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> 2.0l engine with 1.8 heads - what FI set up to use?
Tdskip
post Dec 3 2018, 07:39 AM
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Counter to popular belief I do not stay up late inventing hairbrained questions for you all, although that is tempting sometime given the wealth of knowledge here. As of around 10:30 AM today this will be a real life scenario.

Let’s imagine I have a 2.0l case running 1.8 heads with a single Weber that runs but I want to convert back to FI.

Let’s further image that I have both a 1.8 FI set up and a 2.0 FI set up sitting in the shelf.

Which FI set up would I be best advised to use on this engine, and for bonus points and adding to the community knowledge here, why?

BTW - planning on doing a tech day on this with/for the SoCal mafia once I get a plan together. Given what seems to be a trend back to FI (or at least renewed interest) I think it could be a useful tech day for the community.

Thanks!
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914Sixer
post Dec 3 2018, 07:49 AM
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For me, I would go with pieces from a bus engine. Use the 2.0 intakes, and larger throttle body. Your choice for fuel injection from there.
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TheCabinetmaker
post Dec 3 2018, 08:13 AM
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2.0 intake tubes and throttle body will not fit in 1.8 heads without modification. I would get 2.0 heads and 96mm pistons and build a true 2056. Why fart around cobbling crap together when the proper parts are readily available?
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Tdskip
post Dec 3 2018, 08:18 AM
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QUOTE(914Sixer @ Dec 3 2018, 08:49 AM) *

For me, I would go with pieces from a bus engine. Use the 2.0 intakes, and larger throttle body. Your choice for fuel injection from there.


Good morning Mark, thanks for the fast response.

So just stick with the 2.0 L set up from ECU to throttlebody two injectors?

By the way-that combination gauge I bought from you is beautiful. Great experience dealing with you on that, thank you.
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Tdskip
post Dec 3 2018, 08:26 AM
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QUOTE(TheCabinetmaker @ Dec 3 2018, 09:13 AM) *

2.0 intake tubes and throttle body will not fit in 1.8 heads without modification. I would get 2.0 heads and 96mm pistons and build a true 2056. Why fart around cobbling crap together when the proper parts are readily available?


Good morning, hope you had a good weekend.

To answer your question-because I have other projects and wanted to see if there was a "easy "way to simply swap out the car for FI based on what I had access to on the shelf.

Building/refreshing an engine is on my to do list of skills to acquire, but that seems a lot more involved then swapping out an FI system.

So run the 1.8 L set up since it'll work with the heads? Would that result in less fuel flow them with the 2 L engine wants or is the system capable of keeping up for street use?
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TheCabinetmaker
post Dec 3 2018, 08:31 AM
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I'll let the ljet experts answer that
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Tdskip
post Dec 3 2018, 08:41 AM
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QUOTE(TheCabinetmaker @ Dec 3 2018, 09:31 AM) *

I'll let the ljet experts answer that


Thanks Curt - have a good morning.
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Mark Henry
post Dec 3 2018, 08:55 AM
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I've built a 2.0 head 2056 engine with Ljet, I saw no difference in power compared to 2.0 Djet.
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Mark Henry
post Dec 3 2018, 08:57 AM
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Only power loss will be because of the 1.8 vs 2.0 heads.
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Tdskip
post Dec 3 2018, 09:06 AM
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QUOTE(Mark Henry @ Dec 3 2018, 09:57 AM) *

Only power loss will be because of the 1.8 vs 2.0 heads.


Mark! Thanks for both responses.

Can we drill into some of the details here, both for my benefit but also to add to the knowledge base if people search on this topic again?

It looks like the 1.8 L in the 2.0 L fuel injectors or a different part number, are they actually interchangeable or do they have different flow rates etc?

It would seem, yes I've actually been doing some research, that you can't enter interchange the 1.8 L in the 2.0 L components, so sticking with a complete 1.8 or 2.0 L is the way to go, correct?

Will the 2.0 L system bolt on to an engine with 1.8 L heads? It seems like there is some debate whether that will work or not?

