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Nay
11-10-2010, 06:29 PM
I'm starting to put the pieces together to (hopefully) do a GM Atlas 4.2L I6 engine swap in my 80. I can't do this kind of work really at any level and I am looking for a shop that can handle the swap and electronics - we have a lot of great "vendors" here on RS, but the x-factor is I am not going with a Toyota powerplant or transmission.

Discussion thread (not mine) on Mud for this swap here:

http://forum.ih8mud.com/80-series-tech/420699-new-build-gm-4-2l-atlas-into-91-fj80.html

I'm looking at the Atlas because it is an inline six with V8 power and (so is said) as good or better than a V8 torque curve - I love the I6's and this engine just seems ideal for an 80. It is lightweight (all aluminum) and should deliver a 50% improvement in fuel economy to go with the major HP increase. Engines are relatively cheap in the yards, parts should be around for years and years.

Why ditch a perfectly good 1ZFE with relatively good miles that has had its headgasket replaced as preventative measure by Mr. Slee and Associates? I am sick of the narrow power band, the horrid fuel economy, the lack of lungs at altitude, and the less than stellar NVH especially over 2,900 RPM. I could go forced induction (assuming SC remain available), but I am extremely wary of the fuel vapor smell issue emerging on our engines, which is clearly exacerbated by forced induction and altitude, and it does nothing for fuel economy.

Anyway, recommendations for shops (including by their owners :D) is much appreciated so I can start looking at total costs/time to get this done to see if it is viable in the relatively near future.

:cheers:

Corbet
11-10-2010, 07:32 PM
I can't see doing the swap for increased fuel economy only power. At which point is it more cost effective to just do forced induction, SC or turbo. If its a lot cheaper to go with a TRD SC then I'd go that way. You can buy a lot of fuel for the cost of a swap. I have no idea what the end cost would be for this proposed swap. But I'm sure I could install a SC for less.

Plus you break down on the road some where with a SC any Toyota dealer should be able to service your truck. With a swap there will be more potential issues there.

Landtank turbo when done? 2UZFE?

I did a SBC swap in my 60 and the little things nickel and dime you.

Nay
11-10-2010, 08:20 PM
I can't see doing the swap for increased fuel economy only power. At which point is it more cost effective to just do forced induction, SC or turbo. If its a lot cheaper to go with a TRD SC then I'd go that way. You can buy a lot of fuel for the cost of a swap. I have no idea what the end cost would be for this proposed swap. But I'm sure I could install a SC for less.

Plus you break down on the road some where with a SC any Toyota dealer should be able to service your truck. With a swap there will be more potential issues there.

Landtank turbo when done? 2UZFE?

I did a SBC swap in my 60 and the little things nickel and dime you.

A 50% increase in fuel economy will save me between $750-$1,000 a year in fuel costs, so this swap has a reasonable payback period that also comes with a major increase in power. This does make for a compelling case vs. any V8 swap as both the upfront and operating costs will be lower without sacrificing any material power for what I am after in a swap.

The 2UZFE has quite a bit less horsepower than the Atlas 4.2 and is far more expensive for the engine itself, while delivering significantly worse fuel economy. I also have a soft spot for inline six engines compared to V8's. That engine platform is the heritage of our rigs, and the Atlas 4.2 seems to be everything we wish the 1ZFE could be. Great fuel economy, flat torque curve from near idle to a 6K redline, VVT above 4K about where the 1ZFE is huffing at best, close to half the weight of the 1ZFE, which further improves the power to weight ratio. It also appears to fit perfectly, which makes sense given it would be replacing a 4.5L I6 and the engine bay of the 80 was designed for an I6.

I won't mod the 1ZFE. I started getting the fuel vapor issue this summer, and swapping out the charcoal canister did not completely cure it. This was minimal for me compared to the issues some are reporting (very high vapor pressure, boiling fuel), but it makes me loathe to invest in the 1ZFE, particularly since forced induction will not help the fuel economy or other issues and appears to be a factor in the vapor issue.

Call me crazy, but when a whole bunch of 80's suddenly start showing this issue, regardless of model year or mileage, all at once, that's like installing lightbulbs over a two year period and having them all burn out at the same time and thinking the problem is with the bulbs rather than say the power supply (or in our case, the fuel supply).

There was a turbo 80 on the OCG run last weekend, and the fuel smell was strong for most of the trail anywhere within about five feet of his rig (I had some minor fuel smell, but it also wasn't that warm, and on SC on Father's Day it was about unbearable - not much fun for family wheeling). I have yet to see any long term proposed solution for this since we can't control fuel mixtures, and GM, for better or worse, is built for our corn-fed country. IMO, that makes investing in a modern GM powerplant a smart move, especially when you have to wonder how long Toyota will continue to support our aging platform.

