Just installed md isothermal manifold gasket, ccv.
09-25-2005, 06:59 AM
#1
Just installed md isothermal manifold gasket, ccv.
then i took it for a spirited 50 mi drive. when i got home, i opened the hood, placed my hand on the plenum, and what did i feel? lukewarm at best. actually btwn lukewarm and cool. the **** works!
now what i didn't do is go for a 50 mile drive and do the hand test before i installed it. someone go do that and post back here. as i recall, the plenum normally gets pretty hot.
my z feels stronger upon accel, even in 5th.
good work, tony!
ps: i poured some oil into the plastic bag the gasket came in to lubricate it.
now what i didn't do is go for a 50 mile drive and do the hand test before i installed it. someone go do that and post back here. as i recall, the plenum normally gets pretty hot.
my z feels stronger upon accel, even in 5th.
good work, tony!
ps: i poured some oil into the plastic bag the gasket came in to lubricate it.
Last edited by Z BOY; 09-25-2005 at 07:06 AM.
09-25-2005, 07:50 AM
#6
I can attest to the fact that after 10 minutes you can't leave you hand on the plenum for long - it get's that hot. Temperature measurements that I took show the upper plenum getting in the 120ºF to 150ºF range. I can't wait to get my gasket and get it installed.
Trending Topics
09-25-2005, 01:56 PM
#8
frankly, i'm amazed at how cool the plenum and tb were after my test drive. i mean, i figured it would be better, cuz tony is pretty much a genius, but it far exceeded my expectations. it was like they weren't exposed to heat at all. you guys will love it.
09-25-2005, 02:22 PM
#9
The idea of thermal gaskets is not new, what Tony appears to have come up with is a improved gasket that is not as thick as previous ones. The MD gasket is 1/16" thick where as the others I've investigated were 1/8" thick. That doesn't sound like much but when you have the plenum spacer in place, that doesn't leave a whole lot of room between the plenum and strutbar and/or strutbar and hood.
09-25-2005, 07:18 PM
#11
Thanks for the props guys!
Yeah, I really researched many different materials for this application. And like you said DavesZ#3, there isn't much room to work with under the strut bar so material selection makes a big difference when you want to have the lowest heat transfer.
I looked into fibrerglass composites, silicone based materials, nylon, phenolic, and various plastics before selecting Aramid as the material of choice.
Of all the materials reviewed, Aramid has the lowest thermal conductivity @ 0.18 WMK. Most other materials are 0.24 WMK or higher. This may not seem like much of a difference, but it means the Aramid can be 25% thinner and have the same insulating effect. Or another way, with the same thickness used, Aramid will conduct 25% less heat! That's a trait worth utilizing.
Phenolic based compounds have a WMK quite a bit higher than most of the other compounds and at 500'F, phenolic doesn't have as good a long therm heat resistance as Aramid.
Aramid is a kevlar like material. Very similar chemical structure but rather than being used for bullet proofing, Aramid is used for fire proofing.
At extreme temperatures it can be made to decompose and vaporize, but it will never melt. In fact, it is so heat resistant, you can take a piece of the Iso Thermal gasket material and light it on fire with a torch. You will see that it can be made to ignite but what burns is the rubbery binder that holds the Aramid fibers together. After it burns out, the gasket is still there... At least the Aramid is anyways. The Aramid does not burn... it just stays in place like nothing happened. The ramainder is like a dense felt pad.
Yeah, I really researched many different materials for this application. And like you said DavesZ#3, there isn't much room to work with under the strut bar so material selection makes a big difference when you want to have the lowest heat transfer.
I looked into fibrerglass composites, silicone based materials, nylon, phenolic, and various plastics before selecting Aramid as the material of choice.
Of all the materials reviewed, Aramid has the lowest thermal conductivity @ 0.18 WMK. Most other materials are 0.24 WMK or higher. This may not seem like much of a difference, but it means the Aramid can be 25% thinner and have the same insulating effect. Or another way, with the same thickness used, Aramid will conduct 25% less heat! That's a trait worth utilizing.
