Cooling the Clutch and flywheel...

[knownenemy]

OK; I have a possible issue, and I'm looking for opinions on an idea for a solution to it.

The issue is;
I've bought an aluminum flywheel, and I'm told they overheat with big power.
My HP will likely be over 500 at the crank.

Is there a method people use to somehow keep it from overheating the clutch/flywheel?

I was thinking of drilling some holes into the bell housing of my trans, or something.
On the side that faces front, so when the cooling fans kick on,
they'll blow air into the bell housing and cool the clutch.

Surely this all sounds "off the wall" to a lot of members,
but I'm just looking for input on the subject.
I honestly don't know yet if this will actually be an issue.
So, I intend to assemble, test, and if there are overheating issues,
I'll tear it apart again, and take necessary actions.

Thanks, in advance, for the input.
Have a great day.

[Chris W]

Cooling ports in casing is not a good idea. You could affix air fins to pressure plate (making sure to rebalance and verify clearance) to induce air flow and leave dust shield off. Be careful when driving through puddles and avoid dirt roads.

Correct solution is don't use aluminum flywheels for high HP applications. A lightened steel flywheel is recommended for those vehicles to avoid insert warping and clutch disk breakdown.

Chris-TU

[acannell]

OK; I have a possible issue, and I'm looking for opinions on an idea for a solution to it.

The issue is;
I've bought an aluminum flywheel, and I'm told they overheat with big power.
My HP will likely be over 500 at the crank.

Is there a method people use to somehow keep it from overheating the clutch/flywheel?

I was thinking of drilling some holes into the bell housing of my trans, or something.
On the side that faces front, so when the cooling fans kick on,
they'll blow air into the bell housing and cool the clutch.

Surely this all sounds "off the wall" to a lot of members,
but I'm just looking for input on the subject.
I honestly don't know yet if this will actually be an issue.
So, I intend to assemble, test, and if there are overheating issues,
I'll tear it apart again, and take necessary actions.

Thanks, in advance, for the input.
Have a great day.

I do know that the corvette has two big vent holes for the clutch, but Im not sure where the inlets are or how the system is designed overall to vent heat that way. Ive never seen inside there. But heres a post describing it:

"It has been our experience that the 2 worst GM V8 vehicles out there for having issues with clutches are the GTO and the F-bodies. I would like to point out one thing that they have in common: They do not have an "exhaust" for clutch debris and heat. The back of the bell housing does not have vents like the Corvette and especially the C6. The 2 C6 vents are about 2" by 3/4" just beneath the clutch and in the back of the bell housing whereas the C5 was about 1/3 the size. The late model Camaro has a large vent roughly equivalent to the C6 size."

http://www.corvetteforum.com/forums/...ur-clutch.html

[shadow88]

You're looking for input, so here's mine. To get a clutch in that tiny bell housing to handle 500 crank horsepower and probably similar torque will probably have pretty high clamping forces and have a puck style clutch. These types of clutches tend not to slip too much and won't create large amounts of heat. So my 2 cents is to make the power you want to, get a clutch that'll handle it, and I doubt you'll have to worry much about cooling.

[Dr. Johny Dodge]

what thay said +1

don't drill or cut the bellhouseing - at least not if you like haveing feet & toes

you could put as many holes as you like in the sheetmetal front covers for the bellhouseing though

find a guy with a louver press and you could even make vented openings that scoop air in and dump it back out if he can stamp louvers short enough to stand on end on the bottom cover

[knownenemy]

Great input.
shadow88, I had that same thinking.
If I get a 4 puck, unsprung disc, this would keep excessive heat down.

When I assemble everything, I'm going to try and get actual values with the laser temp probe.
(This will be a while from now, but I will do this)

Thank you guys.

[Shadow]

Don't Hammer on it with a Hot clutch! I can hot lap the Charger with the set-up that's in it with Zero issues, but with an AL flywheel I would do 1 pass and let it cool.

I don't think it will be heat from 1 run that will do you in. I think it will be several runs getting the insert hotter and hotter till it has no choice but to fail ;(

[c2xejk]

At one time wasn't there talk of adding some kind of thermal compound between the steel insert and the aluminum flywheel to help transfer heat away from the insert. I believe the opinion was that the problem was not the flywheel itself overheating (Al), but the insert not transmitting the heat away from the clutch...

[Ondonti]

At one time wasn't there talk of adding some kind of thermal compound between the steel insert and the aluminum flywheel to help transfer heat away from the insert. I believe the opinion was that the problem was not the flywheel itself overheating (Al), but the insert not transmitting the heat away from the clutch...

I go with this based on my experience. I don't really think there is a solution though
I pretty much gave up since everyone always sells me the wrong style (new) Fidanza insert and never includes new hardware.
The only thing they are really good for in big power setups is saving axles.
I won't even put an aluminum flywheel in my daily driver. I wish I could but its too much hassle to keep rebuilding them + clutch engagement and holding power will always be worse.

[Dr. Johny Dodge]

thermal compound , if like that used on a computer's cpu to heat sink or water block is paste like

I'd worry about it being thrown out from between the parts and contaminateing the clutch

[Chris W]

thermal compound , if like that used on a computer's cpu to heat sink or water block is paste like

I'd worry about it being thrown out from between the parts and contaminateing the clutch

^ THIS!

