Building a 2270 motor with LH-Jet, A discussion thread.... |
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Building a 2270 motor with LH-Jet, A discussion thread.... |
boxsterfan |
Jan 30 2014, 11:33 AM
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#1
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914's are kewl Group: Members Posts: 1,776 Joined: 6-June 03 From: San Ramon, CA Member No.: 791 Region Association: Northern California |
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:
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.
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Jake Raby |
Feb 1 2014, 08:22 AM
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#2
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Engine Surgeon Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
The issue with this is the compromises that are made when equipping a larger engine with stock FI. The added displacement won't offer any more power due to the constraints placed on it by the stock FI.
You will find it challenging to have stable AFR across the entire RPM range. If you have low enough standards, and are open to compromise, by all means, proceed. After 2056cc I determined the law of diminishing becomes common place with stock FI. In the late 90s I built quite a few 2270 engines with stock FI, narrow power bands and tuning challenges is how I'd define them. |
r_towle |
Feb 1 2014, 10:23 AM
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#3
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Custom Member Group: Members Posts: 24,624 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
The issue with this is the compromises that are made when equipping a larger engine with stock FI. The added displacement won't offer any more power due to the constraints placed on it by the stock FI. You will find it challenging to have stable AFR across the entire RPM range. If you have low enough standards, and are open to compromise, by all means, proceed. After 2056cc I determined the law of diminishing becomes common place with stock FI. In the late 90s I built quite a few 2270 engines with stock FI, narrow power bands and tuning challenges is how I'd define them. Did you ever try EFi I from a larger motor? I believe he is talking about gathering all the parts from a different LH jet motor that may be in the range of his motor....so it would be stock! but not stock 914..... |
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