Lightweight Flywheels, NOT just for Race cars anymore.

[spmdr]

Back in the '90s, I worked on several Alpines.

One had a Weber 38/38 DGAS, it was FAR and away the Zippiest Alpine I had ever driven!

For the longest time I attributed the performance to the Carb.

However, recently, I think the Most likely scenario is that Zippy Alpine

had a LIGHT Weight Flywheel!

The recent change to the Weekend Racer Alpine to an Aluminum Flywheel

has made a significant change to the FEEL of the car!

Seeing the car is street legal, I test it on the street quite freely.

Changing to the light weight flywheel has not been a problem on the Street.

At this point, the pressure Plate and Clutch disc are standard SV Alpine parts.

And with the BIG cam in the WR Alpine, you would think the weak low RPM

Torque would also cause a problem with a light weight flywheel, but I'm not seeing it.

I'm now re-energized to find a source of light weight Flywheels for ALL of my Alpines!

I suspect a majority of Alpine owners, given a choice, would choose a light Weight

Flywheel.

DW

 

[GlennB]

Why not engineer your current flywheel? The Alpine Tuning Guide has a section describing how to lighten the flywheel and any local engineering shop should be able to do it. Remember that the gain from change to rotating mass means that the weight needs to be taken from as close to the outer edges as possible. The standard flywheel is 23 lbs, the Harrington Le Mans is 19 lbs and the Rootes Competition Dept used 14lbs if I recall. My local shop took my flywheel down to 16 lbs and stopped when they started to break into the cover bolt holes. At 16 lbs I have a very lively road going engine with no issues about idling stability. Your flywheel looks like it is a 7 1/2" setup so good for lightening at the outer edges.

 

[alpine_64]

I used the Rootes factory SII special tunning guide as the starting point on my SII flywheel... And kept going. It's been discussed previously in threads ( goes back to 2007 when I did it) and while many people said it would make the car to tricky around town at low rpm... Didn't notice that at all ..but the response was MUCH better..

I won't quote the exact weight as it's not to mental hand anymore.... But I will find it.. and is in the old forum archives with photos . And the mod to for the 1725 oil pump to the 3 main distributor and sump ( all 1 project when I was switching out the gearbox)

The flywheel mod.. and balancing is a big positive change for the car .. an aluminium one would be a nice buy if easily avaiy

 

[spmdr]

I have trimmed down Stock Iron Alpine flywheels in the past and even trimmed the Aluminum one.

But you can't safely trim an Iron flywheel to get to the weight of an aluminum flywheel.

The lightweight aftermarket STEEL flywheels are a choice and the current direction I am leaning.

I may have to start over in my search to see if anything else/new has come on the scene in the last few years.

DW

 

[DanR]

Modern DriveLine in Boise ID is making flywheels for me (V6 FORD) and providing the pressure plates and clutch disc. Bet they can do the Alpine also. Ask for Paul

 

[BEpine]

This is what my brother and I did to our flywheels, I had mine balanced afterwards with the clutch pressure plate bolted on.
Took off about 3 lbs.

 

[spmdr]

The Aluminum one above looked closer to a standard SV originally.

Some Iron SV examples. DW

 

[jdoclogan]

Here is the TVR Racing in the UK lightened flywheel

Cost - (299BP) = $370 USD including shipping (2020)
Weight - 4.35 kg = 8.59lbs
Clutch - 215mm = 8.46 inches

The same company also makes a flywheel for the 1725 engine with 7.2 inch clutch. It weighs in at 3kg = 6.6lbs.

 

[Five Reviver]

This is the (steel) one which TTV Racing sell to match 1725 OEM fitment - no change to std clutch. 3.6kg - it’s less than half the weight of a lightened OEM. I can tell you it drives in traffic with no negatives and the positives are a revelation. You just won’t believe the change to the responsiveness of the engine. I’m no expert, but having used this flywheel, I would not build a standard 1725 engine (or any other) without inserting this little beauty into it.

