Manifold and Carb overflow tubes on a BJ7

[PeterB]

Can anyone explain or have a couple of pics of how the 2 overflow tubes comming out from under the manifold and the 2 from the float bowls on the carbs get routed down though the engine area. If the pics are too big to post you can send then to me at isailboat@myfairpoint.net

Thanks,
Pete

 

[Keoke]

Hi Pete, There is considerable info regarding these drain tubes in the archives as it was just recently a forum topic. If you need more info we certainly should be able to help .--Regards--Keoke

 

[vette]

Peter, i will try to remember to look at mine tomorrow. But Some years ago, the last time I worked on my carbs, I do remember that I extended mine with small diameter gas line tubing and routed them down past the frame, the intend was to keep them and any fuel that might weep from them as far away from the exhaust system as possible. I believe I used wire tyes to keep them where I wanted them.

 

[Stretch]

The carb plastic overflow tubes come together above the carb heat shield and are routed together down through a hole with a grommet in the heat shield. The metal manifold drain tubes are formed around the exhaust manifold and then go close to straight down through two small metal tabs that are attached to longer through bolts for the oil pan in the front and back.

 

[AUSMHLY]

Hi Peter,

Stretch explains very well how they are routed.
Here are two photos.

My manifold drain tubes are copper.

1. The small metal tabs that hold the copper overflow tubes I made out of plummers tape and painted engine green.

2. My carb overflow tubes are gas resistant rubber tubes I got from the local auto parts store and cut to length.

3. The rubber grommet came from the hardware store.

Sometimes it's cheaper and quicker to make your own parts or pick them up locally. They may not be absolutely correct, as what the vendors provide, but if they fit, work and look close enough, it's an option.

Cheers,
Roger

 

[PeterB]

Thank you both very much, the description and pics are extremely helpful!

Pete

 

[tahoe healey]

Roger, I got no grommet. What size is it? The one I have in my junk box has a hole too small for those big pipes. (I cannot cut it larger cause of the outside rim)
TH

 

[Patrick67BJ8]

I haven't seen it discussed here before, but the copper drain lines are a good source of "airleaks".
Patrick

 

[AUSMHLY]

Roger, I got no grommet. What size is it? The one I have in my junk box has a hole too small for those big pipes. (I cannot cut it larger cause of the outside rim)
TH

Hi Rich,

The size you need is dependent on the size of your "big pipes". I'd suggest you try a couple different sizes till you find a good fit. They are available at the hardware stores.

Cheers,
Roger

 

[AUSMHLY]

I haven't seen it discussed here before, but the copper drain lines are a good source of "airleaks".
Patrick

My first question is are the copper pipes not correct?
Second question, will you elaborate on "airleaks"?

Thanks,
Roger

 

[tahoe healey]

Copper tubes were original.Mine were pinched off by the PO. Made no difference when replaced but they do seem to drain the manifold (aka, more drips on the floor when engine off).

 

[Keoke]

I haven't seen it discussed here before, but the copper drain lines are a good source of "airleaks".
Patrick

My first question is are the copper pipes not correct?

No they are not correct,

Second question, will you elaborate on "airleaks"?

The Manifold drain pipes were fashioned into a lazy Z shape so as to provide as long an air path as possible to insure that intake manifold air leaks do not occur.

Thanks,
Roger

 

[tahoe healey]

Keoke, if they are not correct how come the second part of your answer regarding how they were shaped?

 

[GregW]

I think Keoke was referring to the material of the pipe, copper being incorrect.

 

[Keoke]

Keoke, if they are not correct how come the second part of your answer regarding how they were shaped?

Hello TH, because the pipes as shown are straight drops they have not been shaped in to the lazy Z pattern to extend their length. Yes Greg, I used copper too which is incorrect

 

[Patrick67BJ8]

Keoke, if they are not correct how come the second part of your answer regarding how they were shaped?

Hello TH, because the pipes as shown are straight drops they have not been shaped in to the lazy Z pattern to extend their length. Yes Greg, I used copper too which is incorrect

If they are not copper than what are they?
The "lazy Z" is correct. I have dismantled original cars 25 years ago and can recall this shape. Even a lazy Z, air will still have air traveling up the tube(copper or whatever). I know guys who have shut off the tube by removing it and capping the fitting to the manifold. The tubing just seems to let you know when you have a jet leaking, but you can usually figure that out by the smell of the gas and the rough idle(and engine dying).
Patrick

 

[Keoke]

Keoke, if they are not correct how come the second part of your answer regarding how they were shaped?

Hello TH, because the pipes as shown are straight drops they have not been shaped in to the lazy Z pattern to extend their length. Yes Greg, I used copper too which is incorrect

If they are not copper than what are they?---STEEL!

The "lazy Z" is correct. I have dismantled original cars 25 years ago and can recall this shape. Even a lazy Z, air will still have air traveling up the tube(copper or whatever). I know guys who have shut off the tube by removing it and capping the fitting to the manifold. The tubing just seems to let you know when you have a jet leaking, but you can usually figure that out by the smell of the gas and the rough idle(and engine dying).
Patrick

 

[AUSMHLY]

Thanks to Keoke for his good eye and attention to detail.
My british mechanic just happens to have a BJ8 in his shop.
Here's a photo of an orginal "lazy Z" shaped overflow tube.

Cheers,
Roger

 

[Keoke]

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