LSX Carburetion manifold

[emeraldlion]

Anyone know if the carb conversion will fit under the stock hood. I was hoping it would but I'm starting to believe it won't fit.

[MAG58]

It works

 

Here in fact is an LS carbie in an S30 with no hood bulge.

[emeraldlion]

Beautiful. Thank you, not sure how I missed that one

[MAG58]

It was in the for sale section, I just remembered it was there

[Cable]

Change your mind already about using the factory EFI?

[FlatBlack]

It works

 

Here in fact is an LS carbie in an S30 with no hood bulge.

 

Nooooo!! Not a carb-er-ett-or!! It has coil packs!!

Edited June 19, 2010 by flatblack280

[emeraldlion]

Not entirely cable. Weighing my options? In the long run I think they will both come out costing similarly. The fuel injection is extremely tempting so I'm a little torn at the moment. I have a friend that asked me if I wanted his demon 850 last night for a near steal and it got my gears turning again. If anyone wants try and talk me out of it I'm game.

[Cable]

I have a friend that asked me if I wanted his demon 850 last night for a near steal and it got my gears turning again. If anyone wants try and talk me out of it I'm game.

 

That's easy, an 850 Demon (or 850 anything) is too big even for a cammed 6.0 spinning to 7000 RPM. Plus, you can forget about any type of mileage with any type of race or even mechanical secondary (aka double-pumper) style carb.

 

Another thing I forgot to mention about the nicer things about LSx EFI besides MPG:

 

-Instant starts, regardless of outside ambient temp (freezing or hot) or engine temp

-Instant throttle response, no lag after cam (most) swaps

-No washing the cylinders down with raw fuel like carbs tend to, especially when overly rich

-No fuel in your oil (see above)

-PCM can self adjust/adapt to altitude and air density changes for optimum power and efficiency

-Easier to adapt for nitrous, turbocharger(s), and/or supercharger (if desired)

 

What transmission were you planning on running btw?

[emeraldlion]

700r4. Well, some extremely good points. Didn't think the 850 would be too too big. In defense I'm not too concerned with instant starts or bad mpg as this is a fun car. With that said the mileage is obviously a HUGE difference with efi and is something that is difficult to ignore. As far as lag after cam I haven't thought of this but with the 240 I owned it had a 4 barrel and pretty radical cam and didn't really mind it much. The 240 was a 2.8 with mild head work that got 12 mpg and I loved it. The raw fuel in oil I wasn't aware of. Didn't even know this occured.

[zdlite]

I fit a mechanical secondary Holley 750 DP and GMPP intake under the stock hood of my 240. I made my own mounts so I was able to get the engine pretty far back and low. Most people think that is a good thing.

 

I have pretty good hood clearance with a full size Moroso drop base air cleaner with a 3 inch element. I did move the stock hood latch since the air cleaner base gets within an inch or so of the firewall.

 

Don’t believe all the smack about carbs. This isn’t the 1970’s anymore. Tune the carb with a wideband O2 and you will have good mileage and excellent throttle response. You have to adjust air bleeds to get the most out of a carb on an LS motor, especially with the open plenum manifolds that come with these motors. Once you get the carb set up right the these cars are amazing.

 

Most people set carbs up too rich to cover up other problems. That is where the poor mileage gripe comes from. Go the Innovate site forums or the conversion section at LS1tech to get some good info about carbs. I drilled out all the press in bleeds and idle feed restrictors and replaced them with brass set screws that I hand drill to whatever size I want. Lots of info on the Innovate site about doing that. I can set the cruise AFR pretty much anywhere I want it. That is the key to good mileage.

 

The part about carbs doing a poor job of metering fuel when cold is absolutely true. EFI is one of the big reasons modern motors live longer than the old carb days. But if you are like me and the car only sees a few thousand miles a year of summer time driving then cold starts are a huge don’t care. Besides, motor oils are so much better than they were even a couple of decades ago. If you change it at least yearly (Mobil 1 says every 6 months) and don’t neglect your engine like an old station wagon then IMO it isn’t the same worry it use to be.

 

One last thing, carbs should be sized base on airflow (i.e. HP), not displacement. Thus the old first gen rules really don’t apply to the better breathing LS motors. Most guys go with a 750 on the 6.0/5.7 motors. GM recommends a 750 for their LS2 crate motors. That 850 would work well with a 402 stroker motor. Also IMO mechanical secondary is the way to go on Zed. These cars are light, don’t give up on the top end HP.

