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HEI Help!
https://slantsix.org/forum/viewtopic.php?t=35682
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Author:  BlueBandit [ Thu Jun 04, 2009 9:01 am ]
Post subject:  HEI Help!

When converting to HEI what do I do with all the wires coming from the air cleaner computer?

Author:  HardCharger [ Thu Jun 04, 2009 9:05 am ]
Post subject: 

Hi Blue Bandit,

I think you are referring to lean burn stuff eh? I think you'll have to do some searching for lean burn info to figure that out.

HEI upgrade is simple assuming you read and understand all of these threads.

http://www.slantsix.org/forum/viewtopic.php?t=28732


http://www.slantsix.org/forum/viewtopic.php?t=33516


http://www.slantsix.org/forum/viewtopic.php?t=34726

Author:  SlantSixDan [ Thu Jun 04, 2009 10:23 am ]
Post subject: 

If you are converting to HEI, you wouldn't want to be keeping the Lean Burn computer.

Author:  BlueBandit [ Thu Jun 04, 2009 10:28 am ]
Post subject: 

But what do I do with all the wires going to it?

Author:  Reed [ Thu Jun 04, 2009 10:48 am ]
Post subject: 

Converting from lean burn to HEI is perhaps the simplest HEI conversion out there. The lean Burn cars already did not come with a ballast resistor. To wire the HEI in, all you have to do is connect the HEI module to the distributor and the (+) and (-) feeds on the coil. The (+) coil feed will power both the HEI module and the coil. That's it.

As you have noted, this leaves you with a whole mess of wires that used to go to the lean burn computer. If you are tidy, you can spend the time unwrapping the wiring harness and removing just those wires that went to the computer and the components the lean burn system used ut which you will not be using (air charge temp sensor, O2 sensor if equipped, carburetor, etc...) If you want a quick and dirty solution, just follow the bundle of wires that went to the computr back to the point where it brankched off the main wiring snake and cut them off. Be sure you don't alos cut the power feed for the choke pulloff for the carb, the wiring to the alternator, and the wiring for the coolant temp sensor.

Author:  BlueBandit [ Thu Jun 04, 2009 10:56 am ]
Post subject: 

Thanks. I just wasn't sure about some of the wires. I had heard that the voltage regulator might have also been tied to the ESC computer but maybe that wasn't true. I appreciate it.

Author:  00spy [ Thu Jun 04, 2009 1:50 pm ]
Post subject: 

When I did my HEI setup , I ended up taking all the lean burn wiring out. It was not hard ,just a little time consuming. With mine , it all came out in one piece ,and only had to cut the hot wires( I think two of them) ,which were like 4 or 5 crimped together .


Dave

Author:  BlueBandit [ Thu Jun 04, 2009 4:12 pm ]
Post subject: 

What kind of power and gas mileage gains am i looking at from the HEI conversion?

Author:  Reed [ Thu Jun 04, 2009 4:17 pm ]
Post subject: 

Quote:
What kind of power and gas mileage gains am i looking at from the HEI conversion?
None to significant. Your power and gas mileage gains will depend on too many variables to give a stock answer. Most lean burn systems stopped working right long ago, leading to poor power and fuel economy and clogged catalytic converters. Plus, your original lean burn carb is most likely worn out by now. However, you may have the rare still functioning lean burn system with a decent carb, unclogged cats, and no vacuum leaks. Add to these possibilities the wide vairation in your potential choice of distributors and carburetors to replace the lean burn ones, and you have an unanswerable question.

I would hazard a ugess that you will see at least 2-5 MPG increase and a noticeable improvement in power and idle quality. If your vehicle has catalytic converters I would recommend removing them at this time as well since (a) they are probably clogged up after all this time and (b) they won't work with the non-lean burn carb.

Author:  00spy [ Thu Jun 04, 2009 4:24 pm ]
Post subject: 

Hey Reed , wouldn't the converters work as long as the air pump is still connected and working.

Dave

Author:  BlueBandit [ Thu Jun 04, 2009 4:28 pm ]
Post subject: 

When I got the truck from my grandpa the cats were melted down either from the lean burn comp. or the fact that the carb floats were gummed up. I built a 2 1/2 inch single exhuast with a high flow cat and a magnaflow XL muffler. I rebuilt the carb and it passed emissions last year great but that could have been because of the new cat. It had trouble this year and so I want to get rid of the lean burn so I know that's not messing with the emissions. I'm in Utah but I can get away with not having the lean burn comp. as long as it passes the cut points. Love the truck and i want to stay with the slant cause it's different around here (not many slants anymore).

Author:  Reed [ Thu Jun 04, 2009 6:51 pm ]
Post subject: 

I thought the same thing about the cat- so long as the air pum pis hooked up, it should be okay. I tried that on my brother's 83 Dodge van. It worked okay until the float in the carb failed and dumped too much gas through the system. The brand new high-flow cat I installed overheated due to too much gas and the internal element melted and collapsed, clogging the muffler line. I don't recommend using a carb with a cat. If you must, make sure the carb is running as lean as possible and is in good shape.


I have had well tuned 318s and 225s with no emissions systems but the PCV run as clean as a new car with all the emissions controls.

Author:  BlueBandit [ Mon Jun 08, 2009 6:40 am ]
Post subject: 

Did the HEI conversion this weekend and it works great. The truck idles better, has a little more power, and I will just have to wait and see what the fuel mileage does. The port on the carb (Holley 1945) that the air pump works off of works great for the vacuum advance on the dizzy. It advances just like it needs to. The port we talked about in the other threads wasn't the right vacuum. Appreciate the help. thnks

Author:  Reed [ Mon Jun 08, 2009 8:37 am ]
Post subject: 

Quote:
Did the HEI conversion this weekend and it works great. The truck idles better, has a little more power, and I will just have to wait and see what the fuel mileage does. The port on the carb (Holley 1945) that the air pump works off of works great for the vacuum advance on the dizzy. It advances just like it needs to. The port we talked about in the other threads wasn't the right vacuum. Appreciate the help. thnks
Make sure that the port on the carb that you use for the distributor has NO vacuum at idle and has FULL vacuum off idle.

Author:  SlantSixDan [ Mon Jun 08, 2009 8:38 am ]
Post subject: 

Quote:
The port on the carb (Holley 1945) that the air pump works off of works great for the vacuum advance on the dizzy.
The truck will run even better when you hook the vacuum advance to the correct port on the carburetor.

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