Carb'd LS3 fitment?

[Alex]

(for anybody who has their SLC sitting infront of them) Do you think a carb'd LS3 would fit, or does the angle of the glass and whatnot pretty much force you to go EFI? (i.e., air cleaner wouldn't fit). Too hard to tell from pictures.

 

[Dave]

It will fit.

 

[Howard Jones]

It will fit. I measured mine. I may need to build a custom air filter base to offset the filter forward but thats not a big deal. I did it on my GT40 and it works fine.

SBC V8, Tall single plane intake manifold, and 750 Holley DP is the plan.

 

[Alex]

Oooooh, this is sounding good - I'm too stupid to figure out EFI :laugh:

Btw, with a carb, how the heck do you run a throttle cable? I imagine it's got to be some type of weird S (or something) that starts in the front, goes forward then snakes backwards, down along the the rear of the frame, then back up to the throttle lever on the carb....but that seems like it would easily get hung up along the way?

 

[Alex]

It will fit. I measured mine. I may need to build a custom air filter base to offset the filter forward but thats not a big deal. I did it on my GT40 and it works fine.

SBC V8, Tall single plane intake manifold, and 750 Holley DP is the plan.

By fit in your measurements, are you using a 'proper' sized air filter, or a weiner? Kinda like how in a cobra a carb fits, but without a dropbase and a really large hoodscoop, most people (depending on engine selection) are limited to a weiner filter that's got to choke the carb (I was able to squeeze a 14x4 using a drop base and a really large/wide hood scoop)

 

[Jack]

Alex
Suggest running throttle cable from pedal area along the center "spine tube", the upper one. From there go directly thru the firewall alumimum to the front of the engine. Pic of Daytona Prototype if you e-mail me. [email protected]

 

[Alex]

e-mailed :thumbsup:

 

[Alex]

While we're talking about carb'd LS(x) motors, could anybody please explain to me how the ignition works in it?

What I mean by this is, on GM's site, I see continual reference to needing an LS(x) ignition controller. I look at the product and it has all sorts of stuff like MAF and 02 sensors included (so obviously not for carb)

If the entire engine is being built up from scratch from just a bare block (i.e., not even a short block as a starting point), can one have a system similar to a Ford 351w - i.e., you have an MSD distributor that the spark plug wires connect to, then the distributor is connected to an MSD ignition box (e.g., 6al-2), and MSD coil, and then the ignition box is connected to your electrical, like the I2 1+1 million relay system (or ISIS system)

 

[Jac Mac]

Crank trigger & MSD Digital DIS-4 with 4 coil packs should handle that.

 

[Crafty]

Why would you want a carb on an LS engine?

Most of the Ultima guys have nothing but trouble with carbs and many of them end up switching to EFI.

I have a supercharged LS2 in mine and once the tune is set up you dont need to touch it.


I suggest reading this book before making a decision. Amazon.com: How to Tune and Modify Engine Management Systems (Motorbooks Workshop) (9780760315828): Jeff Hartman: Books

Its not really that complicated at all.

 

[Alex]

Most of the Ultima guys have nothing but trouble with carbs and many of them end up switching to EFI.

I like its simplicity - it's relatively easy to trouble shoot and install, and is great for me. Remember, not all of us on here have a great automotive background - for some of us, changing brake pads is a huge achievement :laugh:

What type of problems were they having - once your carb has been tuned, I don't see the problem with it.

Yes, it is finicky at times, for example with my cobra I've learned

- If I don't put in 91 (i.e., get some bad gas) I've got to pump the tank out because the car will stall everytime I try to clutch in

- If I increase in elevation too much the car will stall when I clutch in for a light (big deal, I don't go anywhere, heh)

- If I give it a 'hard' run and keep the RPMs high for a while, when I come to a stop it tries to stumble for a second or two (big deal, I just blip the throttle beforehand and its happy)

- Engine takes a while to warm up. Above freezing temps, I usually have to stay on the gas pedal at 1500RPM for 2-3minutes before it can idle on its own. below freezing and I might be waiting 4-5minutes before it can idle on its own. (not a big deal once I learned that with no computer, I am the computer keeping the car alive until it can stay alive on its own)

- If I've been driving a while and stop for more than 5minutes, it usually takes a few seconds of my flooring the gas pedal and cranking it before it will come back to life (big deal)


So yea, i'm just curious what type of problems you guys were having - I know for some people, for example, not being able to just turn the key and go is a "problem". For me, eh, who cares, just sit and enjoy the scenario while you're keeping it alive for a few minutes. :laugh:

 

[Jack]

Alex, you'll need the items that Jac Mac indicated. Should not have a real heatsink problem with the LS engine. Folks around here do it all the time. I actually prefer the electronics which are simple enough to do. Shoot me an e-mail & I'll explain some
of the details..

jack...

 

[Kevin]

GM sells a complete CARB LS3 package

 

[Cam]

Alex, just had my injected ls376 crate delivered last week. It's a piece of Art.

The harness is so well marked my 6 year old was showing me how to plug it together. in fact i may turn over all slc building to him!

The ignition is sweet. 8 coils, 1 per cylinder. the plug wires are about 3" long. dunno about you but i get tired of throwing away 7 good plug wires to fix one missing cylinder.

Here is a carbed ls376. 19171225 - GMPP LS376 515HP LS3 Carbureted Crate Engine - 19171225

 

[Craig Gillingham]

cam is it a GM plug and play.

 

[Paul Osborn]

cam is it a GM plug and play.

Dude, you're talking like Yoda.