8x Series V8 Swaps (9 Viewers)

[NeverFinis]

Hopefully this isn't too dumb of a question, I feel like I've done nothing but read build threads and watch videos on swaps lately and my brain is fried....

It's come to the point that I'm ready to swap out the old tired 3FE for something that can comfortably and reliably pull up and over mountain passes. It's going to be a pretty long process for me since time is limited, so I'm going to first start by sourcing a motor and then working on refreshing and building that up a bit, and then gather up the other parts needed over time. Is there any general majority "consensus" when it comes to 5.3 vs 6.0 vortecs? Along with that, what about gen 3 vs gen 4? Obviously price is the main difference there, but is the extra cost of the gen 4 worth it? I know the gen 3 has some trickier stuff when it comes to the gas pedal, but it seems like it's relatively straight forward as long as you pull the tac module from the donor too is that correct?

Sorry for what I know is a pretty basic question, just when I feel like I have a solid plan and start to search for motors, I get overwhelmed with info and I feel like it's back to square one since I want to make sure I get everything that is needed. Either way, I'm nervous/excited to begin on this journey!

To add to what White Stripe said, there was improvement to some latter year Gen 3s engines that came with full floating wrist pins that became standard on Gen 4 engines.

I would avoid AFM, but get VVT if possible. This is why I ended up with a L96, an engine with VVT but without AFM. You can remove AFM from any engine, or run it until it fails.

5.3 vs 6.0? 5.3 are much cheaper and easier to get. Save money where you can.. Costs add up. 5.3 also have a thicker cylinder walls and people use them over 6.0 if they are using boost.

Personally, I prefer a 6 speed over a 4 speed due to better 1st gear.

 

[tyjova]

To add to what White Stripe said, there was improvement to some latter year Gen 3s engines that came with full floating wrist pins that became standard on Gen 4 engines.

I would avoid AFM, but get VVT if possible. This is why I ended up with a L96, an engine with VVT but without AFM. You can remove AFM from any engine, or run it until it fails.

5.3 vs 6.0? 5.3 are much cheaper and easier to get. Save money where you can.. Costs add up. 5.3 also have a thicker cylinder walls and people use them over 6.0 if they are using boost.

Personally, I prefer a 6 speed over a 4 speed due to better 1st gear.

That’s awesome info thank you so much! I think that’s the main part that I’ve been getting hung up on now as I’m searching around salvage yards for motors. Seems like while maybe the 6.0 is a bit better for the larger size, 5.3 is the more cost effective route. I think what you mentioned about the L96 is exactly what I have been needing to hear. I’m fine with spending a bit more on the newer motors but it seems like the newer also tends to come with more complications like the AFM. I guess more than anything what I’ve been trying to narrow down is what the most recommended year range is motor wise for my search. Obviously searching for compatible motors for a 2008 or whatever GM vehicle spits out an ungodly amount of results and it gets real overwhelming real quick. It’s just one of those things where I want to make sure I’m 100% getting the “correct” thing since it’s not like I can just go back to auto zone or whatever and make an exchange haha

 

[Mixelplix]

@tyjova I don't know what your resources are - so my suggestion may or may not work for you.

I was in your position about a year or two ago. I was paralyzed by engine size, generation, trans compatibility, cost, ect. I eventually had a few realizations that helped me.

First, don't get hung up too much about displacement. You're going to be, at minimum, doubling your horsepower. You'll be happy with any modern v8.

Second, decide what trans you want. If you think you'll be happy with a 4speed, then 3rd gen will be fine for you. If you want a 6speed, then it will likely be a 4th gen.

Lastly, I would suggest scanning whatever your preferred selling platform is, and keeping your eye out for running vehicles. Having a running car will allow you to scavenge parts that you would have to buy otherwise if you got a pulled motor from a junkyard. Additionally, if you have the means, you can part out the donor and make some money back. In my area, there are countless rusted chevy trucks which no longer pass inspection. That's a liability for the current owner, but an asset for you.

I bought an 08 Escalade with a 6.2 and 6 speed for $3000. And while I haven't started my swap yet, I'm sure I can part out the donor to the point where it would have cost me nothing.

 

[MANUCHAO]

The bigger the motor the better the low end torque which is important in a cruiser. So go with as big of displacement as you can afford.

^^^^ This..... !!!
X 1,000

 

[tyjova]

@tyjova I don't know what your resources are - so my suggestion may or may not work for you.

I was in your position about a year or two ago. I was paralyzed by engine size, generation, trans compatibility, cost, ect. I eventually had a few realizations that helped me.

First, don't get hung up too much about displacement. You're going to be, at minimum, doubling your horsepower. You'll be happy with any modern v8.

