Epoxy in the Kegger
Grand Champion
Joined: Nov 2004
Posts: 6,099
Likes: 6
From: Colorado
Here's a few as an example. I've seen others with much more epoxy then these. These aren't molded very much either, they are just basically poured in and left to dry. I've seen some with pretty smooth blending in the corners.
Last edited by Silver_Dodge; Jun 4, 2013 at 01:04 AM.
Veteran
Joined: Jun 2008
Posts: 389
Likes: 1
From: Fairfax VA
sounds like a bad idea. You are just adding a heat sink in the intake. It might show slightly better numbers at first, but I am sure once it heats up and the intake traps all that extra heat your numbers will drop. There is a reason they call it an 'airgap'.
Record Breaker
Joined: Jan 2009
Posts: 2,087
Likes: 0
From: Indiana
no, but i accidentally touched the exhaust manifold on the Oliver 1850 while towing irrigation
Had the person used conductive epoxies that are filled with Al,Silver, Au, then, yes, it would thermally add more mass thus absorb more heat, but, that leads to yet another issue. The last thing you want to do at the intake is to absorb and retain heat. This causes thermal loading at the intake level which, is the exact opposite of what the engineer designed in.
In the OEM design, the intent is to quickly absorb and dissipate the heat with thin walls- not retain heat with a lot of extra MASS. The last thing one wants is a super heat retaining intake that heats up the air as it passes into the combustion chamber. That's a way to drop HP for certain.
What you really want is a cold intake that keeps the air as cool as possible thus creating a denser air mixture at the intake level. This is why the Air Gap is called an air gap- there's a gap to allow air to flow in and around the intake thus providing for better cooling.
The other dumb thing about this in principal is just the mere idea of some material that may dislodge and end up ruining the valvetrain.
I work and specialize in chemicals used in bonding and, the question is, what is the material that was placed inside the intake that is bonded to the upper level on the intake?
Who makes the product, 3M, Dow Corning, Emerson, Eccobond, Epibond, ProSeal or, is this another Home Depot product intended for home remodeling use.
What's the heat rating of the epoxy in question and, what is the glass transition temp (Tg) of the product along with sheer stress and peel strength over time on Al? How was it cured? If it was not cured properly, you can forget about meeting the properties listed in the Technical Data Sheet.
There's many types of epoxies and, not all work on Al for one and, not all will work at that temp range without degrading over time.
If the epoxy is rated too high on the Tg, you may have embrittle material that will crack over time due to numerous expansion and contraction of the base material that it's bonded to thus ending up with some of the material flaking off and ending up in the valvetrain.
If the epoxy is not designed to be flexible and has poor Coefficient of Thermal Expansion, it will fail quickly.
The other factor is that Al is porous and, more so with cast aluminum than bar stock. This leads to yet another issue and that is surface tension issues- more so, lack thereof. It can't be degreased 100% and, with high heat, it induces failure rapidly. In order to adhere fully, the surface must be completely free from all oils, grease, and petroleum products in general.
I know for sure that here's oil and gas residuals in the pores of that intake, and, there's a high probability that it will bleed out under the epoxy thus weakening the bond lines. At that point, all you need is some thermal cycling to break it free like an ice cube from an ice tray to land it in the lifter valley.
I don't know why people do what is seen here because, it is really a bad idea with bad consequences if the material were to end up being sucked into the intake. Your looking at chipping and cracking or bending a valve with epoxy if it's hard enough. Then, when the piston comes up, BANG< you've just bent the crap out of the valve not to mention dinging the top of the piston and a possible force applied to the wrist pin and connecting rod.
Stupid practice is what this is. Just plain stupid. Trying to save a few bucks like this leads to spending $$$$ for repairs later.
Last edited by cmckenna; Jan 26, 2010 at 02:54 PM. Reason: Cooling of intake by means of air gap
That's not even a heat sink technically speaking because, the epoxy is not glass filled nor metal filled so, it's not doing squat as far as being thermally conductive. That material is probably rated at around .228 Btu-ft/ft2h °F which is not going to do anything for thermal conductivity.
Had the person used conductive epoxies that are filled with Al,Silver, Au, then, yes, it would thermally add more mass thus absorb more heat, but, that leads to yet another issue. The last thing you want to do at the intake is to absorb and retain heat. This causes thermal loading at the intake level which, is the exact opposite of what the engineer designed in.
In the OEM design, the intent is to quickly absorb and dissipate the heat with thin walls- not retain heat with a lot of extra MASS. The last thing one wants is a super heat retaining intake that heats up the air as it passes into the combustion chamber. That's a way to drop HP for certain.
What you really want is a cold intake that keeps the air as cool as possible thus creating a denser air mixture at the intake level. This is why the Air Gap is called an air gap- there's a gap to allow air to flow in and around the intake thus providing for better cooling.
