My LM7/4L60e Build (1 Viewer)

[SMG]

Ah, my favorite part! The only real similarity to the 5.7 is 8 cylinders, after that everything is much nicer.

It fires at the touch of the key. My 5.7 on it's best day never did that.

It is smooth, not just at idle, but throughout acceleration. Throttle response is excellent. However, some folks say that there is a difference when you romp on it (a lag) because the transmission downshifts electronically rather that with a TV cable. Me, I don't expect to romp on it in the rocks.

Fuel economy is waaaaay different than the 5.7. If you compare the stock OEM specs, you are basically getting more H.P. and torque from fewer cubic inches while using less gas, what a deal! When you are off-road fuel economy is a plus.

It's quieter! It took me a while to figure out why. It's because, even with the OEM air cleaner and filter on the 5.7, you're not hearing the TBI (a modified carb) sucking in air and fuel. In the 5.3, the plenum, direct fuel injection and air intake system don't produce the same sound.
Seriously, the first time I took it down the street I thought I was in a completely different vehicle.

Then there IS the cool factor.

Aww man! This makes me want to swap mine from a TBI to LS, and I haven't even started mine yet!

 

[reddingcruiser]

Aww man! This makes me want to swap mine from a TBI to LS, and I haven't even started mine yet!

If you haven't started yet and are serious, use the LS-series engine. LM7's are fairly plentiful and I've see complete donor packages (engine and trans) from Silverado's and Tahoe's locally on craigslist for $900 - $1500. You'll pay a little more from a dismantler but you usually get a warranty.

 

[SMG]

If you haven't started yet and are serious, use the LS-series engine. LM7's are fairly plentiful and I've see complete donor packages (engine and trans) from Silverado's and Tahoe's locally on craigslist for $900 - $1500. You'll pay a little more from a dismantler but you usually get a warranty.

What's the difference between the LS and the LM7?

If I were to do it, I would really like to keep my NV4500 and Advanced Adapter bellhousing. Would this be possible? Just swapping the engine with the mounts you spoke about?

I meant to say, haven't started the engine yet. I'm waiting on a couple of small parts.


Thanks

 

[reddingcruiser]

What's the difference between the LS and the LM7?

If I were to do it, I would really like to keep my NV4500 and Advanced Adapter bellhousing. Would this be possible? Just swapping the engine with the mounts you spoke about?

I meant to say, haven't started the engine yet. I'm waiting on a couple of small parts.


Thanks

View attachment 1509106

Yeah, You're pretty deep into your swap. Looks very nice, though.

Without getting into the weeds, the main difference between the LS and LM designations is the cast iron block of the LM7 light truck engines. Both have aluminum heads. Since the SBC is already lighter than the stock Toyota 6 cylinder engine, it's no big deal. Otherwise, there is a whole slew of vehicle and year-specific differences to explore that affect vehicle performance. Many of these can be altered by reprogramming the PCM. Some things, like cam shafts, require a mechanical intervention. Different years have different intake runner configurations, with later model engines having larger and much more efficient configurations, especially if you are a 'go fast' person.

 

[reddingcruiser]

I'm' pretty sure the bell housing and NV4500 transmission will work, though I've not delved into the details. The LS-series motors do not use the upper left hand bolt location because of interference with a oil galley, but they use all the others. The locating pins (pilots) are the same. As far as flywheels and pilot bushing/bearings are concerned, I'm sure there is a fellow 'mudder that has done this conversion.

 

[SMG]

Thanks a lot for the info. My friend owns a junk yard so I may have him keep an eye out for a low mile engine.

I know it sounds crazy, but I've been wondering about an LS engine just in-case this engine runs like a turd.

My main concern was if it would work with my current drivetrain.

Thanks again for the info, I may have to pick your brain in the future.

 

[peytonkristen]

Reddingcruiser

Just got finished reading your entire thread. All I can say is WOW!! I'm impressed with the entire setup.

