Does anyone know how to..or...have done this?

Went by S-Wings here in Denver the other day to have a talk with Mike/owner about some quirks or problems I have been having with my '81 Wagon...nothing major wrong of course. Have to say first of all...Mike is one helluva expert on Subarus and he is great help.

My wagon is running rough after a hot start or after running in the heat for a long time...felt like vapor-locking mostly. Go to find out that Subaru used something called a "F-1 Kit" on the ea81s...Hitachi carburetors..a device that was installed in the engine block itself and helped keep the carb from overheating from the block heat...don't remember the details exactly..but..my wagon is not equipped with one...hence the "vapor-locking". Not the typical vapor locking that normally happens when the fuel lines overheat and cause the gas to percolate and then the car runs rough or dies....so with that said..here is the question:

Has anyone designed/built a carb heat-shield/cooler? A plate that could be installed between the carb and intake manifold that would use coolant from the radiator to cool the carb. I have a new radiator that has the automatic trans cooling lines that are plugged because I have a 4 speed manual trans..so if I just somehow fabricated a shield/cooler and a pump of some sort to channel anti-freeze/coolant to and from the radiator...there ya go...maybe the first of it's kind...eh? Does anyone know where I should start in order to make the shield/cooler device? Mike said he has never seen one..so...think I'm gonna give it a shot.

Also want to say thanks again to Mike at S-Wings...and Diamond thanks you too.

Any input on this idea is greatly appreciated.:smokin:

I would just make a carb riser out of wood. Wood is an EXELENT inselator and eazy to machine. If youre heart is set on running water as a coolant to it, then I would make a riser out of aluminium, drill 4 long holes length wise through it. U can tap all 8 openings in it with 1/8" pipe threds, put a plug in 6 of them, and a hose fitting in 2 of them.

Well, the V-8 guys take a piece of, um, darn. Similar to the stuff clipboards are made of. Insulative, non metal, dense. Put that on top of the intake, bolt the carb to it, after cutting a hole through it, of course. Like a huge, ridiculous gasket. It insulates the carb from heat coming off of the intake, and to a degree, heat radiating off the engine. Could be part of an idea.

I think radiator-temperature water would still be too warm for your application. The fuel will still boil at those temps.

Would dropping the float level in the carb help alleviate symptoms like this? Anyone?

Hrmmm...wood...cork board...or aluminum? I was leaning towards aluminum myself to incorporate with the coolant line idea...and yes...lowering the float 1/8" would help remedy the problem...but my float level is already a hair below the mark...so I think the previous owner already knew about the vapor locking. After researching some hot rod websites I found some info...one idea was to install an "air pan" that directs incoming air from the cowl vents to the carburetor to aid in cooling...that and a a shield would be more realistic of an idea...you think? Anyhoo...keep the brains cranked on this one for me...Thanks:smokin:

There was a vapor lock problem with the early EA81s but they only fix from subaru that I'm aware of was a relocation kit for the fuel pump. The kit relocated the fuel pump from the engine compartment to the back of the car were the the fuel pump was located on the later EA81s

Dang...okay...well...here is another idea. Would cooling the air going into the carb help? How about the "Tornado Fuel Saver" which is installed in the air filter housing which changes the way the air gets sucked into the carb? A device that states it increases fuel mileage and horsepower...but nothing about cooling the air. I emailed the company to inquire about that possibility...so...we will see. Mike at S-Wings said that the vapor locking is happening on the bottom bowl of the carb and was alleviated by the F-1 Kit...not the fuel lines or pump causing the "hiccups"...hehe.:smokin:

While the engine is running, the carb is going to be nice and cool, because there is air flowing through it, and also because of the venturi inside. So how do we keep it from getting warm when the engine stops?

I suggest the carb be bolted down to a wooden or phenolic spacer, like SOOBME suggested. I'd avoid aluminum anything, because it's gonna conduct heat too good. Insulate the fuel lines from engine heat, maybe with the fiberglass material GM puts on hoses that go around exhaust manifolds. Cool air from the front of the car, feeding the carb or just blowing on it, will cool things off in general. I think the insulative spacer will do you the most good.

My 82 EA81 has a white plastic shield under the carb and above the intake manifold. The thing can be pulled out and is not bolted to anything. Seems as though it could potentally be a shield of some sort?

Anyone know if this is some sort of fix for that?

For what it's worth,
Glenn
82 Hatch, transforming :evil:
01 Forester, wants d/r tranny:mad:

Hello...Sweet82...by any chance can you post a picture here on the board or email a pic? Maybe I can fabricate one or find one at a junkyard. On second thought...Snotrocket...I agree with you...got to thinking that aluminum expands and contracts more too becuase it can dissipate heat much quicker than most other metals...and that even might cause it to develop a leak in a gasket later by warping...so....bingo on that one...hehe. Also leaning towards the "fiber gasket" heat shield idea...dunno how to spell the material but just read it in the earlier post...short term memory...big time...bah.:smokin:

Dude the fix is easier than you think do like Craig suggested and relocate your fuel pump to the rear. If it is in the front it will be by the firewall drivers side. If you have 2 fuel filters eliminate the front one [ I beleive this was Subarus fix ) . thats how my 80 was fixed. I would not use wood it is a great insulater, but it will absorb gas can you say with the heat spontainious combustion.

roosofallevil:evil:

Phenolic. Sort of like the stuff older distributor caps are made of. It is an early plastic. Very slightly absorbent, nothing to worry about. And its fairly strong, easy to work with, maybe a bit brittle, and it won't burn unless direct flame is applied for a LONG time. Good stuff.

But if moving the fuel pump is a fix, well, that sounds easier.

Years ago I had a Dodge Dart that vapor locked, till I took a big clip board and cut it to shape and put the right holes in it. It was big, like 10"x 12" so it worked like a heet sheeld AND an inselator. I used that for 3 years before I got rid of the car, and never had another problem with it.

Hello...SOOBME...question for you. Did you make the holes for bolts for the spacer to be installed between the carb and manifold...or did you install it another way...and did you have to find longer bolts? Thanks:smokin: