How Much Intake Manifold Heat Is Enough? Testing The Vaporization Temps Of Modern Gasoline 

A MASTER MECHANIC/ RESTORER taught me; WHEN PROPERLY TUNED, TIMING SET & CARB SET PROPERLY ITS: 1 2 3 relatively quick pumps to floor & wait 10-15 seconds for fuel to atomize and turn to vapor. Then turn key and it fires everytime and idles smooth and clean!! IT WORKS!!

P.S. I'm 78 years old so that theory has been around for a long, long time. All us Motor / Gearheads love your show. Been a MOPAR man since 1962, when I first got interested in speed and noise. Only new car I've ever owned was a 1964 Plymouth. Thank you very much for that idea ( RICHARD PETTY )❗👍🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸✌

Remember fuel line going thru a "Coolcans" full of ice?

I have been trying to balance this low temp boiling point problem with street driven carburetors for many years. I demonstrated this once for a customer who brought me a small block Chevy/Nova combo. It was properly and neatly installed, all new and the tune was reasonably close. He had a steady power loss as the temp came up but no overheating, max 195f. I cooled the engine with a larger radiator down to a steady 170deg f. Helped a little but after several miles on a warm/hot day he still started losing power. I plugged the exhaust crossover in the intake and fabricated a heat shield with insulator gasket under the Edelbrock carb, helped more. I demonstrated the gas boiling in the carb by running the Edelbrock carb with the top off, manually keeping the fuel bowls filled. Did this from a cold start to full temp. As the carb bowls reached around 150 deg f you could see the fuel start to boil. It, the fuel, looked really hot boiling. When I stuck my finger in the boiling fuel in the bowl and held it there it demonstrated that it wasn't as hot as it looked.

The Clifford intake has a water box built into it. When I first installed that intake on my slant, I didn't hook it up because I didn't have any extra heater hose. I barely made it around the block. Next day, hooked it into the cooling system and I've been driving without a problem since.

After several attempts with wraps and oil line cooling hoses we came up with either an oil cooler or a heater core for under the manifold. Installed a temp probe at the plenum to maintain temp at 150 to 165 degrees F. It was definitely a street killer of V8's. Just some thoughts.

Back when I was a smog mechanic. I learned that a carburetor at 100° outside temperature would run at 32°/freezing, that's why guys at the out in the desert with their sand buggies added really huge Jets to make it not stumble, what they didn't know it was ice crystals forming inside the carburetor. Thanks for remind me of something I forgot. Keep up the good work I like the way you teach these new kids.

Fabricate an aluminum plate and bolt it to the bottom of your intake. Drill and tap two 1/2" pipe thread holes in the plate. Screw in two heater hose fittings. Attach a heater hose to each pipe fitting. You now have a heated intake manifold. So very simple and easy to do. Install a shut off valve on one hose to limit heat buildup. I made one for my old Plymouth flathead six and the drivability increased by 50%. You got this!

I believe that as soon as you stomp the gas after the intake reaches 150 degrees, the intake charge (atmosphere) will suck most of that heat away, I have a homemade aluminum intake that even in the summer would develop a layer of frost/ice between the carb and the head, I wrapped the runner with the oil cooler hose and improved driveability enormously

Just for fun, I looked up C16: boiling begins at 193 and the upper end of vapor range [90%] is 226 degrees. That puts a midpoint around 209 degrees. Vaporization is done [no liquid remains] at 351 degrees. Jenkins was near a walking encyclopedia of all things combustion engine.

Garage 54 in Russia made a perspex intake manifold for a Lada, the result was interesting and probably shows what you are talking about at cold manifold temps. worth the 20 mins or so to watch

You could make a small heat exchanger out of copper pipe and stick it to the bottom of the intake and circulate coolant through it. Use a heater valve to regulate the flow so you can get the temp you want.

Not knocking the carb, but I now see why port injection is more controllable and preferred in modern engines when it comes to fuel efficiency and energy production. The injector is atomizing cold fuel right on the hot bits.

