2 liter FI engine build

Keep it on topic, it will make it easier to find what you need.
Post Reply
BammBamm
Posts: 240
Joined: Fri Jul 31, 2015 1:23 am
Your car is a: 1982 Pininfarina Spider
Location: az

2 liter FI engine build

Post by BammBamm »

I have seen many threads about building the best 2 liter engine. I have noticed they all suggest carbs instead of FI. Does FI not give enough gas? Can I use bigger injectors? I plan on building a 10to1 compression engine with domes Pistons and upgraded valves. Suggestions??
Bill Woodbury
Design Engineer
Zero Shock Seating
1982 Spider 2000
User avatar
joelittel
Patron 2018
Patron 2018
Posts: 1013
Joined: Tue Mar 08, 2011 6:53 pm
Your car is a: 1980 Spider 2000 FI
Location: Evanston, IL

Re: 2 liter FI engine build

Post by joelittel »

When I built my 2L i was told not to go over 10:1 or I wouldn't be able to use pump gas. You probably wouldn't exceed 10:1, even with 10:1 pistons, because of the thickness of your gasket etc, unless you've decked your block.

The Bosch L Jet isn't programmable so it can't provide the best AFR at all times. Other than that it works well. Carbs do a better job of handling the AFR across the rpm range so you get better overall performance with a hi-po build, but only when compared to the L-Jet. I guess megasquirt works better than carbs or the L-Jet.

There's a thread that discusses injector flow, but my impression was that finding the right injectors was going to be difficult.

Another thread discusses swapping the air flow meter with a larger one, 1980's bmw m5 i believe.... but I'm sure that will take some effort as well.

Some people have opted for an intake manifold from a Thema connected to a megasquirt box.... looks the biz but you have to remove your brake booster and rig up some sort of throttle linkage to go this route. Not to mention, build a megasquirt and harness.

http://www.hiperformancestore.com/ljetronic.htm
This guy used to sell a "black box" that was designed to add performance to the L-Jet but I've never met anyone who has used it.

Vick Auto sells a megasquirt kit that replaces the L-Jet. This is probably what you need. The guys that have this kit love it from what I've heard.

if you haven't purchased your pistons yet I'd consider a turbo..... lots of YouTube videos out there making turbos look like a blast to drive.
vandor
Posts: 3996
Joined: Sat May 23, 2009 1:23 pm
Your car is a: 1971 124 Spider
Location: Texas, USA

Re: 2 liter FI engine build

Post by vandor »

Stock FI is fine up to 120-130 hp. I had a 2 liter with stock FI (except for the air cleaner) with 10:1 compression and 40-80 cams. Ran great, had a lot of power, was dyno tested to have ~130 HP at the flywheel.
Csaba
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
narfire
Posts: 3959
Joined: Sat Dec 27, 2008 2:14 am
Your car is a: 1980 124 spider
Location: Naramata B.C.

Re: 2 liter FI engine build

Post by narfire »

I agree with the stock FI system.
Larger ( 84.6-85mm) low dome pistons with shaved flywheel in the lower end. I found the most noticeable improvement came from the head work, cams and adjustable cam wheels being degreed in properly. Headers as well. Oh yea 2" + exhaust pipe.
I have a nice torquey engine that although is not a screemer but does accelerate well from 3400-5000 rpm, great in the twisties.
Make sure the brakes are up to snuff as well...
80 FI spider
72 work in progress
2017 Golf R ( APR Stg. 1)
2018 F350 crew long box
Post Reply