The fact that I would end up with a GM engine mated to Toyota electronics is the greatest concern. That's why I want to talk to a shop(s) that have done this type of swap in order to understand the potential issues before diving in.

But I am either going to leave it alone or go down this route - the numbers from power to economy are too compelling for sticking with an I6 platform that was regularly rated as one of the 10 best engines in production during its run and is dirt cheap at boneyards.

One other thing is the GM 4L60E transmission has a lower first and second gear than the 80's A343F, and a taller overdrive. Perfect for running 5.29's with improved HP and torque curve without pushing so much RPM at highway cruising speed.

:beer:

RLMS
11-10-2010, 09:04 PM
Nay, on average, late model sbc swaps range from 8-15G's
I am assuming yours would be no different.

Justin

Corbet
11-10-2010, 09:04 PM
I'm interested in what a final cost would be for the swap. Its hard to argue anything without that.

I have not experienced any of the fuel vapor issues personally so I can not comment on that. My truck mileage wise is young compared to most (126K). Electrical could be a big issue. Its my biggest concern long term with my truck even without planned modification. How much can you mess with a harness that is 15+/- years old, brittle in many places and not be chasing down shorts for the next 10 years?

What are your thoughts for/against a diesel power plant?

RLMS
11-10-2010, 09:17 PM
I think a merc.617 or a cummins 4bt diesel with manual fuel components and great MPG, power, reliability, easy part hunting and most any tranny combonation is...too me..Priceless!
That and I love the smell of burnt diesel:hill:

Justin

Nay
11-11-2010, 01:26 AM
I'm interested in what a final cost would be for the swap.

Me too :D

My truck mileage wise is young compared to most (126K).

I have 145K - my concern isn't longevity of the 1ZFE (except having to live with it for the next 15 years :hill:)

Electrical could be a big issue. Its my biggest concern long term with my truck even without planned modification. How much can you mess with a harness that is 15+/- years old, brittle in many places and not be chasing down shorts for the next 10 years?

My biggest concern, too. That's why I want to find somebody experienced to talk through the swap. Part of my goal is to learn the connections in the swap, which can be accomplished through this process. I am not going to learn anything by leaving it alone, so on some level my experience and capability go up in relation to leaving it stock, not the other way around. This is often the value in a big mod - you learn a lot about your rig.

What are your thoughts for/against a diesel power plant?

I don't want a Cummins. That engine class cannot compare for long family interstate trips to places like Moab, or skiing day trips. The 80 is a big SUV that is my mountain truck for my family. I wheel it hard, but it does far more highway miles with four kids and two dogs in the back. The 4.2L by all accounts I can find should improve NVH against the 1ZFE substantially (the GM heads on TrailVoy admit that the 4.2 is smoother and quieter than the 5.3 and 6.0 V8's), but a Cummins goes the other way, big time.

A Toyota diesel is basically a powerplant that has virtually no U.S. technical support, and it is extremely expensive. If the argument is that a GM engine swap will leave you stranded because your average Toyota dealer can't work on it, then a Toyota diesel is a complete non-starter because you are talking about having to import increasingly rare parts.

A Trailblazer is about the same weight as a stock 80 (4,600 lbs). I've read reports that fuel economy is not great (14-16) on the stock truck, as well as reports of 18-20 where the owner wasn't babying it. That's a big spread that requires some more research on my part.

The key will be how "easy" it is to do vs. the fitment required for a V8 and the relative cost of the engines. All of this may lead to a swap that works well financially over the years, but that's what I'm trying to figure out. I'm not a power freak - I can live with the 1ZFE. It's just not all that enjoyable when I can't even get up Monument hill without the damn thing dragging ass and getting 7-8 mpg in the process.

Maybe I'll go and test drive a Trailblazer while we debate the merits :D

sleeoffroad
11-11-2010, 08:39 AM
I'm looking at the Atlas because it is an inline six with V8 power and (so is said) as good or better than a V8 torque curve - I love the I6's and this engine just seems ideal for an 80. It is lightweight (all aluminum) and should deliver a 50% improvement in fuel economy to go with the major HP increase. Engines are relatively cheap in the yards, parts should be around for years and years.


Nay, do you have a link for some HP and torque curves. I have always been underwelmed with Chevy gas engines as used in their SUV's and Pickups. On paper the specs always look good, but when you drive them you go meh, not that good on real life. Never driven any with this motor in it, but I am curious. Maybe need to go testdrive something with one of these motors.



