Carburetor Running Turbo Engine?!

[RBert]

Hey all so i was talking to this guy at work who is a car nutter (like 40 lives at home with his dad and spends all his money doing up one of his 10 commodores haha)

so anyway he also has a datto 1600 and a 1984? Bluebird, and this is where my question lies.

Apparently the Bluebird is running a 2L datsun engine (not sure which one) with a custom turbo setup consisting of carburetor to turbo to throttle boddy, and at first I'm like wtf is that even possible and then he explains it to me (most of which i didnt understand) and how it doesn't run and intercooler and some other shit.

car makes 184HP at the wheels on 8psi

so anyway when i get home I inform my dad who is also quite experienced with cars, although Im willing to say probably not as much as this guy. But my dad says its not possible....ARGUMENT BREAKS OUT..so on so on hahaha.

Can anyone confirm this please so i can settle it once and for all?

Ill try get pics (he had them on his phone to show me)

Cheers

[drift nut]

yes this is possible, from what i understand from what you've said, he's running a in a draw through configuation

[Socrates]

+1 to drift nut, correct.

the other way it can be done is plumbing the turbo into the carb, which needs some mods to jets to not lean out.

[RBert]

yes this is possible, from what i understand from what you've said, he's running a in a draw through configuation

Thanks very much, any chance you or anyone can explain this a little more?

also cheers socrates for your input.

[boiracer]

yes def possible, draw thru is the way to go. and turbo's have been around longer than every day fuel injection.

my bro used to have a kombi with a setup like this. only issue you have with a draw thru is that your pulling your fuel mixture thru the turbo itself, which can make it a small pain to get tuned and running right. my brother kombi had an SU carby infront of it, seemed to give tyhe most progressive flow.

in your post you speak of a throttle body aswell?? that doesnt need to be there, as the carby is the throttle body in these setups.

[luke gtr]

Similar set up to older superchargers on v8s

But now you use a turbo as the compressor.

The fuel also helps cool the turbo, and at those levels, shouldn't really need an intercooler.

[Cowboy1600]

Turbo sucks air through the carby. Turbos need to be built with different gaskets - ones which won't break down when they get fuel on them.

Apart from that it's cake. Strombergs are one of the most popular carbies to use but webers are good too, as the above pic shows.

[RBert]

Wow thanks so much guys....this is why i love SAU haha

one more thing, can someone explain how the fuel doesnt explode from the heat generated by the turbo?

cant wait to see the look on my dads face

Edited September 20, 2011 by RBert

[Cowboy1600]

Not enough pressure and no source of ignition, ie. spark.

Cylinder pressure is up around 150+psi, where as a turbo may be producing 25psi between the turbo and inlet. And fuel doesn't ignite well without a direct source of ignition. Drop a lit cigarette into fuel and it's not likely to ignite.

Edited September 20, 2011 by Cowboy1600

[luke gtr]

As above, fuel has a fairly high spontaneous combustion point(with source of ignition), and the heat of the turbo just isn't hot enough on the inlet side.

The fuel actually helps to cool the inlet down by using the heat in the air to vaporise, in a way similar to water injection.

[mad082]

everything above is correct. there have been various cars over the years running carby turbo setups. in fact there was even a turbo VB commodore (unsure whether it was a holden thing or just a thing done by a few dealers). very rare. a mate of mine actually has one of the setups tucked away in his cupboard.

[RBert]

thanks so much guys really appreciate this.

[Cowboy1600]

Oh, and your mates car would be an L20B which is a very, very popular engine to do suck through set ups on. They are tough motors. Although for racing applications many people use L18s as they rev harder. You can bore them out to nearly 2L (bore and stroke can go past this but you lose some revs). Again, incredibly tough motors.

I've owned 1600s and 180bs with either L18s or L20bs (and one Z18et which is an L18 bottom end with a twin spark head, EFI and turbo) and if you saw the sheer destruction I tried to force upon them you would be horrified. Simply horrified.

[iseekool]

Oh, and your mates car would be an L20B which is a very, very popular engine to do suck through set ups on. They are tough motors. Although for racing applications many people use L18s as they rev harder. You can bore them out to nearly 2L (bore and stroke can go past this but you lose some revs). Again, incredibly tough motors.

I've owned 1600s and 180bs with either L18s or L20bs (and one Z18et which is an L18 bottom end with a twin spark head, EFI and turbo) and if you saw the sheer destruction I tried to force upon them you would be horrified. Simply horrified.

Off topic

Would a Z18ET head bolt directly onto an L20 bottom end with no mods? Sounds tempting.

Definately have a soft spot for the L series engines. Indestructable. Mine has done roughly ~300,000k, odometer stopped at 250,000km - Always gets a flogging when it's driven, but oil is changed every 5000km with out fail - all original parts.

Currently my Bluebird's stock head is off being reconditioned and mechanically cleaned, so much carbon gets caked onto the exhaust ports - it's crazy.

Only reason for the head coming off is because one of the head bolts snapped, but lucky no blown headgasket. Just doing the cleaning and reconditioning due to all the effort taking the head off.

[Cowboy1600]

It will, but manifolds are different. They are a crossflow head.

Try and get your hands on an A87 head off an L18. They are the high comp, big port heads and get L20s singing up to 1000rpm harder than stock.

Failing finding an A87, the W53 is next best option.

I had an A87 and a factory EFI head (and complete set up_ in my shed until late last year. In fact I think the guy who bough the EFI stuff off me is selling it again. Check Ozdat

[StevenCJR31]

a BLOW THRU carby set up has been used many times over the years, its a matter of sealing the carb up so it doesnt leak boost. . . .no fuel in the turbo that way . . .as for the L series L20B, lots of mods are easy to do on these motors including stroking using Z series parts

[zebra]

Blow through setups suck balls.

Need a rising rate reg, and all sorts of stuffing around to get fuel to flow out of the jets and not have air flow into them.

[mad082]

on the L20 discussion, my mechanic mate had a L20 in a 1600. it was bored and stroked. made about 155hp at the wheels (still natro) from memory. only problem was that it kept arcing out headgaskets because of how bored out it was (gasket was too thin between cylinders).

[Cowboy1600]

a BLOW THRU carby set up has been used many times over the years, its a matter of sealing the carb up so it doesnt leak boost. . . .no fuel in the turbo that way . . .as for the L series L20B, lots of mods are easy to do on these motors including stroking using Z series parts

That's great mate, but we're talking suck through.

Z24 cranks stroke them out to 2.4L and they go like hell. But it requires a fair bit of work to get a Z crank to fit an L series.

[zebra]

on the L20 discussion, my mechanic mate had a L20 in a 1600. it was bored and stroked. made about 155hp at the wheels (still natro) from memory. only problem was that it kept arcing out headgaskets because of how bored out it was (gasket was too thin between cylinders).

The world needs more angry Ford 2.0 pinto's and L20s etc imo

and im a Big engine nutter