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Keane165's 1970 LeMans

2022 June
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L83 and 6L80 in 63 Catalina.


Old guy44
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Awesome start already Old Guy! Thank you very much. I can't wait to see your next installment. This is hot rodding at it's finest.

Edited by Frosty
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Nice job on the engine and the write up! Waitin on the next chapter. :pop_corn:

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Top notch old guy :dancingpontiac:

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:dancingpontiac:cool write up :cheers:

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Great write up old guy.... and here i was thinking any engine  would fit piece of piss into a big frame like a wide tracker!!!! 😏 NOT haha:cheers:

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Final hookups. Lets see if we can’t finish this thing up. If you are going to use an LT there are a few things that will be problematic. The first thing is the loom you choose. Be careful of your supplier. I actually purchased two, the first did not have the correct connectors at the front of the engine for the cam advance and would not even start the engine. Don’t remember who it was but they were in Michigan. After repeated attempts to contact them unsuccessfully I gave up and got my credit card company involved. Long story short they eventually said to send it back and when they got confirmation that the supplier had received it they refunded my money. I then spoke to a friend of a friend who had done several LS installs and he said to contact Howell for a loom. They supplied me with a loom and did a bench program on the PCM. I plugged it in connected 4 wires and it started right up. I like the Howell loom because it has a long loom for the PCM which allows the PCM to be installed inside the vehicle. Getting the PCM out of the engine bay makes for much cleaner wiring. Because the A/C unit takes up so much room under the dash I needed to make a box that is installed in the left foot vent for the PCM. It is not readily available but that is the only spot that had enough room. Now here is where the confusion starts. At the time of my install LT installations were still relatively new. The Howell loom came with four external relays. One for the PCM and ALDL. One for the injectors and coils. One for the O2 sensors and one for the trans. It also comes with a connector kit to connect to the factory cooling fans. So the obvious assumption is that the cooling fans will work through the PCM. Not so. There is a wire connected to one of the relays that has an aux fan label on it to connect to the A/C clutch. Connecting it to the A/C does in fact send power to the fans but the fans don’t run. Seems that the original truck fans are brushless motors that work through a square wave signal. That signal is not available through the computer. Hayden who is a familiar name in the area of engine cooling does now make an auxiliary switch that supposedly works through the PCM to supply that signal to PWM fan motors but I do not know of anyone that has actually installed one. I went to earlier brush motor fans and they worked fine with the system. At the time I contacted Howell and they knew nothing of the PWM fan issue at that time. In addition the PCM does not trigger the fan relay, I needed to install a Davies Craig digital fan switch DC 0444 to get the fans to work with the A/C off. The last I heard no one had figured out how to trigger the fans through the PCM but no matter it is a relatively easy fix.

Next on the list is fuel. The Indian fuel tank had no means of installing an in tank pump so I went with a Walbro 255 frame mounted pump. A word of caution here. Make sure that you have a Walbro and not a Chinese knock off. I originally ordered a Walbro and the supplier substituted a knock off which lasted for about 4 or 5 thousand miles, thanks to the Auto club I got home. The Walbro pump has a lot of writing on the case and the knock off has none. Secondly is the fuel supply to the high pressure pump. The LT has a cam driven pump that supplies up to 2600psi to the fuel nozzles so the electric pump is only supplying “low pressure” to the engine driven pump. If you look on line you will find a very well written article about fuel control through the electric pump. The article goes into great detail about why you need to wire in the original fuel control module to more precisely control the fuel pressure to the engine driven pump. The article goes into great detail and has a lot of logical sounding arguments but here is where theory and reality conflict. Don’t know about you but my years in the car scene have proven to me that reality and theory don’t always travel the same road. I have a 200 something Corvette filter regulator that has a pressure regulator built into it. They are easy to find, they are all over ebay. There is an inlet from the electric pump and outlet to the engine pump and a return line that is keeping the pressure at 46? psi. Don’t remember exactly what it is but it has been working flawlessly for over 10,000 mi so far, except for the pump failure.

Another issue with the L83 is vacuum for power brakes with the vacuum pump removed. I picked up vacuum at the throttle body. When every electrical connection on the wire loom had been accounted for and the engine ran there was one thing on the left side of the throttle body that was not connected. I pulled the throttle body off took whatever it is off and found a hole. I drilled it out and tapped it to 3/8 24, ran a die over a piece of 3/8 copper tubing and found that it screwed in just fine. I put my piece of tubing into a flaring tool to make a bubble on the end and screwed it into the throttle body. Put some JB weld on it, screwed it in and let it sit overnight. I fabricated a vacuum tank that fits underneath the battery and the system works just fine. I do have vacuum valves all over the system to keep things from draining the tank. The same thing could be accomplished anywhere on the plenum. It looks like there are individual runners but in reality the plenum is just an open space. All the ribs on the top give the appearance of individual runners but not so.

