LT1 with 4-barrel--why not?

[Guest 240SBB]

OK, after checking out some of the itemized lists on this board on what it takes to put a fuel-injected LT1 into a Datsun Z (in terms of money and time), I'm wondering why more carbureted LT1s aren't being pursued. I'm not talking about the old LT-1s of the 70's, but putting an Edelbrock manifold and 4-barrel carburetor on a late-model LT1. Doesn't Edlebrock make a manifold for this purpose? Anyone have any experience with this kind of setup in any car? I've owned a 1996 Z-28 and loved the LT1's power characteristics. How much would and how would the performance of an LT1 be affected by not using a computer to run the show? I've heard or read somewhere that the LT1 will accept a traditional distributer and that the Edelbrock manifold referred to above is designed accordingly?

[Guest BigE]

You can do it. I've seen it a few times. One local guy has a 94 Camaro with a carbed LT1 and some massive Dart heads. I think the reason you don't see more of it is because it's only advantageous for a pure race car. The LT1 is pretty powerful and with a few tricks can be made extremely powerful. But to go carb, you have not only pull the intake, but also you have to "detach" the computer. If you simply unhook it, you'll get that nice little SES light. Also, it tends to go nuts if you try and use the 4L60E automatic that came with it. Being that this is a hybrid project, I would say that if you just got a long block LT1 and a non computer controlled tranny, you'd be set. But then again, if you were going to do that, you could have just gone with a traditional SBC 350 which is cheaper. I guess there's just not a good reason to go carb LT1. The few people I know personally that have done/are doing it say it's because they hate dealing with the computer. I guess that's their perogative, but I'll take a 10 second programming change over a 10 minute carb rejetting any day.

 

Just random thoughts. Hopefully, it made some sense.

[80LS1T]

Well I on the other hand havent really heard too much about people turning the EFI LT1 into a Carbed LT1. I have heard of people who change out the OPTISPARK distributor for a regular HEI distributor.

 

The big thing with the LT1 is that it has a low profile intake, its EFI and you dont have to move the hood latch because the distributor is up in the front on the timing chain cover. If your just going to carb it then you have just taken away all the positives of the LT1. Yeah it has alluminum heads but you can get those for a regular SBC and save your self some trouble trying to convert a EFI to Carbed.

 

I say if you like the carburator then get a regular SBC and get some good flowing alluminum heads with a good intake and be done with it. Much easier and much cheaper!

 

 

Guy

[zgeezer]

If you really want to carb an LT1 on the cheap using SBC pieces "in the garage" Then you might want to consider this. 1. Chevrolet sold an LT1 package with a carb rated by GM @, as I recall, 375HP. That manifold is available, but pricey. GM performance catalogue listed, last year, a block off plate to replace the OPTISPARK. A standard issue aluminum aftermarket intake manifold should match four bolts on the LT1 heads: the first and last bolt on each head. Redrill the manifold to match the LT1 heads, remove the quill holder inside the LT1 block (this piece locates the oil pump drive on the camshaft). Your SBC manifold will locate the distributor and, since the LT1's intake is dry, your SBC intake will have a large highly visible hole that used to mount a thermostat. Good for a real "What the Hell????" response when the hood is popped.

 

Save all the computer pieces b/c you'll probably end up using them at some time. Can't beat the computer,.... really.

 

g

[Mike C]

I have 2 LT1's, and enough parst to FI one of them. The other will get the GM Performance Parts 4 barrel intake which comes with the plugs needed for blocking off the optispark. You pull the oil pump drive stub and use a conventional distributor.

 

GM built 2 302ci LT1 cars (LT1 block and L99 crank) for the 30th anniversary of the Camaro. The FI version was put in a 97 camaro and the carb one in a 67 camaro made as a Z/28 replica (since only 602 were originally made, needless to say they are a bit pricey-even for the general.) The carbed version made about 40 horses more than the FI version. Actually, an iron head LT1 should make as much power as a 70 LT-1 with a better idle and less spark lead. In addition to better flow with smaller valves, you get flat tops instead of dome pistons for better flame travel and a hydraulic roller cam. RIght now there are two gen II sbc in the paper, an aluminum head LT1 for $750 and an LT4 for $1250. There is no way you can get the same power from a gen I motor for that price.

 

Long story short, the carb may not have the driveability of the FI in all weather and altitude, but it can make good power very affordably, with significantly less work. Ditch the entire serpentine setup and fab a low mount alternator setup using a short ribbed belt and you are good to go in a street/strip Z.

[Guest 240SBB]

Thanks for the insight, guys. I was just wondering if it would be worth it or not. I did own a 350 LT-1 block with 202 heads, aluminum intake, 750cfm, and headers on it with about 9.5 compression. It ran pretty good, but did not have the long torque curve like my 1996 LT1 had. Another thought I had was that I want a 6-speed tranny--just figured I'd pick up a wrecked F-body, pull the motor/tranny, save the FI for a rainy day, then sell what I could of the wrecked parts car. I figured this could probably be done cheaper than getting a crate motor and T-56 seperately, or whatever. Then again, maybe I should just wire up the dang FI to begin with.

[80LS1T]

If your that worried about the EFI then just buy a painless wiring kit from Street & Performance. The only down side to that is they are like $600+ ....yeah what a rip off!

 

 

Guy