FLYNAVY30

I apologize if this is a dumb question, but Im new to the C3 side of the house. I was just hoping someone could give me a run down as to the mechanical differences between the LT1 and the L46.

Thanks

Mashman

Basically, an engine is a air pump, to get more power, you need to move more air. The big block cars move more air because they have larger cylinders. So at the same RPM as the base engine, the big block will move more air. The LT1 moves more air by being able to run higher RPMs. The engine is designed to allow the motor to run higher RPM.

F4Gary

Solid lifters, 6500 rpm redline, aluminum intake, huge (780 cfm) Holley carb. Basically, an LT-1 is the 350 ci version of the Z-28.

Barry's70LT1

Some more of the details of LT-1 over base 350..
- Larger Valves
- Push Rod Guide Plates
- Screw in Rocker Posts
- Forged TRW Pistons (11:1 domed)
- Shot Peened / Magafluxed (pink) Connecting Rods
- Forged Steel Crank
- Electronic Ignition (Transistor)

FLYNAVY30

I apologize, should have been more specific....LT-1 vs. L46. I know both had 11:1 comp, just curious as to what the other differences are

Alan 71

Hi FN30,
When you read the lists that people have posted.... carb, intake, cam, lifters, a person might begin to wonder if the 70 LT-! might have been a little-under rated at 370HP compared to the L46's 350hp.
Really QUITE different engines. And, oh the noises a 70 LT-! makes!
Regards,
Alan

LT-1 kid

I kinda think the 70 LT-1 is a little over rated, the L-46 had more low end power, LT-1 had more power at high rpms, only diff in the 2 was the LT-1 has an alumminum high rise intake, sold lifters,bigger duel feed carb, and TI, thats it, the L-46 could be order with the TI.

joewill

First, the standard 350, is not the L46, so not sure exactly what you are asking. The HP ratings for standard engine was 300 HP, the L46 was 350 and LT1 was 370 HP. Cam specs, Heads, intake, Valve sizes, carb ( Holley or Rochester), Main journal bolts, LT1 had solid lifters, allowing higher RPMs before valve float.

All had similar peak torque, but the torque curve would be longer and higher up in the RPM band for the higher HP engines. The base engine would pin you to the seat just like the LT1, but the LT1 would pin you to the seat thruout a longer rpm range.

Barry's70LT1

The L-46 (350/350) did not have screw in rocker studs or push rod guide plates.
The L-46 also had a forged steel crank, however I don't believe it had the tufftride heat treatment on the journals.

There was not a great deal of difference in performance between the L-46 and the LT-1 up to 6K rpm, however the LT-1 could go beyond that, as mentioned, then it would out perform the L-46 by a fair margin.

F4Gary

My '72 does not have push rod guide plates or an electronic ignition.

MotorHead

You can knock 70 or more hp off the Lt-1 it was rated at Gross hp

Mike Ward

So were all other engines of the same era.

F4Gary

Not in 72. 255hp (underrated to boot).

7t9l82

omg! although there were subtle differences in the heads , the intake on the LT-1 was better and it had a solid lifter cam. they were very close to the same engine. the 350/350 was really a better street engine. some knowledgeable chevy guys said there was more power difference in the intake than the cam, on the street. both were excellent performers. whoever cam up with changing horsepower ratings didn't help anyone.

bugzbunny

Sorry but that's wrong. My L-46 1969 has pink connecting rods, 11.1 domed pistons. Forged steel crank.

Barry's70LT1

Sorry to contradict your contradiction, the original poster stated the differences between a LT-1 and a "std 350" . Your L-46 is not a std 350. In my response, I stated "LT-1 vs "Base/std" 350.

Yes, you are correct, the L46 (non std 350) does have the items you listed.

ignatz

I'm curious as to whether the LT-1 aluminum-rise was the same as the Z28's? I bought one from the local Chevy dealer and had it on my L46 for the longest time.

stingr69

Thread is almost 5 years old.

jackson

L46 was an option … base motor was 300 hp L48


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jpatrick62

I've looked at the acceleration times recorded back in the day and the L46 was actually faster than the LT-1 up to 70 - 80 mph. In the 1/4 mile the LT-1 was about 1.5 tenths of a seconds faster.