problems with fuelfumes inside the car (again)

[nicolas]

what can i do about it?

the car runs good and all is fine untill i stop the car and shut off the engine. it seems that the heat off the engine rises and gets the fuel in the carbs to boil and escape into the enginecompartment and trunk above. this is a type3, so it gets behind the rearseat and into the car itself. not nice for the little one...

so what can i do to prevent this. it also seems that some fuel is still on the butterflies after being shut off and that gives an even bigger fuelcloud.

what can i do?

[wolfswest]

I have the same problem.     Maybe we can make our own "teflon" gaskets....  I found this on the net, maybe it's something we can use.  check it out:

http://www.nkineede.nl/catalogus/product_1010

[BeetleBug]

Thicker gaskets for a start. Dont let the heat escape up to the carbs.

[Lids]

use ceramic(better insulator) spacers, what carbs are you running?

[nicolas]

sorry i didn't really fill in much off the blanks did i...

so i am running 42DCNF's on Berg short manifolds that fit under the decklid off a type3. i have installed some thick (4 to 5 mm) gaskets that are made off some sort off black plastic like original type3 gaskets between the manifolds and carb with on both sides a paper gasket glued on. i think it is the same as the alfas used on their carbs.

so the problem is only appearing when i shut the engine off and the heat is allowed to rise...

btw what does ceramic spacers look like?

[Jim Ratto]

how hot does the engine get (when running)?

[Lids]

they are a brown colour

pic on lees thread: http://cal-look.no/lounge/index.php/topic,6900.30.html

[lawrence]

Have you made sure the fuel smell is not coming from the fuel tank? I used to have a strong fuel smell in my car as well. I covered a few small holes that led right into the cabin when I insulated the trunk recently and the fuel smell has gone away. I am going to buy a new gasket for the fuel neck as well. Good luck.

[Zach Gomulka]

Hmmm... I only had that problem with those carbs before I put air cleaners on. Everytime I floored it a strong wiff of 91 octane would enter the cabin. Once I put on proper filters the issue went away. I would look towards the fuel tank as well.

[nicolas]

how hot does the engine get (when running)?

stays steady in the 85°C - 90°C always ran like that.

Hmmm... I only had that problem with those carbs before I put air cleaners on. Everytime I floored it a strong wiff of 91 octane would enter the cabin. Once I put on proper filters the issue went away. I would look towards the fuel tank as well.

the problem is worse without filters for sure.

Have you made sure the fuel smell is not coming from the fuel tank? I used to have a strong fuel smell in my car as well. I covered a few small holes that led right into the cabin when I insulated the trunk recently and the fuel smell has gone away. I am going to buy a new gasket for the fuel neck as well. Good luck.

i have sealed and checked all the fittings and gaskets. i even put new clamps on the breather hose from the tank.
but the smell comes from the backside off the car.

is there someone who has had problems with the carbs still dripping fuel after the engine has been shut off? i remember reading a post about this, but forgot where and what the cure was.

the smell only appears when the engine is shut off and stands for a few minutes.

but thanks for the help allready and i will recheck all the things said.

Lids, i will look at those and see if it can work better.

[Jim Ratto]

how hot does the engine get (when running)?

stays steady in the 85°C - 90°C always ran like that.

Hmmm... I only had that problem with those carbs before I put air cleaners on. Everytime I floored it a strong wiff of 91 octane would enter the cabin. Once I put on proper filters the issue went away. I would look towards the fuel tank as well.

the problem is worse without filters for sure.

Have you made sure the fuel smell is not coming from the fuel tank? I used to have a strong fuel smell in my car as well. I covered a few small holes that led right into the cabin when I insulated the trunk recently and the fuel smell has gone away. I am going to buy a new gasket for the fuel neck as well. Good luck.

i have sealed and checked all the fittings and gaskets. i even put new clamps on the breather hose from the tank.
but the smell comes from the backside off the car.

is there someone who has had problems with the carbs still dripping fuel after the engine has been shut off? i remember reading a post about this, but forgot where and what the cure was.

the smell only appears when the engine is shut off and stands for a few minutes.

but thanks for the help allready and i will recheck all the things said.

