Project Madera: A Jimmy GT

[skorpioskorpio]

Originally Posted by jimbug

Yes it was a compliment and way to build it the way that you want!

Then thank you, because a rappers shoe with family truckster taillights isn't what I'm going for

[watahyahknow]

considering putting a atlas engine in a square body pickup as i heared some good stories about the relyable power they make when fitted with a turbo, i keep my eye on this one

cool idea about the fiat oilpan
so you now need to machine the whole bottom part of the pan till theres only 2 inches left up from the gasket seal part and leave the dustplate for the clutch then make and weld a flat piece of alu plate over the hole
do you still need to put the stiffener ribs to the dustplate back again ? they look kindah in the way of the new oilpan
is the casting thick enough to just make a bunch of treaded holes around the circumference make a gasket and bolt the flat part onto the original cast part

thinking about all the machining needed
it might be simpler to have that 2 inch pan part cut out of a 2 inch sumtin thick piece of aluminium billet complete with the bottom the holes for the fiat pan and a seperate dustplate for the clutch bolted to the back of it and call it done
might even be able to leave material in the cavity as a studgirdle inside the pan for the mainbearings with the mountingbolts going trough and through.... if it wasnt for the brackets for the accessories on the side you mentioned the cad file shouldnt be THAT hard to make

[skorpioskorpio]

The pan has already been sliced:




The cut is nice and flat. I'm going to go pick it up next week, at this point I'm planning on just CADing up the plate in Solidworks which I decided to teach myself to use last week. If I CAD up the contours for the new bottom I can replicate the ribs of the Fiat pan which I think will be pretty cool, not that anyone will ever see it but I'll know. Oh and the dirt skirt ribs are gone.

The pan rim is about 3/16 give or take and I plan on doing the new bottom, probably our of 3/8ths with the ribs taking up about half the thickness. I plan to leave some extra girth where the Fiat pan mounts. A bolt on bottom probably wouldn't work too well, I don't think there is enough sealing area given the placement of the rail bolts which would probably bow out the pan bottom, You'd have to completly goop the thing up with sealant. To really make a wise joint like that you need close tolorances, not a lot of flex and something like Hondabond which is specifically make for mating machined surfaces without physical gaskets.

I thought about doing a full milled pan, but we're talking a really hunky chunk of aluminum even if you are just doing the top pan section without the sump, you're talking maybe about a grand just for the block of 6061 aluminum.

[skorpioskorpio]

So I've been working out the design for the intake manifold in Solidworks. The original plan was to cast it from a 3d print, however the casting house wanted to get their model maker involved so it went from very reasonable to really expensive really quickly. After looking at it I really need to keep it really short anyway, so I'm looking at milling it. I only have access to a 2 axis mill so my first design, which I really like BTW:

Needed to be radically simplified:

And may need to be simplified even further by the time I'm done. I also need to slice up the basic layout from a block of wood first just to get the angles right. Clearance on the number 1 cylinder is obstructed in all sorts of ways, and has to exit just right to clear everything.

I've decided to move things along I'm probably going to use actual Weber DCOEs at first instead of the DCOE pattern throttle bodies. The whole fuel systems becomes simpler, and I can do all the electronics later. No pressure regulation, no loop back tank, no 02 sensors it's all old school with a new school block. To start then I'll just need a crank triggered wasted spark ignition since there is no distributor on the Atlas engine. I will probably need to run premium in it, where the electronic version could get away with regular. Anyway this was one of the advantages of using the DCOE patterend throttle bodies, it gave me options.

Oh and after months of waiting my headers finally arrived, sorry for the poor angle on the shot:


Also Frame is coming along, here it is on the fab table being mocked up:

[jjzepplin]

You have some serious skills sir.

[skorpioskorpio]

If you are refering to Solidworks skills, thanks, if you are refering to my fab skills, I wish I could take credit, but I can't. The frame is being put together by T J Dalrymple at his shop space in Burbank, CA and the pan slicing was done by Findlay's Machine shop in Santa Monica, CA. I don't have the shop space to do it myself, I wish I did, I'd be a lot further along.

