Difference between LT1 and std 350?
Thread Starter
Le Mans Master
Joined: Sep 2002
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From: Redacted
Difference between LT1 and std 350?
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
Thanks
Last edited by FLYNAVY30; Jan 30, 2014 at 02:42 AM.
Melting Slicks
Joined: Mar 2008
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From: Austin Tx
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.
Race Director
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From: Grapevine Tx
2018 C3 of Year Finalist
2016 C3 of the Year Finalist
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.
Melting Slicks
Joined: Oct 2001
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From: Halifax, Nova Scotia, Canada
- 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)
Thread Starter
Le Mans Master
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From: Redacted
Team Owner
Joined: Sep 2006
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From: Westminster Maryland
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
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
Melting Slicks
Joined: Sep 2007
Posts: 2,147
Likes: 284
From: cary Il
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
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
Safety Car
Joined: Sep 2007
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From: Indy Indiana
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.
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.
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Melting Slicks
Joined: Oct 2001
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From: Halifax, Nova Scotia, Canada
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.
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.
Last edited by Barry's70LT1; Jan 30, 2014 at 03:05 PM.
Race Director
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From: Grapevine Tx
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My '72 does not have push rod guide plates or an electronic ignition.
Race Director
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From: Grapevine Tx
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Le Mans Master
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From: melbourne florida
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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. 
Instructor
Joined: Apr 2010
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From: Gilbert Arizona
Sorry but that's wrong. My L-46 1969 has pink connecting rods, 11.1 domed pistons. Forged steel crank.
Melting Slicks
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From: Halifax, Nova Scotia, Canada
Yes, you are correct, the L46 (non std 350) does have the items you listed.
Le Mans Master
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From: Unreconstructed, South Carolina
L46 was an option … base motor was 300 hp L48
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Last edited by jackson; Feb 16, 2019 at 10:37 PM.
Burning Brakes
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From: Maryland
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.