My strange rambling with Inline 6 engines.

"Frank Grimes" (FrankGrimes) 01/09/2018 at 17:01 • Filed to: None

3

10

I used to read more car magazines than I do now. the engineering and advancements of vehicles always interested me so when I read articles about the technology and durability testing of the GM Atlas 4200 in 2001 or 2002 i became a big nerd for these engines. An american all aluminum I6 with DOHC drive by wire nearly 300hp and as much torque was pretty cool even when compared to V8s of the time. I remember reading about millions of miles of testing brutal off road racing of the engines. I thought these motors were really cool and maybe I was the only one. Then much later an article in Car Craft made me think I wasnt the only one. A 470hp atlas in a 69 Firebird.

Years passed and I forgot about Inline 6 engines. I started becoming a bit obsessed with another The ford barra motor after seeing Australians making big power on stock motors. I began to learn about the advanced design of these things and began to lust after one. A turbo barra powered fairmont wagon would be such a fun daily driver and sleeper street car.

This led me to wonder if there might be an alternative to waiting until I was rich and could afford to ship over the oceans a container of junkyard barra engines. I thought about the Atlas again wondering if an Atlas could make 600hp and began comparing the barra and the atlas. Turns out I was missing some cool pieces of the high performance Atlas story.

Before the Trailblazer SS got an LS they were considering a twin turbo Atlas and went so far as to produce a concept using shorter rods piston squirters and low comp pistons as well as the mentioned twin turbos adding a water to air intercooler the motor produced 400hp and 400ft/lb and rushed the trailblazer to 60 in 5.35 seconds and a 1.4 mile in 13.9 seconds.

In 2000 GM had Falconer buld a 5 liter version that produced 600hp and the engine went in to a trailblazer looking truck and raced the baja 500 and 1000 and also won overall in 2000 at pikes peak.

So there isnt really an ending or conclusion to this story. I still dont have a barra or an atlas nor do I have any car one of these might go into. I am back where I started wanting a turbo I6 and dropping it into a sedan or wagon, but at least I know I am not so crazy thinking a high powered atlas is a good idea!

In the meantime I will be stalking ebay and LKQ and other greasy places looking and dreaming about Barras and Atlas engines.

Check out this article to learn more about the history and development of the GM atlas engine

!!! UNKNOWN CONTENT TYPE !!!

Jordan and the Slowrunner, Boomer Intensifies > Frank Grimes 01/09/2018 at 17:39

0

I have a lot of miles of LS and 4.3 under my belt, and I much prefer the Atlas. It’s a great engine.

kanadanmajava1 > Frank Grimes 01/09/2018 at 18:22

1

The Falconer version shares pretty much no parts with the production engine. It was kind of partially outsourced proof of concept to use of the engine in motorsports.

I have one ‘08 engine in my garage. My plan is to mate it with a turbocharger, a ZF GS6-53BZ 6-speed manual and shove it into a very crappy looking ‘69 Charger. Sorry, wrong brand but I just want to have a Charger with a modern straight six.

The bellhousing adapter is progressing very slowly. Currently it looks that the bolt circle in the bellhousing is large enough to clear the starter ring. But it’s going to be very tight.

Frank Grimes > kanadanmajava1 01/09/2018 at 18:55

0

yeah it doesn’t i remember reading about the atlas and the baja racing and testing was used to show the legnths GM went to test the atlas but really they are totally different things, and even on the falconer site mentions it was used to show the durability of the atlas so its bullshit when really they are showing the durability of a custom engineered engine and the skills of falconer not GM.

Frank Grimes > Jordan and the Slowrunner, Boomer Intensifies 01/09/2018 at 18:57

1

My only experience is in a rented trailblazer a long time ago driving across the country. I was impressed with the power and smoothness and quiet of it.

PS9 > Frank Grimes 01/09/2018 at 19:08

0

Make an American GT-R? Are you kidding? All we have is an engine! That’s nowhere near enough!

“And that, GM, is why you fail.”

kanadanmajava1 > Frank Grimes 01/09/2018 at 19:43

0

A bit weirdly the Falconer blocks and heads seem to have GM casting numbers. But these two example engine do not seem the share the same crank. the lower one has 8 flywheel bolts but the other one has a very weird number of 12. All Atlas engines have 8 bolts but 5 and 4 cylinder engines use a bit smaller bolt circle.

The bellhousing bolt pattern seems to be the one used with SBCs but it’s missing the upper hole. All Atlas family engines have their own bolt pattern. The Falconer cylinder head has weird “auxiliary head bolts” protruding outside the block sides under the exhaust/intake ports. I don’t remember seeing anything similar in any other engine. There are probably regular amount of main head bolts under the valve cover.

The biggest difference between LL8 and Falconer engineer seems to be reversed exhaust and intake sides. I guess they didn’t want to use the exhaust piping in the side of the steering gear. But it’s weird that they did prototype this with Falconer engines. The Falconer’s ports are also angled while they are straight in the LL8. Maybe way to expensive to leave them angled. 

daender > Frank Grimes 01/09/2018 at 20:38

0

Join the growing crowd! I’m looking at Barras with more interest since my R33 dreams (please keep hating it, people, it keeps the prices low) is being replaced by AUS utes. I’m really coming around on the XH/XG utes since they’re up for (early XGs) or eventually up for (XHs) importing around the same time frame as R33 Skylines.

I’d take mine in XR6 turbo form with lots of upgrades, please.

FTTOHG Has Moved to https://opposite-lock.com > Frank Grimes 01/10/2018 at 00:01

0

I had a TrailBlazer as a loaner for a few days back in 2011 while my car was in the shop. I was impressed with the Atlas. The rest of the vehicle not so much.

MoCamino > Frank Grimes 01/10/2018 at 15:58

0

I’ve always thought the I-6 4.2 (or even the I-5 3.7) would make a really cool engine swap into my G-body El Camino. It has a weak malaise-era 305 and a 4 speed in it now, so either would be a vast improvement and would be cool just based on the “different” factor. I looked into it a while back and I think it turned out it would really not be any cheaper to do than dropping in an LS. Add to that the fact that those Atlas motors are pretty tall, so I’m not even sure it would fit in my cruck.

415s30 W123TSXWaggoIIIIIIo ( •_•))°) > Frank Grimes 01/10/2018 at 21:17

0

I like straight motors, I have an I5 and an I6 with another I6 on the way! Looks like a cool motor, I’d look at one of these for a swap for sure.