300K + on my 3FE now. Subscribing as I see this in my future.
Any idea if it would slip as easily into a FJ62 ?
Any idea if it would slip as easily into a FJ62 ?
New Build: GM 4.2L Atlas into '91 FJ80
- Thread starter TwoTonic
- Start date
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Are you going with the 4l60E GM transmission?
I was just looking up gear ratios, and the ratios look excellent for my use. Lower ratios for first and second, high ratio for OD. That's perfect for running 5.29's with the extra power of the 4.2.
A343F 4L60E
2.804 3.059
1.531 1.625
1.000 1.000
0.753 0.696 (overdrive)
Of course, this is assuming a 4L60E adapter is available for the t-case.
alia176
SILVER Star
one thing though, the 4l60E is rated for 6,000k and if this conversion took place on a more "built up" 80, would a 4l80E be a better choice? Not knowing a thing about transmission controls and all that, just a naive suggestion on my part I guess.
I've been doing some Google based reading on this, and the general view is that a 4L60E can be built to be fairly bulletproof behind modded V8's (there are companies who sell these) and the 4L80E has something like a 2.48:1 first gear, which you can forget in our application IMO.
The 4.2L weighs about 400 lbs, so you are losing some 300-400 lbs of engine weight (I have Googled and searched here and cannot find a weight for the 1ZFE so am going off of "IIRC" figures that have been mentioned over time), and the transmission is about 135 lbs and I imagine some bit lighter than the A343F, so for my rig this is about a 7%-8% total weight reduction and would keep me well under 6K, and I tow very rarely. Overbuilding costs weight, and weight is the enemy of sticking with any I6 platform over a V8 (not sure what to do about those four growing kids
).I don't know what it would take to mate this engine to the stock tranny, but the gearing improvements of the 4L60E make a compelling reason to stick with the transmission used with the engine, particularly given long term parts availability by moving to a GM platform.
In some reading on GM boards, there is admission that this engine is more refined under throttle than the available V8 platforms (5.3/6.0). It just seems ideal for an 80 that will be kept on a moderate diet for weight control (if you love the inline six platform).The 4.2L also has a turbo aftermarket, although that is of no interest to me
I wish I could do this kind of swap - I am getting pretty committed when funds are hopefully available next spring, but I am at the mercy of somebody who can actually do the work without it becoming a $10K project.
I was just doing some simple math to look at fuel savings:
- my annual mileage usage has grown to 10K. I get 12 mpg on average mixed highway/city.
- 20 mpg mixed seems conservative on the Blazer/Envoy boards.
- @ $3/gal, I spend $2,500 a year on fuel for 10K miles
- @ 20 mpg, that would drop to $1,500, saving a $1K/year.
- I have 37's, so 18 mpg seems more realistic, but across the board a 50% fuel economy improvement seem conservatively realistic, so that's $833 annual savings. Even if you go more conservative you are looking at $750 pretty easily.
Assuming $2,500 total in parts, that is paid back in under 4 years, labor is the x factor. But even somewhere around an 8 year payback given the greatly increased enjoyment of the rig and the fact that the payback will increase if fuel costs rise significantly means I would have a good hedge to protect the long term investment. The payback period also shortens if I need to drive my 80 more (I don't commute except once a week as it stands now).
The figures are pretty compelling when you choose a low cost platform that can be had at those costs for a low mileage starting point. This also doesn't factor in selling a 1ZFE with headgasket PM replaced by Slee plus A343F in perfect working condition, both with under 150K miles, assuming a buyer in the market.
- my annual mileage usage has grown to 10K. I get 12 mpg on average mixed highway/city.
- 20 mpg mixed seems conservative on the Blazer/Envoy boards.
- @ $3/gal, I spend $2,500 a year on fuel for 10K miles
- @ 20 mpg, that would drop to $1,500, saving a $1K/year.
- I have 37's, so 18 mpg seems more realistic, but across the board a 50% fuel economy improvement seem conservatively realistic, so that's $833 annual savings. Even if you go more conservative you are looking at $750 pretty easily.