[watahyahknow]

a while back i seen someone using trottlebodies from a motorcycle for his car
there cheaper to buy if you can find them used and another good thing is they usually have the linkages that can be adapted to work on a inline engine

according to the website you need to find those for a Suzuki GSXR 750, 1000, and 1300 (Hayabusa) ITB's up to '02 are the best for altering the spacing
the newer ones are paired together

[skorpioskorpio]

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.

[watahyahknow]

think you can get that msd computer they make for carburated ls1 engines to work too
think the best pricewize would be the megasquirt for both the engine injection and ignition

i been looking in the northstar swap a long while back , there was this company that made a bunch of stuff for them including adapterplates to fit inline transmissions
they seemed to be more intoo the sandrail stuff though

[LUV2XCLR8]

Just spent a 1/2 hour going through the whole thread.

Subscribed and Intrigued

[skorpioskorpio]

MSD in their infinite wisdom made that LS unit completely non-configurable including number of cylinders, basically it can do a V8 with a 24X or 58X trigger (2 different models BTW, it's either 24X or 58X not one unit that does both). It fires 2 cyl TDC every 90 degrees, period. So I guess you could use it for a 4 cyl as well just don't hook up half the coils, but not a 6 which would need to fire 2 cyl every 120 degrees.

Yea the guy in Barstow, CA that does the Northstar stuff is the only guy and he's very very expensive. Just what it takes to do a serpentine setup in a rear wheel drive configuration Northstar will run $4-5000, and if you are using the prefered FWD engines, you have to have that to do anything. You need not only the pulley and mounts but a whole new custom billet front cover and a few other engine front pieces. It gets real expensive real fast.

The guy who did that 'Busa ITBed Northstar engine setup was willing to do more but you supplied the throttle bodies and it was whenever he got around to it. It wasn't terribly expensive but wasn't exactly off the shelf either. Kinsler did an ITB Northstar setup as well, not cheap.

I'm not sure the GSXR ITBs would work well on the Atlas, the Atlas is around 700cc per cylinder, vs the Northstar which is 575cc. I think all the GSXR ITBs taper down, and I'm not sure any of them are much larger than 40 or 42 mm on the small end. Mine are 45mm and I had a lot of people telling me to go to 50mm, though my feeling on this is a Jag engine with a really close bore and stroke combination making around the same HP with Weber carbs would use 45mm DCOEs (with 38-40mm venturi chokes).

In the end ITBs are really a stupidly simple thing and reality is that if you left the injectors in the head (which makes manifold design really tricky) OR you put the injectors in the manifold, you could just use regular Webers with the passeges plugged as ITBs. It's just a tube and a butterfly and sometimes an idle air bypass, but not always.

[watahyahknow]

i think you need to look at the rpms as whell those bua engines scream at about 10000 rpm while a atlas gets to about 6000

[skorpioskorpio]

The Atlas hits it's undesireable harmonics around 65-6700 rpm, it is rev limited to 6300. However there are available harmonic balancers to move that all up 1000 rpms. Bi-metal balancers can make these engines free of destructive harmonics well into the 8000 rpm range. There are guys racing them that routinely and intentionally push them past the harmonics and into the 9000 rpm range and unintentionally past 10K.

Remember that straight sixes have impecable balance and it is the length of the crankshaft and the resonance frequencies that are the problem not the rotating balance. If a 6 never stays at the rpms of these frequencies for any period of time they are not self destructive. The rotating assembly of the Atlas is very capable of very high rpm operation the valve train doesn't float until past 10K, though I don't know how long and sustained I'd want to push a long timing chain.

The Atlas crank is designed without a keyway for the balancer so to add a high rpm capable balancer the crank needs to be removed and notched for a keyway.

