Technical How can a valve cover heat up fuel lines?

JohnDaviz

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its vice versa. Aluminum is a better heat transfer material than the plastic. So IF it has an impact it is the aluminum.
 
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9krpmrx8

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Just curious what the fuel temperature difference is on the m18 valve cover compared to oem with the factory beauty cover on? I would imagine that the oem valve cover with the cover would heat the fuel lines more than an aluminum valve cover. I also would think that difference would be miniscule compared to how much the injectors itself heats the fuel since it is actually in the combustion chamber. If it truly is an issue with heat radiating from the valve cover causing an issue could one temporarily use a thermal blocking material between the line and the valve cover to test. I would be willing to bet there was no difference and any issue resolved by switching the valve cover back was coincidental.

It would be interesting to hear from someone who used the Fuel it or Spool ethanol analysers before and after to see temp differences.

I thought it was fuel cooling on the Hellcat but it's for charge temps. Mercedes does or did use fuel coolers though that tapped into the AC system.

 
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martymil

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It would be interesting to hear from someone who used the Fuel it or Spool ethanol analysers before and after to see temp differences.

I thought it was fuel cooling on the Hellcat but it's for charge temps. Mercedes does or did use fuel coolers though that tapped into the AC system.


You cant measure the temp after the HPFP using the ethanol sensor as its a non return style system, you have to use a IR non contact thermometer.

Yes chilling the fuel will help somewhat especially if your running pi as this would have the best benefit.
 
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The Convert

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You cant measure the temp after the HPFP using the ethanol sensor as its a non return style system, you have to use a IR non contact thermometer.

Yes chilling the fuel will help somewhat especially if your running pi as this would have the best benefit.
That’s wrong Marty. You do not have to use a non contact ir thermometer. You can also use thermocouples, and the thermocouple would likely yield more accurate measurements.

Those measurements are only surface temp though, and not an indicator of fuel temp. You still need to look at cte of the material the rail is made of, cte of the fuel, and rate of flow to even begin to have an idea of actual fuel temp.
 

Coupes66

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I have been refining and testing the n54 for almost 3 years in extreme temperatures of 110f+ on twins and single turbo on 93.

I don't know anyone that has done such harsh testing period.


Marty, I have a couple of questions and observations on the datalog and timesheet. Firstly, with the timesheet, if you had a sticky set of tyres and got that 60' time down to 1.8s which wouldn't be that difficult, you could drop your time by at least 0.4sec. Is the datalog for the 11.75s run? It appears that you take off in 1st gear, rev to 6,900 rpm, change into 2nd gear with wheel spin, change into 3rd, then 4th and finally 5th gear. Are you going over the line in 5th at 128 mph? Also, I noticed there were timing corrections up to 8 degrees on at least 3 cylinders throughout the run. I thought you said there were no timing corrections. The other observation was the iat which goes from 100F to 127F. In my 10.7s run , my iat went from 100F to 120F. There appears to be some possible potential gains in this area.
 

martymil

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This was an old run and since then we fixed the timing corrections and yes there is much that can be gained in that run as it wasn't the best.

We.heat soaked the shit out of the ic lining up on purpose, we.where extreme temp testing some mods and the effect they would have on the run.

This was just to test the mods and was never to pull a fast time

Sticky tyres and a harder launch would see a.flat 11 but the car has another 27rwk and way more torque since then so a possible high 10 would be on the cards.

But I'm not really interested but not bad for 93 fuel as most are barely running that on e85
 

gmagnus7

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So the argument is that certain valve covers (including stock) have poor fitment causing physical contact with the fuel lines? And that VTT's doesn't? Wouldn't the primary concern be abrasion and wear over time at that point? Sure physical contact will technically increase the fuel temperature (conduction > convection & radiation) but with how much fuel is pumping through those lines I'd imagine the delta temperatures to be insignificant. Should just grab a temperature gauge and put it on the fuel lines for the stock vs VTT cover. Sounds like a bunch of theory and no data though, still funny how rattled people get lmaoooooooooooooooooooooo
 

The Convert

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So the argument is that certain valve covers (including stock) have poor fitment causing physical contact with the fuel lines? And that VTT's doesn't? Wouldn't the primary concern be abrasion and wear over time at that point? Sure physical contact will technically increase the fuel temperature (conduction > convection & radiation) but with how much fuel is pumping through those lines I'd imagine the delta temperatures to be insignificant. Should just grab a temperature gauge and put it on the fuel lines for the stock vs VTT cover. Sounds like a bunch of theory and no data though, still funny how rattled people get lmaoooooooooooooooooooooo
Marty’s argument is that the M18 cover is too close to the lines because it is shaped like stock and that the heat of the vc is jumping the air gap and heating up the fuel.
 

martymil

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LOL Metal radiates heat thus heating other metals in close proximity if no airflow is present.

Stock vc cover not so much as plastic is an excellent heat insulator vs aluminium, you don't need a science degree as its pretty basic stuff.

I agree that the fuel does flow pretty quickly through the rail and pump but the injector lines are a lot slower to move their contents and this is where
the most heat transfer will happen, it might not be a lot but might be the difference on a 100f+ day when the fuel inside the tank is already stinking hot
to tip it over the edge.

If you live in a cool climate this is not really a concern but I rather take steps to minimise fuel temps in unfavourable conditions.

