Limequat's 4.2l I6 Swap

adampecush

Regular Supramaniac
May 11, 2006
2,118
3
38
Edmonton
limequat;1355083 said:
Why's that?

There is too much variation (microstructure, impurities, surface porosity, etc) in the cast structure to get an even color and finish. I'm sure some places will do the work for you, but i doubt you'll be happy with the results.
 

RedGT

New Member
Aug 18, 2006
94
0
0
Baltimore, MD
Im glad to see someone having some imagination with putting this engine in a supra but make sure the engine is a 2006 or newer. The 2004-2006 engines have problems with valve seat wear. it will cause a missfire at idle. There is a GM bulletin about this and head replacement is required. And also this engine is not fun to work on. To replace the cylinder head you have to either have a special tool to keep timing on the crank that only works half the time, or tear off the oil pan, to get to the front cover. I know my way around this engine since I am a GM tech and this wouldnt be my first choice to swap into a supra. Just my opinion.
Oh, and you may want to stay away from early production engines also (2002) they had problems with the cylinder sleeves coming apart.
 

tacoma_kyle

New Member
Apr 12, 2009
50
0
0
Klamath Falls, OR
Forged or cast doesnt matter so much as when it breaks. Remember you can have a forged part, but if it is too small then it may break sooner.


And are you sure, limesquat, that motor will bolt to a R154 without issue? I am just thinking potential issues with clutch match-up and tranny input shaft length vs bellhousing length. The shafts may have been common from Toyota to Chevy applications, but Toyota R150/151 input shafts are shorter than R154 shafts.
 

limequat

Dissident
Apr 1, 2005
532
0
0
Detroit
RedGT;1355368 said:
Im glad to see someone having some imagination with putting this engine in a supra but make sure the engine is a 2006 or newer. The 2004-2006 engines have problems with valve seat wear. it will cause a missfire at idle. There is a GM bulletin about this and head replacement is required. And also this engine is not fun to work on. To replace the cylinder head you have to either have a special tool to keep timing on the crank that only works half the time, or tear off the oil pan, to get to the front cover. I know my way around this engine since I am a GM tech and this wouldnt be my first choice to swap into a supra. Just my opinion.
Oh, and you may want to stay away from early production engines also (2002) they had problems with the cylinder sleeves coming apart.

Yep, I did get the 2006 for these reasons and the higher output. Every engine has it quirks. If I find myself doing a head swap, I don't think pulling the pan too is going to be too much additional work. For the moment, I don't plan on opening it up, though. Any tips, tricks on the 2006+ that I should know about?
 

limequat

Dissident
Apr 1, 2005
532
0
0
Detroit
tacoma_kyle;1355747 said:
Forged or cast doesnt matter so much as when it breaks. Remember you can have a forged part, but if it is too small then it may break sooner.


And are you sure, limesquat, that motor will bolt to a R154 without issue? I am just thinking potential issues with clutch match-up and tranny input shaft length vs bellhousing length. The shafts may have been common from Toyota to Chevy applications, but Toyota R150/151 input shafts are shorter than R154 shafts.

Yep. I'm using the AR5, but I've already proven that the AR5 is interchangable with the R154 in terms of mating up to the 7m. You probably wouldn't be able to use the older R150/R151 without some modifications.

I'll use all GM parts, but if using the R154, you'd just sub in a toyota clutch disk.
 

limequat

Dissident
Apr 1, 2005
532
0
0
Detroit
I was going to have the local welder weld me up an oil pan - by splicing an I5 pan with the I6 pan. He quoted me $700, so I decided to take a break from the pan and work on engine mounts.
Also, I picked up a core engine so that I could work on fabrication without fear of damaging the 06 motor.

Here's my first mockups using the core engine. With no pan on, I can set it right into the chassis:

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p1355797_1.jpg


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The pics are hazy from all the welding I'd been doing with the doors closed.
 

limequat

Dissident
Apr 1, 2005
532
0
0
Detroit
fixitman04;1355900 said:
how are you going to deal with the drive by wire tb??

I'm using the stock trailblazer PCM and sensors. I'll either use the entire Trailblazer pedal or graft the sensor onto the Supra pedal.
 

limequat

Dissident
Apr 1, 2005
532
0
0
Detroit
The Trailblazer engine is tall. With a stock crossmember, it would probably poke through the hood a couple inches.

So I made these:

p1359879_1.jpg


p1359879_2.jpg


p1359879_3.jpg


They're combination crossmember spacers and engine mounts. This way I don't have to weld on the Supra chassis. The mounts are made from 1.5" x 1.5" solid steel stock with 1/8" sheet steel welded on to form the engine mounting points.

Here they are bolted between the frame and crossmember:

p1359879_4.jpg


p1359879_5.jpg


p1359879_6.jpg
 

mobes

Supras are never 'done'
Apr 5, 2005
719
2
18
Bozeman, MT
I always thought the Supra needed a body lift :)

Is the engine mounted off-center or are the mounts just off-center?
 

limequat

Dissident
Apr 1, 2005
532
0
0
Detroit
mobes;1359887 said:
I always thought the Supra needed a body lift :)

Is the engine mounted off-center or are the mounts just off-center?

Yeah, it may take some work to get the suspension sorted after this.

For some reason, the stock engine-side mounts are asymmetrical, so the frame side mounts need to be oppositely asymmetrical for the engine to be square to the chassis. Weird.