Aluminum Flywheel?

[jumpinjan]

It takes a little distance to disengage the clutch. Maybe, a 1/4 inch, I would think. So I don't think the lateral shift due to the clutch release arm is a problem. However, I would make sure the geometry is right and makes the bearing centered & squared on the clutch release fingers. Do you follow me?
Also, I don't understand the Tiger return spring other than to keep the slave piston secured in the cylinder. Otherwise, the pressure plate spring will return the piston back into the cylinder (at rest)
Jan

 

[jdoclogan]

Jerry,

I didn't follow how you concluded the throw out bearing remains centered against the pressure plate as it travels in its arc motion. I considered switching to a roller bearing when I swapped in an overdrive transmission. However, when I looked at how the lateral position of the bearing changes as it travels from not engaged through engagement, I concluded the roller bearing would get trashed in short order due to not always being centered against the pressure plate.

Mike

The original carbon release bearing is centering by design having slight and continuous contact with the "center" of the pressure plate's special receiver. Examples of pressure plate's special receiver in the center of pressure plate below:



There isn't any major arc motion needed before pressure is applied. If you consider the mounting of a pressure plate (PP) onto the flywheel (FW)/with clutch plate the PP is approximately 6mm off the FW.


The motion of the carbon release bearing (which should be the same for a roller bearing type with the same lever arm mount) is minimal as shown in the following sequence of photos.

Release Bearing (RB) in start position - note the two black lines on the transmission shaft and the vertical pivot point with clip - one black line right at the front surface of the RB and the other black line 6mm toward the forward position of the transmission shaft.


As the clutch lever pushes the RB into the PP 6mm note the lateral movement you recognized Mike.


The vertical pivot points for the RB correct the lateral change in the RB's position.


If one uses the release ball bearing you could have the lever adjusted either with the bearing in continuous motion and centered. Or slightly (1mm) off the receiver and centered. With very little arc motion and the vertical pivot mount points there wouldn't be that much travel (6mm) before the pressure plate is released.

 

[jdoclogan]

It takes a little distance to disengage the clutch. Maybe, a 1/4 inch, I would think. So I don't think the lateral shift due to the clutch release arm is a problem. However, I would make sure the geometry is right and makes the bearing centered & squared on the clutch release fingers. Do you follow me?
Also, I don't understand the Tiger return spring other than to keep the slave piston secured in the cylinder. Otherwise, the pressure plate spring will return the piston back into the cylinder (at rest)
Jan

Yes, I do follow you literally and figuratively.

 

[spmdr]

As far as Tiger clutch return springs. I put one on my Tiger way back when I was driving it quite a bit on the street.

After replacing a TOB ONLY, it was clear there was a problem with having the TOB ride on the PP fingers all the time.

JUST adding a spring stiff enough to do the job of retracting the TOB from the fingers was also stiff enough to add WAY too much free play into the peddle!

To do it correctly required a longer rod to keep from retracting the TOB too far.

Later I concluded the main problem was the low quality of the TOBs I was using/available.

 

[jdoclogan]

Dan, putting in an adjustable spring is what I was thinking with regard to finding the sweet spot for the clearance of the roller TOB application in place of the Alpine's original carbon TOB for the #41 project.

 

[Alpine 1789]

I remember a discussion here many years ago about the pros and cons of roller bearings and someone posted a very good article or video on the subject. I can't be sure this was it, but did just find this video on why not to use roller bearings in an MGA, which I believe have the same design as our cars.

I know that many disagree with this advice and that many Alpine owners swear by them, so to each his own. But, I found this pretty convincing.

 

[jdoclogan]

I remember a discussion here many years ago about the pros and cons of roller bearings and someone posted a very good article or video on the subject. I can't be sure this was it, but did just find this video on why not to use roller bearings in an MGA, which I believe have the same design as our cars.

I know that many disagree with this advice and that many Alpine owners swear by them, so to each his own. But, I found this pretty convincing.