I want to apologize ahead of time because I'm probably going to be asking many questions before i'm done with mine.

Here's my setup: A 77 FJ40 that previously had a SBC mocked up with the stock 4 spd transmission. The motor mounts appear to be in the correct position and the driveline has been modified to fit.

I plan on going with an LM7 engine mated to the stock 4 speed transmission.

First I need to source a motor. I've been told to find a 2007 or earlier because of the fuel management system. Not sure if that's good advice or not. Your thoughts? The LSX mounts are a necessity. I also see you had a custom built harness. Did they rework your existing harness or is it new? And the PCM? I think the electronics part of this install is my biggest concern. Wondering how much of the electronics issues will be avoided by my keeping the stock transmission, if any?

Did you put the battery under the seat out of convenience or necessity? I would like to keep it under the hood if there is room. I have a Long Range 28 gallon fuel tank that will take up the space under both seats.

The braided lines and fittings take your setup to the next level. Where did you source the bulkhead fittings for the firewall? Mine will get a complete rewire in the process.

I'll have more question later! Thanks!
Scott

 

[reddingcruiser]

@peytonkristen, I agree that the fuel management system on the earlier LS series engines is easier to deal with, look for engines that use a separate fuel return line. They are pretty easy to spot when you look at the D/S of the fuel rails. This means returning fuel all the way to the tank, but fewer headaches.

Once you have your engine selected you'll need to decide whether to buy a custom harness or 'build' one from the OEM harness. I've successfully built harnesses before, but it's a PITA and one wrong/bad connection can cause days of grief. I had Howell EFI build my harness, eliminating everything I didn't need, adding length to trunk line to get the harness in the cab and adding gauge wires to eventually run a Dakota Digital dash. It's not especially cheap but it's clean and plug-n-play. They'll ask you all the right questions so you get what you want and need. Make sure they include a wire for the Low Range signal to the PCM. In the OEM GM t-case switch it simply grounds out the wire when low range is engaged. You can use a simple on-off switch to ground to do the job. Without it the PCM is going to get confused when you are in low range.

Howell reprogrammed the PCM for my gears and tire size and deleted everything not necessary to run the engine, and transmission. If you don't do this you'll get flooded with error codes as the PCM looks for things that no longer exist, like seat belt sensors, door locks, oil level, alarms, etc. You'll also need to come up with a way to hook up a speed sensor. Mine came with the automatic trans adapter, try Advanced Adaptors and/or Howell for an answer.

My battery is under the seat because I don't like looking at it under the hood, it's the hot rod guy in me. Since you won't have the A/T oil cooler to deal with, if you route the air intake towards the D/S you'll have plenty of room for the battery.

I have a friend here in Redding that owns a fastener business and he also carries a great collection of Russell and Fragola AN fittings (there are a lot of hot rod guys here!). Otherwise Summit should have everything you need. Stick with -6AN throughout if you go this route.

Since it looks like you are going to be deep into this build I would rewire also, and I did. Food for thought, I separated the OEM FJ40 wiring completely from the ignition and charging side since the majority of the engine wiring requirements are in the harness, including the alternator signals that come from the PCM. Both sides have their own fuse blocks, making troubleshooting much easier. Charging power goes direct to the battery and If you can get the OEM starter cable and charging wire setup I highly recommend it, makes the install much easier.

If you still have the stock Toyota steering column you'll need to make sure the key positions are compatible with those necessary to start and run the LM7. Some older FJ40 ignitions DO NOT provide continuous power to the PCM during the starting cycle.

You'll also need to decide about the exhaust issue. The OEM Corvette LS exhaust manifolds will work, but can be pricey and are not that common. Block hugger headers work great.

 

[White Stripe]

What's the difference between the LS and the LM7?

If I were to do it, I would really like to keep my NV4500 and Advanced Adapter bellhousing. Would this be possible? Just swapping the engine with the mounts you spoke about?