The other dumb thing about this in principal is just the mere idea of some material that may dislodge and end up ruining the valvetrain.
I work and specialize in chemicals used in bonding and, the question is, what is the material that was placed inside the intake that is bonded to the upper level on the intake?
Who makes the product, 3M, Dow Corning, Emerson, Eccobond, Epibond, ProSeal or, is this another Home Depot product intended for home remodeling use.
What's the heat rating of the epoxy in question and, what is the glass transition temp (Tg) of the product along with sheer stress and peel strength over time on Al? How was it cured? If it was not cured properly, you can forget about meeting the properties listed in the Technical Data Sheet.
There's many types of epoxies and, not all work on Al for one and, not all will work at that temp range without degrading over time.
If the epoxy is rated too high on the Tg, you may have embrittle material that will crack over time due to numerous expansion and contraction of the base material that it's bonded to thus ending up with some of the material flaking off and ending up in the valvetrain.
If the epoxy is not designed to be flexible and has poor Coefficient of Thermal Expansion, it will fail quickly.
The other factor is that Al is porous and, more so with cast aluminum than bar stock. This leads to yet another issue and that is surface tension issues- more so, lack thereof. It can't be degreased 100% and, with high heat, it induces failure rapidly. In order to adhere fully, the surface must be completely free from all oils, grease, and petroleum products in general.
I know for sure that here's oil and gas residuals in the pores of that intake, and, there's a high probability that it will bleed out under the epoxy thus weakening the bond lines. At that point, all you need is some thermal cycling to break it free like an ice cube from an ice tray to land it in the lifter valley.
I don't know why people do what is seen here because, it is really a bad idea with bad consequences if the material were to end up being sucked into the intake. Your looking at chipping and cracking or bending a valve with epoxy if it's hard enough. Then, when the piston comes up, BANG< you've just bent the crap out of the valve not to mention dinging the top of the piston and a possible force applied to the wrist pin and connecting rod.
Stupid practice is what this is. Just plain stupid. Trying to save a few bucks like this leads to spending $$$$ for repairs later.
Had the person used conductive epoxies that are filled with Al,Silver, Au, then, yes, it would thermally add more mass thus absorb more heat, but, that leads to yet another issue. The last thing you want to do at the intake is to absorb and retain heat. This causes thermal loading at the intake level which, is the exact opposite of what the engineer designed in.
In the OEM design, the intent is to quickly absorb and dissipate the heat with thin walls- not retain heat with a lot of extra MASS. The last thing one wants is a super heat retaining intake that heats up the air as it passes into the combustion chamber. That's a way to drop HP for certain.
What you really want is a cold intake that keeps the air as cool as possible thus creating a denser air mixture at the intake level. This is why the Air Gap is called an air gap- there's a gap to allow air to flow in and around the intake thus providing for better cooling.
The other dumb thing about this in principal is just the mere idea of some material that may dislodge and end up ruining the valvetrain.
I work and specialize in chemicals used in bonding and, the question is, what is the material that was placed inside the intake that is bonded to the upper level on the intake?
Who makes the product, 3M, Dow Corning, Emerson, Eccobond, Epibond, ProSeal or, is this another Home Depot product intended for home remodeling use.
What's the heat rating of the epoxy in question and, what is the glass transition temp (Tg) of the product along with sheer stress and peel strength over time on Al? How was it cured? If it was not cured properly, you can forget about meeting the properties listed in the Technical Data Sheet.
There's many types of epoxies and, not all work on Al for one and, not all will work at that temp range without degrading over time.
If the epoxy is rated too high on the Tg, you may have embrittle material that will crack over time due to numerous expansion and contraction of the base material that it's bonded to thus ending up with some of the material flaking off and ending up in the valvetrain.
If the epoxy is not designed to be flexible and has poor Coefficient of Thermal Expansion, it will fail quickly.
The other factor is that Al is porous and, more so with cast aluminum than bar stock. This leads to yet another issue and that is surface tension issues- more so, lack thereof. It can't be degreased 100% and, with high heat, it induces failure rapidly. In order to adhere fully, the surface must be completely free from all oils, grease, and petroleum products in general.
I know for sure that here's oil and gas residuals in the pores of that intake, and, there's a high probability that it will bleed out under the epoxy thus weakening the bond lines. At that point, all you need is some thermal cycling to break it free like an ice cube from an ice tray to land it in the lifter valley.
I don't know why people do what is seen here because, it is really a bad idea with bad consequences if the material were to end up being sucked into the intake. Your looking at chipping and cracking or bending a valve with epoxy if it's hard enough. Then, when the piston comes up, BANG< you've just bent the crap out of the valve not to mention dinging the top of the piston and a possible force applied to the wrist pin and connecting rod.
Stupid practice is what this is. Just plain stupid. Trying to save a few bucks like this leads to spending $$$$ for repairs later.
