Float needles and float

[Monkeyzak]

I am online trying to buy the above items. My guess was they would be cheaper from an su specialist. They are. They do a needle and float kit

Do you know the size of the float needles?

This company​is cheaper and seem upgraded.

Id appreciate your thoughts on doing this. ?

http://sucarb.co.uk/float-chambers-spar ... loats.html

[Hasbeen]

SU & Zenith float chamber needles & seats are interchangeable.

However SU, Zenith new, old, or original, they will not work if your fuel pressure is over 2 PSI.

Check the pump, & fuel pressure before buying anything.

Hasbeen

[Cobber]

I'll echo Hasbeen, check the fuel pressure before you do anything!

[Monkeyzak]

How do I do that?

[Cobber]

You beg, borrow, bludge, buy, hire or steal one of these

http://www.ebay.com.au/itm/Car-Fuel-Pressure-Vacuum-Tester-Gauge-Test-Tool-Carburetor-Valve-Fuel-Pump-Kit-/192062361033?hash=item2cb7cf0dc9:g:K7IAAOSw44BYYNzI

Having obtained one of these by fair means or foul, you intercept the fuel line between the fuel pump and carbies install a tee piece into the fuel line, fit the gauge to the tee piece, start the car give it a bit of a rev (wont need much) and observe the pressure reading, then shut the engine off and note the pressure again.
At no time should the pressure get over 2.5 psi, it should preferably be at or just under 2 psi most of the time.

If satisfied with the readings, remove the gauge and tee piece and then see to the needles and seats etc.

If you have high readings, then you need to see to the fuel pump.
There should be a spacer between the fuel pump and engine block, this may be missing if so you will have quite high pressure readings.
if your pressure readings are only a bit high you can pack the pump out with one or more gaskets.
it will be a bit of trail and error, experimenting to see how many gaskets you'll need to get the right pressure reading.
Once done remove the gauge and tee piece. Happy happy joy joy!

[busheytrader]

Gunson have a similar vacuum and fuel pressure gauge in the U.K. for around £20 or less...

When I had the 2.0L engine both fuel bowls were overflowing after about 40,000 miles on the car. They had to have their needle valve assemblies replaced as they'd both worn a ring around the top and were obviously no longer sealing. Both floats were fine.

[Hasbeen]

One of the problems here is the cheapskate been counters at Triumph when our cars were designed & built.

If you look at our engines, they angle down at the back. However our carb float bowl is attached to the body of the carb at right angles. As the front one is infront of the carb, [up hill], & the other is at the back of the carb [down hill], the float level in relationship to the main jet is quite different in each carb, much lower in the back carb. The been counters probably saved a pound by having one standard carb, rather than 2.

When setting the mixture you actually unknowingly set the main jet in the rear carb a little lower to correct for this difference.

Now look at a TR3, or any of the Ferguson tractor/Standard Vanguard engined TRs, & you will see the float bowls are attached at a different angle to each carb. This angle corresponds to the engine angle, & corrects for it, giving the same float level in each carb.

They also had copper floats, & adjustable forks, allowing the float level to be set as required. The copper floats were more buoyant, & allowed for a little higher fuel pressure, before flooding.

How much more efficient this is than our set up I don't know, but we used to set the float level in our racing engines at 1/16" below the top of the main jet. It gave better mixture control, & a little more power. Ours are to all intents not adjustable.

Many may have noticed that due to these different angles of the float chamber, it is always the higher one, the front carb that floods on our cars.

I have reengineered my float bowl attachment to approach, but not quite equal, this better system of old, when cars were built as well as possible, rather than to a price. Is it worth the effort, probably not if you are not racing.

What it means is not much to performance, but it makes the carbs more sensitive to fuel pressure. Follow Cobbers excellent tutorial, & the system once working properly is perfectly adequate.

Thus ends Hasbeens rant for the day.

Hasbeen

[Monkeyzak]

Posted my reply in the wrong place

Pump cleaned out. Packed full of rubbish

New needle valves and floats

Some random wiring dealt with.

Took the car out for about 5 or 6 miles. Decent speed and it was fine. Imagine the carbs might need adjustment but running like it should I think.

Hopefully be driving it properly after the weekend when the sparks been back to tidy it up

[dursleyman]

Good stuff, hope you can begin to enjoy driving it now, that is what our cars are for.

[UKPhilTR7]

Sounds like you are on the right road for success.