Good video Jim, except for the dark moments showing the movement of the bearing fork. Of course I have a "however." What is shown in the video is exactly what Mike recognized. What my investigation indicates is because of the vertical pivot points and the contact with the pressure plates receiving point the bearing surface adjust for the non-contact motion shown in the video. By non-contact I mean, when the lever is moved in the video the arc travel occurs and the inside diameter of the bearing begins to come closer to the transmission shaft to the point it is actually touching the shaft. If there were a contact surface on the outside diameter of the bearing, the pressure plate's center receiver, the vertical pivot point would adjust the bearing holder to the center never allowing the inside diameter of the bearing to touch the transmission shaft. Thus, it is centering the bearing surface. For the Alpine's hydraulic setup it is OK for the carbon surface to be in constant contact with the pressure plate's receiving surface as well explained in the video. Note: the bearing surface doesn't elliptically move in the exaggerated motions shown in the video. It stays centered. The roller bearing should do the same. The problem with the roller bearing is those that ride the clutch "leave their foot on the clutch." Or as inherent with the Alpine setup the bearing surface is in constant contact with the pressure plate's receiving surface. These and other misuses will definitely wear out a roller bearing and you will get the results shown in the video. Many explanations can be given why some have no problem with the roller bearing while others do. That is why I'm most likely going to fabricate a simple adjustment system so the roller bearing is not in constant contact with the pressure plate's receiving surface. Also, my dad taught me to "NEVER RIDE THE CLUTCH." Wow, that brought back a scary memory.

 

[HPMotors]

I have been building a SV that is intended to go vintage road racing. Engine build is fine, transmission build is done, but my stumbling block has been sourcing a light flywheel and a high performance clutch

This thread has been very informative on many levels. I called TTV in England a few months back regarding their aluminum flywheels. And was told that 1) they didn’t have a flywheel for the 7 1/2” disc and 2) they didn’t have a clutch for the larger setup. Surprised to see a clutch and flywheel package in this thread a few pages back, but it was 8 1/4 right?or did I miss something?

At this point, due to time constraints, we are likely going to use a stock flywheel that has been lightened per Sunbeam racing designs. The travails others have gone through makes this a fairly simple decision. So that leaves us looking for a performance clutch / pressure plate setup. Would really like a spring 6 or 8 puck disc. Any ideas on sources for such a beast?

 

[alpine_64]

I have been building a SV that is intended to go vintage road racing. Engine build is fine, transmission build is done, but my stumbling block has been sourcing a light flywheel and a high performance clutch

This thread has been very informative on many levels. I called TTV in England a few months back regarding their aluminum flywheels. And was told that 1) they didn’t have a flywheel for the 7 1/2” disc and 2) they didn’t have a clutch for the larger setup. Surprised to see a clutch and flywheel package in this thread a few pages back, but it was 8 1/4 right?or did I miss something?

At this point, due to time constraints, we are likely going to use a stock flywheel that has been lightened per Sunbeam racing designs. The travails others have gone through makes this a fairly simple decision. So that leaves us looking for a performance clutch / pressure plate setup. Would really like a spring 6 or 8 puck disc. Any ideas on sources for such a beast?

You can use the series II special running booklet as a starting point on the FW lightening... I did that for my street alpine and kept going.. Took another 1.8kg off and it didn't hurt durability or drivability .. So for a racer coukd go further

 

[HPMotors]

You can use the series II special running booklet as a starting point on the FW lightening... I did that for my street alpine and kept going.. Took another 1.8kg off and it didn't hurt durability or drivability .. So for a racer could go further

Right, we are using a diagram from the factory competition guide.

what I’m needing, because a LOT of looking hasn’t found one, is a competition clutch that bolts to the stock face of the flywheel.

As an aside, the factory carbon tob physically CANNOT stay centered as the arc movement of the lever moves it left and right as it moves in and out. This movement is of course quite small, but it is there. The bearing type stays centered as they typically ride on a tube, a”spigot shat” as the Brits call it. The fingers on the operating lever slide back and forth on the back side of the tob.

insofar as riding the clutch pedal, this is always great advice. Not only don’t ride the clutch, but I also tell all of our Miata customers to shift into neutral when stoping. This advice is based on the fact that over the course of changing literally hundreds of Miata clutches, either the tob or pilot bearing has failed before the clutch disc is 100% used up. Of course this applies to street cars, not 400 HP drag racing Miatas which can burn out a clutch in one pass.

 

[alpine_64]

I would see what competition clutches volvo racing guys ate using, you can use volvo 144 clutches on the early motors.. So that might be a start. Jerry in his thread found race clutches in the UK from http://ttvracing.com/clutches/

 

[DanR]

I have been building a SV that is intended to go vintage road racing. Engine build is fine, transmission build is done, but my stumbling block has been sourcing a light flywheel and a high performance clutch.....

Henry, Perhaps you could call Ram Clutch in Columbia, SC 803-788-6034

May take some persuasion like I had to do to get a clutch disc for my V6.