Tony - I'd take the temperatures you were reading off that bare aluminum sheet with a BIG grain of salt - IR thermometers measure radiated infrared, and are typically calibrated for an emissivity (how readily a surface emits IR) of 0.95. Materials like that aluminum normally have an emissivity closer to half of that or less, and as a result will read lower than their actual temperature. To test it, try painting a part of the surface of your aluminum plate flat black, then heat it again and repeat your measurement with the IR gun, pointing it at both the painted area and the plain area right next to it. My bet is that the black area will "appear" a lot hotter to the thermometer, thought both are actually the same temp. Just something to be aware of with IR thermometers, and something that's much more obvious with IR cameras that show an image - shiny metal will often look cold relative to more emissive things nearby. When measuring components on a circuit board that have metal cans, I usually put a piece of blue painter's tape on them to get a more accurate reading. The painted parts of the engine are likely much closer to reading their true temp, though still might show a bit cooler than they truly are. The header should be pretty much spot on.

Tony, a simple and low-cost mod is to install a temp sender to measure the manifold temp. not the air temp! the temp of the metal of your manifold. Your pick of a coolant or oil temp sensor, then use a toggle switch to display it on a suitable OEM gauge! FWIW use a toggle switch with enough poles to include the switching needed for indicator lamps..

I had a 1980 LeBaron that the previous owner put large piece of aluminum under the carb. And a shroud under the exhaust to the intake. 30 pluse years being a mechanic, was wondering what they were thinking. Now I know why my slant 6 ran so good. You figured it out. Sad part is somebody beat you to it. Love your channel. Keep it up.

My wrenching mostly occurs in the context of my 1951 pickup with a slightly later 235 “Stovebolt” inline 6. This is a familiar issue to those with Stovebolts. The factory 216/235 setup works really well for a driver. It’s a heat flap on the exhaust manifold that warms the intake under the carb. A bimetallic spring opens/ closes to regulate it. One of the challenges for those who run aftermarket aluminum intakes or especially headers, is having a way to heat the intake absent the factory setup. Some intakes have provisions for a tube that supplies coolant or exhaust via copper lines. Some have rigged up their own setups. Lots and lots of disparate opinions on how well the aftermarket setups work, if at all. For your application…a drag only car, I suspect your idea of a long warm up is the most logical place to start. One concern: since you’re running with no charging system, will the battery voltage drop enough during the warmup to create ignition system weirdness?

tony I am an old gezzer, my fist attempt at racing was a Pontiac 261 6. I made a 3 signal manifold, it did basically the same thing, the first couple laps it was a dog, so I a made a heating device for /under the manifold and plumed heater water to it and back , it worked great

I like your tunnel ram demo. It explains my hair loss when I was 24. I was helping a buddy with a hesitation problem on his tunnel ram in a '65 Chev pickup. I was watching under the hood when he hit the gas. It lean back fired and this huge fireball came out from under the hood and burned the hair off the top of my head... My hair never came back... HAHAHA

I agree with @ homotorsports . Will the higher air fuel mixture flow during burnouts cool off the plenum more than it can reheat before you make your run. You should test it before the weekend so you don't waste the trip to find out it doesn't reheat and it does the same as your other runs and bogs.

Jeep 258’s had an electric plenum heater under the carb in the intake..

I wonder if you drilled and tapped the intake to take a temp sensor, let the sensor butt up against the casting, so it reads the casting temp then add a temp gauge for it. It may not read the exact temp but I'm sure you could likely figure out a delta using a gauge and the temp gun. That could make for some fun and easy data collecting and testing.

You're on to something here. I had a 39 year career as a Chief Engineer in a power plant and during that time I worked along with quite a few combustion engineers. We wouldn't have used air pre-heaters, on power boilers, ahead of burner windboxes if hot air didn't speed combustion. There is a lot going on in an engine intake manifold. A cool dense air mixture is a good thing going in but once the fuel enters the plenum it should pick up enough heat to give a kick (you call flash) to the fuel mixture to get efficient combustion so there is no stumble or bog coming off the line. I'd be careful adding auxiliary heat. You're probably better with an extended warm up time if you can make due with that. Fred

It is interesting to note that not a single slant 6 racer heats the intake and none of them is having your problems. Maybe you you should reach out the "rusters" owner and ask his advise.

I always enjoy your content Uncle Tony. It seems you broke from your normal way of optimization of the existing systems. The engineer may have had more than fuel economy in mind when they made the exhaust manifold bolt to that section of the intake, possibly they ran into the same issue you are fighting during the R&D. Keep up the good work on Plan Z!

