• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

need a photo

Share this page

Carbs don't have return pipes. The hot weather in PR might be a contributing factor for a vapor lock condition. A heat sheild could definetly help that problem, but you said you can't put it on with the Ratco linkage. I'll give Tony a call, and see if he has a solution. Maybe you could cut away a clearance area for the bracket that gets in the way.
 
Dale, are you running your electric pump or is it still sitting idle as a back up?

Like Art said, carbs don't have return pipes. The Moss parts blow-up shows two different feed pipes but one is for early cars, the other for late cars. No car uses both at the same time.

I agree with Art about cutting clearance away from the heat shield to make room for the linkage. Jegs also has header sleeves that you can put around each individual pipe while the header is installed. I'm planning on trying these myself.

If PR started getting ethanol mixed into the gasoline, then vapor lock could really be an issue. The ethanol lowers the threshold for gasoline to vaporize. resulting in a greater chance of vaporlocking.
 
Forgot to ad...

Some cars had overflow pipes (not TR6's though) to direct fuel away from the hot exhaust if the floats stuck and the float bowls overflowed. They were not return lines though, unless you consider they were returning gasoline to mother earth.
 
Thanks Alan.

Yes Shawn, our gasoline is now ethanol mixture.

The vaporlock occurs more in slow moving traffic than
fast speed driving.

Now that I know what is causing the engine shutdowns,
I'm not as worried about total breakdowns.

thanks all,

dale

d
 
Tinster said:
Thanks Alan.

Yes Shawn, our gasoline is now ethanol mixture.

The vaporlock occurs more in slow moving traffic than
fast speed driving.
Click to expand...

Several things to start with.
1. Make sure that the gas hoses are as far away from "hot" parts of the engine as possible. If your gas line is metal, slide it inside of a rubber hose to give you a bit of insulation.
2. Gas vaporizing is also a function of pressure. Each one of your filters is causing a pressure loss. The lower the pressure the more likely the gas or ethanol is to boil. If you are having constant vapor lock problems try getting rid of the filters. It might just solve the problem.
3. the filters cause another problem. As the ethanol starts to boil the "bubble" in the fuel filter will get larger and reduce the amount of area for the gas to flow through.
3. Header wrap is a VERY bad idea. It will in all likely hood either warp of crack your exhaust manifold.
 
After running it hard & sitting in Puerto Rico traffic (took us 3 hours to go 17 miles), he's boiling the gas....& the bubble gets to about half the size of the filter!

<span style="font-style: italic">(& I'm still figuring out TR's...so, theres no balance tube, eh! Well, he still needs to reroute how he has it installed & get some heat shields or wrap his headers)</span>
 
Shield, reroute and/or insulate the fuel lines, get rid of all but ONE filter. NO header wrap.
 
Lagged my s/s extractors and put an ali heat sink between my carbs and the hot tubes!, still have probs on sitting at lights etc after a hard run, and same on restart unless left to cool for about 20 mins
 
DrEntropy said:
Shield, reroute and/or insulate the fuel lines, get rid of all but ONE filter. NO header wrap.
Click to expand...

Here's what I've got Doc:
Fuel hoses well away from the engine head.
One filter before pump, one filter after pump.
Steel Tee joint and steel lines ONLY connecting carbs.

I'm wondering, since the Ratco unit makes a temp shield
impossible to fit, if insulation on the carb bowls might help?

I've a good many SF of that foil faced carpet underlayment.
I could glue some to the bowls. Should the foil side be
installed facing the hot manifold or toward the carb bowls?

thanks,

dale

fuelLines.jpg
 
Dale - show Doc a photo of the carb side of the engine....then, go out & reroute everything so it looks just like the diagram in the Moss catalog.

Problem with fuel lines is that its not allowing fuel to flow to both carbs equally...

Heat problem isn't in fuel lines - its in carbs, both the bodies & fuel bowls...remember, your fuel bowls are integrated under your carb bowls so they're the closest thing to your headers...& no way to insulate them without an external heat shield......

Look at them closely, then cut a piece of thin metal that'll fit between the carbs & headers & pop rivet some heat shield material to the back side of the metal (closest to headers) like what I was showing you with my hands....you can get that stuff in sheets at Auto Zone or Pep Boys.

Just put your designer thinking hat on...hehehe
 
tony barnhill said:
Problem with fuel lines is that its not allowing fuel to flow to both carbs equally...
Click to expand...

The short run from the "T" to the front carb doesn't make a bit of difference over the longer run to the rear carb once the fuel is flowing. Fuel will flow evenly to both carbs without a problem once both float bowls are full and the fuel pressure is constant. If one carb isn't getting the same amount of fuel into the float bowl then look to the float heights, the needle valve or for an obstruction in the fuel line.
 
Back
Top