[C2] Which clutch.
Melting Slicks
Joined: Sep 2016
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From: Wauconda IL
Melting Slicks
Joined: Apr 2013
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From: McCloud CA
C2 of Year Finalist (appearance mods) 2019
Pro
Joined: Dec 2023
Posts: 662
Likes: 202
From: Katy,TX
Did it come with a flywheel? If not be sure to get the correct one as most of their 383s use the Vortec SB external balance flywheels or Flexplates. Get SFI flywheel and clutches! Better to prevent a blowup with good parts than use a "scattersheild" and crappy parts.
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Le Mans Master
Joined: Nov 2015
Posts: 7,479
Likes: 2,650
From: Really Central IL Illinois
If you are not racing it and dumping the clutch with slicks on it, your 10-3/8" clutch will live longer than the rear tires. The tire width is the weak point in the drivetrain and will go up in smoke before the clutch does. If it ain't broke, don't fix it, send me the money to fix my broke.
Thread Starter
Burning Brakes
Joined: Dec 2017
Posts: 947
Likes: 250
From: Deshler Nebraska
I was counting on the tires being the weakest link and preventing the braking of drive line parts.
We know the 427 came with the 10.5 inch clutch from the factory. The only question is the material the clutch was made from on GM clutch and what my NAPA clutch is made out of.
We know the 427 came with the 10.5 inch clutch from the factory. The only question is the material the clutch was made from on GM clutch and what my NAPA clutch is made out of.
Le Mans Master
Joined: Nov 2015
Posts: 7,479
Likes: 2,650
From: Really Central IL Illinois
I know nothing about special clutches for the Blueprint engines. Without some identification of the NAPA clutch you have now, there is not a good way to determine reliability.
There are a few different street clutches of the original GM diaphragm pressure plate design. The facings on the disc can be organic, semi-metallic, ceramic, etc. The harder the facing, the longer life of the disc but greater wear on the flywheel and pressure plate.
If you have the part number of the NAPA clutch, you can identify the facing. I don't believe GM would have spent additional money to put anything other than an organic faced clutch in at the factory, but I have no idea what was actually used.
There are other factors with clutch wear, pressure plate force, differential gearing, tire grip, driving habits. If you have it apart, you can evaluate the conditions you subject the drivetrain to and chose the most compatible clutch assembly. If it is not apart and not broken, I would recommend you DRIVE IT.
There are a few different street clutches of the original GM diaphragm pressure plate design. The facings on the disc can be organic, semi-metallic, ceramic, etc. The harder the facing, the longer life of the disc but greater wear on the flywheel and pressure plate.
If you have the part number of the NAPA clutch, you can identify the facing. I don't believe GM would have spent additional money to put anything other than an organic faced clutch in at the factory, but I have no idea what was actually used.
There are other factors with clutch wear, pressure plate force, differential gearing, tire grip, driving habits. If you have it apart, you can evaluate the conditions you subject the drivetrain to and chose the most compatible clutch assembly. If it is not apart and not broken, I would recommend you DRIVE IT.
Thread Starter
Burning Brakes
Joined: Dec 2017
Posts: 947
Likes: 250
From: Deshler Nebraska
Napa NCF 1104021 is the part #. They don't give a hp or torq rating on their web site.
Org. car came with a stuck clutch. I had the p.p. resurfaced. Current 327 motor is tired. Replacing it with a Blueprint 383/ 426 hp/ 440 torq. Not into doing fast starts, like smoking the tires. I do like acceleration, like most Corvette owners. I esp.like acceleration when I need to pass or in 2nd gear on up.
I bought the above clutch with the hopes that it would be used with the 327. Knew or expected the hp/torq from the 327 would not be a problem with this NAPA clutch.
So with doing a motor change I was/am questioning if this is the correct clutch for my situation/driving ways.
Org. car came with a stuck clutch. I had the p.p. resurfaced. Current 327 motor is tired. Replacing it with a Blueprint 383/ 426 hp/ 440 torq. Not into doing fast starts, like smoking the tires. I do like acceleration, like most Corvette owners. I esp.like acceleration when I need to pass or in 2nd gear on up.
I bought the above clutch with the hopes that it would be used with the 327. Knew or expected the hp/torq from the 327 would not be a problem with this NAPA clutch.
So with doing a motor change I was/am questioning if this is the correct clutch for my situation/driving ways.
Le Mans Master
Joined: Apr 2001
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From: Sarver Pa
2021 C1 of the Year Finalist - Modified
1st and 2nd gear is relativly easy on the clutch unless you have big sticky tires. It's 4th gear that put the most stress on the clutch under heavy acceleration. It's all about gear multiplication, 4th is 1 to 1..
1967 Pedal Car Champion
Joined: Mar 2020
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From: US-PNW
Team Owner
Joined: Sep 2002
Posts: 38,369
Likes: 2,085
From: California
Ya right, we bet you will beat on it!
10.5 dual friction picking from the Centerforce catalog can be tricky, as they like to just list modern applications on their higher end unit. Their regular clutch will be what they suggest for our cars. Ugh! We prototyped their first Corvette Dual Friction clutch in my Dad's Corvette many Moons ago!
10.5 dual friction picking from the Centerforce catalog can be tricky, as they like to just list modern applications on their higher end unit. Their regular clutch will be what they suggest for our cars. Ugh! We prototyped their first Corvette Dual Friction clutch in my Dad's Corvette many Moons ago!