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Über Genius
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Historically short amount of time, though I already have 8 units accounted for now...Strike when the iron's hot!
It's your project so I wouldn't tell you how to do it.
I know there are quite a few people that don't check websites as often and probably a few that will miss out because of it.
 

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Thanks to everyone participating in the group buy!
There is currently 1 more available flywheel reservation in the group buy to hit the minimum of 10.
If you would like it, please message me ASAP.

1) I will be sending the complete list of group buy participants to Aasco by close of business on 4/16.
2) The goal is then for all participants to call Aasco Motorsports (714-758-8500) on 4/17 (no earlier as they won't have the list) with your payments, they accept Credit, Debit, or Paypal.
2a) Our point of contact there is named Jordan, not to be confused with me...
2b) The payment is 50% of $315, so $157.50 by close of business (5pm PST).
3) I will have updated details and cost for the extended clutch studs early next week, these should be $15-25ea and will ship out with the flywheel, payment for these are to be made to me.
4) Approaching Friday 5/8 I will contact everyone again to remind them to make their final payment to Aasco including the total for tax (7.75%); this will be $181.91.
4a) At this point all flywheels will be complete and paid for, Aasco will release all of the flywheels to me in person.
4b) Each individual will need to pay me directly for the shipping which at current time is $18.30 for flat rate USPS post in the continental USA.
4c) My plan is to have all flat rate boxes, with shipping labels with me when I pick up the flywheels. At this point if you have paid for the shipping and clutch stud (if you are getting one) I will be going straight to the post office from the machine shop to ship out.
 

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Opel Rallier since 1977
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Just a suggestion: Ship in bigger boxes. I have a prior shipping box for these and it is 14x14. That allows for cardboard packing around the flywheel edges. The tight fit of these in a 12x12 USPS box as described will likley have some ot the flywheels chewing their way out the side of the box during transit. Have you asked Aasco if they have some boxes for these?

Jordan, if I may ask, are these drilled for a certain pressure plate? And if drilled, do the tapped holes include inserts?
 

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Jordan, if I may ask, are these drilled for a certain pressure plate? And if drilled, do the tapped holes include inserts?
I believe that they are drilled for the 2WD version of the light truck S-10 pressure plate. Someone was questioning about whether or not they are doweled in the correct spot. Hardened inserts or helicoils do very little to strengthen the holding effort of the fastener in the surrounding material. They will however, keep the aluminum threads from gauling with repeated use. For as often as you change your clutch disk, even in racing, they should be fine as is. Any fastener inserted in aluminum should have anti-seize applied regardless. That being said, I would most certainly inspect the quality of the threads cut. Most machinists don't use nearly enough lubricant when cutting aluminum and the result is ragged. I'm probably preaching to the choir here because you sound like you know your stuff. Including this here for the benefit of all participants.
 

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They are drilled for S-10 clutches witch is the same patterns for 2wd or 4wd version.

Members are suggested to install the 2wd versions because they have lower spring pressures, and are easier / smoother to operate.
 

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Opel Rallier since 1977
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Hardened inserts or helicoils do very little to strengthen the holding effort of the fastener in the surrounding material. They will however, keep the aluminum threads from gauling with repeated use.
Here is how to look at it IMHO: Different materials have different shear strengths and these 3 materials have very different shear strengths, listed in order of decreasing strength: cast iron, medium carbon steel (graded bolts) , and aluminum.

So put a steel bolt in to a cast iron flywheel and the threads will pull off of the medium carbon steel bolt before they will rip out of the cast iron. But aluminum has about 55% of the shear strength of cast iron and is lower than medium carbon steel, so when you put the same steel bolt in aluminum flywheel, then the threads will want to rip out of the aluminum first. Which is what we all know will happen from practical experience.....!

So that is one of the 2 reason I want stainless inserts in my AL flywheel. The other is the fact that the diameter of the insert is significantly larger than the bolt and that will significantly increase the pull-out force in the AL flywheel. In fact, put an 8 mm insert into AL and you now will have about the same pull-out strength of an 8 mm tapped hole in cast iron. I've been through the numbers on all of this, and decided to install inserts in my AL flywheels (which are from a group buy many years back and came undrilled), so it would never be a worry. I was used to R&R clutches pretty often from my competition days, so that may color my attitude; I've streched quite a few 8 mm bolt threads in the iron flywheels.

IIRC, once the holes are drilled and tapped for an 8 mm bolt, they are too large to properly drill and tap for an 8 mm insert. So you go one way or the other.

If you have a non-inserted AL flywheel, I would recommend to:
  • Keep the torque on the 8 mm steel bolts down in the 10-12 ft-lbs range, to not put excess strain in the AL threads. This is simply a concession to the lower shear strength of the AL material.
  • Use blue lockite on the threads, both as a locker, a thread lube for consistent torque, and to limit corrosion between the steel and AL
These are obviously working OK un-inserted, just like the 4 bolt pressure plate patterns on the original pressure plates work. It always surprises me that a few bolts in tension can hold so much force, but I see it in other things, like Mopar shaft rocker systems, where five 5/16" bolts on each shaft hold all sorts of crazy valve spring pressures just fine.
 

