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skorpioskorpio · 07-19-2014, 07:49 AM

Interestingly the roots of the project hover around 'busa throttle bodies, well sort of. I knew from the beginning I wanted a modern engine design in an old truck, specifically a '75 or older truck, the year California considers too old to care about if it's older and I'll never need a C.A.R.B certificate for anything I do and I'll never need to smog it. Essentially it's off the grid and I can rewind the clock to good old fashioned hot rodding and take advantage of all the modern advances.

At first I was looking at maybe a Northstar engine, and seeing a youtube video of one with 'busa ITBs really got me, it sounded rude and knarley, and snapped to rpms almost instantly. This is a link to that vid:

http://youtu.be/nhoAR3UfLRo

Then I started looking into what it would take to actually use a Northstar, not so easy. The best examples of the engine were used in front wheel drive cars, and required lots and lots of mods to put things in the right place to turn it 90 degees and run it to a rear wheel drive setup. All very ugly and all very expensive, and in the end the engine doesn't really have a very good reputation, lots of oil burning issues, failed head gaskets and almost any of many common failures renders it non-rebuildable. ...and it still runs a cross crank, so it still sounds like a typical American V8. I considered it to the point of thinking about getting a flat crank made for one. Eventually it became obvious this was too far out there. It's also wider than a big block.

The ITB thing stuck, that was going to be whatever the engine choice. I make my living as a disaster recovery engineer, so even though I was set on ITBs I always wanted to give myself the out of running carbs.

I have a last year 2003 GMC Sonoma with the 4.3l V6 and the ZQ8 handling package and a limited slip, great little truck but of course it seems to throw a check engine light within days of it's smog check every single time one is due. Anyway, when I bought it as an end of year model the new Canyons were already shipping with the 5 cyl version of the Atlas. Being an inquisitive guy I asked about it at the time and was told that it was a great engine that made more power than the V6 and there was a 6 cyl version that was a beast in the Envoy. It got filed away and what made that bit of archive data pop out again years later is hard to say.

I really wanted an overhead cam, 4 valve per cylinder engine in this project, preferably from the company that made the body. I was always fascinated with the Offenhouser and Cosworth engines in my youth, I also love the sound of an engine that fires in even pulses.

I am well aware the LS motors do the job quite well but I don't find them interesting or exciting, to me they are a rehash of a 60 year old design. The ZR1 engine is really interesting, but carries a crazy price tag and nothing about it is common with anything else. Ford makes some interesting modern V8s with their modulars, even a V10 version, but that just seems wrong to drop one into a GM truck. Europeon and Asian engines, even wronger.

When I started looking into the Atlas it seemed to meet all the requirements, modern 4 valve DOHC engine with a bore and stroke really similar to an old Jag E-Type 6. Very respectable HP (near 300 stock from 4.2 liters on regular gas), relatively small displacement (gas is $450/gal in California, highest in the US and seems to go up if an Arab sneezes), adaptable, has a great reliablity record despite a lot of urban myths that it doesn't (usually propagated by guys who try and tell you why a small block Chevy is the only engine practical to swap into ANY project), oh and lets not forget cheap, my engine with less than 10,000 miles on it cost me less than $1500 shipped from 2500 miles away. It has all the same type sensors as an LS engine, same 58X trigger, same coil interface.

What's usually easy is harder than it should be with this engine: oil pan is all wrong for most everything and it's cast with important stuff in the casting like AC compressor mounts and the cover for the bellhousing. It would seem like the idea of a simple wasted spark ignition triggered off of a common trigger wheel configuration would be something simple, but without commiting to fuel injection and an ECU, mmm not so much. As a matter of fact if you specifically want just a crank fired stand alone ignition for something other than an LS engine you have a choice of one, ElectroMotive. There is no aftermarket intake manifolds of any sort for this engine and the stock one looks like a plastic toy. The bellhousing pattern is unique to the Atlas Engines so anything other than a 4L60/65/70E trans is tricky.