Great great video!! Made me think back. The Wright Brothers first motor had no carb. It dripped gasoline a plate that vaporized the gas as the motor heated up. How they got it to start I can not imagine much trust this arrangement to fly blows me away😜

You have to have a good heat source because vaporizing gas takes a lot of heat because of the latent heat of vaporization. When you heat the manifold up and it vaporizes some quantity of gasoline, that process takes a bunch of heat. More than you would think. It's basically an evaporative cooling effect.

Smoky Yunick used to swear on 200-210 degrees for circle track engines the hot air engine had a inlet temp of 450 degrees

Use a heated coolant from the heater feed ports to a heat a block bolted to the bottom of the intake. You could use a heater control valve to regulate temperature.

As soon as I saw that Amway squirt bottle, I knew this was going to be a great UTG !

This content is fascinating. I know others may think not but they don't get it. I love this subject. Atomizing and vapour and heat. Really, really good stuff that I'm going to be watching for your results with great interest. Thanks UT!

Why not make a plate that bolts up like the stock exhaust manifold and run engine coolant through the plate? You could run a 160 thermostat and hopefully get your 150 under the carb. I used to be in the Ford 300 scene and that’s what we did. Your correct on how the carb needs to be facing. The 300’s would do the same thing without heat. With no heat my 300 was not drivable at outside temps under 55 degrees F. I love the Slant content btw

Great experiment! I have heard of the water passage heater blocks for those manifolds. Never had an issue with my cast iron (keyword cast iron) manifold.

Don't forget too, that when fuel boils off the heat of one's intake manifold, it is flash chilling the manifold. So the heat is instantly being lost to the fuel, meaning that just heating it with the ambient heat of the engine compartment will not last very long. You need a steady heat supply to keep it from icing out.

Wicked good vid Uncle Tony! I love how you break it all down in easy ways to understand. Can't wait to see the vid of Plan Z's next pass! Cheers from Maine!

Good stuff Tony. I like the “choke” analogy for getting enough vapor to run a cold engine. David Visard talked about racing a Chrysler that stock had a hole to vent exhaust gas onto the bottom of the intake. He blocked the hole, but had to engineer a carb that would make very fine droplets. Darin Morgan says that the droplets in the chamber when it ignites, do nothing but heat your exhaust valve. George Bryce says it’s mostly just the pressure in the power stroke for the first half that do the work. That’s why you open the exhaust halfway down on the power stroke since the pressure isn’t doing much work anymore anyway.

I have seen so many tuning problems that just come down from a cold intake manifold. Many always blame the carb. End up with an over jetted mess that still doesnt run well. Uncle Tony clearly shows that in this video. Like he said, i also grew up around blocked off intake heat for power. But on a hot street car, that can be a real PITA... I used to get on this forum that mostly talked on Ford 240/300 inline six truck engines. The first thing most guys did was put exhaust headers on, a open plenum 4 barrel intake. Then try and live with it as a daily driver. I tried to help many on there with their tuning issues, some figured it out. Adding a coolant plate under the intake plenum to warm it, is a good bandaid fix. On my truck set up the same way, but no tube headers. I made my own split cast iron exhaust manifolds, that retained the factory heat riser bolted the the intake manifold. My 390 Holley 4 barrel works perfect, with the jets that came in it... Any inline six engine suffers from too cold of an intake, because it hangs away from the engine heat, unlike a V8. That is any inline six modified like this... Uncle Tony, i believe you will have to bite the bullet, and add some form of heat to your Slant six intake, ( more than you want). Just to get the car to launch well, even if it costs you some top end power... Love your videos !

Australia 1970 , Chrysler Australia used the mighty Valiant VG 4 door Pacer as their race cars , the standard 245 CI HEMI 6 was taken out to 251 CI and a 4 BBL Carter carb fitted , these cars went HARD ! kept up with the Ford and GM V8's on the long tracks and beat them on Australia's short tacks because of a 3 speed manual gearbox just using 2nd and 3rd . But ,, as you say Uncle Tony they had no end of trouble with the 4BBL flooding when fitted the standard V8 way ,, it had big top end power but bogged and with a 3 speed was slow at start and out of the corners . So what they did was exactly what you have done here and turned the 4BBL 90 degrees and it fixed that major problem , they became very competitive , then in 1971 the VG was superceded by the mighty VH 2 door Charger with 265 CI and triple Webbers and 280hp on the E38 3 speed and 320hp on the 4 speed E49 ,, Australia's fastest accelerating production car until 2002 when Ford made the 6 cylinder 'Barra' Turbo 6 , Falcon BA . So from 1971 to 2002 they were the fastest ,, good history . FYI , the 4BBL Pacer was named so , not because the had a 4 barrel carb , 4BBL stood for ' Four Big Bad Litre's ' Love Plan Z and look forward to Saturday , Thanks Uncle Tony .

