i love the weather, my datto doesn't

[cdub42]

there is nothing worse than sitting in the daily I5 rush in the afternoon with my Z getting hotter and running richer by the minute sitting in stop and go traffic on I5 for 2 hours in the afternoon when it takes me 45 mins to make the same trip in the morning. then when there is an accident or an actual reason for the stupid traffic, its like playing russian roulette with vapor lock. im not driving my Z nearly as much as id like to be these days. which sucks cause burning up interstate is a kick in the pants in that thing. 

[ArchetypeDatsun]

I know the feeling my 810 doesn't like it either we get up to the triple digits here in Oregon.

[nerdistmonk]

I know the feeling my 810 doesn't like it either we get up to the triple digits here in Oregon.

 

does the Z datto's vent from gas cap? or do they use the canisters?

[cdub42]

I know the feeling my 810 doesn't like it either we get up to the triple digits here in Oregon.

my Z does alright when its hot. it just gets a bit rich. its the sitting in traffic that kills it

 

does the Z datto's vent from gas cap? or do they use the canisters?

mine vents from the bowls into the filter plenum. i think my fuel line routing has alot to do with it also. i ran mine up and across the firewall instead of in front of the motor. the headers dont help that either. 

[nerdistmonk]

my Z does alright when its hot. it just gets a bit rich. its the sitting in traffic that kills it

 

mine vents from the bowls into the filter plenum. i think my fuel line routing has alot to do with it also. i ran mine up and across the firewall instead of in front of the motor. the headers dont help that either. 

When i meant how does it vent, i meant the gas tank and the carb, vapor lock is usually an issue with either gas 'boiling' in the lines and filling them with vapors or its the gas tank becoming pressurized and preventing the pump from pulling enough fuel to the carb (though that would be very noticeable since it usually only occurs when you try to drop the hammer and it sputters, also it will hiss when you open the cap)

 

As for vapors in the lines leading to the carb, just make sure to keep them as cool as possible, if the exhaust is near them that could be your problem also. (You could try insulating them with something keep the radiating heat off them, gas vaporizes when warm and stays more liquid like in cooler environments)

 

anyways just my 2 centavos. I dont own a Z but the concept is the same on any vehicle.

[cdub42]

its the gas boiling in the carbs. the tank is vented. the stock heat shield isnt enough for the headers. i been thinking of routing some ventilation to the carbs  in addition to re routing the fuel lines. ive had the idea in the back of my head of making some copper coils in a ducted chillbox to super cool the fuel before it hits the SUs. since temperature decreases as pressure decreases... im thinking of a conical enclosure with the intake (discreetly) on the front and vented to the low pressure area directly behind the headlight. basically a Venturi housing fuel lines..

[bananahamuck]

but if you don`t,, or forget to,, fill the box with cool ,,,, ? .,,, wont it then do the opposite and warm the fuel because of the underhood temps?  I see your theory though,,,  our MR2s have a side vent with a small fan down the tunnel for cooling underhood temps but they also have alot of perforations in the hood to let the air back out though.

 

 

Maybe what you need is a summer hood with (( TASTEFUL )) scoops and, or vents and a not summer hood.

 

Again,,, notice the word tasteful

[DaBlist]

On HOT ROD TV's Road Kill Series they are always taking the hood off when they have heat related problems. I have also seen were the hoods have been modified to sit up in the back a couple of inches leaving a gap for the hot air to escape.

 

 

[cdub42]

like this?

 

i was thinking of using a NACA intake and building a plenum that works with the venturi effect to cool the air. no liquid required, but if i add a liquid to the system, i should in essence, have a super efficient swamp cooler. its squarely one of those projects thatll happen eventually.. i need to do more thinking on it. 

[cdub42]

On HOT ROD TV's Road Kill Series they are always taking the hood off when they have heat related problems. I have also seen were the hoods have been modified to sit up in the back a couple of inches leaving a gap for the hot air to escape.

when im stuck in hot traffic, i do that. i hit the hood release and drive around with it popped. dont really have to worry about it flying off lol

[DaBlist]

I have a carbureted car with a fuel return line that is T'd in right as it enters the float bowl. I mentioned it to someone and they said it was to prevent vaporlock. Makes sense having the fuel circulating

[cdub42]

i think the return on mine was long since removed by PO. 

[nerdistmonk]

having any kind of return on the feed to the carb before it enters the carb will reduce the volume of fuel reaching the carb, i just went through that mess on mine, its direct-fed now, it seems temperature is his problem, this will sound tacky but try giving your fuel line a crinkly covering of reynolds wrap, make sure to wrap it in a way so theres buffer space between the wrap and the lines this will keep radiating heat from transferring into the fuel line itself. As for convection heat a hood vent or scoop allowing air to blow over all of it will do alot of good also.

 

Im sure theres a nice professional way to insulate those lines, im just thinking in my normal method on my truck though.

[Sealik]

i think the return on mine was long since removed by PO. 

 

You should hook it up

 

having any kind of return on the feed to the carb before it enters the carb will reduce the volume of fuel reaching the carb, i just went through that mess on mine, its direct-fed now, 

 

In most applications there is more than enough fuel for carbs....which, should be returned to the (cooler) tank via a return line

 

[datzenmike]

The newer fuel tanks let air IN only to replace fuel removed. Any extra vapors produced are collected by the canister when motor off or drawn into carb if running.

 

ALWAYS run a return line. Cooler fuel from the tank is constantly circulated past the tee to the carb(s). The return line has a pin hole opening to provide a restriction in it. If it were open, gas would simply flow back into the tank. The small hole forces the pump to build up pressure and that is what forces it into the carb(s). During shut down times when under hood temps soar, IF gas in the lines should boil, the bubbles are easily pushed through the pin hole and into the tank.

[cdub42]

 

 

the PO removed most of the venting system to the tank including the return line. the only thing i changed after i put the new motor in was the location of the filter, it was front right and i relocated it to the firewall (pulled loose for clarity) 

 

im thinking my routing is prefuct and i need to go buy a few feet of tubing now.