07-19-2014, 07:49 AM	#158
skorpioskorpio Registered User Join Date: Nov 2010 Location: Los Angeles, CA Posts: 1,018	Re: Project Madera: A Jimmy GT Interestingly the roots of the project hover around 'busa throttle bodies, well sort of. I knew from the beginning I wanted a modern engine design in an old truck, specifically a '75 or older truck, the year California considers too old to care about if it's older and I'll never need a C.A.R.B certificate for anything I do and I'll never need to smog it. Essentially it's off the grid and I can rewind the clock to good old fashioned hot rodding and take advantage of all the modern advances. At first I was looking at maybe a Northstar engine, and seeing a youtube video of one with 'busa ITBs really got me, it sounded rude and knarley, and snapped to rpms almost instantly. This is a link to that vid: http://youtu.be/nhoAR3UfLRo Then I started looking into what it would take to actually use a Northstar, not so easy. The best examples of the engine were used in front wheel drive cars, and required lots and lots of mods to put things in the right place to turn it 90 degees and run it to a rear wheel drive setup. All very ugly and all very expensive, and in the end the engine doesn't really have a very good reputation, lots of oil burning issues, failed head gaskets and almost any of many common failures renders it non-rebuildable. ...and it still runs a cross crank, so it still sounds like a typical American V8. I considered it to the point of thinking about getting a flat crank made for one. Eventually it became obvious this was too far out there. It's also wider than a big block. The ITB thing stuck, that was going to be whatever the engine choice. I make my living as a disaster recovery engineer, so even though I was set on ITBs I always wanted to give myself the out of running carbs. I have a last year 2003 GMC Sonoma with the 4.3l V6 and the ZQ8 handling package and a limited slip, great little truck but of course it seems to throw a check engine light within days of it's smog check every single time one is due. Anyway, when I bought it as an end of year model the new Canyons were already shipping with the 5 cyl version of the Atlas. Being an inquisitive guy I asked about it at the time and was told that it was a great engine that made more power than the V6 and there was a 6 cyl version that was a beast in the Envoy. It got filed away and what made that bit of archive data pop out again years later is hard to say. I really wanted an overhead cam, 4 valve per cylinder engine in this project, preferably from the company that made the body. I was always fascinated with the Offenhouser and Cosworth engines in my youth, I also love the sound of an engine that fires in even pulses. I am well aware the LS motors do the job quite well but I don't find them interesting or exciting, to me they are a rehash of a 60 year old design. The ZR1 engine is really interesting, but carries a crazy price tag and nothing about it is common with anything else. Ford makes some interesting modern V8s with their modulars, even a V10 version, but that just seems wrong to drop one into a GM truck. Europeon and Asian engines, even wronger. When I started looking into the Atlas it seemed to meet all the requirements, modern 4 valve DOHC engine with a bore and stroke really similar to an old Jag E-Type 6. Very respectable HP (near 300 stock from 4.2 liters on regular gas), relatively small displacement (gas is $450/gal in California, highest in the US and seems to go up if an Arab sneezes), adaptable, has a great reliablity record despite a lot of urban myths that it doesn't (usually propagated by guys who try and tell you why a small block Chevy is the only engine practical to swap into ANY project), oh and lets not forget cheap, my engine with less than 10,000 miles on it cost me less than $1500 shipped from 2500 miles away. It has all the same type sensors as an LS engine, same 58X trigger, same coil interface. What's usually easy is harder than it should be with this engine: oil pan is all wrong for most everything and it's cast with important stuff in the casting like AC compressor mounts and the cover for the bellhousing. It would seem like the idea of a simple wasted spark ignition triggered off of a common trigger wheel configuration would be something simple, but without commiting to fuel injection and an ECU, mmm not so much. As a matter of fact if you specifically want just a crank fired stand alone ignition for something other than an LS engine you have a choice of one, ElectroMotive. There is no aftermarket intake manifolds of any sort for this engine and the stock one looks like a plastic toy. The bellhousing pattern is unique to the Atlas Engines so anything other than a 4L60/65/70E trans is tricky.