 

[fireroad]

This is the (steel) one which TTV Racing sell to match 1725 OEM fitment - no change to std clutch. 3.6kg - it’s less than half the weight of a lightened OEM. I can tell you it drives in traffic with no negatives and the positives are a revelation. You just won’t believe the change to the responsiveness of the engine. I’m no expert, but having used this flywheel, I would not build a standard 1725 engine (or any other) without inserting this little beauty into it

Thanks for the info! If the shipping to the US is reasonable I may just give it ago. When you say "no change to standard clutch" which clutch size do you have? According to the SS catalog my SV is an early model so 7 1/4 and 10 spline.

 

[alpine_64]

This is the (steel) one which TTV Racing sell to match 1725 OEM fitment - no change to std clutch. 3.6kg - it’s less than half the weight of a lightened OEM. I can tell you it drives in traffic with no negatives and the positives are a revelation. You just won’t believe the change to the responsiveness of the engine. I’m no expert, but having used this flywheel, I would not build a standard 1725 engine (or any other) without inserting this little beauty into it.

What did they slug you for duty when it arrived in AU?

 

[spmdr]

Yup, I have a pile of stock Alpine iron flywheels, and I hope to never use one again!

In hind sight, changing to a lightweight flywheel would have been a single change

that Rootes could have done to give the Alpine a more sporty car feel!

And that TTV SV replacement flywheel is just the ticket I was planning to get!

I just have not seen the STD SV version until now.

DW

 

[alpine_64]

Yup, I have a pile of stock Alpine iron flywheels, and I hope to never use one again!

In hind sight, changing to a lightweight flywheel would have been a single change

that Rootes could have done to give the Alpine a more sporty car feel!

And that TTV SV replacement flywheel is just the ticket I was planning to get!

I just have not seen it until now.

DW

I think Jerry had posted some images of his and the preseure plate and cover for his race project

 

[alpine_64]

@spmdr :

Weight comparison of Flywheels

I'm becoming more familiar with the Roy Stetina race car I acquired from Max Phameier's estate. I received a wonderful response from Wayne Stetina, the son of Roy Stetina, as I inquired about any knowledge he might have of his fathers SCCA racing Alpine. Besides knowing the car number (21) he...

forum.sunbeamalpine.org

Jerry's is the larger flywheel from the early cars.. more drilling by TTV for lightening on the bigger dia one.

 

[spmdr]

TTV has made more Sunbeam versions than are seen on their web site.

.....and posted by Jerry, so far....

Email just sent to TTV.

DW

 

[spmdr]

I'm just so glad I didn't spend All kinds of Time trying to get the Heavy Flywheel engine to pick up rpm

with Bigger accelerator shots with the Webers!

DW

 

[Five Reviver]

What did they slug you for duty when it arrived in AU?

Zero if I remember correctly

 

[Five Reviver]

Thanks for the info! If the shipping to the US is reasonable I may just give it ago. When you say "no change to standard clutch" which clutch size do you have? According to the SS catalog my SV is an early model so 7 1/4 and 10 spline.

I’m using the later SV fine spline clutch as I’m running a John Roseby ‘hybrid’, gearbox (Hillman Hunter GT box with J type overdrive and Alpine SV gearset installed by John).
TTV previously had the 2057 flywheel listed only for the Hillman Hunter, so to make certain it was correct before I bought it, Limey from this forum kindly sent TTV a new OE Series V flywheel to compare and they confirmed that the specs were exactly the same. That’s why they now have it listed for the Alpine.

 

[Five Reviver]

There’s one more thing to remember if you instal one of these fabulous flywheels: every time you start the car, it reminds you it’s there by ringing like a bell.

 

[spmdr]

Seeing I don't have any yet, I'll just assume the Bell ring is a Safety Feature.

...When it stops ringing, YOU have a problem?

And/or, still keeping a measure of optimism, sounds like Music to my ears?

Some of the Vintage Racers also Ring.

DW