Phenolic based compounds have a WMK quite a bit higher than most of the other compounds and at 500'F, phenolic doesn't have as good a long therm heat resistance as Aramid.
Aramid is a kevlar like material. Very similar chemical structure but rather than being used for bullet proofing, Aramid is used for fire proofing.
At extreme temperatures it can be made to decompose and vaporize, but it will never melt. In fact, it is so heat resistant, you can take a piece of the Iso Thermal gasket material and light it on fire with a torch. You will see that it can be made to ignite but what burns is the rubbery binder that holds the Aramid fibers together. After it burns out, the gasket is still there... At least the Aramid is anyways. The Aramid does not burn... it just stays in place like nothing happened. The ramainder is like a dense felt pad.
09-26-2005, 08:04 PM
#14
Registered User
Join Date: Dec 2004
Location: houston
Posts: 65
Likes: 0
Received 0 Likes
on
0 Posts
tony,
I have your 3/8 spacer and understand the principle behind the added plenum volume for the front 2 cylinders...........
Can you explain how long the air is inside the plenum? What velocity? The heat transfer rate from the hot plenum surface to the air (I know its a variable, but how about an average?) Did you take measurements of air flow temperature with and without the thermal gasket to verify that the air is heating up therefore expanding and reducing the air charge?
There is no doubt that the plenum gets very hot! Heatsoak has been discussed in other threads, but I have not experienced this (or did not recognize it when it happend)........so just a few questions.....
Thanks Shooter
I have your 3/8 spacer and understand the principle behind the added plenum volume for the front 2 cylinders...........
Can you explain how long the air is inside the plenum? What velocity? The heat transfer rate from the hot plenum surface to the air (I know its a variable, but how about an average?) Did you take measurements of air flow temperature with and without the thermal gasket to verify that the air is heating up therefore expanding and reducing the air charge?
There is no doubt that the plenum gets very hot! Heatsoak has been discussed in other threads, but I have not experienced this (or did not recognize it when it happend)........so just a few questions.....
Thanks Shooter
09-26-2005, 09:44 PM
#15
I did the same thing on Sunday evening along with the plenum spacer and was amazed on how cool the car ran after about 30-40 minutes. The plenum was lukewarm to the touch and the TB was ice cold! I remember burning myself many of times at the track from heat soak that the plenum would incur, but with the Isothermal gasket and CCV from motordyne, I for once can stop burning myself! 
I will add a new update on my TS reflash with dyno results thread when I get the A/F ratio remapped and get a new dyno number at the g35driver.com dyno day
I will add a new update on my TS reflash with dyno results thread when I get the A/F ratio remapped and get a new dyno number at the g35driver.com dyno day
Last edited by Rickdogg; 09-26-2005 at 09:49 PM.
09-26-2005, 09:48 PM
#16
Originally Posted by Z Boy
ps: i poured some oil into the plastic bag the gasket came in to lubricate it.
09-26-2005, 10:04 PM
#17
Hi Shooter,
The air isn't in the plenum for too long, but the transfer rate is much higher in that area than it is in the intake tube for example. Because the flow in the runners is pulsed/oscilating flow, it has a way of scrubbing the hot boundary layer right off the plenum. The air flow in there is very turbulent.
I havn't been able to measure the difference in air temperature just yet, but I know it will be somewhat high. Probably about half the difference between the ambient and the plenum temperature, possibly more.
I did a similar measurement on the stock intake tube and found there was indeed a considerable amount of heat getting into the air through the simple plastic stock air tube. I wouldn't have believed it if I didn't measure it myself with thermocouples.
Even if it would be difficult to put thermocouples into the lower plenum air stream, there is another way to find the heat input... I found that when the Iso thermal system is installed, it cut the heat soak rate in half.
Now that is heat only comming up through the lower intake manifold. Rather than the normal plenum temperature rise of 3-4 degrees/minute, the gasket cut the soak rate to about 1.2 degrees/minute.
This is important. It tells us exactly how much heat is soaking in through the lower manifold. The mass of the plenum assembly is known. The heat capacity of aluminum is known. Therefore, the total number of BTU/minute of soak are known.