Now to the final tune. I had it running for over a year looking for someone who could dial in the PCM. What Howell supplied ran fine but there were little trans glitches that bugged me from time to time but I could not find a tuner. I finally found Andy Burdess in Iowa 641-691-7452 who worked with me for about a month and a half dialing it in. Could not be happier with the results and he was very reasonable. Fixed all the trans glitches and got me about 40-50 more full throttle HP. Have not put enough miles on it to verify but it seems to be getting better mileage also. Somewhere in this narrative I mentioned the engine oil cooler lines. The HP he got me on full throttle was a lean on full throttle which caused a knock that backed down the timing. The L83 has 11:1 compression and runs on regular fuel. Combustion temperature is critical in allowing this. Part of this is that the fuel is spraying in under tremendous pressure.
When this happens, it is the same phenomenon as the expansion valve on you’re A/C, it causes a tremendous drop in temperature. The other thing is that there are nozzles in the crankcase that spray oil on the bottom of the pistons to cool the crown. In my case the way I drive the absence of the oil cooler is not an issue. If however you plan on performance and driving hard oil temperature could be an issue. If the oil gets hot enough it could raise the piston temperature and cause a knock that will retard the timing. Just a thought.

The air intake is a unit I picked up on ebay which is working fine. My original thought was to use the truck air box but the engine bay is too full of engine. If you have noticed the dent in the intake tube it is to clear the hood ribs. The pan is a half inch away from the crossmember. So the issue of fit is that there is not as much room in the engine bay as it appears.

Another issue with the L83 is vacuum for power brakes with the vacuum pump removed. I picked up vacuum at the throttle body. When every electrical connection on the wire loom had been accounted for and the engine ran there was one thing on the left side of the throttle body that was not connected. I pulled the throttle body off took whatever it is off and found a hole. I drilled it out and tapped it to 3/8 24, ran a die over a piece of 3/8 copper tubing and found that it screwed in just fine. I put my piece of tubing into a flaring tool to make a bubble on the end and screwed it into the throttle body. Put some JB weld on it, screwed it in and let it sit overnight. I fabricated a vacuum tank that fits underneath the battery and the system works just fine. I do have vacuum valves all over the system to keep things from draining the tank. The same thing could be accomplished anywhere on the plenum. It looks like there are individual runners but in reality the plenum is just an open space. All the ribs on the top give the appearance of individual runners but not so.

Now to the final tune. I had it running for over a year looking for someone who could dial in the PCM. What Howell supplied ran fine but there were little trans glitches that bugged me from time to time but I could not find a tuner. I finally found Andy Burdess in Iowa 641-691-7452 who worked with me for about a month and a half dialing it in. Could not be happier with the results and he was very reasonable. Fixed all the trans glitches and got me about 40-50 more full throttle HP. Have not put enough miles on it to verify but it seems to be getting better mileage also. Somewhere in this narrative I mentioned the engine oil cooler lines. The HP he got me on full throttle was a lean on full throttle which caused a knock that backed down the timing. The L83 has 11:1 compression and runs on regular fuel. Combustion temperature is critical in allowing this. Part of this is that the fuel is spraying in under tremendous pressure. When this happens, it is the same phenomenon as the expansion valve on you’re A/C, it causes a tremendous drop in temperature. The other thing is that there are nozzles in the crankcase that spray oil on the bottom of the pistons to cool the crown. In my case the way I drive the absence of the oil cooler is not an issue. If however you plan on performance and driving hard oil temperature could be an issue. If the oil gets hot enough it could raise the piston temperature and cause a knock that will retard the timing. Just a thought.

The air intake is a unit I picked up on eBay which is working fine. My original thought was to use the truck air box but the engine bay is too full of engine. If you have noticed the dent in the intake tube it is to clear the hood ribs. The pan is a half inch away from the crossmember. So the issue of fit is that there is not as much room in the engine bay as it appears.

The power steering and A/C were a matter of having hoses made up. The A/C compressor is a variable displacement and the destroke is also controlled by square wave. I just connected the destroke to the clutch signal line so it is always at full stroke and am controlling the clutch through an adjustable low pressure switch on the return line. I have had it out in triple digit weather and it blows a steady 42 degrees at the center outlet. That could probably be dialed in a few degrees lower but the switch is not conveniently located.  

Now things that I would have done differently. I mentioned that I welded a strap to the bottom of the crossmember. My thought was that it would stabilize the crossmember and prevent movement from the heat of all the welding. Again, theory and fact on different roads. It did not work. All the welding pulled the top of the frame members in and now the best I can do on the alignment is 0 camber and 0 caster so the steering is a bit twitchy. Eventually I will pull the front fenders off again and grind the upper control arm mounts off and move them out about 3/8 of an inch. If I knew then what I know now I would have made a couple of jacks out of at least a 1” fine thread bolt that I could have placed between the tops of the frame members on either side of the crossmember to keep pressure on them while the welds cooled. The other thing is the front frame horns. I mentioned that they would up being off quite a bit. If I had it to do over I would have found a better way to stabilize them. And lastly the engine placement. Those things are bigger than they look. I would have measured more closely at the beginning to make sure that the fit was right. Would have saved me a lot of work.

Hopefully this narrative which has turned more into a book than into a post will be of some use to someone.

If there are any questions I have not answered let me know.

Edited by Old guy44
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i think you did a great job old guy👍 well done and great detail :cheers:

is that injection pressure correct at 2600 psi ?

 i can relate to the walbro pump, i bought a kit from tanks inc and it came with a walbro  in tank pump, very happy with it as i had done my home work on them and all comments i found said they where a good pump..

i did like your idea of installing the pcm inside the car, makes for a happy pcb👍

Edited by 64 kiwi boni
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So I read on the injector pressure that it can go that high. I do know that with all the sound deadening off of the engine the injectors click like valve noise.

Now you know why this will be my last car. I don't have another build like this left in me. I would have liked to have had this combination when I cruised Van Nuys boulevard in the 60's. Maybe my memory is rusty but I do not remember ever having anything this fast back then. 

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