Building a 2270 motor with LH-Jet, A discussion thread.... Options

[boxsterfan]

First off, I am not anywhere near an expert in engine building, cam selection (how duration and lift affect the motor at idle and driving), injector flow rates, etc, etc, etc... So now that I have that out of the way, I still want to figure out the bits and parts that ***may*** make it possible to run a 2270 motor with LH-Jet. The primary reasons I am looking at this setup are because:

• L-Jet likely is not a good setup for this based upon my reading (issues with cam, idle troubles, hesitation, full power, etc...).
• I don't want to run carbs.
• I don't believe I want to tackle MegaSquirt (leaving the door open though).
• It sounds like fun/dare to be different.

1. The first question that comes to mind is will it be LH-Jet 1.0 vs LH-Jet 2.0?
From my research, LH-Jet 1.0 was pretty rare and used in the early 80's but then a switch to LH-Jet 2.0 occured. The primary difference between the two was that LH-Jet 2.0 utilized a Throttle Position Sensor (TPS) whereas LH-Jet 1.0 did not.

2. If LH-Jet 2.0 variant is the desired setup, which sub-variant would be used?
There appears to be a couple sub-variants within LH-Jet 2.0 primarily consisting of LH-Jet 2.2 and LH-Jet 2.4. It appears one of the primary differences between the two is that the LH-Jet 2.4 utilizes a "trigger flywheel" and the LH-Jet 2.2 does not. What exactly a "trigger flywheel" is I am not sure....I am guess that this is a notch or mark on the flywheel that is monitored by a sensor with the data fed back to the ECU.

3. What would the "build" sheet look like for such a setup?

Of course, this list can get complicated, but the desired build here is a street car with spirited driving. I would want excellent low-end torque, around 140-150HP on the motor and good pull all the way through the RPM range up to XXXX RPM (not sure where redline would be). Note also, the car will remain as a narrow body with 4-lug wheels.

• 2270 motor with which CAM?
• What plenum could work here?
• What intake runners would work here?
• Which fuel injectors could work here?
• Need to upgrade fuel pump?
• ECU - need to pull from Volvo/Saab from 80's
• FI Wiring Harness - need to pull from Volvo/Saab from 80's and will require customization
• Need any relay boards?
• Hot-wire MAF Sensor - need to pull from Volvo/Saab LH-Jet system
• IAC - Electronic Idle Controller - need to pull from Volvo/Saab from 80's
• O2 Sensor - need to pull from Volvo/Saab from the 80's - where to mount?
• CHTS - Utilize the existing CHTS (TS2) input into the ECU as a substitute for the coolant temp sensor (just have to figure out the proper resistance)
• Cold Start Valve - probably not needed here in the Bay, but what could be done here? Or does existing on the Type IV motor work here?

Of course, if you have already done this setup, it would be great to here from you, how the car drives, pain points, etc, etc....

[boxsterfan]

Where can I find information on keeping the proper ratios for the size of the intake/plenum and runners as it relates to the size of the motor?


Note: I didn't take flow dynamics in college. (IMG:style_emoticons/default/shades.gif)

[skeates]

Where can I find information on keeping the proper ratios for the size of the intake/plenum and runners as it relates to the size of the motor?


Note: I didn't take flow dynamics in college. (IMG:style_emoticons/default/shades.gif)

I'd imagine that these days a simple google search would get you what you need on that front. If not, I've got one of them fancy college text books with all that information in it. I can look into scanning the bits that you would need (though be warned that the book has a habit of breaking out into a flurry of formula and greek symbols from time to time).

Regarding the fuel injection system decisions, I would recommend going the route which gives you the most control over your motor. It seems to me that the limiting factor here is the ecu more so than the FI sensors. A fully programmable ECU should be able to handle a myriad of sensor options. A few have been mentioned here already (including Megasquirt), but it sounds like you are more interested in problem solving than in applying something proven (which is fantastic by the way!). Some other options you might check into are piggy-back ecu controllers and/or aftermarket software for your ecu which would allow you to program it. At the end of the day I doubt you will be satisfied with your set-up if you can't tune it to your motor. Cam profiles, intake and exhaust plumbing, motor displacement, etc. all play massive roles in tuning. Even if someone else sends you a map for their Type IV engine your engine's needs will likely be quite different! So, my .02 is that whatever you end up with ecu wise that you have full control over your timing, and fuel maps!