Assuming $2,500 total in parts, that is paid back in under 4 years, labor is the x factor. But even somewhere around an 8 year payback given the greatly increased enjoyment of the rig and the fact that the payback will increase if fuel costs rise significantly means I would have a good hedge to protect the long term investment. The payback period also shortens if I need to drive my 80 more (I don't commute except once a week as it stands now).
The figures are pretty compelling when you choose a low cost platform that can be had at those costs for a low mileage starting point. This also doesn't factor in selling a 1ZFE with headgasket PM replaced by Slee plus A343F in perfect working condition, both with under 150K miles, assuming a buyer in the market.
- Thread starter
- #46
4L60 vs 4L80
It's a good question-- I've got a couple of rigs with 4L80s in them, one's a Silverado HD and the other a long-wheelbase 1T Express Van (which is a surprisingly good tow vehicle, oddly, with the long wheelbase and forward seating position-- even with the stiff rear suspension-- have towed amazing loads with what looks like a family van.). The 4L80 is considered virtually indestructible, but the ratios and the fuel economy are both a big turn-off. It can be configured to connect via a transfer case for 4WD. But, even for a built FJ80 it seems like overkill. That 2.48 in First is a killer and, at least in my Silverado, it's Overdrive ain't Over enough-- I'll turn 2500 RPMs on the freeway, when it could be pulling the truck empty at 1800, so the mileage suffers. 4L80 internals are very rugged, so it also chews a lot of HP at speed too.
The 4L60 is very rugged in stock configuration, but can be built to be very strong. The 4L60 is upgraded to 4L70 for use in the Trailblazer SS-- behind an LS2 it's holding 400HP/TQ and, in turbo'd trucks, a lot more with no internal work. So, if I was building a really heavy-duty FJ80 I'd still opt for the 4L60, but probably look for the TrailBlazer SS version (same external dimensions and fit) and never worry about it.
It's a good question-- I've got a couple of rigs with 4L80s in them, one's a Silverado HD and the other a long-wheelbase 1T Express Van (which is a surprisingly good tow vehicle, oddly, with the long wheelbase and forward seating position-- even with the stiff rear suspension-- have towed amazing loads with what looks like a family van.). The 4L80 is considered virtually indestructible, but the ratios and the fuel economy are both a big turn-off. It can be configured to connect via a transfer case for 4WD. But, even for a built FJ80 it seems like overkill. That 2.48 in First is a killer and, at least in my Silverado, it's Overdrive ain't Over enough-- I'll turn 2500 RPMs on the freeway, when it could be pulling the truck empty at 1800, so the mileage suffers. 4L80 internals are very rugged, so it also chews a lot of HP at speed too.
The 4L60 is very rugged in stock configuration, but can be built to be very strong. The 4L60 is upgraded to 4L70 for use in the Trailblazer SS-- behind an LS2 it's holding 400HP/TQ and, in turbo'd trucks, a lot more with no internal work. So, if I was building a really heavy-duty FJ80 I'd still opt for the 4L60, but probably look for the TrailBlazer SS version (same external dimensions and fit) and never worry about it.
- Thread starter
- #47
Atlas NVH
We're coming to the conclusion that much about the Atlas is just "easier" than the V8s--- as much as I like the LS/LQ series it's almost like the Atlas-6 is a natural fit in there. Things like exhaust clearance, pan (with a rear sump) fit, steering linkage, etc, just match up better. So, even though the initial cost of the engine (5.3 vs 4.2) is similar (great examples of either can be had for under $500), the cost of mods to make the motor fit is just a lot lower with the Atlas.
The 4.2L is also got the natural dynamic balance of an I-6 going for it-- no first order vibration-- and is probably a lot smoother than the V8 from that perspective. I'm the first to admit that the I-5 has a little roughness to it... No way to make that 5-cyl a smooth beast like the I-6. But, I'm also an Audi fan and there's no exhaust sound like the off-kilter I-5 screech of the original Audi Quattro... The Atlas 5 reminds me of that a little bit, it's coarser than the 6 by far.