Second, decide what trans you want. If you think you'll be happy with a 4speed, then 3rd gen will be fine for you. If you want a 6speed, then it will likely be a 4th gen.

Lastly, I would suggest scanning whatever your preferred selling platform is, and keeping your eye out for running vehicles. Having a running car will allow you to scavenge parts that you would have to buy otherwise if you got a pulled motor from a junkyard. Additionally, if you have the means, you can part out the donor and make some money back. In my area, there are countless rusted chevy trucks which no longer pass inspection. That's a liability for the current owner, but an asset for you.

I bought an 08 Escalade with a 6.2 and 6 speed for $3000. And while I haven't started my swap yet, I'm sure I can part out the donor to the point where it would have cost me nothing.

Makes perfect sense! I like the idea of the 6 speed so maybe I'll lean towards 4th gen, but like you said in reality anything that gets put in there is going to feel like a massive upgrade. I think you're right, I'm probably getting too much in the weeds on this when really if I just keep an eye out for any and all motors/donors I can make most anything work if the right one comes up. I'd love to just get an entire donor vehicle but parking space is limited for me currently which is why I was going to start with at least picking up a motor to refresh in the garage until I move here in the next 6 months or so to a hopefully larger spot to do something like this. The smart thing to do would be to just wait until I have a larger driveway and get the donor and all that but I honestly don't think I have the patience for that since I'm so excited to get going on this!

I definitely appreciate all the help and guidance, sounds like it's one of those things where you can do all the planning you want but you really just need to dive in one way or another and work out the kinks as you go.

 

[mattnandie]

I guess I need to update my build thread! Picked up an L86 and 10L80. Also ordered my Torfab kit!

 

[cruisermatt]

100% bolt-in AC hose kit for Gen 3/4 truck compressor (and assuming using 4l60e/6l80e with stock crossmember/transfer placement) will be available to order soon. Will be a suction hose and high pressure hose (from compressor to condenser) already crimped to length, with adapters for firewall and condenser (with optional trinary switch port on condenser adapter) and compressor adapters.

 

[thatcabledude]

100% bolt-in AC hose kit for Gen 3/4 truck compressor (and assuming using 4l60e/6l80e with stock crossmember/transfer placement) will be available to order soon. Will be a suction hose and high pressure hose (from compressor to condenser) already crimped to length, with adapters for firewall and condenser (with optional trinary switch port on condenser adapter) and compressor adapters.

View attachment 3539589

View attachment 3539590

Nice Matt. Is that adapter with crossover tube on the heater hoses your creation too? Pretty slick.

 

[cruisermatt]

Nice Matt. Is that adapter with crossover tube on the heater hoses your creation too? Pretty slick.

No, I have made them in the past but I don't anymore since I don't believe they are necessary. My opinion is they are outdated myth. All that crossover is doing is bypassing the thermostat until it's open, and then all the water is going to flow anyways. there's just no need to do that and add four new potential leak points. They certainly don't hurt anything just not necessary.

 

[thatcabledude]

No, I have made them in the past but I don't anymore since I don't believe they are necessary. My opinion is they are outdated myth. All that crossover is doing is bypassing the thermostat until it's open, and then all the water is going to flow anyways. there's just no need to do that and add four new potential leak points. They certainly don't hurt anything just not necessary.

I’ve never used anything to crossover myself. I do have a couple adapters in that spot on my 80 to neck down to Toyota sized heater hose though.

 

[NeverFinis]

I want to thank @tmxmotorsports for sending me a spare tach to test.

I couldn't find much on the XRA6731A chip that Toyota used, other than some Russian websites. Usually one should be able to find a document to describe how to implement the IC.

What I did find is that the POT (variable resistor) that is on the board can be used to adjust the RPM vs Pulses. What this means is if your motor is outputting 2 or 4 pulses/revolution , rather than 3, this POT can be used to adjust the RPM to that frequency. That POT is a multiplier, which makes it super simple to adjust for motor swaps with different number of cylinders. I am sure Toyota did it this way to make it useful for 4 cyl, 6 yl, and 8 cyl engines.

I will update this post once I measured the resistance on either side of the POT. This way someone can just set the POT and get close...without having a frequency generator.