I love how you're experimenting. Very cool. As far as testing vaporization on the aluminum plate, I'd suggesting making a plate about the size of the carburator baseplate in the form of a dish. That alum. plate you used probably has a big temp gradient making it inaccurate. The google says gas has a starting boiling point of 95F. Heat a bit of gas in that dish with an oven thermometer for temps. The infrared gun may not be as accurate as a direct reading thermometer immersed in the gasoline.

I do agree with monitoring Temps at the track before modification. But depending on what the coolant Temps are you could fabricate a water jacket under the plenum and run water lines with a valve to control flow and have some control on how much it heats the bottom of the plenum

This is awesome and great info makes sense why vapor lock is more of a thing than it used to be

I run all my engines at 160 Fahrenheit 70 Celsus. Dyno tests have shown this temp to make the most Horsetorques. So what you are saying makes total sense to me.

Had two darts as a teen and both had slant sixes. The stock configuration had the exhaust manifold attached to the intake (And both cars would vapor lock on summer days). This configuration was the norm going back to the inline 4's, 6's and inline 8's of the 20 -30's. On Chevy v8's I would restrict both heat runners with a piece of stainless sheet metal with a 1/4 inch hole in each because the Holly carb would warp the throttle plate and cause air leaks. Another important thing with engine temp is making sure your oil gets to 215~220 to cook off any moisture that can accumulate in the crankcase from the PCV system sucking humid air in.

plenum temps before n after a burnout should tell you the cooling power at full throttle.

Genuine hotrod stuff right there. Thanks Uncle Tony!

I think you got the mixtures in a CCVC engine arse about Tony. The prechamber is the overly rich one and that lights the ultra lean mixture in the combustion chamber. A great idea for taking care of emissions.

ford used to use an adaptor that went between the carb and intake that had water running through it. maybe you could find one and use that. that would give you engine heat at the intake.

You could always mount a block heater on the bottom of the intake underneath the carburetor to preheat the intake. Love your videos, keep it up.

Interesting video, how about building a tunnel ram for the slant. Simple exhaust tubing and a box for a plenum up through hood. Would be a cool experiment.

You want to get one of those Dutra or Aussiespeed 4 barrel manifolds for that. You'll probably pick up a few HP too, but I think the casting is actually thicker and that one you have looks pretty thin so it'll likely shed heat pretty quickly, the opposite of what youre trying to do. I was reading the Grumpy Jenkins power secrets book the other day, and he said they use off the shelf GM block heaters to pre heat the engine before running to temp. It's amazing what they achieved back then with only factory GM blocks and castings and a tenth of the aftermarket gear available compared to today!

Grump painted the outside of the gas tank white and the inside black to keep the fuel cool. Also ran extra long hose in the coil to reduce fuel temperature. Grump was the boss. His influence was far and broad

Absolutely excellent video Tony !! Your explanation made perfect sense especially when you heated the plate !! Great work !!

Science with Unk Tony! The way you explain things makes it so easy for me to digest. Thank you for sharing your knowledge with us all. It's valuable, really valuable to us that are just beginning this hotrod journey

From what I remember from technology class in high school was 200 was the degree that metal molecules become the most compact and strongest for wear (that is a brief summary)

I've made copper gaskets back in the day, and it's pretty easy. Copper will transfer heat from the head as soon as it heals up.

Awesome video. Thank you. Now understand a little bit better why my '86 AMC Eagle has a factory electric heater element in the intake under the carb. I had an idea, but it didn't click until this video.

In high school I had a 292 Chevy 6 with a 2bbl and dual 3-1 headers, I had the Same issue the truck ran great with a 10-1 compression and a ported head but would never launch of the line it would stall pop and rip away the answer years later I figured out the solution with a manifold heater

I had a similar problem when I hot rodded a 69 Rambler American with a 258 inline six cylinder. Like the slant six the manifolds had a boss/flange where the manifolds bolted together. When I installed headers the intake lost the heat important for winter drivability. I made a steel plate to bolt to the intake manifold flange. Welded fittings to it and ran the heater hose through it. To regulate the temperature, plumb a shut-off valve into the line. Adjust it to get the temp you want. Or… Be a little more sophisticated rig a variable thermostat into the line. You could set it for the ideal temperature. It would be self regulating to keep the manifold temperature constant. I would put the variable thermostat downstream to keep the intake manifold at the temp you want.

