If you love something let it go...... (1 Viewer)

[jfz80]

Secret power s***


So when’s the diesel going in?

 

[lt1fire]

Strangely enough there is a 2.8 Dmax in storage that will bolt straight up to the 8l90E if I so desire :

Pulled out of a 2019 Chevy Express from the same place I snagged the L84

But right now with diesel being 8l90 cents more a gallon the added mpg savings isn't much compared to a DI V8

I was waiting for Tor to do his 2.8 Dmax he was starting to work on after falling out with cummins over some flaws in their 2.8 but when diesel prices skyrocketed that process stalled. So the path of least resistance and documentation right now is the LT swap.

 

[gasman4u]

This may be an ignorant question, but what is the rationale of the LS swap?

From my neophyte point of view -
Pros: It's a GM platform, creates much more power/torque and keeps up with modern traffic, takes gasoline, common parts availability and mechanics are much more familiar with working on them.

Cons: It's a GM platform and mechanics are much more familiar with working on them. You get rid of a lot of the reliability these platforms have a pedigree providing.

Is this the 30,000 ft view?

 

[lt1fire]

This may be an ignorant question, but what is the rationale of the LS swap?

From my neophyte point of view -
Pros: It's a GM platform, creates much more power/torque and keeps up with modern traffic, takes gasoline, common parts availability and mechanics are much more familiar with working on them.

Cons: It's a GM platform and mechanics are much more familiar with working on them. You get rid of a lot of the reliability these platforms have a pedigree providing.

Is this the 30,000 ft view?

Well its a LT swap not a LS lol I kid I kid
Rationale is

1. more power
2. more torque
3. better mpg
4. newer trans with better ratios and more gears if going auto, cheaper and easier to find trans if going manual
5. parts availability
6. cost to do a GM V8 swap is tiny compared to cost to do yota V8 swap and you get more power doing a GM swap anyway
7. and reliability/parts availability

Now #7 does contradict your cons but the reasoning is most people do a low mileage V8 swap when their yota I6 is up there in miles so you are gaining lots of time on that motor before something needs to be done. Also your cons are super accurate GM V8's, especially from the gen III to gen IV models are extremely reliable. I'm not going to say a LS will run as long as a 2uz every time but i've seen loads of examples well over 500k and still running fine, hell one of my old work trucks was around 663k on a Gen 3 5.3. Their sensors aren't as robust as denso made yota ones but mechanically a GM based V8 will last a long time. Mechanics are much more famililar with them but when you compare the sheer number of them to the amount of I6 yota motors that only hit the US market in forklifts or landcruisers, its just a numbers game. The Gen IV and V motors came in the same years, Chevy and GMC vans, Chevy and GMC Trucks, Chevy and GMC SUV's, the Corvette, the Camaro, the Impala, the Caprice, etc...... The Gen III came in all of those along with loads of Pontiac, Oldsmobile, Saab, Isuzu vehiles. Most people with a cruiser will do all their PM on time with quality parts. Large amounts of the people out there driving tahoes will run 10k over the oil change recommendation and throw the first chinese made part they can get for the lowest price on there. Even the Gen I and II engines are stout. Ive had tons over the years and never had to rebuild one or do any major work that wasn't me doing it a huge power increase. I've had 5 suburbans now and 289k was the lowest miles on one when I sold it. All original motors.

The cons of the swap is really the trans despite being a pro at the same time. The 4L80E is bomb proof but doesn't have the most amazing gear ratios and only 4 forward gears. The 10L8/90E is also bomb proof and gives you great gear ratios along with 10 forward gears. However mating the newer trans to older GenIII and IV motors gets a bit complicated. the 6l and 8l have good ratios and have a good amount of forward gears but do have some flaws that may want to be addressed so you don't run the risk of having to pull it back out at some point. Generally lots of the issues have to do with heavy towing and not doing PM on it but a TQ converter change is recommended on both. The 4l60E is a pretty terrible trans in terms of power holding ability, gear ratios and only 4 forward gears. You can spend a bunch and get it fixed up but they are still a pretty weak design. That same work truck I had was on its 4th 4l60E trans at the same mileage.

Hope that answered some questions.
I've always wanted and thought that a diesel swap was going to be it for the 80 but right now I need the easiest thing possible and MPGs with DI on the V8's has gotten so much better it is just what i'm going to go with now.