 

[jdoclogan]

Just received the racing clutch assembly from TTV Racing. They made a new design just for the Sunbeam Alpine that includes the Flywheel (different than my previous purchase that goes with the original clutch and pressure plates). They increased the height of the flywheel to accommodate their shorter light weight pressure plate (PP) and accommodate for the OEM clutch slave lever's short throw. The rotating weight comparisons are listed below:

OEM Alpine Flywheel/OEM Alpine PP/OEM Alpine clutch plate = 35lbs 8oz / 16.102 kg
TTV lightened Flywheel/ OEM Alpine PP (hard to find)/ OEM Alpine clutch plate = 21lbs 8 oz / 9.752 kg
TTV modified lightened Flywheel/ TTV PP/ TTV clutch plate = 19lbs 7oz /8.788 kg

Obviously a 14lb / 6.35 kg rotational weight loss using a complete TTV assembly as opposed to OEM is significant. The cost is much more to incorporate the modified design of TTV's lightened Alpine flywheel, TTV PP and TTV clutch plate assembly ($1000) vs only getting TTV's lightened flywheel ($370) plus cost of finding an 8.5 inch PP (if you can find one) and clutch plate (around $100 from Sunbeam Specialties). I will be moving forward with this complete TTV configuration by installing it into one of my stock Series IV/1592 Alpines.

 

[bernd_st]

Jerry,

are you sure to run such a lightened setup on a stock street engine ? For a race engine a different story though ...

 

[jdoclogan]

It is intended for a race engine. However, I want to put it into my Series 4 to test it in a street engine just to see that everything lines up. I'm particularly interested in the throw-out bearing arm movement.

 

[bernd_st]

Ok, that makes sense then...

 

[HPMotors]

Very glad you found this flywheel and clutch from TTV - However I am disappointed with them! I had been searching for an aluminum flywheel for months and found TTV. Their online store had the flywheel, but no clutch assembly. No answers to emails. As a last gasp effort, I called them direct to jolly old! Took three attempts but finally got a person at the other end, very nice etc etc, but he informed that they did NOT have a clutch for their flywheel - which I thought amazing. You make an aluminum fly wheel, don't have a clutch for it and cannot recommend any other clutch manufacturer that makes one that fits. By the way, he told me the stock clutch would not fit. This was for a 1968 series V Alpine with the ten spline input shaft. Is it possible you have the 25 spline shaft?

Too late anyway, as we ended up lightening the stock flywheel - got about six pounds off of it. At this time it is already in the car with a fresh engine and rebuilt tranny. About a week away from firing this puppy up. Car is to be used for vintage racing.

 

[RootesRooter]

It might not make a difference to your clutch problem, but is it possible you got the spline count reversed? It's only the very late SV that has the 25-spline shaft. All other Alpines have 10.

Very glad you found this flywheel and clutch from TTV - However I am disappointed with them! I had been searching for an aluminum flywheel for months and found TTV. Their online store had the flywheel, but no clutch assembly. No answers to emails. As a last gasp effort, I called them direct to jolly old! Took three attempts but finally got a person at the other end, very nice etc etc, but he informed that they did NOT have a clutch for their flywheel - which I thought amazing. You make an aluminum fly wheel, don't have a clutch for it and cannot recommend any other clutch manufacturer that makes one that fits. By the way, he told me the stock clutch would not fit. This was for a 1968 series V Alpine with the ten spline input shaft. Is it possible you have the 25 spline shaft?

Too late anyway, as we ended up lightening the stock flywheel - got about six pounds off of it. At this time it is already in the car with a fresh engine and rebuilt tranny. About a week away from firing this puppy up. Car is to be used for vintage racing.

 

[jdoclogan]

Are you part of the HP Motors in Greenville SC? If so I like your involvement with the Miatas. You are having fun with life.
Sorry to hear that TTV gave you so-so assistance. I had good communications etc. Good you were able to remove 6lbs. The TTV one is 14lbs lighter, but hey, you would probably out drive the competition anyway. I was able to get a NOS stock 8.5" pressure plate and can get a new 10 spline clutch plate from Sunbeam Specialties. All 8" and 8.5" PPs with matching clutch plate will work with the TTV Sunbeam Alpine lightened flywheel. If you have a ten spline input shaft this would work. Dick is correct that the later Series V has the 25 spline input.
Let us know how the fresh fire up goes.

 

[jdoclogan]

In order to replace the carbon ring affair something like that could be an option:

https://www.ebay.co.uk/itm/Made-in-...56c9430307:g:ae4AAOSwAB5dXGtQ&redirect=mobile

Bernd I did go ahead and purchase this throw out bearing. Now I need to adapt the TTV PP to accommodate a center spring system to contact the fingers with the roller throw out bearing. Similar to an aftermarket Alpine PP shown below.