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Theses flywheels will not have pressure plate dowels. To cover this really quick, follow along. This is simplified with some assumptions.
Assumptions:
Flywheel and pressure plate are perfectly flat and rigid.
Mechanical friction is ignored.
Analyzed with kinetic friction coefficient for conservatism.
Pressure plate is held by friction only, no bolt loading in shear.

Pressure plate bolt pattern diameter = 10.5"
Number of pressure plate bolts = 6
Pressure plate bolt size = 5/16-18
Grade 8 bolt clamping load @ 18 ft-lb (reference table) = 4719lb
Kinetic friction coefficient between aluminum and mild steel (pressure plate to flywheel interface) = 0.47
Moment arm to pressure plate bolt (half of bolt pattern diameter) = 5.25"

Kinetic friction force at each bolt location = Kinetic friction coefficient x clamping force--> 0.47*4719= 2217lb
T, Max torque held at each bolt = Friction force x moment arm to pressure plate bolt = 2217*5.25= 11,639 in-lb
Max torque resolved by all flywheel bolts = Max torque x number of bolts = 11,639*6= 69,835 in-lb = 5,819 ft-lb

Torque required to slip the pressure plate on the flywheel is 5,819 ft-lb, this also has the assumption that the pressure plate / flywheel already exceeded the static friction force which is ~20% higher than kinetic.
On the surface this would look like you need a 5,819 ft-lb engine to slip the pressure plate on the flywheel, though force transients in the drive line can be extremely high due to engine and drive line inertia. Though bottom line, the clutch disk/pressure plate will never be able to hold a high enough torque to cause the pressure plate to slip on the flywheel even without dowels.

Mercougary and Manta Rallier,
I also have a concern with the longevity of the threaded holes for the pressure plate, in my world I work with a lot of key locking inserts and helicoils.
I have requested another quote for all threaded holes to have key-locking inserts such as McMaster-Carr
I recommend we go with black oxide instead of stainless due to the risk of galling.
Aasco will have the quote to me this afternoon.
 

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Opel Rallier since 1977
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Just FWIW.... the dowels do add something to the rotational strength, but I have no doubt that it will be fine without them. IMHO, it just makes installation easier. (And some of the dowel discussion may have been for dowleing from flywheel to crank IIRC, but for most uses, again, not an issue.) I did not critique your analysis, but I expect it is fine; if you want to be throrough, it may need some consideration of shock loads. And the friction surface on the flywheel is not AL, it looks to be a high carbon steel insert from some quick online references.

As for the thread inserts, I just wanted to get some info out there. OK by me for non-SS inserts, but using blue locktite will usually prevent galling. It's up to the buyers to decide if it is worth the insert cost; I just prefer it for the reasons stated. BTW, I used 20 mm long inserts in my recent setup, installed with red locktite. Gives a good deep threaded hole. The drilling and tapping was all the way through the flywheel to accommodate this insert length.
 

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Manta Rallier,
Dowels are certainly preferred for resolving shear load with friction as a bonus, though dowel pins need to be very precisely located to actually be effective (for more than 1 that is). For a pressure plate the the main benefit of dowels is precise centering relative to the crankshaft axis, if it is off center it will increase the dynamic unbalance.
Looking at the construction of a lot of stamped steel pressure plates I'm often surprised how much irregularity there is, though they tend to work fine without a noticeable dynamic vibe.
If one really wanted to take it to the next level they could index the the pressure plate on the flywheel with minimal run out, match drill for dowel pins, and then dynamically balance the pressure plate/flywheel assembly. I think this is overkill for most applications.

In reference to the consideration of "shock loads" that was in the description I had for "force transients". The margin to account for dynamics in this are enormous, if we consider a monster CIH engine with 250 ft-lb of torque there is still a factor of safety of greater than 23 to slipping.
The friction interface I am referring to is the pressure plate (steel) to flywheel (aluminum) interface, the steel clutch friction insert is unrelated to the pressure plate mounting interface.
 

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Opel Rallier since 1977
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Manta Rallier,
Dowels are certainly preferred for resolving shear load with friction as a bonus, though dowel pins need to be very precisely located to actually be effective (for more than 1 that is). For a pressure plate the the main benefit of dowels is precise centering relative to the crankshaft axis, if it is off center it will increase the dynamic unbalance.
Looking at the construction of a lot of stamped steel pressure plates I'm often surprised how much irregularity there is, though they tend to work fine without a noticeable dynamic vibe.
If one really wanted to take it to the next level they could index the the pressure plate on the flywheel with minimal run out, match drill for dowel pins, and then dynamically balance the pressure plate/flywheel assembly. I think this is overkill for most applications.
I agree that dowel pins are really for locating. The Opel 4 bolt plates of yesteryear had pretty consistent holes and the bolts had shallow shoulders on them for locating. Good enough for 7500 to 8200 RPM over and over back in the day for me. Have not yet spun the S10 plate all that high, maybe 5+k RPM, but all smooth so far.