The vapor fuse thing makes sense. Good explanation. I’m interested to see how it plays out.

For the winter time in NJ back years ago I used to have a plate that would snap in between the headers. It was a place I could stick a Sterno heater under the intake to pre heat and warm it up before I take off .

Tony, For my build, I used a Clifford Performance 6=8 coolant heated intake manifold with great results. I put a Holley HP 4150 on it with flawless results. It might be worth the time and $ if you want to stick with the 4 barrel. I was tempted to go with the triple 2 barrel Weber side draft kit, but it was a LOT more $. I can't wait to see what you finally settle on for the solution to this issue.

Also when you are using the choke it's actually dropping the atmosphere pressure to allow the fuel to vapourize.

I find this very interesting and its a good reminder that engine needs heat to operate correctly. Trying to make everything run cool is not always the best solution. Good Work Tony.

Need to get one of those thermal cameras to see how the heat is spreading throughout the runners. Can get some decent resolution thermal cameras now for a couple hundred dollars. Also good to see how the heat is distributed through the exhaust headers.

The Canadians have a stick on heating pad that’s electric for use on tool boxes, metal workbenches, etc. Certainly lightweight, and may also be DC.

Uncle Tony, your timing is almost perfect. I've just been watching David Vizard talking about how much fuel needs to be vapour and how insulating the intake too much from engine heat can drop power. He also expounds on booster types and how much each type reacts to flow signals and how different designs of booster atomize fuel. Have you guys been coordinating this?

I had a Dodge Colt that had a coolant heated carb. I never heard of that, besides carb de-icers on WWII radials, which were oil heated ( some electric late in the war) It started leaking, but not knowing the design, figured it was a blown head. Ended up selling it to a guy that ice races on lake Winnepesauki who was happy as shit to have finally found one!

Those IR temperature sensors have a setting (resistivity?) that effects the reported temperature. Perhaps not super critical but the actual measured temperature is affected by the metal type and surface treatment. So a black cast iron surface needs a different meter setting vs a painted/anodized aluminum one. it's been a while but I think a 5- or 10-degree Celsius error is possible.

Very interesting problem Unk. Something you might try is a whiffer....A few ounces of acetone might start that cold gas burning. Depending on how much is used, you may have to back off the timing a bit....OR....Some winter blended gas. We use lots of it in the frozen north

I'd be looking for a better intake manifold for the slant six. Something where the runners curve down and then up so that the air/fuel doesn't need to make a sharp 90 degree turn. Something more like the tunnel ram at the beginning of this video. You may have to custom fabricate one.

Before this vid there was an ad for Fast X. Diesel launched a car off a highway about 30 feet down on to another road, and kept driving. Do whatever Vin Diesel does Tony. Obviously, it works.

G'day, I recon a heat riser pipe, bolted to underside of manifold, extending down to exhaust. 4-6 inch dia. or multiplesmaller pipes. If it's too hot, drill holes in it. If not hot enough, add more pipes. Anyway, good luck with it.

This is so innovative but also the science behind it is as old as dirt. But this is hot rodding, this is the test and tune that you learn from and blow people's minds as to how you figure s**t out. Nobody else on RU-vid talks about this stuff and thats exactly why im here. But i do still blame squirrels every day but you cant do much about it. The only thing you need to do is add a old style temp gauge in the intake plenum so you can keep an eye on it in the staging lanes. I Cant wait to see what happens next!

Hello Tony, Your plan of not adding a hot spot under the carb until more testing is done is wise. Hell this who idea (though I think likely) could be completely wrong. If this does work adding a independently powered hot spot might well be a good idea (as you said). While the traditional way of doing this is with exhaust heating or coolant heating, there has also been electrical heating. Knowing your liking of low budget, you should know that the AMC 258 using the aluminum intake for the 2 barrel carb used this system. My thought is if you could have a hot spot under the carb with the remainder of the manifold relatively cold, the accelerator pump shot would hit the heater and vaporize. Given the relatively small mass of the heater, it would cool significantly. Any following air/gas would not be overly heated leading to a best of both worlds. Well in theory. p.s. I really like your videos, it is easy to show how to go fast using $, it is nice to see someone showing how to do it with skill and time. One can always turn to the $ if I run out of either. Fortunately I have not had to, as putting someone eases skill/time in my rig would not make it truly mine.