Toyota's 3 Pulses/Revolution * 60 seconds:

(42Hz/3 pulses/rev) * 60 seconds= 840 RPM
(250Hz /3 pulses/rev) * 60 seconds = 5000 RPM

SwapTime (V8) 4 Pulses/Revolution * 60 seconds:

(42Hz/4 pulses/rev) * 60 seconds = 650 RPM
(250Hz /4 pulses/rev) * 60 seconds = 3750 RPM

Resistances

Stock (1FZ-FE), 3 Pulses/Rev:

A <-> B 44.56 kΩ
A <-> C 54.91 kΩ
B <-> C 96.7 kΩ

Two different Tachs adjusted for SwapTime:
4 Pulses/Rev:

A <-> B 57.93 kΩ
A <-> C 44.15 kΩ
B <-> C 96.7 kΩ

A <-> B 58.83 kΩ
A <-> C 42.73 kΩ
B <-> C 99.1 kΩ

B <-> C is just measuring the total resistance of the POT. There is variance between POTS.

I think A <-> C resistance is being used by the XRA6731A chip. Get close to that reading for 4 pulses/rev.

 

[tmxmotorsports]

I saw that pot and was wondering why that would be there. Makes sense to me now. So if we use a scan tool that shows the v8 rpm can we just adjust the tach to the rpm the scan tool shows and be done?

 

[tmxmotorsports]

Oh and by the way your very welcome just trying to help and understand why some swaps the tach works right off the bat and some don't and some use the Dakota box and some don't. Good on you for your time and technical support..
Thank you @NeverFinis

 

[thatcabledude]

Pretty cool.

Speaking of tachs. Mine died while driving a week ago. Fluttered for a few secs then dead.

 

[tmxmotorsports]

Pretty cool.

Speaking of tachs. Mine died while driving a week ago. Fluttered for a few secs then dead.

What set up are you using? Just wondering if it's the tach or something else. You've been swapped for a while correct?

 

[thatcabledude]

What set up are you using? Just wondering if it's the tach or something else. You've been swapped for a while correct?

Dakota Digital box and the unmodified stock cluster. Been set up and running that way for 90k+ miles so I guess it might have just crapped out. Haven’t tinkered with it yet.

 

[PIP]

I had no idea that tach was adjustable. Neat!

I got this setup working pretty good in diesel swaps to drive the 80 series tach. With a common gm sensor. No electronics, not even a pullup. I was thinking because the setup is so simple it might even be worth it to make it work on an LS or LT 80 swap too? It would bolt on in place of one of the belt idler pulleys. Any interest in something like that?

 

[NeverFinis]

I saw that pot and was wondering why that would be there. Makes sense to me now. So if we use a scan tool that shows the v8 rpm can we just adjust the tach to the rpm the scan tool shows and be done?

Yes, I think you can simply adjust that POT until the tach agrees with the scan tool. Tach has to be out of the dash, and just connect the tach signal to the P, Battery Positive to + and Battery Neg to -. I used the bolts that hold the tach in to attach the wires to the function generator.

Oh and by the way your very welcome just trying to help and understand why some swaps the tach works right off the bat and some don't and some use the Dakota box and some don't. Good on you for your time and technical support..
Thank you @NeverFinis

Yep, I think some GM ECMs output a +5V tach signal, rather than +12V signal our tachs expect . Either use a pull-up resistor (GM recommends starting with 5K) needs to be used, and/or that resistor on the tach needs to be bypassed. I don't think a Dakota box for the tach is needed at all. I am using a GSS-3000 so my transmission dash lights work.

Pretty cool.

Speaking of tachs. Mine died while driving a week ago. Fluttered for a few secs then dead.

From my recent research, the most likely cause is a broken solder joint, which is easily fixable. Sometimes it is a bad capacitor. Most of the Toyota tachs that fail are using newer SMD components, not pin through hole components like ours. The latter is much sturdier.

 

[tmxmotorsports]

Yes, I think you can simply adjust that POT until the tach agrees with the scan tool. Tach has to be out of the dash, and just connect the tach signal to the P, Battery Positive to + and Battery Neg to -. I used the bolts that hold the tach in to attach the wires to the function generator.



Yep, I think some GM ECMs output a +5V tach signal, rather than +12V signal our tachs expect . Either a user pull-up resistor (GM recommends starting with 5K) needs to be used, or that resistor on the tach needs to be bypassed. I don't think a Dakota box for the tach is needed at all. I am using a GSS-3000 so my transmission dash lights work.



From my recent research, the most likely cause is a broken solder joint, which is easily fixable. Sometimes it is a bad capacitor. Most of the Toyota tachs that fail are using newer SMD components, not pin through hole components like ours. The latter is much sturdier.

Sweet!

 

[cruisermatt]

I had no idea that tach was adjustable. Neat!

I got this setup working pretty good in diesel swaps to drive the 80 series tach. With a common gm sensor. No electronics, not even a pullup. I was thinking because the setup is so simple it might even be worth it to make it work on an LS or LT 80 swap too? It would bolt on in place of one of the belt idler pulleys. Any interest in something like that?

Did you mean to post a pic ? sounds interesting