TR2/3/3A Alloy flywheel

S

Snowkilts

Jedi Hopeful

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• Oct 14, 2017

• #1

I've seen alloy steel flywheels for TRs being sold at a couple of places, including here: https://www.bpnorthwest.com/alloy-light-flywheel-tr2-tr3-tr4-tr4a.html

Similar weight and pricing as aluminum. Has anybody tried these? Any thoughts?

 

Last edited: Oct 14, 2017

K

karls59tr

Obi Wan

Bronze

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• Oct 14, 2017

• #2

While on the subject...how would a lightened flywheel affect driveability for everyday driving?

 

M

malbaby

Jedi Warrior

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• Oct 14, 2017

• #3

IMHO....I would keep to the original steel flywheel providing the ring gear is OK....alloy can be problematical.
I lightened mine down to about 22lbs if I remember correctly, together with a full balance of all rotating engine/clutch components.
Engine accelerator response is much better.

 

OP

S

Snowkilts

Jedi Hopeful

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• Oct 15, 2017

• #4

malbaby said:

alloy can be problematical

Click to expand...

How so?

 

TRMark

Jedi Knight

Bronze

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• Oct 15, 2017

• #5

Snowkilts said:

How so?

Click to expand...

Curious about that also. I have seen comments about problems with aluminum flywheels but not steel. How light is too light for street use.

 

M

malbaby

Jedi Warrior

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• Oct 15, 2017

• #6

Steel much stronger than alloy... clutch exerts a lot of pressure on the flywheel.

 

B

bobhustead

Senior Member

Gold

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• Oct 15, 2017

• #7

One of the things a flywheel provides is momentum (smooths thing out between the bangs). These cars don't want to idle smoothly in the first place. I say stick with steel.
Bob

 

OP

S

Snowkilts

Jedi Hopeful

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• Oct 15, 2017

• #8

malbaby said:

Steel much stronger than alloy... clutch exerts a lot of pressure on the flywheel.

Click to expand...

The part I'm asking about is an aftermarket alloy steel flywheel. As compared to aftermarket aluminum flywheel (with steel wear insert) which seems widely available, or the stock flywheel which I assume is cast iron.

 

D

davmar1960

Freshman Member

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• May 6, 2023

• #9

If you use the alloy flywheel does the clutch mating surface need to be scuffed ? It is very slick

 

Hamish Racing

Jedi Warrior

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• May 7, 2023

• #10

I have a lightweight steel flywheel. You can see it in this video at around 2:30+

I also have a hot cam. It’s still very drivable on the road. See here

It has a great acceleration pickup.

Lightweight Steel Flywheel Assembly TR2-4A, Morgan +4 etc - Triumph Special Tuning

Lightweight steel flywheel assembly 4 cyl TR engine applications. Improves throttle response enormously, without unduly affecting tick over. Approx 5.5kg Requires diaphragm clutch to be fitted.

triumphspecialtuning.com

 

D

davmar1960

Freshman Member

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• May 11, 2023

• #11

Thank you

 

T

TR-3rg

Jedi Hopeful

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• May 12, 2023

• #12

Hi,

I have a 10 pound Firenze aluminum flywheel in my 1960 TR-3a. I love it. Its factory drilled for a TR-3 and the smaller TR-4a pressure plate. The metal insert is for a TR -4 a disc. It works fine with either pressure plate. In my opinion, this is what the car should have had from the factory.

I do have a recurved distributer with 12 initial and 32 total. Starts at 1600, all in by 2400. That really helps the low end drivability. I dont know what its like with a stock Lucas distributer.

Another benefit, the engine shuts off, no dieseling.

Good luck, Roy

 

G

groupdeville

Jedi Hopeful

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• May 14, 2023

• #13

Sadly, the makers of the lightweight alloy steel flywheels do not seem to produce them with drillings for the TR2/TR3 coil-spring pressure plate, for those of us who prefer the near-bulletproof reliability of the earlier design. So, the flywheel choice then becomes between having a stock TR2/early TR3 flywheel lightened down to 16 or 17 pounds or the aluminum Fidanza unit.

 

T

TR-3rg

Jedi Hopeful

Offline

• May 14, 2023

• #14

My Fidanza flywheel was drilled for both pressures plates. The steel friction surface is for the smaller TR4a disc. I rant he stock tr-3a pressure plate pressureand TR-4a disc for a couple of years. I now have theTR-4a / TR-6 pressure plate because I went to the Supra 5 sp conversion.

Fidanaza lists as the "1954 -1965 TR-4 / 1965-1966 TR4a" flywheel. I think its part number 172441. Just double check be fore ordering!

Roy