Any compound that would liquefy with heat would not be the ideal choice in a centrifuge-like atmosphere.

Heat transition issues with aluminum flywheels are obvious in the steel insert photos below.




Chris-TU

[Vigo]

I would run the thermal paste and see what happens. If it gets pushed out by centrifugal force it will be exiting away from the clutch disc anyway. I dont think there's a downside to at least trying it.

Having said that, if you dont want to try and learn anything and just want a 500 hp 4 cylinder you never have to take apart (snicker) i would just buy the lightened steel version and be done with it.

[knownenemy]

I would run the thermal paste and see what happens. If it gets pushed out by centrifugal force it will be exiting away from the clutch disc anyway. I dont think there's a downside to at least trying it.

Having said that, if you dont want to try and learn anything and just want a 500 hp 4 cylinder you never have to take apart (snicker) i would just buy the lightened steel version and be done with it.

I'm going to look into the thermal paste to see what's available.

I also intend to see if the NHRA pros have used anything similar.
(Understandably their clutches are far more advanced than what I may use, but I'm going to check anyway)

"500 hp 4 cylinder you never have to take apart" lol; if only.
With how clean I'm going to leave things in the engine bay,
I really don't think removing the trans will be much of a task.
So I'm definitely going to try several different setups, and use what's best.

I may even try some of my outrageous ideas.
Either way, the flywheel/clutch/pressure plate will no longer be the weight it usually is.
I'm hoping to reduce a large part of it's resistance on the rotating assembly.

Thanks for all the suggestions.
And any other ideas, keep 'em coming.
Especially those who've attempted something like this with results(good or bad)
I'd love to hear what others have found, and learn what NOT to do as well.

[GLHNSLHT2]

Don't slip the clutch. I don't get how inserts can get to look like what Chris posted. I was doing 2nd gear burnouts at the track (in the waterbox and leaving it with the tires still spinning) and had 30k daily driven miles on my 20 bolt fidanza and when I took the drivetrain out the insert looks almost brand new. So does the 6 puck sprung SPEC disc. I have a stage 5 SPEC waiting to go in though I keep thinking about going to a 3 puck solid hub disc with the stage 5 pressure plate. I think the inserts above are from idiots that just slip the hell out of the clutch. For those people then maybe an aluminum flywheel isn't the answer but I don't think just because you make X amount of power that you should stay away from them.


Duct some hoses into the dust shield and run them to small computer fans, let them blow through the bell housing and vent out the timing window.

[Chris W]

I think the inserts above are from idiots that just slip the hell out of the clutch.

You should be careful who you call an idiot GLHNSLHT2. They are in this thread contributing info and may not appreciate it.

Chris-TU

[Ondonti]

Don't slip the clutch. I don't get how inserts can get to look like what Chris posted. I was doing 2nd gear burnouts at the track (in the waterbox and leaving it with the tires still spinning) and had 30k daily driven miles on my 20 bolt fidanza and when I took the drivetrain out the insert looks almost brand new. So does the 6 puck sprung SPEC disc. I have a stage 5 SPEC waiting to go in though I keep thinking about going to a 3 puck solid hub disc with the stage 5 pressure plate. I think the inserts above are from idiots that just slip the hell out of the clutch. For those people then maybe an aluminum flywheel isn't the answer but I don't think just because you make X amount of power that you should stay away from them.


Duct some hoses into the dust shield and run them to small computer fans, let them uthe bean d vent out the timing window.

Aluminium flywheels are okay for cars like yours. Water box burnouts are probably one of the easiest things in racing for your clutch to handle

[acannell]

hmmm..from Fidanzas website:

"In addition, aluminum flywheels are much better at dissipating heat your clutch and can greatly improve clutch performance and life; and all Fidanza Performance aluminum flywheels feature a replaceable hardened steel clutch friction surface, which means they are infinitely re-buildable and will deliver years and years of exciting drivability."

[acannell]

according to science the stock flywheel at 5000rpm has about as much energy stored in it as a 2500lb car moving at 12 mph

[knownenemy]

hmmm..from Fidanzas website:

"In addition, aluminum flywheels are much better at dissipating heat your clutch and can greatly improve clutch performance and life; and all Fidanza Performance aluminum flywheels feature a replaceable hardened steel clutch friction surface, which means they are infinitely re-buildable and will deliver years and years of exciting drivability."

This ^^

according to science the stock flywheel at 5000rpm has about as much energy stored in it as a 2500lb car moving at 12 mph

RIGHT!
And that's what I'm attempting to reduce.
I think reducing the resistance on the rotating assembly is the easy part;
keeping the heat it creates in so doing is the trick.

I respect all opinions here.
I rely on my fellow forum members, and other resources for help.

The overall opinions I've come across elsewhere have cheered for the aluminum flywheels;
I'm not familiar with using the Fidanza piece,
but the AASCO flywheel I have, in its design,
has left room for the insert to expand and contract with heat.
But the less it must do this, the better.

I like the idea of running some kind of airflow to the clutch.
Maybe add a 1.5" sleeve, and run a flexible tube from a scoop under the front bumper.

[Dr. Johny Dodge]

the backing plate / splash shields in the inside side of my 79 f150 have nice scoops stamped into them ahead of the knuckles

there's a bit that sticks out kinda like a louver - same thing done to the lower bellhouseing cover would probably be all the venting needed once the car's moveing forward