Something I've been thinking about for a while. As the title states. Are there issues with 1.8's that there isn't with 1.7's and 2.0's? Enlighten me.

I think mostly it's the L-Jet.

Otherwise, mechanically, I think the 1.8 is better than the 1.7... better heads, anyhow.

They are rated at less power then the 1.7 (due to emissions) and have a funky fuel injection system.

Zach

I don't know but from what I read 1.8 cases tend over heat and loose oil pressure (warp) the metal is differant. 1.8 head or good to modify.

Steve

I dig the l-jet in my bus, seems pretty reliable. I think djet is a more archaic design and future bosch systems were developed from ljet but I'm not 100% sure.

Vacuum leaks cause bigger problems with ljet I believe.

YES , If there is a vacume leaks in a L-jet it will run lean and hotter . Over heat,(warp) I think Jake has covered this many times in past threads.

Steve

yea that. Thats typically why a stock 1.7 is better to have than the 74+ 1.8's. it probably is better overall motor, but the FI and emissions stuff hindered its true potential.

Nothing wrong with ljet..just not a lot of experience in the 914 community. drove my 75 for 2 years with the ljet before I yanked it for the 3.2l that is going in it. Ran like a dream. Only thing to watch for is vacuum leaks as the ljet system likes things air-tight!

The 1.8l engines were rated the lowest in HP though..but the heads are desireable!

I've heard they're more reliable than 928 engines.

(Sorry, I couldn't help it.)

Porsche even stated that the L-jet is the more modern EFI system. i think it gets a bad rap because of the 76 hp rating and "everybody" wants more hp. I like my L-jet and it runs very good (knock...). 'course, my D-jet also is running very good too.

The November issue of Excellence actually gives comparable $ values for the 1.8's as for the 1.7's.

My daily driver is a 1.8L with L-Jet. I have 2 D-jet cars and the one L-Jet. I like the L-Jet better. IMHO its a simpler system with less expensive parts that can seriously break (read: MPS). Yes it is less tolerant to vacuum leaks, but this isn't too big a problem. If your car is tuned well there shouldn't be any no matter what system you have.

In driving both, the 2L is faster by far, but the 1.8 makes a great daily driver. Not that D-jet can't do it, but I get around 40mpg driving back and forth to work (highway). Its great.

Hey All,

Maybe I'm biased because all I got is a 75 1.8 running L-Jet(all smog stuff is gone). I can hang with the stock 2.0's that I have been on runs with as long as there are not to many drag strips. I do feel like I have to drive the hell out of it to keep up. But it does keep up!!

On the torgue side the 2.0's don't start to pull away till late 3rd gear(around 65 mph). My top end is around 95 on a down hill slope ....

The FI system is very simple. I am a simple man and I have been able to learn the system with ease. I am thinking of modifing it to go on my 2056 later this winter. Somebody talk me out of it and tell me what carbs I should be running!

Oh, I got about 30 mpg from Thur to Sun at the RCR. All types of driving over all kinds of gradients. 16x7 rims with 205/55 and 911 front end so I would assume I am a little heavier than stock?

JKP

I'll try to talk you out of carbs. if not L-jet, then consider SDS, Megasquirt or Microsquirt or some modern fuel injection system.

The knock is that the 1.8's are pretty gutless compared to a 2.0l. Now a 1.8 vs 1.7 is about the same...I like Ljet as its pretty simple and there's hardly any maintanence..

Going from 8 cylinders to 4 Rick?

Slight

Would a stock L-Jet setup from a 1.8 work OK on a 1.8 based 2056?

Think back guys...

1973 was the tipping point for fuel emissions.....

Before 1973, no emissions issues....

After 1973, there were emission requirements...

Since emission control was in it's infancy, most of the fixes involved "detuning" an engine in some way with retarded timing, revised fuel/air maps, air injection, etc.

That being said, I like the L-jet. Simple, reliable, and darned near bulletproof. Yes, it is sensitive to neglect (air leaks) and the barndoor sized air flap has a little less response than some systems, but it is reliable.

I have an updated system in my 1986 Vanagon (2.1 L) called a Digifant and (except for dirty fuel filter issues and a single worn out switch) it's been 100% reliable since 1986. It looks just like an L-jet on the 914 and has a neat feature where when you take your foot off the gas, the injectors stop flowing until the engine is at 800-1000 rpm. Can you say zero emissions when downshifting?

I'm surprised that someone hasn't adapted the Digifant to the 914. Mebbe it's the water cooling thing.

Later versions switched from the air flap to a hot wire airflow for improved throttle response.

Ken

no knock here.
We have all of them and the 1.8 is a great motor...

Tune it, change the hoses and drive the hell out of it.