Why ditch a perfectly good 1ZFE with relatively good miles that has had its headgasket replaced as preventative measure by Mr. Slee and Associates? I am sick of the narrow power band, the horrid fuel economy, the lack of lungs at altitude, and the less than stellar NVH especially over 2,900 RPM. I could go forced induction (assuming SC remain available), but I am extremely wary of the fuel vapor smell issue emerging on our engines, which is clearly exacerbated by forced induction and altitude, and it does nothing for fuel economy.

FWIW, I have a used SC that has 60k on it for $2k if anyone is interested.

subzali
11-11-2010, 10:16 AM
Nay, what is this fuel vapor issue you're referring to for us non-80 educated?

Nay
11-11-2010, 11:30 AM
Nay, do you have a link for some HP and torque curves. I have always been underwelmed with Chevy gas engines as used in their SUV's and Pickups. On paper the specs always look good, but when you drive them you go meh, not that good on real life. Never driven any with this motor in it, but I am curious. Maybe need to go testdrive something with one of these motors.

FWIW, I have a used SC that has 60k on it for $2k if anyone is interested.

Christo, I have been looking for a chart (googling) and not finding one - lots of talk about 90% of max torque available by 1,600 RPM and pretty flat up to redline (plus talk of a flatter curve than the V8's), 10:1 compression ratio, but I haven't been able to find an actual chart.

I need to test drive, too, before I get too overly excited. My guess is that it will feel "normal" by today's standards in a heavy SUV, which is actually what I am after. The SC would certainly accomplish this, but I may be fearing too much for the future of our engines in avoiding that route re: the fuel vapor concern.

nakman
11-11-2010, 11:31 AM
Nay, what is this fuel vapor issue you're referring to for us non-80 educated?

right here Matt, see the mud link inside http://www.risingsun4x4club.org/forum2/showthread.php?t=14326


I'm curious what domestic vehicles have this engine.. can anyone name a few? Is it just the Chevy Trailblazer? :D

Nay
11-11-2010, 11:36 AM
Nay, what is this fuel vapor issue you're referring to for us non-80 educated?

EDIT: Nakman beat me to it.

MUD threads document the debate:

http://forum.ih8mud.com/80-series-tech/292965-excessive-fuel-tank-pressure.html

http://forum.ih8mud.com/80-series-tech/423771-i-wonder-fuel-tank-pressure-engine-temps.html

I'm a little bit paranoid about this, I admit, but with :Princess: and kids onboard for most trips, it is a deal breaker. I have yet to see anybody propose an actual solution - it's either "debate the conditions that cause the issue" or "fuel is what it is, live with it".

FWIW, I have never had a high pressure issue in the tank, just smell from the engine bay (even after buying a $280 OEM replacement charcoal canister).

Nay
11-11-2010, 11:38 AM
right here Matt, see the mud link inside http://www.risingsun4x4club.org/forum2/showthread.php?t=14326


I'm curious what domestic vehicles have this engine.. can anyone name a few? Is it just the Chevy Trailblazer? :D

2002-2009 GMC Envoy, Envoy XL, and Envoy XUV
2002-2009 Chevrolet TrailBlazer and TrailBlazer EXT
2002-2004 Oldsmobile Bravada
2004-2007 Buick Rainier
2003-2008 Isuzu Ascender
2005-2009 Saab 9-7X

Corbet
11-11-2010, 11:43 AM
2002-2009 GMC Envoy, Envoy XL, and Envoy XUV
2002-2009 Chevrolet TrailBlazer and TrailBlazer EXT
2002-2004 Oldsmobile Bravada
2004-2007 Buick Rainier
2003-2008 Isuzu Ascender
2005-2009 Saab 9-7X

So basically yes, just Trailblazer's, and its clones.:hill:

I was never impressed with the power of the I6 in the Envoys I sold while working at the GMC dealer in Silverthorne. Nor were many buyers. We sold far more V8's

Nay
11-11-2010, 12:49 PM
I was never impressed with the power of the I6 in the Envoys I sold while working at the GMC dealer in Silverthorne. Nor were many buyers. We sold far more V8's

Here's the torque curve from the GM website (not power to the wheels off a dyno) - ignore the overlay, this came off TrailVoy and is not apples to apples. It is literally all I could find.

It's interesting as you read posts about the 4.2L I6 vs. 5.3L V8, you hear both sides. Some say the V8 is far better, some say there is no real difference in basic driving. Some claim to get the same fuel economy out of the V8, others say the I6 is better. A lot of people clearly prefer the V8 largely for its exhaust note, and readily admit it. Pretty much everybody on the TrailVoy forum acknowledges that the 4.2 shines at higher RPM (many say it only shines at higher RPM) - this is where I think about not being in overdrive on steep climbs and running at around 4K RPM for an extended period as needed.