 

[lt1fire]

Also i'm not saying GM in general is more reliable or as reliable as toyota just that their V8's are and have been for a long time way up there in terms of reliability

 

[lt1fire]

Plus you got to remember my 80 was a 3fe powered one and may be the slowest US released cruiser ever. It was much heavier than all the cruisers that came before it and didn't have a huge increase in power to compensate, but did get at great slush box of an auto box with terrible gear ratios. While all the older models got manual transmissions with pretty aggresive gears comparatively. The 62 did have the same engine and pretty much the same trans but was lighter also.

 

[gasman4u]

Well its a LT swap not a LS lol I kid I kid
Rationale is

1. more power
2. more torque
3. better mpg
4. newer trans with better ratios and more gears if going auto, cheaper and easier to find trans if going manual
5. parts availability
6. cost to do a GM V8 swap is tiny compared to cost to do yota V8 swap and you get more power doing a GM swap anyway
7. and reliability/parts availability

Now #7 does contradict your cons but the reasoning is most people do a low mileage V8 swap when their yota I6 is up there in miles so you are gaining lots of time on that motor before something needs to be done. Also your cons are super accurate GM V8's, especially from the gen III to gen IV models are extremely reliable. I'm not going to say a LS will run as long as a 2uz every time but i've seen loads of examples well over 500k and still running fine, hell one of my old work trucks was around 663k on a Gen 3 5.3. Their sensors aren't as robust as denso made yota ones but mechanically a GM based V8 will last a long time. Mechanics are much more famililar with them but when you compare the sheer number of them to the amount of I6 yota motors that only hit the US market in forklifts or landcruisers, its just a numbers game. The Gen IV and V motors came in the same years, Chevy and GMC vans, Chevy and GMC Trucks, Chevy and GMC SUV's, the Corvette, the Camaro, the Impala, the Caprice, etc...... The Gen III came in all of those along with loads of Pontiac, Oldsmobile, Saab, Isuzu vehiles. Most people with a cruiser will do all their PM on time with quality parts. Large amounts of the people out there driving tahoes will run 10k over the oil change recommendation and throw the first chinese made part they can get for the lowest price on there. Even the Gen I and II engines are stout. Ive had tons over the years and never had to rebuild one or do any major work that wasn't me doing it a huge power increase. I've had 5 suburbans now and 289k was the lowest miles on one when I sold it. All original motors.

The cons of the swap is really the trans despite being a pro at the same time. The 4L80E is bomb proof but doesn't have the most amazing gear ratios and only 4 forward gears. The 10L8/90E is also bomb proof and gives you great gear ratios along with 10 forward gears. However mating the newer trans to older GenIII and IV motors gets a bit complicated. the 6l and 8l have good ratios and have a good amount of forward gears but do have some flaws that may want to be addressed so you don't run the risk of having to pull it back out at some point. Generally lots of the issues have to do with heavy towing and not doing PM on it but a TQ converter change is recommended on both. The 4l60E is a pretty terrible trans in terms of power holding ability, gear ratios and only 4 forward gears. You can spend a bunch and get it fixed up but they are still a pretty weak design. That same work truck I had was on its 4th 4l60E trans at the same mileage.

Hope that answered some questions.
I've always wanted and thought that a diesel swap was going to be it for the 80 but right now I need the easiest thing possible and MPGs with DI on the V8's has gotten so much better it is just what i'm going to go with now.

Awesome write up. MUCH more detailed than I was hoping to get. Thank you!

It also makes me have a lot of crow to eat next time my GM-fan neighbor sh*t talks with me.

 

[NCFJ]

A buddy of mine was a fleet mechanic for over 30 years. He told me he serviced more trucks with GM 5.3L and 6.0L Vortecs (LS in a truck) with over 500K and only regular oil changes and a set of spark plugs once in a while. A stock LS3 6.2L crate motor has 430 HP and 425 ft pounds of torque. more than enough to push a fat LC around. LS series motors have 6 bolt mains and can handle boost that most can not. Boosting stock internals to 1000HP is not uncommon. Simply put, GM got both the SBC and the LS platform right. The level of aftermarket support for this platform is also a huge factor.

On a personal note, aside from the stock Yota diesels available in the LC platform, I'd not entertain a diesel. Just me.

 

[lt1fire]

Adapter and engine mount kit is on its way

 

[mattnandie]

Any updates on this build?

 

[lt1fire]

Any updates on this build?

There was but in another thread lolz.
Right now it is where it was. My job is 100% commission and tied to the economy, closer really to the Fed interest rate. When there are a bunch of hikes in a row it tends to give the market and investors major jitters so my job slows down. Right now i'm in the slow season anyway so funds to get the truck to me or to finish getting all the needed parts are tight and i've been finishing off a new engine and a ton of other new parts in our subaru wagon.