Rich

in 1973 Porsche introduced the 2.0 to replace the six. emissions laws were also changing. compression was lowered as a result. with lower compression came lower HP ratings. in 74 Porsche bumped the displacement of the 1.7 from 90mm to 93mm bores. I speculate this was done to maintain power output simi-level as more emissions equipment was added, further bogging down the motor. In 75 the exhaust was changed to make it burn hotter just to keep pace with further changes in federally regulated emission laws. auto makers of the era were all scrambling to meet the new standards and few were able to comply without great sacrifices to power output and engine longevity. Enter Mr. smog pump 1975...

the 1.8 engine responds dramatically to an increase in compression and back-dating the exhaust system. in its stock form, with all the extra smog junk, they run weaker and hotter than a 1.7. the 1.8 heads have different chambers and bigger valves. an early 1.7 with it's small valves and higher compression makes for a snappier motor off the line but a 1.8 with the same 8.4 compression will keep pulling after the 1.7 has peaked

I see far more cracked 1.8 heads than 1.7 heads
L-Jet has superior smoothness in daily driver applications

throw some 96mm jugs on that L-Jet beast, bump her up to 8.6 to 1 and smile for days

don't forget to change the 2 o-ring in the L-Jet oil fill cap

to answer the post diectly...
more heat, more head cracks.
vacuum leaks make it run like pooh
low compression make it a dog
more people fear L-Jet

Correct me if I'm wrong, but wasn't the '74 1.8 the first car to use the then new Bosch L-Jet. Too bad it wasn't used on the 2.0's in '74-'76.

yup. it was later used on the 2.0 type 4 powered 912e. it was low compression...and power

I had a 2.0 car and currently have a 74 1.8L car with ljet.

The 1.8 doesn't give the kick in the pants the 2.0 did, but it accelerates more smoothly. Just by watching the speedo, it doesn't seem much slower but does feel slower. It's like a 2.0 with a hangover.

The 1976 912E had a 2.0 with L-jet. sensitive to leaks and grounds, but runs great. The 1.8L had a lower compression than the 1.7. I have built two engines with the 1.8 euro pistons which raise the compression ratio of a 1.7. With the bigger heads of the 1.8 it is a great combo.

Al, did your 914e get its 2056 as indicated in your signature?

Better yet, swap the whole 1.8 block for a real 2056 (with 2.0 heads), runs great with stock L-Jet! The air flow meter limits the extreme top-end, but otherwise it's as punchy as a carbed 2056 and much smoother to drive. Somewhere around here I have a set of L-Jet intakes that have been modified to fit the 2.0 heads... BTDT

well of course a 2056 would be preferred but not everyone here has a set of 2.0 heads, rods and a crank

Finally an answer to my question.



1.8 case/heads w/2.0 crank and rods. I've been thinking about slapping an L-Jet setup back on it but was wondering if the system would support it.

i have a stock 1.8 with l-jet, and its the best running engine ive ever had in my car, the l-jet can be tricky, but it takes patience and knowledge to get the going. but ive been this particular l-jet system in my car for over 3 years, and my dad ran it for about 14 years before that, so set them up right, treat them right and they will last forever, better fuel mileage too, thats been my experience.

THE 912E WAS A 2.0 WITH l-jET

So, I must be one lucky dude. I have a 1.8 that leaks oil from every possible oriface, yet runs great with l-jet. I also have a 2.0 with stock d-jet that was not running so well when I pulled it from the parts car about 8 years ago.

I don't think that this is a complete hi-jack by asking what you guys recommend if I want the most bang for my buck on a lower budget rebuild given the parts I have on hand. Which case, crank, rods, heads? I would probably put a new set of P/Cs on it anyway, unless I find that I have euros in my 2.0. If not, what P/Cs?

From what I have read, I would much rather have l-jet than d-jet due to the simplicity. Why do most people use d-jet on mildly tuned 2.0 based engines, other thant the difference in manifold bases?

I plan to buy Jake' rebuild dvd soon. Is this a good starting point for my project?

Thanks, and sorry if this is viewed as a hi-jack...

Ken

2.0 or bigger running with ljet should be tuned with an LM1, definitely doable. Catch with ljet is that after X RPM (I want to say 4500), the AFM flap is fully open and the mixture is based on a ratio set for the 1.8's needs to "redline". This mixture cannot be adjusted as far as I know. So there is the potential for higher RPM leanout with a larer displacement engine. It would be cool to come up with a system that would trick the injectors to dump more fuel into the engine at these higher rpms (if they aren't maxxed out already), but chances are if you are capable of playing those tricks you've already moved on to aftermarket efi

2.0 buses came with ljet, but they also aren't RPM monsters . . .

if budget is key...use the heads that are in the best condition, 2.0 heads have bigger valves, better spark plug position but are more prone to cracks. buy some 96mm AA Ps&Cs and throw on the L-Jet

test ALL FI components first. if you start an FI test check out thread, I'll post some goooooood basics on that.

I had my 75 1.8 Ljet on a 2.0 engine for almost 20 years. now its back on my original rebuilt 1.8 again. Never a problem. The Ljet has almost 225000 total miles on it.