Clutch Heat Shield question..
Clutch Heat Shield question..
(OP)
Dismissively I was so glad to be done with Thermo in school, I sold my textbook back. Now I wish I hadn't.
We're working on a slipping clutch for VERY high performance drag racing applications and the problems always arise in the heat shield. The structural elements are all titanium while the friction surface contacts are Grade 50 steel. Friction surfaces are mounted to the structural titanium using 48 grade 8 bolts, and it is one solid piece of steel about .300" thick with six symmetrical grooves cut in it. Anytime the clutch is slipped just a little too much, the steel warps .003 to .006 from it's original flatness, rendering it useless.
My theory is that the heat is staying in the steel and is not able to use the mass of the structural titanium to help dissipate the heat because the conductivity of the steel. Other clutches similar to this use 6 or 9 individual steel pads instead of one piece heat shields that are even thinner, which I think will help our problem with expansion and contraction being a factor, but the question is will it help make the titanium a better heat sink for the steel?
Anyone have any ideas?
We're working on a slipping clutch for VERY high performance drag racing applications and the problems always arise in the heat shield. The structural elements are all titanium while the friction surface contacts are Grade 50 steel. Friction surfaces are mounted to the structural titanium using 48 grade 8 bolts, and it is one solid piece of steel about .300" thick with six symmetrical grooves cut in it. Anytime the clutch is slipped just a little too much, the steel warps .003 to .006 from it's original flatness, rendering it useless.
My theory is that the heat is staying in the steel and is not able to use the mass of the structural titanium to help dissipate the heat because the conductivity of the steel. Other clutches similar to this use 6 or 9 individual steel pads instead of one piece heat shields that are even thinner, which I think will help our problem with expansion and contraction being a factor, but the question is will it help make the titanium a better heat sink for the steel?
Anyone have any ideas?





RE: Clutch Heat Shield question..
RE: Clutch Heat Shield question..
I think the problem with air slots on the structural side has been the integrity of the steel when you maintain a one-piece heat shield. The plate loads exerted are in excess of 3 tons and the slipping of the clutch creates enough heat to make the steel glow bright red.
RE: Clutch Heat Shield question..
Ed Danzer
www.danzcoinc.com
www.dehyds.com
RE: Clutch Heat Shield question..
I dont drag race however it is my understanding that some drag racing engines are cooled with ice in order to dispense with a water cooling system. Is that true?
RE: Clutch Heat Shield question..
We have thought about introducing CO2 into the bellhousing, as they already use compressed CO2 to shift the gears in the transmission. Most of the heat is generated in the fisrt half second of the run, where the clutchslips the most. It then slips slightly at each of the gear changes as to not knock the tire loose as the 4,000 horsepower engine continues to accelerate.
I think we may have solved the problem of the warpage by making the heat shield segmented instead of keeping it one soild piece. At 10,000 RPM's, the titanium wants to flex a little, which also flexes the steel heat shield. As the steel and titanium expand, contract and flex at different rates, as well as conduct heat at incredibly different rates, the titanium always returns to it's normal shape and the steel, being exposed to the brunt of the heat and friction, is a slave to what the titanium wants it to do. I was told by three friends of mine who have been doing clutches for these blown alcohol and nitromethane powered vehicles for some time and they confirmed my suspiscions.
RE: Clutch Heat Shield question..
RE: Clutch Heat Shield question..