When the engine is running and the plenum is in thermal equilibrium, the heat transfering through the lower plenum is equal to the heat transfering into the air.
Because we know the air flow rate (can be found), and the heat capasity of air is known. We can calculate the rise in temperature of the air.
The only problem is, I havn't done the calculation yet.
Its not hard, it will just take a little time to gather all the variables and constants.
I could either do that or just put thermocouples in the flow stream of one of the runners and be done with it.
The air isn't in the plenum for too long, but the transfer rate is much higher in that area than it is in the intake tube for example. Because the flow in the runners is pulsed/oscilating flow, it has a way of scrubbing the hot boundary layer right off the plenum. The air flow in there is very turbulent.
I havn't been able to measure the difference in air temperature just yet, but I know it will be somewhat high. Probably about half the difference between the ambient and the plenum temperature, possibly more.
I did a similar measurement on the stock intake tube and found there was indeed a considerable amount of heat getting into the air through the simple plastic stock air tube. I wouldn't have believed it if I didn't measure it myself with thermocouples.
Even if it would be difficult to put thermocouples into the lower plenum air stream, there is another way to find the heat input... I found that when the Iso thermal system is installed, it cut the heat soak rate in half.
Now that is heat only comming up through the lower intake manifold. Rather than the normal plenum temperature rise of 3-4 degrees/minute, the gasket cut the soak rate to about 1.2 degrees/minute.
This is important. It tells us exactly how much heat is soaking in through the lower manifold. The mass of the plenum assembly is known. The heat capacity of aluminum is known. Therefore, the total number of BTU/minute of soak are known.
When the engine is running and the plenum is in thermal equilibrium, the heat transfering through the lower plenum is equal to the heat transfering into the air.
Because we know the air flow rate (can be found), and the heat capasity of air is known. We can calculate the rise in temperature of the air.
The only problem is, I havn't done the calculation yet.
Its not hard, it will just take a little time to gather all the variables and constants.I could either do that or just put thermocouples in the flow stream of one of the runners and be done with it.
09-27-2005, 05:44 PM
#18
Registered User
Join Date: Sep 2003
Location: Del Rio, Texas
Posts: 790
Likes: 0
Received 0 Likes
on
0 Posts
Hate to cause problems, but my car's plenum is "lukewarm" as well after a bunch of driving. The plenum gets hot when there isn't much air flowing through it. If I get done driving at night and immediately pop the hood, the plenum and intake pipe are both cool to the touch. In 5 minutes though, it's scorching.
When you're driving the car, many times more air goes through the plenum than when it's idling. A test "after" driving isn't what we need, it's a test "while" driving.
When you're driving the car, many times more air goes through the plenum than when it's idling. A test "after" driving isn't what we need, it's a test "while" driving.
09-27-2005, 06:30 PM
#19
Just someone buy a "digital doc", I have one on my computer, it has tempurature tapes and bulbs that you put on each device you want to measure, it is used to turn on fans, but you could use it to just get the temps. Think it runs on 5 or 12V, I paid around $50 about two years ago. Then you could get temp readings whenever you want them, from 8 locations if I am not mistaken, just have the passenger read the temps, because I don't want you killed while driving.
09-27-2005, 07:12 PM
#20
Originally Posted by UsafaRice
...When you're driving the car, many times more air goes through the plenum than when it's idling. A test "after" driving isn't what we need, it's a test "while" driving.
The Iso Thermal decreases plenum temperatures significantly while driving. And it is true that how you drive affects the plenum equilibrium temperature.
I did all of my pre/post benchmark testing with the car in cruise control at 70 mph on the same stretch of freeway for 10 minute intervals, with the same ambient temperatures. I had thermocouples all over the plenum and measured a 30'F-60'F drop in temperature.
Two others measured plenum temperatures immediatly after stopping the car and measured temperatures consistantly in the same locations with an infarometer. OCG35 documented his measurements over a 2 week period very extensively. Using the same commute, he measured a 36'F-81'F drop in temperature. Others have done it less scientifically but all positive results the same.
When Iso Thermal is installed, weather you measure it or just feel the plenum, it is clear that it significantly reduces plenum temperatures.