6k for the trio.

 

The crate LS2 looks like it is 6.0L LS2 with a different induction system. That being said, the torque curve is a good 20-30 ft-lb higher than the FI motor at all RPM’s. Plus the torque curve doesn’t fall off as the engine approaches red line. The HP curve is still climbing at 6500 RPM.

 

Any suggestions on carb choice and jetting will be appreciated. Going to be a summer's only car.

 

I am stoked. Going to be a busy summer. This set up will allow me to use the stock tank and all the stock gauges (except maybe tach). Should be the ultimate sleeper. And no HP tuner or laptops needed (get enough of that at work).

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Pop N Wood,

 

Congratulations !!! A few folks have negative comments about carbed LSX motors, but I like IT !!! I picked a GMPP catalog and saw that combo and it caught my eye. Also, I have been reading your thread about a LSX/TKO combo- I am trying to find my Hot-Rod or HotRodding Magazine, but there is a 69 Camaro utilizing MCcleod parts to make it work. I was reading on LS1tech several months ago, and a I guy in Great Britain is in process of a LS1/TKO swap ( I can not remember the car he was working on) but he also referenced MCcleod providing the parts to make the combo work. Please keep us posted, again great motor and Congrats.

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Thanks

 

If I had bought a used engine with a working FI I never would have considered pulling it off for a carb. FI is definitely better in most respects. As for complexity, being an electrical engineer who designs and builds programmable radars I think I could have learned how to program the FI more easily than what I am going to have to learn to set up this beast. Can anyone recommend any good carb power tuning books?

 

But with a crate motor the carb makes a lot of sense. When starting from nothing the FI adds a lot of cost. Plus I don't have any smog restrictions. Little worried about mileage but probably not enough to keep my foot out of it.

 

This set up is a little more true to the original car. I even plan to reuse the stock choke cable and lever. I mean compare the picture of PrOxLaMuS© engine bay sans engine with my 240 after pulling the motor

 

11216263186.jpg

 

empty_bay.jpg

 

The 240 had less than a dozen wires going to the entire engine, and that is only because the mechanical voltage regular is mounted on the fender. I don't mind losing the distributor though. The spark box can be programmed with plug in modules or via a serial port, so there is some "high tech" potential involved there.

 

I should scan and post the torque curves from the GM performance parts catalog of the carbed motor compared to the FI LS2 and even the LS6 crate motors. All three have the exact same cam specs and I believe heads, but the carbed version is out pulling the FI variants at all RPM's plotted. This (currently) is one of the more powerful small block crate motors GM sells.

 

I just ordered everything over the last few days, so will take pics as the stuff comes in. With two relatively young kids, a house and full time job this swap is going to progress in bits and pieces. Will probably spend a good portion of the football season watching games, and fabricating. Of course my good friend Jim Beam will be there to help me :)

 

80496 Holley huh? really think this 6 liter can make use of 950 CFM? I might cam it in the future, but still seems like a lot of carb. Plus I am a little nervous putting a carb with no choke at all on a street car. How well does something like that start in say 40 degree weather? Would like to get 6-8 months a year use out of this thing.

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I talked to a Corvette buddy today (carbed LS1/4L60 E in a 94 Camaro), Don is utilizing a Barry Grant 850 Demon Carburetor. His drivetrain came out of a 2000 Camaro- and he did the cam and different valve springs. He is still playing with different MSD modules, and right now he says it is running lean and trying to figure out the primary and secondary settings.

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"80496 Holley huh? really think this 6 liter can make use of 950 CFM? I might cam it in the future, but still seems like a lot of carb. Plus I am a little nervous putting a carb with no choke at all on a street car. How well does something like that start in say 40 degree weather?"

 

It doesn't flow 950, Don't worry about a cold start, give it a couple of pumps and it will light off.

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That TKO trans wont shifter very well over 6000 rpm. They shift fairly slow and dont do so well. The T56 is a better choice if your going to be shifting at higher RPMS.

 

Justin

 

Yeah, I've heard that. But they also claim to have redesigned everything in 2004 including the shift forks and shifter.

 

Time will tell I guess.

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Congrats! I can relate with ya, Im have a LSX sitting in my 240Z as we speak and will probably be scrapping the EFI for a carb, or at least run a edelbrock victor jr carb'd intake with a 90 degree elbow and 90mm tb. My car is more drag oriented as it has a powerglide with a 4k stall and will have a 4 link with 325/60/15 drag radial out back. Im working on the rear now, along with some rust repair though so that part can still change at any time. Good luck with it!!

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