Which leads me to believe it's a lot about how much you like an I6 as a platform vs. a V8 and what you use your rig for, understanding that any preference for the I6 is ultimately "thinking in support of feeling" (much like $12K diesel swaps :D).

corsair23
11-11-2010, 02:16 PM
So...

About 60 more HP but torque is almost identical except the max torque comes on later on the Chevy I6?

http://www.off-road.com/trucks-4x4/tech/engine-specifications-19425.html

rover67
11-11-2010, 02:59 PM
I really like the v8 (vortec 5.3) I put in my truck....

i did all the work and I want to guess it was around 5-7k with a new h55f tranny included.

i can see upwards of 16mpg on the interstate with the 35's going 70mph but i rarely go that slow..

i learned a lot about the swap over the years (had it swapped for 4 years now and 80k miles) you are welcome to drive it any time or come by and look at it.

Nay
11-11-2010, 03:35 PM
So...

About 60 more HP but torque is almost identical except the max torque comes on later on the Chevy I6?

http://www.off-road.com/trucks-4x4/tech/engine-specifications-19425.html

You have about 2.5K more RPM where the 4.2 is going to be pulling towards redline - imagine trying to run your 1ZFE at 4.5K-5K RPM.

This is generally spoken of "the area under the curve". The 1ZFE has a very narrow band where it feels optimal - for me that is 2,400 to 2,900 RPM. Under 2,400, it is an absolute dog, and 3K and over and it simply is not a smooth or quiet engine and it does not want to pull to redline - naturally aspirated, you pretty much start to hit a wall.

This is where max HP/Torque figures don't tell the story - the VVT on the 4.2L is reported to really kick in at 4K RPM. You aren't ever driving a 1ZFE in that range over distance, and the GM engine is really getting its legs in that range (according to what I am reading).

So being within 90% of max torque from say 1,600 RPM to 6,000 RPM is something that the 1ZFE is simply not capable of, and that is what is so frustrating about it - the narrow performance band when you also factor in NVH.

That all of this comes with materially better fuel economy is compelling - at least right now, on paper. It would also be compelling to buy Slee's SC, upgrade the cooling system, and be done with it :hill:

subzali
11-11-2010, 04:25 PM
Sorry for being stupid, but what's NVH?

sleeoffroad
11-11-2010, 04:46 PM
That all of this comes with materially better fuel economy is compelling - at least right now, on paper. It would also be compelling to buy Slee's SC, upgrade the cooling system, and be done with it :hill:

I doubt you are going to get materially better fuel economy if you push that motor to 4k all the time. As for v8 vs i6, I would take the 4.7l toyota motor about the 1fz anytime. I am curious to get our swap on the road to see how it feels in the 80.

Nay
11-11-2010, 05:32 PM
Sorry for being stupid, but what's NVH?

Noise, Vibration, and Harshness.

Nay
11-11-2010, 06:07 PM
I doubt you are going to get materially better fuel economy if you push that motor to 4k all the time.

True, but it would be nice to be able to run it at higher RPM when needed, especially at higher altitudes with the VVT vs. the wheezy 1ZFE.

Given I run 5.29's, I especially like the GM 4L60E auto ratios:

A343F 4L60E

2.804 3.059
1.531 1.625
1.000 1.000
0.753 0.696 (overdrive)

You get the lower ratios for first and second, but then OD is quite a bit taller. It is good to be able to run with OD Off @ 70 mph at the higher RPM without the engine fighting itself and delivering half the already miserable fuel economy.

Still all on paper, but I am having a hard time putting any holes in the numbers.

RedCreeper
11-11-2010, 06:14 PM
Jumping in with a saying i heard growing up around Jeeps.....

Clifford Performance says 6=8

A stage 3 is over the top build of a inline 6 popper. Bored out, cam, carb, head work etc... My dads 258 was i think a stage 2 and it had gobs of torque and you can wind that puppy way up there. Really like those motors. I like the torque from the straight 6s, better for wheeling i think.

Leaving now....... :bolt:

sleeoffroad
11-11-2010, 06:37 PM
People always way they will take the torque of the i6 above the v8 for off-roading. Here is some dyno graphs as measured at the wheels.

1FZFE
http://www.sleeoffroad.com/forum_pics/stock_vs_sc_turbo.jpg

and

2UZFE

http://www.sleeoffroad.com/products/images/avo/dyno%20graph.jpg

Compare the v8 torque to the i6 torque. I would still take the v8 anytime plus I would take the turbo in both cases.