I meant to say, haven't started the engine yet. I'm waiting on a couple of small parts.


Thanks

View attachment 1509106

I don't think it will be a turd. The TBI will give adequate power. But the LS EFI Computer is quite a bit smarter than the tbi stuff. If you have your TBI pretty much wired up might as well keep it. Consider a EBL ECU upgrade though-not too expensive and updates the tbi computer considerably and makes it much easier to tune if you need to. Or try as is with current ecu and see how it runs, you can always upgrade the ecu to a EBL

 

[peytonkristen]

@reddingcruiser I'll be setting the motor into the mounts in the next couple of weeks so I can measure and see how things fit. I was wondering if the stock exhaust manifolds would fit or if it was necessary to change them out because of clearance issues. If they can't be used, which headers did you use?

 

[reddingcruiser]

The stock LS-SERIES Corvette exhaust will fit, but block - hugger headers (Summit, etc.) are an easy installation. I used Summit headers and wrapped them to keep down the heat under the hood. Works great.

The LM7 truck exhaust manifolds will not fit, they dump just about dead center on the frame rails.

 

[cseitz]

Do you have any pics of your front driveshaft at the transfer? I just recently went through this swap, but after a rubicon shakedown test, I realized I need to do something different with my front DS. It would be greatly appreciated!

 

[reddingcruiser]

Do you have any pics of your front driveshaft at the transfer? I just recently went through this swap, but after a rubicon shakedown test, I realized I need to do something different with my front DS. It would be greatly appreciated!

Would it be a safe bet to say your front drive shaft was trying to occupy the same space as your trans oil pan?

My first Rubicon trip last June with this setup exposed that problem when I used the OEM FJ40 u-joints and slip yoke. While it fit and the front drive shaft didn't exactly wear a hole in the transmission pan, I wasn't happy about the long term prospects. My fix was to replace the slip yoke with a long travel slip yoke from Marlin Crawler (the same one used on the Tacoma). The upside of this unit is it accepts the Toyota D/S tube. I also replaced the t-case output flange with a round flange from Cruiser Outfitters. The pilot is the same as FJ40, but I had to re-drill the flange for the Tacoma bolt pattern. The lower end is all FJ40. Of course, my pan was already 'shaved' so I had some clearance to work with.

I probably could have taken better pics without the skid plate, but I am in full holiday mode right now. Please excuse the mud, I haven't cleaned up the underside the rig since the Roundup in October.

There's more room than the pic shows. The good news is there's not as much D/S travel at the t-case end as at the axle end.

The slip yoke gives you a lot of D/S travel and has a much smaller diameter than the OEM tube.

 

[cseitz]

Oh I see. So you ran your slip up top. I ended up building a 1-1/4" DOM tube shaft but it is by no means balanced or straight. But it did get me through the con, but I thinking I can build something more high speed worthy. Did you end up trimming the body inside to tuck the tranny/transfer higher up there? Thanks for your help, my tranny is out right now for a rebuild so I want to try and get some of this hashed out now.

 

[reddingcruiser]

Oh I see. So you ran your slip up top. I ended up building a 1-1/4" DOM tube shaft but it is by no means balanced or straight. But it did get me through the con, but I thinking I can build something more high speed worthy. Did you end up trimming the body inside to tuck the tranny/transfer higher up there? Thanks for your help, my tranny is out right now for a rebuild so I want to try and get some of this hashed out now.

My t-case is as high as you can get without cutting the floor pan. My tub is a '72, so it already has the arched section in the front floor pan behind the opening that extends back to the step up to the rear deck. While I didn't trim the floor pan I did trim a little of the flange around the rear tranny opening and the small box sections under the floor that stiffen the area.

 

[1MAC]

The Devil is in the details. Up to this point the big items are in and things look like they are flying along, but this is where things actually slow to a crawl. Hundreds of little things to ponder, many affecting future choices. Geez, if I just left well enough alone.....