This reminds me of why i use WMI in the volutes of the turbos, give it plenty of time to phase change and take as much heat energy as possible. I have gotten drastic reduction in boost temps this way. My cars are fuel injected(on is direct injection) but i do understand your point.

You proved me wrong. Back to the drawing board to make your intake manifold temperature equal. DOH! Mikel

I’ve dealt with many off idle stumbles, flat spots etc. 90% of the time it was the idle mixture screws either too rich or to lean. Even if you think they are set perfect, it’s best to test on an off idle launch. Adjust one way or the other and see if it starts to correct itself, if that doesn’t help at all then deal with the squirters, accel pumps etc. a lot of people jump to adding more fuel out of the box when they stumble.

Keep goin tony love the content you are teaching valuable stuff whether your right or wrong u get people's gears turning in they mind if u want to see if" turning" the carb works better fine do it yourself I know on my offy in my 300 6 sideways or "the wrong way" worked for me but I took the time made an adapter and experimented and had fun and I'm not gonna judge anyone for doin it how it says to do it u always get a thumbs up from me tony God bless u and andy

Great video, I really like the way you show your work. With this Saturday being another step to prove your theory.

I see this on the next “this mag guy says I’m wrong” motor trend episode literally(David’s voice) love utg keep this coming

When you talked about that "pre-chamber" ignition system, that is what they are doing in F1 to be able to run a leaner mixture, and extract the most possible energy from combustion event.

Heat, vaporization and atomization. This is a great subject. There is so much to learn here. Everybody talks about how to get heat to the intake but does not talk about how to maintain it. Since this is just a drag car you let the engine warm the intake by idling the engine to operating temperature. This solves the problem without having to do any extra work or adding parts. What suggestions do you have for making this kind of engine streetable for daily driver use?

What about making a couple sheet metal sheilds from the intake manifold down to the headers to collect some heat?

I agree with all you are saying, I am also remembering the old trick of running fuel through a "cold can " to increase fuel density, and the "come alive " feeling of a carbureted motor on the first cold day of fall. I find I do not always understand all the things I know. I guess we can assume that your intake manifold for water circulation?

Great Analogies. Thanks, Uncle Tony!

After watching the entire video, I can suggest to get the engine temp to normal operating temp. If I can recall, the thermostat in those engines were 180/190 deg. I'm old, so I may be off on the thermostat. But it would help the engine efficiently to warm it up before you run it.

Excellent testing…Just wondering if the the intake temp will drop during the burnout from the air and fuel flow…You can test that before you go

good demo , perfect way to show the concept!

Welcome back professor, nice to see you again.👍

Very interesting. Looking forward to seeing how that changes thing's up at the strip.

Great video as always! Arm chair suggestion: adjust the driver's side shock tower so the carb/intake tilts towards the passenger side. May give more gravity assistance from carb to cylinder head. Luv your channel!

I wonder if the lowered boiling point is because of the ethanol blended fuel

Great Video!

Jeeze, you're like the HVAC Guy of Engines over here. Brilliant explanation.

Awesome video, very informative!

Your channel gets me listening learning but best is keeps me thinking, must be why I look forward to next video looking forward to how you work it all out. No doubt you'll hit your target. Frustration = Fun after aggravation that's a way of life in Canada aye Danny..

Chrysler wants the carburetor set so that the floats react to 1, the slosh on launch [fuel bowls] as well as 2, the tip angle of the engine, based on the angle of the drive pinion angle.

Great video, very informative. Thanks

I blocked off the exhaust crossover on my 390 FE cyl heads in the hopes of extra HP what I ended up doing was creating a stumble at take off if the motor sits for more than10-15 minutes. It all makes sense now , thanks once again for the knowledge Uncle Tony. One of these days I'm going to send you a free f@#$ing pizza.

Humm, really interesting and not an issue I would have guessed, learning from UTG. Looking forward to see the testing results. I would be mildly surprised if this turns out to be the sole source of the issues but after the explanation, I can see how this is a contributing issue. Kind of goes against the idea of cooling the charge for more power.