Anxious to get this I6 going to compare, but I'm guessing we'll love the 290 HP in a lighter, everyday truck.
The gearing's likely to still be a little 'short' for optimal highway mileage, so will be looking at bigger rubber to get highway RPMs down another 10-15%.
I still think 20MPG is do-able with the right ratios.
I've been doing some Google based reading on this, and the general view is that a 4L60E can be built to be fairly bulletproof behind modded V8's (there are companies who sell these) and the 4L80E has something like a 2.48:1 first gear, which you can forget in our application IMO.
The 4.2L weighs about 400 lbs, so you are losing some 300-400 lbs of engine weight (I have Googled and searched here and cannot find a weight for the 1ZFE so am going off of "IIRC" figures that have been mentioned over time), and the transmission is about 135 lbs and I imagine some bit lighter than the A343F, so for my rig this is about a 7%-8% total weight reduction and would keep me well under 6K, and I tow very rarely. Overbuilding costs weight, and weight is the enemy of sticking with any I6 platform over a V8 (not sure what to do about those four growing kids
I don't know what it would take to mate this engine to the stock tranny, but the gearing improvements of the 4L60E make a compelling reason to stick with the transmission used with the engine, particularly given long term parts availability by moving to a GM platform.
In some reading on GM boards, there is admission that this engine is more refined under throttle than the available V8 platforms (5.3/6.0). It just seems ideal for an 80 that will be kept on a moderate diet for weight control (if you love the inline six platform).The 4.2L also has a turbo aftermarket, although that is of no interest to me
I wish I could do this kind of swap - I am getting pretty committed when funds are hopefully available next spring, but I am at the mercy of somebody who can actually do the work without it becoming a $10K project.
We're coming to the conclusion that much about the Atlas is just "easier" than the V8s--- as much as I like the LS/LQ series it's almost like the Atlas-6 is a natural fit in there. Things like exhaust clearance, pan (with a rear sump) fit, steering linkage, etc, just match up better. So, even though the initial cost of the engine (5.3 vs 4.2) is similar (great examples of either can be had for under $500), the cost of mods to make the motor fit is just a lot lower with the Atlas.
The 4.2L is also got the natural dynamic balance of an I-6 going for it-- no first order vibration-- and is probably a lot smoother than the V8 from that perspective. I'm the first to admit that the I-5 has a little roughness to it... No way to make that 5-cyl a smooth beast like the I-6. But, I'm also an Audi fan and there's no exhaust sound like the off-kilter I-5 screech of the original Audi Quattro... The Atlas 5 reminds me of that a little bit, it's coarser than the 6 by far.
Anxious to get this I6 going to compare, but I'm guessing we'll love the 290 HP in a lighter, everyday truck.
The gearing's likely to still be a little 'short' for optimal highway mileage, so will be looking at bigger rubber to get highway RPMs down another 10-15%.
I still think 20MPG is do-able with the right ratios.
- Thread starter
- #48
I was just doing some simple math to look at fuel savings:
- my annual mileage usage has grown to 10K. I get 12 mpg on average mixed highway/city.
- 20 mpg mixed seems conservative on the Blazer/Envoy boards.
- @ $3/gal, I spend $2,500 a year on fuel for 10K miles
- @ 20 mpg, that would drop to $1,500, saving a $1K/year.
- I have 37's, so 18 mpg seems more realistic, but across the board a 50% fuel economy improvement seem conservatively realistic, so that's $833 annual savings. Even if you go more conservative you are looking at $750 pretty easily.
Assuming $2,500 total in parts, that is paid back in under 4 years, labor is the x factor. But even somewhere around an 8 year payback given the greatly increased enjoyment of the rig and the fact that the payback will increase if fuel costs rise significantly means I would have a good hedge to protect the long term investment. The payback period also shortens if I need to drive my 80 more (I don't commute except once a week as it stands now).
