New Build: GM 4.2L Atlas into '91 FJ80

[TwoTonic]

LL8 mounts

Are you using the same mounts for the 4200?

Yes, they are the same--- the LL8's about 4+" longer than LLR, so mount point is different, but it's the same mounting hardware.

The only 'fab' work needed on the truck for the conversion is the mount-ectomy of the old mounts with torch or Saz-all or Cutter Wheel.... the Toyota mounts need to be lopped off and the frame area cleaned up. The the new mount-receiver is welded back to the frame in the right spot.

Other than that, the stock front-rear driveshafts are used, and the stock TC shift lever is used, even cross-member mounts are the same.... there isn't a lot of other cutting and nipping and tucking, unless someone wants a variation on the stock Toyota exhaust. We've even been using factory cats on the trucks-- IT's funny that the 'hotter' 242HP GM-equipped truck ends up performing SIGNIFICANTLY better in emissions testing. They test it as a 1991, which has less stringent local requirements, but in fact the Atlas FJ80 will pass as if it's a 2011.

 

[alia176]

Other than that, the stock front-rear driveshafts are used, and the stock TC shift lever is used, even cross-member mounts are the same.... there isn't a lot of other cutting and nipping and tucking, unless someone wants a variation on the stock Toyota exhaust.

This begs the question, do you still get the famous Toyota "whistle" under hard acceleration?

 

[kbahus]

This swap has the gears turning in my head big time. Come out with a mount kit, oil pan, and a required parts list and I am in. I can do my own wiring, the wiring on this type of swap should be super simple compared to other things I have worked with. Are there any other options out there for tcase adapters or is the $1200 Mark's unit the only one? I wish I still had my fully built 4l60E out of my Camaro

 

[DudeAbides]

Oh man. I've been shopping for a new 80. I think I would much rather get one with higher miles and do this swap, probably come out about the same cost wise as finding a lower mileage 80. I think you'll have a serious winner here if you guys do offer a kit with wiring for us who can turn a wrench but are a little challenged in the fabbing/wiring departments.

 

[efidiy]

For fun here is my 4200 engine on the dyno - final pull 353hp NA

YouTube - Vortec 4200 hotrod engine ported head and custom camshafts by EMTech MotorSports

reduced compression
custom cams 222* @ 050 450 lift
ported head

stock exhaust manifold

3' of 2 3/4" head pipe >>> 4' of 3" pipe - no muffler.

.... yes I did run a stock pan as my prototype was installed in my truck.... needed that to get to the dyno..

 

[TwoTonic]

For fun here is my 4200 engine on the dyno - final pull 353hp NA

YouTube - Vortec 4200 hotrod engine ported head and custom camshafts by EMTech MotorSports

reduced compression
custom cams 222* @ 050 450 lift
ported head

stock exhaust manifold

3' of 2 3/4" head pipe >>> 4' of 3" pipe - no muffler.

.... yes I did run a stock pan as my prototype was installed in my truck.... needed that to get to the dyno..

Awesome-- you got that kind of power NA and with only .450 of lift?
Wow. That definitely confirms the theory that there's more to get with upgrades to the stock heads and cam!

 

[alia176]

Awesome-- you got that kind of power NA and with only .450 of lift?
Wow. That definitely confirms the theory that there's more to get with upgrades to the stock heads and cam!

Oooh, daddy likes to hear that!

 

[efidiy]

Awesome-- you got that kind of power NA and with only .450 of lift?
Wow. That definitely confirms the theory that there's more to get with upgrades to the stock heads and cam!

The late model head is much better than the early head but in stock form, the exhaust port is awful. The early head REALLY is horrible on the exh side

'06 up head (at 450 lift) all measurements at 28" water

stock ported
int. 280 cfm 320
ext. 160 (230-240 cfm)

In stock form the ext side stagnates at 0.1" lift

Dick at Route 66 rebuilders does an excellent job on these head. He is also the engine builder for Miss Opel... www.blackopel.com

 

[Tugarin]

Awesome-- you got that kind of power NA and with only .450 of lift?
Wow. That definitely confirms the theory that there's more to get with upgrades to the stock heads and cam!

How is the project going?

 

[alia176]

The late model head is much better than the early head but in stock form, the exhaust port is awful. The early head REALLY is horrible on the exh side

'06 up head (at 450 lift) all measurements at 28" water

stock ported
int. 280 cfm 320
ext. 160 (230-240 cfm)

In stock form the ext side stagnates at 0.1" lift

Dick at Route 66 rebuilders does an excellent job on these head. He is also the engine builder for Miss Opel... Black Opel

Sorry, if you posted this info already but it looks like you have a nice recipe for additional power. Can you provide some more info like vendor name and cost? Do you have a torque/hp curve from the Dyno by any chance? I wanted to see if the added power would be beneficial for rock crawling application; torque coming on right away at lower rpms.

