L1's Garage

Vehicles & Mobility
16804

So far the vanes haven’t caused me any trouble by getting clogged up with carbon *knocks on wood

hahaha that reminds me of the turbo groms people do. I recall something like a 28mm turbo being what is used.

That’s exactly how mine is; it basically just bleeds off any “extra” fuel pressure the pump makes back into the fuel tank via the return line.
To get mine running right I needed to completely back off the pressure regulator adjustment screw so that the spring was basically putting no pressure on the the diaphragm in order to get my fuel pressure low enough to not overcome the carb float valve. Here’s a picture of the gauge I installed so I can make sure my boost pressure and my fuel pressure stay lock step together (without this gauge it would be a pain to try and troubleshoot):

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One more thing to check if you rule out the fuel pump would be the accelerator pump diaphragms on the carbs, if they are cracked and a don’t work the engine will feel pretty lazy off of idle.

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16805

Sums up the new car market right now :joy:

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16806

Will probably stay that way for some time

16807

There is, it’s called valve float.
Also make sure that the float needles seat properly before doing anything else.
The engine will flood regardless otherwise.

Carbs are no magic, really easy stuff.
You’ll always need a fuel pressure regulator on boosted applications.
6 psi fuel pressure n/a + 5 psi boost pressure means you need 11 psi fuel pressure on 5 psi boost.

Otherwise the engine will starve after a short while on boost.

Be carefull getting the right fuel pump, carbs only work on really low pressures unlike injection systems.

I’ve got lots of experience on carb engines, with suck trough, blow trough and n/a.
All on homebrew projects.
I’d love to help if there are questions.

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16808
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16809

You’re talking about automotive carbs with this statement?
In my experience anything over 2psi pressure differential is going to flood a motorcycle carb since they were meant to be gravity fed with ~0.1psi of pressure in normal use.

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16810

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Let’s be real, if only the intake valves are floating, you’re fine.

Valves open longer means turbo puts more air in the engine

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16811

Yea it’s basically my theory with Nissan Altima drivers, what they lack in speed they make up for in lack of self preservation.

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16812

They are just numbers to explain a concept.
All carbs work the same, there’s not much difference between car carbs and motorcycle carbs. Just formfactor.

Some are CV but those are also on cars and bikes.

But yes in general 2-3 psi fp is expected.

16813

I’d argue a broken conrod is also quite the rev-limiter :stuck_out_tongue:

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16814

Ahhh I took that too literally.
Some of the bigger holleys can take a ton of pressure so I assumed you were talking about those.

16815

My miata still made power on 3 cylinders…

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16816
16817

3 cylinders are kinda main stream now days.

16818

Yeah, not the way I did it tho. :sweat_smile:

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16819

No not really. :laughing:

16820

Look, the valves for cylinder 1 still work, it’s just the piston that’s not so good.

16821

If you don’t wanna get rid of it.
Wouldn’t be easier to just swap the engine?
I mean there are probably plenty out there.

16822

Remove the cylinder and you have a 3 banger problem solved

:troll:

1 Like
16823

Because I have found my true love in motorcycles.

See also:
https://forum.level1techs.com/t/post-what-new-thing-you-acquired-recently/149881/15547

2 Likes