The figures are pretty compelling when you choose a low cost platform that can be had at those costs for a low mileage starting point. This also doesn't factor in selling a 1ZFE with headgasket PM replaced by Slee plus A343F in perfect working condition, both with under 150K miles, assuming a buyer in the market.
Yep, this is exactly my logic on it too. I think it's going to pay for itself easily over the next 40,000 miles. I get a truck that's more fun to drive, it's a little easier on the environment, its performance is better... and I never have to listen to the heat shield rattles on my 3FE catalytic convertor again!
- Thread starter
- #50
Pics of I-5 Atlas conversion
We're just getting the last of the (small) parts together this week. We did my mountain truck FJ80 last year with the same engine family, but an I-5. That truck turned out pretty well.
Pics of the (242HP) I-5 swap are here:
Picasa Web Albums - TL Care
I'll post pics of the I-6 as it comes together...
TT
We're just getting the last of the (small) parts together this week. We did my mountain truck FJ80 last year with the same engine family, but an I-5. That truck turned out pretty well.
Pics of the (242HP) I-5 swap are here:
Picasa Web Albums - TL Care
I'll post pics of the I-6 as it comes together...
TT
Ok cool..... I recall reading through the other swap.
I'd love to see a list of the "small" parts once you are ready to go, if you're willing to share the secrets
I noted in your I-5 build the purchase of GM tuner software. That's where I start to get scared about finding the specific local knowledge to do this right...
I hope this goes well for you. I htink it is an excellent alternative to the GM v8 swaps. We just finished a 2007 5.3 swap into a 71 fj40 and the fittment of everything was a pain in the butt. I'll be keeping tabs on this swap as it has peaked my interest away from some of the diesel options I'm looking at.
I hope you can find away to make the stock fuel system workable for the 4.2.
As a side note, I took a quick look locally and found a 2006 4.2 with 42k miles for $700. That price might have included accessories and wiring as well. If it did include everything, that is an excellent deal, IMO.
I hope you can find away to make the stock fuel system workable for the 4.2.
As a side note, I took a quick look locally and found a 2006 4.2 with 42k miles for $700. That price might have included accessories and wiring as well. If it did include everything, that is an excellent deal, IMO.
alia176
SILVER Star
Excellent info, thanks for typing all that in.
If I can keep my York, this swap would be the cat's meow!!
This may have been posted but what is the torque number for this engine? I see the 275 hp. With a proper tune, could these numbers be pumped up? I assume so given the aftermarket support for the GM engines.
Thanks again. Looking forward to your progress.
edit: the torque is the same as the 1FZFE, read it earlier in the thread. So, perhaps some aftermarket goodies can bump that up, I hope! I wish my 1FZFE engine had a wee bit more torque, perhaps another 75 ft-lbs.
Last edited:
- Thread starter
- #55
Atlas swaps
Most of the units we're seeing tend to be more complete than just a "long block" and finding a good, low-miles, used one is certainly worth a good premium. There's a lot of stock out there (Fortunately, GM built a bazillion of that Envoy/TrailBlazer series) and parts should be available in the aftermarket for decades.
I do find it hilarious that 290 HP of Atlas motor is lying around unloved in these yards for $400-800, while 285 HP of LS1 F-body engine seems to command $2500-4000 because "it's a Corvette engine". Right.
We'll keep you posted on the fuel system-- It's definitely bugging me.
For as many SBC swaps that have been done into FJs over the years, it's amazing on the LQ/LM series (4.8, 5.3, 6.0, in all the flavors) that it's a tough a fit in an FJ80 as it is... Even with the truck rear sump there are clearance issues.
We had a 5.3 (Tahoe) motor on the shop for over the weekend, so set it into this 91 FJ80-- and, sure as heck, just as Wayne and the other guys doing LQ/LS conversions have pointed out... There's a number of clearance nips-and-tucks that need to be done to get it to fit.