Well, I began on the inside of the tub so I could get the trans cover back on, heater in and put the fuel tank in, so I could work on the fuel system.

View attachment 1505319

The red cable in the picture is my starter cable and follows the original path in my 5.7., then I realized in the pile of stuff I got I had the OEM 5.3L battery cable and starter cable setup, so this routing went away. Once the neutral safety switch was hooked up on the Lokar shifter the transmission cover went on.

On my 5.7 TBI I had problems over the years with external fuel pumps. A little reading and I learned the reason they are so much larger than in-tank pumps is because of heat. They need the larger mass to dissipate heat. So, several years ago I decided to put the fuel pump the fuel pump in the tank, just like factory-built TBI and fuel injected cars and trucks. This was made all the easier by talking to the winner of a brand new FJ40 tank at the 2014 Rubithon. Fortunately for me he owned a Toyota truck and only lived about an hour away, so when he called to make the deal I was up for a road trip. The nice thing about a new tank is you don't have to worry about blowing yourself up! And it opens options with heat and flames that would otherwise make even experienced folks uneasy. That said, the earlier version looked like this:

View attachment 1505326

View attachment 1505328

Knowing I needed a minimum of 58psi fuel pressure and after researching high pressure in-tank fuel pumps on the internet, with an emphasis on selecting something that would be on a parts shelf when I needed it down the road, I tripped across the 2003-04 Camaro/Firebird (edit: my bad - 2003 Chevy Tahoe, O'Rielly #MPA30028) fuel pump. After a trip down to O'Rielly's and measuring it against by existing (highly modified) TBI pump I found it was EXACTLY the correct length to sit on the bottom of the tank with just a little bit of spring pressure, as GM had intended. Even better, all I had to do was re-machine one of my original mating ring templates to accept the slightly larger diameter of the new pumps O ring (w/skirt) assembly. With a little grinding I was also able to use the OEM compression lock ring. Cool clips have since replaced the washers holding the ring down.

View attachment 1505331

The only major modification to the pump itself was providing a place for the fuel filler overflow go. The fitting is captured internally with a nut but J B Weld was added for piece of mind. An added plus is the Camaro/Firebird pump has its own baffle, the fuel returns INTO the baffle and a one-way valve allows fuel to flow in, but not out, while in the tank. This means there is no need to find a way to keep fuel at the pump when the rig is off-camber. At the rate these engines use fuel, I would bet there is enough fuel for 15 minutes idle time in the baffle.

As you can see, once again, OEM GM connectors make change-outs easier, and I could live without the overflow connection until I get home if I had to. The GM to AN Fuel line adapters are one of my best 'finds', they make the transition to braided hose and AN fittings a plug-and-play job, and best of all you don't need the silly SST to remove the fitting, unlike the OEM connections! Using the fuel gauge rheostat on the new pump might possible with a little work on the FJ40 tank baffle, which might be an added plus when installing a Dakota Digital Dash.

Do you remember where you sourced the fuel pump/sender mounting ring originally?

 

[archie73]

Do you remember where you sourced the fuel pump/sender mounting ring originally?

I used one from tanks inc for the inside. For the top ring I made my own out of sheet metal and the hole saw I used to cut the tank hole. For reference I used the same pump as @reddingcruiser.

 

[1MAC]

I really like the idea of using a pump that could be replaced at any LAPS instead of a custom aftermarket piece like Aeromotive or Tanks, Inc.
Not sure I understand why you relocated the filler overflow to the pump, though.

 

[archie73]

I really like the idea of using a pump that could be replaced at any LAPS instead of a custom aftermarket piece like Aeromotive or Tanks, Inc.
Not sure I understand why you relocated the filler overflow to the pump, though.

I’m happy with the Tahoe pump mentioned in this thread, no problems with angles on the trail and plenty of power/flow. I was reassured that it was matched to my engine as well. My pump had a provision for the return line already.