And yes on the variables in the pressure plate holes. My Sachs S10 PP was pretty poor in that regard. So I added dowel pins, just for good measure. I had more trouble making consistently straight and evenly threaded dowel pins than anything. But those would be relatively easy to add later if desired... no need to have those flywheel holes heli-coiled.

Don't know who made the AL flywheels 10+ years back. But I am impressed with how well it was turned and made. I decided there was no need to have it balanced for my brisk street use. The runout at the edge was something like .0007" ! Very good work!
 

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Does the Chevy S-10 Clutch Pressure plate need to be balanced with the new Aluminum flywheel?
or you can use it out of the box?

Is there a preferred Chevy S-10 Clutch Kit to buy?

The listing for Chevy S-10 2.8 V6 ..doen't spec, 2WD or 4WD



I got the Luk L04065
I purchase this one



Clutch listings ..
 

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Mike,
I also purchased the LUK 04-065 clutch for this round. I'm fairly confident it is the right one.
I have done the S-10 clutch mod in the past, though I think I ended up with the 4WD clutch as the clutch feel was still very heavy.

Dynamic balancing is not a requirement. It of course could be done, though the flywheel will be very good right out of the box. Quality replacement clutches are manufactured to some acceptable balance range set by the OEM. This combination should not have any balance issues.
 

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Is there a specific year for the S10? Looks like Duralast and Centerforce are also options.
 

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Is there a specific year for the S10? Looks like Duralast and Centerforce are also options.

There a lot of good info in the PDF file posted in post# 473
"""" The correct Chevy S-10 clutch for use in a GT should be from 85 and up 2.8 V6 Chevy S-10. The 2WD clutch is the standard duty and has less spring pressure than the HD or 4WD unit, so the engagement is softer because it had less initial clamping. """"
 

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Opel Rallier since 1977
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Mike,
I also purchased the LUK 04-065 clutch for this round. I'm fairly confident it is the right one.
I have done the S-10 clutch mod in the past, though I think I ended up with the 4WD clutch as the clutch feel was still very heavy.

Dynamic balancing is not a requirement. It of course could be done, though the flywheel will be very good right out of the box. Quality replacement clutches are manufactured to some acceptable balance range set by the OEM. This combination should not have any balance issues.
Pedal pressure is ludicrously low for the 2WD... not in a bad way.

I used a Sachs K1904-03 kit for the 2WD from Rock Auto.
 

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Time for a new group buy!
I have contacted Aasco Motorsport in Anaheim CA to start another group buy for the light weight aluminum flywheels with a steel friction insert and newly machined steel ring gear.
The flywheel is $315 ea. + tax and shipping for >10 units, or $385 for 5 to 10 units.
Lead time is 3-4 weeks after 50% deposit.
I am looking for 9 or more people interested (appropriate qualifier is interested and ready to pay 50% down by 4/17, and the remaining balance by 5/8).
We can individually pay Aasco for the 50% down, and final payment, though it is not their preference.
I am only about 30 miles from their shop so I can pick the lot up and handle the shipping arrangements to each individual.
Another detail is the extended clutch fork studs that need to be made, I can get a local machine shop to make these; the turn around should be faster than the flywheels so they can ship out with the flywheel, I estimate the price to be ~$25 each.
Please respond here or send me a message if you are interested AND ready to buy in.

Also it should go without saying, but I will clarify. I am not the one selling these flywheels or accepting any liability or responsibility for defects, errors, or damage. You are paying Aasco Motorsports directly, I am only organizing this group buy and shipping you product that you paid the manufacturer for.
Is it still possible to attempt this group buy? I’m really interested if shipping to Denmark is possible?


Sent from my iPhone using Tapatalk
 

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Are we still on track with this or waiting for quotes on additional machining? If I decide that hardened inserts are a necessity, I would just as soon put them in myself along with the correct doweling. There are three with equal radial spacing so it should not affect the balance. If it is not part of their original design, I would be hesitant to ask them to do it. OP should green light us for contacting Aasco in lieu of most recent discussions in this thread.
 

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Opel Rallier since 1977
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Hey MC, FWIW. Just be aware that if the holes are tapped in advance for 8 mm bolt hole direct in the AL, the major diameter of those threaded holes can result in 'getting into' the threading for the insert, unless you do the re-threading exactly right. It would be nice of they could be ordered either way, if the insert cost was an issue.

You could get the hole just drilled but not tapped for 8 mm hole and then either tap it for that, or drill it larger to tap the hole for the insert. But you have to be careful to get any tapping into the AL straight. I ended up jigging the flywheel flat on the drill press table, chucking the tap into the drill, and manually turning the chuck and tap while lightly holding the drill control down. That kept the tapped holes (for the main inserts and for the non-inserted dowel pins) very straight and perpendicular to the surface.

As you note, the dowels can be done at any time.
 
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