Most of the units we're seeing tend to be more complete than just a "long block" and finding a good, low-miles, used one is certainly worth a good premium. There's a lot of stock out there (Fortunately, GM built a bazillion of that Envoy/TrailBlazer series) and parts should be available in the aftermarket for decades.
I do find it hilarious that 290 HP of Atlas motor is lying around unloved in these yards for $400-800, while 285 HP of LS1 F-body engine seems to command $2500-4000 because "it's a Corvette engine". Right.
We'll keep you posted on the fuel system-- It's definitely bugging me.
For as many SBC swaps that have been done into FJs over the years, it's amazing on the LQ/LM series (4.8, 5.3, 6.0, in all the flavors) that it's a tough a fit in an FJ80 as it is... Even with the truck rear sump there are clearance issues.
We had a 5.3 (Tahoe) motor on the shop for over the weekend, so set it into this 91 FJ80-- and, sure as heck, just as Wayne and the other guys doing LQ/LS conversions have pointed out... There's a number of clearance nips-and-tucks that need to be done to get it to fit.
- Thread starter
- #56
Atlas Power Upgrades
The "area under the curve" is certainly a lot better on the Atlas-6... it gets to 275-290HP by being able to rev to beyond 6000 RPM while maintaining basically full torque, so I find them more flexible engines (I can't fathom a 3FE spinning to 6000!) due to VVT and great head flow design.
I still need to post the torque curve for the stock unit-- it is amazingly flat.
The downside of all this optimization is that, in NA form, it's tough to bump it up too much without going FI. The guys over on Inliners and TrailVoy have looked at it a lot and most of the usual "tricks" are tougher on the Atlas...
COMPRESSION: it's pretty well optimized to run 85 Octane rot-gut Regular gas on a 10:1 ratio, so efficiency is very high, even running on regular. You might get an incremental bump by milling heads and running Premium. I do like buying cheap gas on mine, while still enjoying a pretty high SCR.
CAMS: GM never offered cam blanks to the after-market to build custom cams from. There is a group buy contemplated over on TrailVoy to get some made... Since it's not been done, no idea how much GM 'left on the table' with cam lift. As efficient as the heads are, this is probably the low-hanging fruit-- assuming cams can be procured-- It's got a very tame stock idle, much like the LQ/LM base engines, so if that's any guide there ought to be quite a bit of gain from swapping cams and valve springs. I'll cross-post if anything ever develops on the custom cam front.
HEADS: As far as we know, there's no aftermarket head being offered (and GMPP doesn't even offer anything) and for good reason. Those stock heads are a wonder of CAD design, computer modeling and production engineering. They flow great out of the box and port-polish jobs haven't yielded much.
FI
On the PLUS side, the internals are REALLY strong (not quite 2JZ strong, but they are tough)... Some of the Inliners guys are running big boost levels (North of a Bar) and getting reliable 500-600 HP out of it.
If I was to bump one up I'd try the cams for 50+HP, for 150+ I'd do boost and methanol/ethanol injection.
Just our idle thoughts on it...
The "area under the curve" is certainly a lot better on the Atlas-6... it gets to 275-290HP by being able to rev to beyond 6000 RPM while maintaining basically full torque, so I find them more flexible engines (I can't fathom a 3FE spinning to 6000!) due to VVT and great head flow design.
I still need to post the torque curve for the stock unit-- it is amazingly flat.
The downside of all this optimization is that, in NA form, it's tough to bump it up too much without going FI. The guys over on Inliners and TrailVoy have looked at it a lot and most of the usual "tricks" are tougher on the Atlas...
COMPRESSION: it's pretty well optimized to run 85 Octane rot-gut Regular gas on a 10:1 ratio, so efficiency is very high, even running on regular. You might get an incremental bump by milling heads and running Premium. I do like buying cheap gas on mine, while still enjoying a pretty high SCR.
