flywheel or flexplate?
Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
flywheel or flexplate?
That may be a stupid question but I would like to know exactly what the difference between a flywheel and a flexplate is.
It is my understanding that a flexplate is used in combination with automatic transmission and a flywheel is used for a manual transmission. Is this correct?
Why are flywheels much more expensive than flexpates?
thanks
Olivier
It is my understanding that a flexplate is used in combination with automatic transmission and a flywheel is used for a manual transmission. Is this correct?
Why are flywheels much more expensive than flexpates?
thanks
Olivier
Pro
Joined: Jan 2002
Posts: 695
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From: Ashley Michigan
Re: flywheel or flexplate? (GrandSportC3)
My understanding was always that a flexplate is for an Automatic tranny, and a flywheel is for a Manual. But, when looking to buy people don't always use the same terminology, so be sure to check.
Le Mans Master
Joined: Nov 1999
Posts: 5,768
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From: San Diego CA
Re: flywheel or flexplate? (GrandSportC3)
Flywheels are for manual transmissions they're weight can vary greatly depending on the material - billet steel, cast iron, aluminum.
Flexplates are used exclusively for automatics and are generally a piece of stamped steel with a ring gear welded on.
Like all car parts quality varies widely.
Price is obvious, which is cheaper , a 35 pound slab of billet steel or a stampied piece of 10 gauge galvanneal with a ring gear weldedonto its curcumference.
Flexplates are used exclusively for automatics and are generally a piece of stamped steel with a ring gear welded on.
Like all car parts quality varies widely.
Price is obvious, which is cheaper , a 35 pound slab of billet steel or a stampied piece of 10 gauge galvanneal with a ring gear weldedonto its curcumference.
Thread Starter
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Re: flywheel or flexplate? (fauxrs)
>>Flywheels are for manual transmissions they're weight can vary greatly
>>depending on the material - billet steel, cast iron, aluminum.
>>Flexplates are used exclusively for automatics and are generally a piece of
>>stamped steel with a ring gear welded on.
>>
>>Like all car parts quality varies widely.
>>
>>Price is obvious, which is cheaper , a 35 pound slab of billet steel or a
>>stampied piece of 10 gauge galvanneal with a ring gear weldedonto its
>>curcumference.
Thanks for the information! However - I have one more question:
When I purchased a "external balanced" engine for my 69 (sold) I had to use another flexplate because the engine was a 383 instead of a 350.
Is this the same way for flywheels or can I use my current flywheel when purchasing a engine with a different size crank (externally balanced)?
Thanks
Olivier
>>depending on the material - billet steel, cast iron, aluminum.
>>Flexplates are used exclusively for automatics and are generally a piece of
>>stamped steel with a ring gear welded on.
>>
>>Like all car parts quality varies widely.
>>
>>Price is obvious, which is cheaper , a 35 pound slab of billet steel or a
>>stampied piece of 10 gauge galvanneal with a ring gear weldedonto its
>>curcumference.
Thanks for the information! However - I have one more question:
When I purchased a "external balanced" engine for my 69 (sold) I had to use another flexplate because the engine was a 383 instead of a 350.
Is this the same way for flywheels or can I use my current flywheel when purchasing a engine with a different size crank (externally balanced)?
Thanks
Olivier
Le Mans Master
Joined: Jul 1999
Posts: 9,206
Likes: 17
From: Sewell NJ
Re: flywheel or flexplate? (GrandSportC3)
350 engines are internally balanced ( 0 balance) while 383 engines are externally balanced (offset or out of balance). I'm not sure if I'm using the right terminology here but a 350 engine requires a flywheel or flexplate that is in perfect balance (0) while a 383 engine, due to the use of a 400 crankshaft must have a flywheel or flexplate that is offset balanced by a certain number of ounces. I believe the reason for this is because the larger pistons in a 400 engine would require crankshaft counterweights that are too big to be accomodated by the engine case. The flywheel or flexplate for a 383 or 400 engine typically has a weight welded to it to throw it out of balance the correct number of ounces. Like everything else there are exceptions to the rule. You can get a 383 or 400 assembly that is internally balanced through the use of heavy metal (Mallory metal) and then use a zero balance flywheel or flexplate. Flywheels and flexplates also come in different sizes and different tooth counts (153 vs 168) that require different starter nosepieces. This just keeps life interesting. :)
[Modified by vettfixr, 9:38 AM 5/1/2002]
[Modified by vettfixr, 9:38 AM 5/1/2002]
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Re: flywheel or flexplate? (GrandSportC3)
[QUOTE
When I purchased a "external balanced" engine for my 69 (sold) I had to use another flexplate because the engine was a 383 instead of a 350.
Is this the same way for flywheels or can I use my current flywheel when purchasing a engine with a different size crank (externally balanced)?
Thanks
Olivier
[/QUOTE]
On any externally balanced engine you will need the correct balancing device at either end of the crank - since your 383 is based on a 400 crank - externally balanced - you will need a harmonic balancer from a 400 and a flywheel or flexplate from a 400.
Internally balance motors use neutral balanced componants so a 350 flywheel/flexplate should NEVER be used on a 400 crank. Also know that the newer 350s, I dont remember where but starting perhaps with the LT1 in the c4 vette are also externally balanced.
When I purchased a "external balanced" engine for my 69 (sold) I had to use another flexplate because the engine was a 383 instead of a 350.
Is this the same way for flywheels or can I use my current flywheel when purchasing a engine with a different size crank (externally balanced)?
Thanks
Olivier
[/QUOTE]
On any externally balanced engine you will need the correct balancing device at either end of the crank - since your 383 is based on a 400 crank - externally balanced - you will need a harmonic balancer from a 400 and a flywheel or flexplate from a 400.
Internally balance motors use neutral balanced componants so a 350 flywheel/flexplate should NEVER be used on a 400 crank. Also know that the newer 350s, I dont remember where but starting perhaps with the LT1 in the c4 vette are also externally balanced.