Corbet
11-11-2010, 07:59 PM
It would also be compelling to buy Slee's SC, upgrade the cooling system, and be done with it :hill:

If I had the $2K right now it would already be gone.


Anyone considered Toyota's new 4.6 V8. Probably very cost prohibitive right now.

60wag
11-11-2010, 08:43 PM
Why does the turbo produce so much more power than the SC?

coax
11-11-2010, 08:51 PM
That graph makes me really want a turbo :cool:

Corbet
11-11-2010, 09:02 PM
Why does the turbo produce so much more power than the SC?

I would assume the turbo is supplying more boost. Christo will have to confirm.

Corbet
11-11-2010, 09:07 PM
Christo why is the turbo 1FZFE power graph get so rough over 4K RPM. Is the fuel management system starting to have trouble at that point?

satchel
11-11-2010, 10:57 PM
I would think the difference in the graph on the power scale between the super charger and the turbo has more to do with the fact that they are completely different engines. The 97 has much more horsepower stock than the 93 does stock. The 93 engine is pretty much the same that are in the FJ62, they beefed them way up in 94-97.

rover67
11-12-2010, 01:19 AM
i know you want a I6, but you should drive my truck sometime. with a big flywheel it wheels nice. it is pretty torquy. you are welcome to wheel it too if you like.

sleeoffroad
11-12-2010, 06:18 AM
Why does the turbo produce so much more power than the SC? Still a low pressure system but much more volume of air.

No, the 93 is a 1fzfe not the FJ62 motor. Just different fuel management between the 93 and 97.

As to why the curve was that rough, can't recall when we did it, but it might have something to do with tuning at that stage. That was dyno tuning before we did the final tuning on the road.

I don't want to hijack Nay's thread, but wanted to show that the belief huge 1FZ torque might be ok compared to a 22R, but not really when comparing to a newer generation v8. The i6 torque curve might be flatter, but the v8 has more torque over the whole rpm range.

satchel
11-12-2010, 08:12 AM
Just looked it up and realized that the FJ62 motor ended in 92. Sorry for the misinformation.

60wag
11-12-2010, 08:38 AM
From the first graph, it's interesting that the SC nets only about 20-30hp at the wheels.

Hulk
11-12-2010, 09:51 AM
From the first graph, it's interesting that the SC nets only about 20-30hp at the wheels.

I don't think you need the SC for wheeling. But it's awesome in the mountains. The 80 finally drives like other vehicles.

Air Randy
11-12-2010, 10:49 AM
The guy that was trying to sell his wrecked 4Runner on the forum sent me an email with this info in case you're interested:

"I also have a 4.3L Chevy Vortec on an engine stand that needs to go. Engine came out of a Blazer with < 2000 miles on it. Engine w/ all accessories, shop manuals, all for $1300".

If I was going to the trouble of a GM swap I would go with a V6 or V8. Probably an easier swap since the V6/8's are a more common swap and take up less room.

Dee's truck has the same motor as Marco's (5.3 vortec) with an auto trans. It starts instantly and runs smooth as silk. Even with 42" tires and 4.88 axles in high range it has no issue with torque with the automatic. Off road it is awesome.

Nay
11-13-2010, 12:02 AM
I don't want to hijack Nay's thread

It's cool, good discussion. I'm not committed to anything and perspective never hurts. Assuming I can keep cooling under control, the SC probably makes good sense for me as time is at such a premium and these things can always be sold at a future swap point.

The reality of time/money/expectations in family life :rolleyes:

Nay
11-14-2010, 05:55 PM
Well, I just got back from buying eight 4-packs of ski lessons (2 per kid), season kid gear rentals, helmets, more outerwear for those growing weeds...

...which means I am going to be driving to the the slopes with a 1ZFE this year...

Thanks for all the inputs, I'll probably revisit all of this in the not too distant future.

:beer:

nakman
12-03-2010, 09:00 PM
Not so fast, Nay.. here you go man http://denver.craigslist.org/pts/2094118665.html

Nay
12-04-2010, 11:16 AM
Not so fast, Nay.. here you go man http://denver.craigslist.org/pts/2094118665.html

That is a seriously good deal if nothing is wrong with it :D

Nay
01-22-2011, 08:56 AM
A potential kit is gaining some steam on mud, hoping it's not another one of those "hope and wait and fade away" deals that plague our hopes and dreams :hill:

353 HP here, still NA:

http://www.youtube.com/watch?v=rjvW8IimN0Y&feature=related