Edited June 19, 2010 by zdlite

[Cable]

700r4.

 

What year? I ask because if it a newer '93+ (4L60e) you'll need some type of computer to run the trans. If its an earlier, non-electronic version, then you are good with either carb or EFI as long as you are running a throttle cable style throttle body. The drive by wire (DBW) throttle body won't work with non-electronic automatic overdrive transmissions due to the lack of throttle linkage for the TV cable.

[emeraldlion]

Right. It'll be a non-computer controlled 700r4 which should be fine. I figured if I did go witht he carb setup and I wanted efi I could later go with something like fast ez efi system. I would be retaining my returnless system so I should by able to switch without too much work. I know it wouldn't be as good as individual injectors but would retain the carb look( which I'm really fond of). I would also be able to use all the truck accessories this way(with exception of changing alt. mounting).

[Cable]

I figured if I did go witht he carb setup and I wanted efi I could later go with something like fast ez efi system. I would be retaining my returnless system so I should by able to switch without too much work. I know it wouldn't be as good as individual injectors but would retain the carb look( which I'm really fond of).

 

If you are interested, I have a Holley Commander 700cfm TBI setup, brand new in the box.

 

I would also be able to use all the truck accessories this way(with exception of changing alt. mounting).

 

 

If you have found a alternator bracket setup that will lower the alternator mounting to allow use with a stock hood, won't run into the strut tower and will retain the rest of the truck accessories (water pump, crank pulley, tensioner, idler) I am very interested in hearing about it.

[emeraldlion]

I haven't yet but will be giving it a look if that's a challenge. Sounds to me that you're saying it's not possible in a manner to make it worth it, in which case I probably won't.

[Cable]

I haven't yet but will be giving it a look if that's a challenge. Sounds to me that you're saying it's not possible in a manner to make it worth it, in which case I probably won't.

 

Not at all, I was being serious. I would love to be able to use a stock hood without having to change my whole accessory drive out.

[emeraldlion]

Well, although I'm no engineer I've gotten creative a few times so if I am able to figure it out I'll definitely post it up for everyone. That is, of course, assuming I end up carbureted and not fuel injected. Like I said I'm not entirely decided yet. I've got some time still.

[phocion]

It works

 

Here in fact is an LS carbie in an S30 with no hood bulge.

 

Not to quibble, but I bought that car, and the hood does not clear the air filter. I am guessing that pic was taken sans carb. I am not saying it is impossible for a carbed LS series to fit under the stock hood, but that particular one does not.

 

I am currently looking at hood options, with my front-runner being a recreation of the Datsun sport cowl.

[emeraldlion]

Wow. Thanks phocion. That's pretty shady. I was wondering what was going on, because the belt wasn't tightened up and the alternator didn't look like it would clear even if the filter did. There ya go cable, fuel injection it is. I really want to retain my stock hood and don't want to fab my own mounts.

[phocion]

Wow. Thanks phocion. That's pretty shady. I was wondering what was going on, because the belt wasn't tightened up and the alternator didn't look like it would clear even if the filter did. There ya go cable, fuel injection it is. I really want to retain my stock hood and don't want to fab my own mounts.

 

Not really shady, I checked it out before I laid down cash and knew it would not fit without serious rubbing. Alternator also impacts the hood, so I have been debating lowering it with a bracket or using a wider recreation of the datsun sport cowl to lump over it and leave it stock. I guess different people have different versions of what "fits" under a hood. My version of fit requires clearance to avoid any contact, even under stress, so this carbed engine does not "fit" under a stock hood. If I had it to do over again, I would probably wait for a FI v-8 conversion, because I have rebuilt the carb, and I am still fighting with the damn thing to run consistently. On the other hand, it is my first carbed engine and has been a good learning experience, so I consider it a wash.

 

edit: here is the alternator bracket I am looking at. I think that it will fit under the hood, but I want to mock one up to be sure before I order: http://www.kwikperf.com/lsx_alt_only.html

Edited June 20, 2010 by phocion

[emeraldlion]

When referring to shady I meant taking pictures of the car with the hood closed then pictures with the carb and aircleaner on. That's slightly misrepresenting in the ad. That's why we don't buy until we see the car in person though I suppose. I would search on that kwik bracket. I think I was reading in a thread that it hits the strut tower ( I could be wrong though I've been reading a lot lately and it's starting to get jumbled).