Thanks.

 

[efidiy]

"Sorry, if you posted this info already but it looks like you have a nice recipe for additional power. Can you provide some more info like vendor name and cost? Do you have a torque/hp curve from the Dyno by any chance? I wanted to see if the added power would be beneficial for rock crawling application; torque coming on right away at lower rpms."


The stock cams are hard to beat for bottom end grunt. I can post the dyno plots latter this week.

What would help is head work, + a set of small diameter long tube headers + a tune. GM left a lot on the table for warranty purposes.

My cams start making power above 3500.

There are smaller lobe profiles that would make power down lower but no cam blanks to get them ground on. Head work Contact Dick through the black opel link in my previous post.

 

[TwoTonic]

LL8 torque curve

I'll second Marc's comments on the stock cam's low-end grunt-- the LL8's torque curve is spooky-flat making 90% of that 275 ft-lb peak from just off idle all the way to beyond 5800 RPM. (Redline's north of 6000). So it makes great torque down low, but has tremendous area-under-the-curve, in that it maintains full torque all the way up (thanks to great head-and-intake-runner designs and VVT).
Er, my 3FE could never even dream of 6000RPM, much less make any power up there.

Somewhere I have the original LL8 factory dyno plots from the 02-03 Tech Training series-- I'll post if I can find it. When you see Marc's actual dyno data you'll be impressed. It's quite a powerplant.

"Sorry, if you posted this info already but it looks like you have a nice recipe for additional power. Can you provide some more info like vendor name and cost? Do you have a torque/hp curve from the Dyno by any chance? I wanted to see if the added power would be beneficial for rock crawling application; torque coming on right away at lower rpms."


The stock cams are hard to beat for bottom end grunt. I can post the dyno plots latter this week.

What would help is head work, + a set of small diameter long tube headers + a tune. GM left a lot on the table for warranty purposes.

My cams start making power above 3500.

There are smaller lobe profiles that would make power down lower but no cam blanks to get them ground on. Head work Contact Dick through the black opel link in my previous post.

 

[Nay]

From the trailvoy forum - these are GM charts, there was some dispute that the overlay of the later model torque curve was done accurately...

 

[TwoTonic]

Yep, that's the one-- Thanks!
I had the original (275HP) version from the GM tech manual (was an EBay find) , but the power curve is amazingly linear-- and it making more power right up to redline

 

[Nay]

Yep, that's the one-- Thanks!
I had the original (275HP) version from the GM tech manual (was an EBay find) , but the power curve is amazingly linear-- and it making more power right up to redline

This also shows you how limited your available HP curve is if the engine likes to run at 2,400 RPM.

I know people will continue to dispute that the 1ZFE isn't crappy cruising at 3K and over, but this is completely contradicted by virtually every gearing thread that says 4.88's are better than 5.29's for 35" tires so you can keep the engine RPM's "stock" because "that is what the engine is tuned for".

 

[efidiy]

dyno data

A couple of notes:

The engine compression is 8.2:1 almost 2 full points less than stock. For sure I gave up power with the CR drop. With stock compression and a good set of headers I bet this engine would have made 390HP.

The exhaust cam is locked - no VVT so I gave up power there as well. This engine is very responsive to cam timing changes. I moved the intake centerline last summer 5* advance and the torque shot up - I really have to be careful to feather into the throttle on the street. I'm thinking of retarding the intake 2* to kill a little bit of power at lower rpm. Mind you I don't go rock crawling with it.

For reference black opel's race engine makes close to 460HP NA with 14:1 CR, 20* more cam timing than what I run, and open headers.

 

[lenross1]

Sub'd

 

[Tugarin]

I am for swapping - as I have 1FZ-F carburettor engine - with extra load and weight as ARB lift and etc - I can feel that engine is underpowered. Especially when I go to altitudes higher than 1500 meters, I have to push the throttle to bottom to keep up with traffic - on 100-110 km. And MPG is terrible, I have reached 30-40 liters per 100 km.
Hopefully swap will solve two issues MPG and power issues

 

[kbahus]

To the OP, do you think you will be offering a hardware kit within 2011? Sounds easy enough to make my own stuff but why reinvent the wheel if I don't have to. I would really like to knock out this swap in the summer or fall.

 

[Walking Eagle]

can't seem to find it, so sorry if it's been covered, have you figured what MPG you're getting yet?