GM 4200 I6 swap?

[Retoxtony]

It’s @Vbb199 . He bought a trailblazer and I think he was going either the turbo or supercharger route. They are a pretty darn stout option, but not any cheaper than an LS in my area.

I’ll look for his posts and see if he has much info.

An LS is the easy way to do it, but I do like the idea of something different. And these I6s seem to plentiful and cheap in my area. Ive found lots for $500 for engine and transmission. I can’t even find a high mileage 4.8 for that price and I’d still need to find a trans.

 

[legopnuematic]

There I believe is someone on YouTube that is (or has) put an atlas in a square.
A guy Corey and his friend Justin (fuelinjectionsucks on YouTube) put a 4200 in a Checker Marathon, it replaced a 283sb and some Borg Warner automatic transmission.
They used a bop th400 and some drilling and cutting to get most of the bellhousing bolts bolted up, IIRC he used a terminator setup for an LS that was unlocked to be able to be setup for a 6cyl. custom exhaust manifold, China turbo, air to water inter cooler.
After getting it tuned up and adjusting the cam timing it seemed to run pretty good.

They are definitely a cool engine with and are (or were) really under appreciated IMO.

 

[Bextreme04]

I’ll look for his posts and see if he has much info.

An LS is the easy way to do it, but I do like the idea of something different. And these I6s seem to plentiful and cheap in my area. Ive found lots for $500 for engine and transmission. I can’t even find a high mileage 4.8 for that price and I’d still need to find a trans.

Your best best is probably to get an entire vehicle if you can. I think they just ran 4l60's behind them in the trailblazer... so nothing special there.

 

[Bextreme04]

I’ll look for his posts and see if he has much info.

An LS is the easy way to do it, but I do like the idea of something different. And these I6s seem to plentiful and cheap in my area. Ive found lots for $500 for engine and transmission. I can’t even find a high mileage 4.8 for that price and I’d still need to find a trans.

Here is his build thread for the trailblazer:
https://www.gmsquarebody.com/threads/03-trailblazer-build.41831/

 

[Strick]

I'm not a GM engineer but have wondered WHY the Atlas 6 hasn't made it's way to the Silverado platform. They make great power & get 300K plus miles in service when maintenance.

HS

 

[bucket]

I'm not a GM engineer but have wondered WHY the Atlas 6 hasn't made it's way to the Silverado platform. They make great power & get 300K plus miles in service when maintenance.

HS

Haven't they been out of production for 10+ years?

 

[Rumbledawg]

the 4.2 is not a bad little motor.
we bought the wifey's XUV new in '04 and she's still daily driving it 20 yrs later and we have had ZERO issues with the motor. keep them bathed in synthetic and they will run forever. as she has the heaviest model of the trailblazer/envoy/oldsmobile triplets, it does seem slightly soft just off the line, then it pulls like a train all the way to 6000.
was not really impressed with the fuel mileage, but her envoy weighs around 5000lbs, so it gets anywhere from 14-18 mpg depending where you are and how you drive.
downside is they are a tall motor, tall enough that the oil pan has a hole for the half shaft to pass through.
they also take a lot of oil. the capacity of her inliner is the same as the big block in my crewcab, 7 quarts
twenty yrs old this year and never missed a beat

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[Hunter79764]

There's a number of folks getting good power out of them. The little brothers were used in the Colorado and Canyon trucks in 4 and 5 cyl versions, and you can use the AR5 manual transmissions from those trucks or the 4L60/65/70e family with the bellhousing from the Trailblazers (which all came with the auto).
I did a 5.4 swap in my Monte Carlo way back, now I'm wishing I'd have done something more unique, either the 4200 or the 8100. On my 87, I'm debating the 6.0 or the 8.1. I know the 6.0 will be fine, but will I wish I'd done something different in 10 years? 3/4T 4x4, so I don't think I'll be happy with a 6 cyl, but a clean half ton 2WD I probably would.

Crap... I just remembered that I have a 2wd half ton that would be about perfect. Hmm. It needs more work than just that, but it gives me ideas that will float around and keep other ideas from actually happening.

 

[Strick]

Haven't they been out of production for 10+ years?

Maybe I should have stated the question as "why GM didn't". Yes, the Atlas are defunct I believe and have been replaced with the 4-banger. I did a 10 hour class on those a couple years back and was surprised how the camshaft lobes slide to deactivate cylinders instead of how AFM previously worked. They have electric water pumps and thermostats as well. The "old way" of fuel management was to keep your foot out of the Q-Jet...that was far less technical than these new-fangled techno wonders.

HS