CAMS: GM never offered cam blanks to the after-market to build custom cams from. There is a group buy contemplated over on TrailVoy to get some made... Since it's not been done, no idea how much GM 'left on the table' with cam lift. As efficient as the heads are, this is probably the low-hanging fruit-- assuming cams can be procured-- It's got a very tame stock idle, much like the LQ/LM base engines, so if that's any guide there ought to be quite a bit of gain from swapping cams and valve springs. I'll cross-post if anything ever develops on the custom cam front.
HEADS: As far as we know, there's no aftermarket head being offered (and GMPP doesn't even offer anything) and for good reason. Those stock heads are a wonder of CAD design, computer modeling and production engineering. They flow great out of the box and port-polish jobs haven't yielded much.
FI
On the PLUS side, the internals are REALLY strong (not quite 2JZ strong, but they are tough)... Some of the Inliners guys are running big boost levels (North of a Bar) and getting reliable 500-600 HP out of it.
If I was to bump one up I'd try the cams for 50+HP, for 150+ I'd do boost and methanol/ethanol injection.
Just our idle thoughts on it...
alia176
SILVER Star
wow, 10:1 AND run on rot gut octane? That's pretty cool.
Thanks for the info.
For the 40/60 guys out there, this would be a great conversion instead of the usual SBC swaps. Talk about power to weight ratio!!!
Thanks for the info.
For the 40/60 guys out there, this would be a great conversion instead of the usual SBC swaps. Talk about power to weight ratio!!!
- Thread starter
- #58
HP Tuners
OK. We're being more thorough about documenting all the little extra pieces needed to get it working this time. The I-5 was bought pretty much as a complete pull, so we cheated a bit on that one. The I-6 came as a long block+ so we're needing to piece it together more.
If there's a local tuner shop, they're likely to have HP Tuners-- As I mentioned, the 'tune' was pretty easy in that we just wanted the stock tune (we're running factory cats, intake, exhaust, etcc) so the majority of it was just turning un-needed stuff off like VATS, CAN bus interfaces, error codes for stuff that doesn't exist in an FJ swap (like radio/XM/OnStar interfaces, etc). I'm sure a friendly local shop wouldn't charge much just to hook it up and un-tick the boxes.
Since taking delivery on my I-5 it's not been hooked up to HP Tuners again. Runs great, idles great, starts great- at sea level or 9000 feet.
I'd love to see a list of the "small" parts once you are ready to go, if you're willing to share the secrets
I noted in your I-5 build the purchase of GM tuner software. That's where I start to get scared about finding the specific local knowledge to do this right...
OK. We're being more thorough about documenting all the little extra pieces needed to get it working this time. The I-5 was bought pretty much as a complete pull, so we cheated a bit on that one. The I-6 came as a long block+ so we're needing to piece it together more.
If there's a local tuner shop, they're likely to have HP Tuners-- As I mentioned, the 'tune' was pretty easy in that we just wanted the stock tune (we're running factory cats, intake, exhaust, etcc) so the majority of it was just turning un-needed stuff off like VATS, CAN bus interfaces, error codes for stuff that doesn't exist in an FJ swap (like radio/XM/OnStar interfaces, etc). I'm sure a friendly local shop wouldn't charge much just to hook it up and un-tick the boxes.
Since taking delivery on my I-5 it's not been hooked up to HP Tuners again. Runs great, idles great, starts great- at sea level or 9000 feet.
- Thread starter
- #59
FJ62
IIRC, the FJ62 3FE/A44x configuration is pretty much identical to the early FJ80's... It 'ought' to fit, but I don't think the shop's done one yet. He's got a prospective project to do a '62, though, so I'll post if there's a test fit done on that one at some point.
IIRC, the FJ62 3FE/A44x configuration is pretty much identical to the early FJ80's... It 'ought' to fit, but I don't think the shop's done one yet. He's got a prospective project to do a '62, though, so I'll post if there's a test fit done on that one at some point.
Since the 4.2 uses the same bellhousing as a SBC, would a bellhousing adapter to the stock toyota transmission be a good option? I haven't looked at the ratios for the fj80 trans, but thought if they were close to the 4l60e you might save a little $$$.
