I'm starting my conversion from double 2bbl's to Fitech four barrel TBI. My two barrels run perfectly, I spent many hours tuning and synchronizing them, instant response, lots of power, but....alas, I live in the SF bay area and traffic is common. My dart is a commute car, daily driver, and I can't sit in traffic on a 90 degree day for more than 10 minutes or so before my carbs boil over. I tried a heat shield, recirculating fuel, cold air intake, on and on, but they just can't take the heat. They are Webers, and operate on only 3-5 psi of fuel pressure. FYI, if the FiTech system works out, I'll be selling my offy intake, carbs, and lots of extras for way cheap, stay tuned on the parts thread.

OK, so part of the FiTech conversion was about moving my battery to the trunk so that I could configure my cold air intake to where the battery was. Here is the pic of the engine bay after I moved my battery to the trunk.

http://s785.photobucket.com/user/67dart ... sort=3&o=3

Here is the trunk battery:

http://s785.photobucket.com/user/67dart ... b.jpg.html

I put the fuel command center (allowing me to not use a return line to the fuel tank) on the passenger side near the radiator. I had a double pulley on the alternator, and had to cut the front pulley part off, just to fit the FiTech fuel command center (that thing is huge).

http://s785.photobucket.com/user/67dart ... sort=3&o=4

As posted previously, I drilled/tapped my temp sensor to accomodate the 3/8 NPT sensor for the FiTech:

http://s785.photobucket.com/user/67dart ... sort=3&o=7

I put the factory temp sensor, actually a Ford 3/8 NPT one, in the drain plug port on the side of the block. It works fine there.

http://s785.photobucket.com/user/67dart ... sort=3&o=8

I pulled the double 2 offy setup, and the Remflex gasket survived for another use.

http://s785.photobucket.com/user/67dart ... sort=3&o=2

It was a lot of work (some distractions) but I got the 4bbl intake installed and dropped the Fitech unit on (didn't have time to actually tighten the nuts). I suppose it was serendipity that the Fitech unit has red anodizing to match my red themed engine.

http://s785.photobucket.com/user/67dart ... sort=3&o=0

http://s785.photobucket.com/user/67dart ... g.jpg.html

FYI, I used a 1/2" wood spacer and a heat shield, though I'm not sure that I need to take these measures, the FiTech runs at 56 psi, I can't believe how hot my engine bay gets in traffic, so it can't hurt to isolate the system at least some. There is plenty of heat from the exhaust manifolds to the intake and since I'm using Dutra duals, I have the heater box on the offy 4 bbl intake for heat to the intake.

I have to configure the throttle cable and kick down and install the wideband O2 sensor (I already have bungs in the down pipes, I'll just pick one), etc. Then I have to figure out how to program the Fitech. The instructions aren't totally clear, the website has a lot of information, but nothing systematic, just random feedback from what I can tell so far. Great information on various boards though. Lots of reading to do.

More to come.

Brian

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Photobucket is blocking your pictures.

Fuel injectors won't be happy with hot (boiling?) fuel either, regardless of the psi. If you were having heat issues you believe are related to engine compartment temp with the carbs, it will only be worse having a sump under the hood with an internal pump that dead-heads the fuel.

The sump is in down low in a cooler area. I don't think the under hood temps were extreme by any means, it's just that the Webers can't take the heat that builds up in dead stop traffic. When I'm driving the car, even cruising at low speeds, the carbs stayed fairly cool, warm to the touch but not hot. I did some driving tests, pulled over, to verify this. It's the dead stop traffic situation, and they were a lot worse before the cold air intake. I think the low hood, and the air cleaners being close to the underside of it, were sucking hot air in when in traffic. The CAI gave me more traffic time, just not enough. The fuel lines were well insulated and it was a return system, it was the carbs themselves that were boiling the gas. I don't think this will be an issue at 60 psi, but if it is, I can do a return line setup with the TBI as well.

Brian

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Not sure why fotobucket is blocking my pics, I paid for the upgrade to fix that...I'll check into it.

brian

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https://tinyurl.com/yynpj4v2

I did a rough calculation, assuming gas boils at 180 F in the Webers at 4 psi, then at 60 psi it would have to get to 325 F to boil the gas in the TBI line. My calculations are rough ballpark, very conservative, but regardless I don't think it'll get anywhere near that hot in the lines or the TBI.

Can others see the photos? They appear to be working, and as I read other threads, I see some pics of others, but some I don't see, I believe this is due to photobucket's new policy (you have to pay for them to host pics on other sites).

b

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I clicked on the links and the photos were blocked. I really hate photobucket now.

alternatives to photobucket?

I'm open to switching, any recommendations?

brian

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https://tinyurl.com/yynpj4v2

Flickr.

Cool project.

Lou

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Home of Slant6-powered fun machines

I'll look into Flickr.

b

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https://tinyurl.com/yynpj4v2

Fuel's still stored in the bowls and collects heat - a return line won't do much for carbs in that regard as very little volume's flowing to the intake so most sits and absorbs heat.

The high pressure pump itself will add additional heat to the fuel as well. Certainly not enough to raise it to 325F, but I'm not certain how that calculation works

If you already have a return line to the tank from your carb setup, why not just use it here? You may need to move the regulator from the sump to the return port of the throttle body though.

You've made me weary about dual webers. I'm planning on such a setup too, and the heat on this side of the Altamont is even worse.

As pressure in fuel system or any other such fluid system goes up so dose its boiling point. I suspect FI injection fuel delivery will be stable at any under hood temperatures generated in traffic.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Nope, can't see them.

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65 Dart station wagon slant 6 - now under construction
47 Dodge Custom 4 Door sedan
87 D100 Short Bed slant 6

Retired USAF 1966-1986
Retired US Postal Service 2004-2014

I suppose if I switch to FLikr or something, then all the old posted photo links won't work, then again if they're not working now, no biggie.

The boiling point of any liquid depends on the pressure. Water boils at 212 F at sea level, but at higher elevations (less pressure) it boils at lower temps, e.g. in Denver it boils at 203 F. If one increases the pressure, the boiling point raises. At 60 psi, roughly 4 times atmospheric pressure, the boiling point of gasoline should be around 325 F. There is no fuel in the TBI system that isn't under this pressure. There is no chance the sump will get anywhere near 200 F, nor the insulated fuel lines, the only question is the TBI itself. Even though that is unlikely (the Webers weren't that hot) I installed a wood spacer and a heat shield.

The weber heat issue is only in traffic, otherwise they perform very well, easy starts (electric choke), instant response, no adjusting once set, perfectly synchronized and matched airflow, probably superior fuel distribution with the dual intake vs the single carb intake. I'm almost afraid the TBI won't be as crisp in response, though I've read from others that it performs very well. Probably the best weber setup, given our exhaust manifold is interlaced with the intake and the carb sits right over all that heat, is to have a side draft intake. The runners would still be heated, but the carbs are lower in the engine bay and off to the side away from the exhaust manifolds. No power assist brakes though (rear carb would interfere).

brian

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...also, as I mentioned, I ceramic coated my exhaust manifolds in black. Black is the most emissive color (think black body radiation), it emits more heat than other colors. While this might be good for efficient heat dissipation from the cast iron manifolds, it is radiating that extra heat to the heat shield and carbs. Maybe this isn't much different than raw cast iron, which is grey, but they sure seem to radiate more heat after I coated them black. Just something to consider. Anyone else have black exhaust manifolds or headers and previously had chrome, silver or white and noticed a big difference in the heat in the engine bay?


Brian

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