That's my argument.
 
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I will say that until you've dealt with a true hot climate, it's hard to understand the heat issues. I'm in phoenix AZ, and have seen charge temps over 180*F out of boost simply cruising with traffic in the dead of summer. Air temp is one thing, temp off the asphalt is another, and it's simply nasty and sometimes 30+ degrees hotter. It's hot enough to start to burn your feet through your shoes when you walk across the parking lot -I melted a pair of rubber gloves climbing on a roof to add a sun screen to a second floor window. This ain't like Massachusetts, for example, which certainly can get what feels like hot, this is another world. Previous comments notwithstanding, any and all you can do to help cooling in those situations is a good thing.
 

rev210

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What started as a question has degenerated rapidly. Can we get out of personal attack and keep it civil?

I am all for the investigation scientifically speaking and we havent yet got there.
So whilst not in agreement 'yet' with Marty on the idea of hotter fuel from valve cover design , I am glad he is willing to investigate it as a contribution to community knowledge.

Bashing people and picking holes in amateur logic might not be the most productive way to investigate it, if we are serious.Put up the science (ideally in research reference) talk about how to apply it .

Can we learn something about the effects mentioned in the thread so far related to the valve cover debate.
Maybe the questions we are asking include;
How temperature ranges and pressures of fuel (and fuel properties) effect combustion, power and knock supression? These are related , as the design of the high pressure system would have these in mind. Lots of scientific articles can be found to discuss as opposed to opinions ,on probably all the contentious points to settle those first.
I found this one an interesting read recently
 
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martymil

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What most will not understand about hot climates and Australia is the worst, thinner ozone and one of the highest UVR exposure if not the highest in the world
just expedites the heat issues.

It can go from a low 5c in the morning to 40c+ by 2pm, and asphalt that is melting and sweating.


This happens a lot more than its reported as we take it as normal

Owning/driving a turbo car has its challenges it these sort of climates and this is why I'm taking steps to develop a series of products to help combat the heat
related problems where others don't experience it.

I'll bet most of the cars/owners never experienced the temperatures we see in their lives yet on a daily basis like we do, now try having fun or racing these
type of conditions.

These conditions bring a unique set of challenges in product design.
 

The Convert

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What most will not understand about hot climates and Australia is the worst, thinner ozone and one of the highest UVR exposure if not the highest in the world
just expedites the heat issues.

It can go from a low 5c in the morning to 40c+ by 2pm, and asphalt that is melting and sweating.


This happens a lot more than its reported as we take it as normal

Owning/driving a turbo car has its challenges it these sort of climates and this is why I'm taking steps to develop a series of products to help combat the heat
related problems where others don't experience it.

I'll bet most of the cars/owners never experienced the temperatures we see in their lives yet on a daily basis like we do, now try having fun or racing these
type of conditions.

These conditions bring a unique set of challenges in product design.
Marty, no one is disputing that Australia is hot or that hotter fuel is worse. This ENTIRE thread is about your comment that the aluminum M18 valve cover puts more heat into the fuel than the aluminum VTT valve cover because the M18 cover follows stock curves, and the VTT doesn’t. You're being called out because you are making ridiculous claims about two products with zero real data to back the statement up. You’re not being called out for saying hot fuel is worse than cold fuel.
 

GreyNBlueE92

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This whole thread is crazy, heat can radiate. Some of you seem to forget. Closer it is to metal, more it radiates. Simple. Who cares if he sells the covers... Buy what you want and call it a day 🤷‍♂️

Edit: Buncha girls....
 
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martymil

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Of course it does when a surface is hot anything in proximity as close as the fuel lines run will heat up especially worse in load load & air flow conditions, how much well enough to cause timing pull.

Temperature wise all i can tell you is surface temps of the fuel lines and when lowered timing corrections are greatly reduced if not stopped.

Buy any rocker cover you like anything that restricts airflow is counterproductive in places like ours.

I do not sell the covers
 

rev210

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Perhaps, I can suggest a very easy way of testing this for anyone interested?

Insulate the fuel lines. Very easy to do, cheap and will be much more effective in testing any changes.
You can choose from sticking something between the lines and the cover (which is still better than valve cover differences) or go the whole hog and even wrap the lines.

What you would like to measure before and after can be the last peice to debate.

I live in Perth ,so even hotter on average than where Marty lives and grew up around drag racing V8s and carby setups in really hot weather. Cold is good but, the reason I am skeptical is that we didnt go insulating the fuel lines over valve covers and manifolds (exhaust areas for sure). The carby setups are waaaay more suseptable to fuel heat, as you could get vapour lock from fuel boiling in fuel bowls. Also some of the volitiles in race fuel can be lost at as low as 130f from memory.
Having said that, just because we didnt do it doesnt mean Marty may be wrong or that the benifit isnt insignificant . The reverse is also the case. Let the science decide and we all win.
 
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The Convert

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This whole thread is crazy, heat can radiate. Some of you seem to forget. Closer it is to metal, more it radiates. Simple.
Not trying to shit on you, I swear, but just trying to understand where you’re opinion is coming from.

Did you attend college?
If so, what did you study?
What general field is your career in?

I ask to understand if you have a science based background and an ability to apply it, and/or an ability to apply it. You could say no college but work for a race team, or PhD in physics but don’t know how to turn a wrench.
 
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