Thanks!
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TheCabinetmaker
post Dec 3 2018, 09:09 AM
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Like i said before, not without modification.
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Tdskip
post Dec 3 2018, 09:21 AM
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QUOTE(TheCabinetmaker @ Dec 3 2018, 10:09 AM) *

Like i said before, not without modification.



Hi Curt - so what are the differences? Head ports for the injectors?
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dr914@autoatlanta.com
post Dec 3 2018, 09:29 AM
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If that is all you have, use the 1.8 fuel injection system, as it is much smoother running than the old 2.0 set up and the intake runners will directly bolt on. The 912e used a similar system, 2.0 engine 1.8 afc type fuel injection system aud it worked well


QUOTE(Tdskip @ Dec 3 2018, 06:39 AM) *

Counter to popular belief I do not stay up late inventing hairbrained questions for you all, although that is tempting sometime given the wealth of knowledge here. As of around 10:30 AM today this will be a real life scenario.

Let’s imagine I have a 2.0l case running 1.8 heads with a single Weber that runs but I want to convert back to FI.

Let’s further image that I have both a 1.8 FI set up and a 2.0 FI set up sitting in the shelf.

Which FI set up would I be best advised to use on this engine, and for bonus points and adding to the community knowledge here, why?

BTW - planning on doing a tech day on this with/for the SoCal mafia once I get a plan together. Given what seems to be a trend back to FI (or at least renewed interest) I think it could be a useful tech day for the community.

Thanks!
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914Sixer
post Dec 3 2018, 09:31 AM
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Bus intake runners are 4 bolt vs 914 3 bolt, so they will bolt directly onto the 1.8 heads.
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Tdskip
post Dec 3 2018, 09:36 AM
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OK - so intake runners are different. Got it.

It sure looks like the injectors will fit, but worth double checking that.
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914_teener
post Dec 3 2018, 10:21 AM
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For 1.8 heads you will need to have a hole machined in the head for the 2.0 intake runners.

Not a big deal.
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Tdskip
post Dec 3 2018, 10:32 AM
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Thanks Rob.

So bus runners, or drill the head for 2.0 runners. I'd imagine that bus runners are cheap, so that seems like (per Mark's suggestion) like an easier way to go. Good to know that a simple mod will work with the 2.0l stuff however.
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marksteinhilber
post Dec 3 2018, 10:49 AM
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OK, so your running a 2.0 L case which tells me you likely have 96mm bore, and standard stroke 2.0 L crank, so probably 2056 cc displacement. The 1.8 L heads are the current performance limiting feature, along with the single carb. Between the 1.8 Ljet and the 2.0 DJet, I would choose the Ljet which is a newer design that can accommodate the increased displacement as proven by use in the 912E. Use the Ljet system as is and it will bolt right up to the heads easily. To insure that it runs well with the brain, make sure all components are working properly, has no vacuum leaks, and is hooked up to a !.8 distributor with the same vacuum connections (advance/retard). If forget if it has one or both.

That said, you may be able to bump up performance by switching to 2.0 heads, use 2.0 runners and adapt to the existing 1.8 plenum. Also consider having your throttle body rebuilt and bored to a larger size by on of the vendors on this site. If you increase the max airflow to the cylinders, you should move up to the injectors used on the 912E and plan on checking A/F ratio to avoid a lean condition at WOT.
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TheCabinetmaker
post Dec 3 2018, 10:53 AM
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The 1.7\1.8 runners are longer and don't line up with the 2.0 plenum. They don't have the same bolt pattern. The throttle body is smaller. You can ask the same question 3 times and word the q different, but it doesn't change the answer.
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Tdskip
post Dec 3 2018, 10:57 AM
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QUOTE(TheCabinetmaker @ Dec 3 2018, 11:53 AM) *

The 1.7\1.8 runners are longer and don't line up with the 2.0 plenum. They don't have the same bolt pattern. The throttle body is smaller. You can ask the same question 3 times and word the q different, but it doesn't change the answer.


Hi Curt - take it easy please, and please also do try to remember that some of us are still new here and learning.

I am trying to understand what and why, which seems like a reasonable thing to do. Now I, and others, know that the runners are physically different.


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