Carbureted motor instead of LT1?
 

Hello everyone, names David been a Camaro owner since my very first car. I'm 25 and very well mechanically inclined.

I have a 1994 Z that Ive owned since around 2004. Was my daily driver for about 3 years till I decided to push the worn out original motor to her limit!

Long story short that was her last run. I pulled the motor and tranny out shortly after. I rebuilt the 4l60 and then life happened and never got to finish my new motor build. Fast forward almost 7 years and I'm ready to do something... Evidently my storage spot was not rodent free and therefore my wiring harness under the hood is all tore up(injector wires, misc Sensors etc) amongst a few other hassles.

Well to my actual question!!!

I was thinking about doing a carb engine set up in the car. Obviously I would have to follow that with a new transmission. Has anyone ever done or herd anything about this type of project before? Is it not cost effective or maybe to much custom fab work?

Will it even fit under the hood with a carb????

Any comments or opinions would be greatly appreciated!! Happy holidays everyone!!

Re: Carbureted motor instead of LT1?
 

Yes it has been done and it will fit, but there is not a lot of room for the air filter and the distributor will be really tight under the cowl and hard to get at or r&r. You have your accessory drives to think about, too. As much work as that all is and add the expense of doing it, I would just fix what you have, but that's up to you, of course. It is possible to get a stand alone controller for your transmission, so you aren't necessarily stuck with buying a new one. You would just have to look into what exact inputs it needs from the engine. Or you might be able to convert it to a manual valve body. You have a few choices there. And I'm not sure how well a 4L60E will work after sitting for 7 years in storage.

Re: Carbureted motor instead of LT1?
 

Thanks for your input Kevin..

Just a thought I had seeing as its not something that (from what I have seen) has been done many times before!

The 4L60E has about 150 miles on the rebuild and when I pulled the pan a few days ago and looked flawless and the fluid was great(LOOKING AND SMELLING) at least. Now looks CAN be deceiving... Any tips on what to look for on seeing if the tranny is still OK without actually tearing into it..

Re: Carbureted motor instead of LT1?
 

Part of the problem with long term storage of an automatic is the multiple clutch plates and seals internally that hold the hydraulic pressure. If they all sit too long, they are likely to compress and possibly the clutches could slip or the seals and pistons could leak pressure. A good transmission guy could give you more exact advice on this, but it is not like storing a manual tranny or an engine where it is just external seals and leaks drying up that you would be worried about. Some guys fill the transmission up all the way (overfill to the vent) to keep everything covered in fluid for long term storage. There might possibly be some additives that can rejuvenate the seals, but I don't have much experience with those - and they are usually bandaids. Again, that might be something a tranny guy would know. Otherwise, I'd say in your situation, just try it out and see what happens.

Re: Carbureted motor instead of LT1?
 

I have a crate motor lt4 in a 68 rs/ss with bowtie intake it is carbed and has a 400 auto behind it

Re: Carbureted motor instead of LT1?
 

What all did you have to do to make the conversion to carbed? Ive thought a lot about the LT4 set up and I think its got a ton of potential.

Re: Carbureted motor instead of LT1?
 

Don't complicate things. The only real advantage with the LT4 is heads that flow 15% better than the LT1 heads. You can have the LT1 heads ported to support up to 500HP at the flywheel.

A single plane intake, converted to the LT1 bolt pattern will cause less headroom problems than the factory LT1/LT4 dual plane carb intake. You will need a conventional distributor (pancake type minimizes cowl/wiper linkage problems). GM made a blockoff plate for the Optispark cavity.

You will need to go to a low pressure (8-10psi) fuel system.

You will need to find a way to drive the tach and the speedometer (normally driven from the PCM). Then eliminate the VATS system. Oil pressure, coolant temp, volt meter and fuel level gauge will be driven by stock sensors.

Re: Carbureted motor instead of LT1?
 

GMPP makes a LT1 carb intake, Opti block off plate (also has timing tab on it)

Iam doing a LT1 carb motor for my 70 Nova.

I don't know what clearance probs you may have re distributor and or carb. you could always run a cowel hood. 4l60E can be vac mod adapted. I am running a T56 behind mine in the Nova

Re: Carbureted motor instead of LT1?
 

For what you're going to spend for an intake, carburetor and a new regulator you could pretty easily afford a new wiring harness and stick with the fuel injection. Just a thought.

Re: Carbureted motor instead of LT1?
 

nothing crazy bolted right up

Re: Carbureted motor instead of LT1?
 

nothing crazy bolted right up .. this was one of the last scoggin dickie lt4's

Re: Carbureted motor instead of LT1?
 

Overall do you think doing that versus keeping the PCM and fuel injected setup would be 1. Cost effective 2. Result in potential higher power gains?

Keep in mind if I were to go Fuel injected I would have to replace the harness (at least the under the hood part, Engine sensors, injector wires etc...) along with going through the entire motor inside and out again...

Re: Carbureted motor instead of LT1?
 

Alright then... I might just have to stick with the injected system.

Im sure the worst part of that would be the tedious part of separating and running the harness again.... UGH all those bright colors don't help for someone with ADHD... ill get so distracted...HAHA

Re: Carbureted motor instead of LT1?
 

There is no significant difference in the power potential between the carb and the EFI, if both are set up right. But there is going to be a large difference in fuel economy. In my opinion EFI is a lot easier to tune and keep tuned. My early cars - 56 Chevy 265, 63 Impala 327, 66 GTO 389 Tri-Power, 73 Grand Prix SJ 455, were all carbed, and all got 10 MPG. And I hated working on the carbs.

Not clear why you would have to "go through the entire motor" if you kept it EFI, but no if you install a carb. Or do you mean you are looking at some other engine than your present LT1? Most of the responses above seem to have assumed you were going to carb the LT1.

Why would you need to replace the sensors? The injector wires are part of the engine harness.

Rob/Shoebox has a great photo of the LT1 harness:

1995 Z28 A4 Engine Harness

Re: Carbureted motor instead of LT1?
 

I know people who swear by carbs ... look how many efi systems were taken off mustangs for carbs .... Myself I love efi. I chose a carb on the lt4 for the look