Lids, i will look at those and see if it can work better.

Unfortunately, short of fabbing an air filter assy (enclosed) like the stock Type 3, there's not a whole lot you can do, in my opinion. I think being the Webers are on short Type 3 manifolds is only exacerbating the problem. Some of the issue is coming from heat being radiated from heads up through manifiolds and into bodies of carbs/float bowls. The other issue is coming from a hot piston/cylinder at rest on intake stroke or at overlap... you've got a piston at probably more than 100C sitting there, slowly cooling, next to an open intake valve. The carbs heats, percolates fuel down throat, into hot intake runner... into hot cylinder... you get the pic. This is why VW's since what 1970?.... run the closed vapor system with charcoal box and lines running vapor back to fuel tank. You don't see "modern", stock factory setup cars running gauze air filters.
My car does same thing on a warm day... if I park it in the garage after a good run, within 10 minutes, there is a fumy fog in garage. I usually leave my garage door up for 30-45 minutes so it will air out a little.
You're right, it isn't good for the little one.
Today's fuels too.... they flash like they're at Mt Everest elevation... that doesn't help things.
Sorry for bad news nicolas

[lawrence]

Nicolas, do you put stack covers on you carbs after you shut the car down? I put my stack covers on right away and also leave my windows cracked open if I plan on closing the car for a while. It wont eliminate the smell but it will probably help reduce it.

[nicolas]

thanks Jim. i think you are right about what you said.

i was kinda hoping the little one would not have to suffer too much braindamage, considering the 'endangered' genepool he had to pick from 

Nicolas, do you put stack covers on you carbs after you shut the car down? I put my stack covers on right away and also leave my windows cracked open if I plan on closing the car for a while. It wont eliminate the smell but it will probably help reduce it.

so it would indeed be nice to have some covers over the carbs and i was thinking today off having something made for both the filters (nonflameble tissue...) or just plasic cups like IDA's have but adapted to DCNF's.

or those cool looking balls those hotrodders put on their cars.

[Jim Ratto]

thanks Jim. i think you are right about what you said.

i was kinda hoping the little one would not have to suffer too much braindamage, considering the 'endangered' genepool he had to pick from 

Nicolas, do you put stack covers on you carbs after you shut the car down? I put my stack covers on right away and also leave my windows cracked open if I plan on closing the car for a while. It wont eliminate the smell but it will probably help reduce it.

so it would indeed be nice to have some covers over the carbs and i was thinking today off having something made for both the filters (nonflameble tissue...) or just plasic cups like IDA's have but adapted to DCNF's.

or those cool looking balls those hotrodders put on their cars.

wait a minute

doesn't the engine cover in trunk seal against floor of trunk with a weatherstrip?
I would think that would stop the fumes

[nicolas]

thanks Jim. i think you are right about what you said.

i was kinda hoping the little one would not have to suffer too much braindamage, considering the 'endangered' genepool he had to pick from 

Nicolas, do you put stack covers on you carbs after you shut the car down? I put my stack covers on right away and also leave my windows cracked open if I plan on closing the car for a while. It wont eliminate the smell but it will probably help reduce it.

so it would indeed be nice to have some covers over the carbs and i was thinking today off having something made for both the filters (nonflameble tissue...) or just plasic cups like IDA's have but adapted to DCNF's.

or those cool looking balls those hotrodders put on their cars.

wait a minute

doesn't the engine cover in trunk seal against floor of trunk with a weatherstrip?
I would think that would stop the fumes

did that and redid that and still get fumes. it boils a really long time. i even have installed the same device as you have to crank the engine without the coil to pump fuel to the carbs and to make sure i don't fire that baby without a drink first. anyway if the fumes get in the trunk they can't be stopped because off the piece off cardboard behind the backseat.
to some extend this enginesetup is worse then a type1 because the type1 has a metal firewall and the type3 a lid into a trunk that is not sealed off...

 

[Wünderwolff]

it's a shame to take a grinder to a perfect car  but couldn't you air the trunk to the engine vents or so? graft in some louvres from the trunk to under the fenders?