jwan

I think i've finally figured out one possible cause of my engine running hot... my header tank! I think its making the engine run lean. Can anyone take a look at my set up and offer an suggestions on why my header tank isn't working. I'd like to keep using a header because if it works it will give longer run times and the truck can run when it flips =)

Btw, its a hayes 2oz tank with brackets from Heliproz. the bulb on the top is an ofna primer bulb/filter.

Savage_Crazy

is any bit of the tank lower then the carb.
when it's a bit lower it might run lean. atleast i think it's so

jwan

does anyone still run a header tank?

rcnitrohead

I used to on my T-maxx, but it didnt look tidy enough for me so its off

-SomeGuy-

Looks like the fuel line between the primer bulb and header tank has a pinch at the bend, that's probably your problem. Put a longer piece on and see how that goes.

cord arrow

Good Eye!!!

ace007

Also check the stone filter inside the primer. I had the same exact one on my x-factor and no matter what it ran hot. Then i took the filter out and it was gummed up with crud so i just left it out and had no more trouble with it.

RLMHPI

What else is new an Axial 28RR if I am not mistaken running hot!! When you installed the engine in your Savy you may have had to remove the carb and turn it around 180 degrees. When I got mine I had to turn it around. Make sure you didn't tear the o rings that seal the carb its also a great idea to check for air leaks and seal the engine. If the engine likes running hot and is not overly lean and you want to drop the temps I suggest a Nova Racing cooling head they work wonders.

jwan

Yeah, i'm about to look at the kink in the line now, but i don't think that's the problem since i've run it before without that kink in the line and still find it lean. I'm just frustrated with this thing cos i really do like the header tank. I don't think its my engine cos I just sealed it all up, and when i bypass the header tank, the temps drop dramatically (along with performance).

What do u guys think about just artificially richening the mixture to bring down the temps? is it normal for a header to make the engine run leaner?

Also with the nova head, does that come with the headbutton built into it? i'm personally a fan of the nova heads, had one on my 21BB and it worked wonders, but i just installed a turbo head button into my engine....

ace007

Just get rid of that primer bulb altogether and your engine will run a lot cooler infact you will need to re-tune it for performance but i bet its that stone filter that is inside thats causing you issues.

jwan

Does the mounting position of the tank matter? could i be the tank is mounted too low? also does having too much fuel tubing make things worse? maybe i don't get enough back pressure from the pipe to push the fuel through the system with a header tank installed?

ace007

From looking at your pics it looks like the header tank is close to the same height as the stock tank. Yes to much fuel line can cause issues i use very little extra fuel line on my savage. I say empty and bypass the header tank re-tune your engine back to the stock tank and see how it works. Then try to set the header up again with shorter fuel lines you want just a little extra tubing as to allow it to move around while you drive it. Also eliminate that blue primer set-up completely and just run fuel tubing then you may have to re-tune again but it should be very minimal. Like i have said before that blue primer gave me overheating issues til i got rid of it and just ran tubing and you can try that first take out the primer set-up and run new tubing from tank-to-tank and see how it goes.

jwan

Ok, I've finally had some time to run the truck, I tried a few things to try and identify what the problem is. I basically ran a whole lot of different sets of fuel system setup with the same needle settings (which are richer than break-in settings). all tests were done on a full tank.

Running on stock tank only, no primer bulb - ran very very very rich. heavily boged down, would not accelerate out of 1 st gear by the sounds of things. I'm pretty sure this is how the truck should be running given the HSN is about 2.5 turns richer than break-in.

Next I used the stock tank only with the primer bulb - ran quite a bit leaner, not as lean as when using the primer + header setup, but definately a big change. To me this means the primer bulb is one source of air leak... safe to say it won't be on my truck much longer...

Header tank with stock tank, no primer bulb - again, this set up it runs much much leaner than what it does with just the stock tank. I actually has decent acceleration and isn't much different from when i had the leaky primer bulb in the system as well.

Finally, i tried to just run the header tank only. I took the main tank out of the equation and fed the pressure hose from the pipe straight into the header tank. Again, judging by the performance, the engine was running lean.

So this is what I have been able to work out from the above tests...

1. its not a pressure problem, since running the header only still runs lean;

2. Running the stock tank only means the engine will run like its meant to... makes me sure i don't have a leaking engine.

3. The primer bulb makes things worse, but when used in conjunction with the header tank doesn't make a substantial difference.

4. Since adding the header tank into the fuel system, and running with the header only, both result in leaner running, the header tank is to blame. Since i've tested for leaks in the header tank, i'm pretty sure mounting position is a possible problem...

Any ideas what i can do to rectify the situation based on these observations? I'm thinking about running it with the header tank anyway and just richening the crap out of it by backing out the HSN even further. Is this a problem? Am i just masking the problem by doing this, or is it just a fact that running a header means I have to run significantly richer settings? Am i losing engine power or life by doing this????

I'm so confused...

Vigilante212

I never thought headertanks would be a good soultion to the half tank lean. As for that fuel bulb I hear they tend to leak alot any air in the fuel line is usually a good sign of this. As for the header tank I cant say for sure some people like them and say they work. Having it higher I dont think helps much especially cince the backpressure is feeding into your main tank first, but I could be wrong.

jwan

I've been doing more searches on this topic, and there's people talking about having the tank above the carb or having the outlet of the tank above the carb... I don't see how you can actually phyiscally mount the tank higher than what i have at the moment. As for the fuel outlet, why does it matter how high the nipple is since the clunk line goes to the bottom of the tank anyway... if it really does make a difference i suppose i could turn the tank upside down and have it feeding the carb from the top nipple and filling from the bottom... would this even work tho...