[watahyahknow]

hmmmm interesting , i had seen a few youtube clips with windowed L6 blocks that had spit out a rod , turns out it makes it verry hard to get the block out withouth the trans and the mecanic opted to lift the whole body off of the chassis

didnt known it was because of the harmonics , my guess is they downshifted manually downhill and got intoo that 6500 range hitting and passing the limiter

how bout one of those rattler ballancers or a fluiddampr these should work verry whell for that sortah stuff
not sure if the taper and general size of the snout would be the same as an internally balanced small or bigblock , that might make the choice of balancers a bit better

as for the long chain , it depends how whell the tensioner and sliders are at both ends of the chain it prolly will slap around a bit at that rpm
think the best solution would be to replace it with a beltdrive
might be that the chain is actually causing the harmonics in the first place

[skorpioskorpio]

Well , lots of things will cause things to go through the side of a block, snapped timing chain is one of them, a rod that can't take the stress of the transition from push to pull. It's usually a rod or something in the valve train. But yea, a down shift too high in the RPMs can cause things to break.

Apparently one of these engines running an ATI super damper at Bonneville and it appears it simply melted apart (The ATI dampers are an inner and outer piece held together with large O-rings).

http://vortec4200.com/forum1/viewtopic.php?f=13&t=1020

One of the guys on the Vortec 4200 board (the above thread) had some dampers made up to cancel out all the harmonics to 7600 rpm. Looks like a nice piece, but $600 + dropping and machining crank + new bearings + new cap bolts since the 4200 is all torque to yeild and I'll be running a close ratio 6 speed so I don't know that I'll need the RPM range really.

A damper on a straight 6 isn't the same as an external balancer on a V6 or V8, it's intended to stop the rock. Inline 4s and flat crank V8s have the rock pretty bad, it has to do with the 2 center pistons up when the 2 outer are down, this creates an expotential moment and at the right RPM will travel throught the crank and and bounce back at the end it will increase the frequency each time it gets transmited through the piece. Ever drive I10 through Louisianna across that bridge in the swamp that goes on for miles and miles? I did, many times in a lifted Suburban, and at about 78 MPH you hit an expotential moment frequency and if you don't change your speed the truck starts to litterally jump off the pavement because the sag between pylons creates one of those frequency events. It takes maybe 5 miles or more, you give up on cruise control pretty fast. Anyway point is that this also happens in a straight 6 but to a lesser degree, firing order makes it the same sort of thing 1&6 are up followed by 2&5 then 3&4. Most V8s do not do this because they run an out of balance cross crank which kind of randomizes things, but limits the the overall RPM potential of the engine and adds a lot of weight in counter balances to the crank.

Even firing engines with odd numbers of cylinders per bank have issues that can only really be cured with counter rotating balance shafts. So singles, triples, inline 5s and any V with an odd number of cylinders per side and V angles that make them fire the same number of degees from each other. Just so you know only 60 degree, 120 and flat sixes for example naturally fire evenly if they are sharing a common crank pin. All 90 degree V6s either fire in a 150-90-150-90-150-90 degree pattern OR use crank pins offset 15 degrees forward or back from center on the same throw.

Belt drive would be tricky, it's not so easy to make the crank to cam chain area dry on this engine, you'd be back to all new billet engine front.

Hmm, maybe this is all too geeky, but I guess it points out why I find push rod engines kinda boring.

But just remember, if you've ever heard a story about an engine that ran so smooth you could balance a nickel on the valve cover with the engine running, the story probably referred to either an inline 6 or a V12.

[watahyahknow]

seen that trick done on a toyota v12 the guy shoehorned that motor (made for a limosine only sold in azia ) in an is200
https://www.youtube.com/watch?v=6bg2p8dK3jY

[skorpioskorpio]

Yea, but that's not some cranked out American Nickel, that's a German Euro, which everyone knows are individually milled and balanced, try that with a Spanish Euro .

[watahyahknow]

eheh heh heh , wat about the greek euro there so crooked they dont even lay down flat

[Wasted Income]

Originally Posted by skorpioskorpio

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.

It's not too late to cut-bait on that I6.

Here is your 4v DOHC American made engine for your project.

If you're gonna be different....BE DIFFERENT

Did I mention it makes 1650 hp?

http://www.enginelabs.com/news/mercu...50-horsepower/

[watahyahknow]

just had a cargeekasm

[skorpioskorpio]

LOL, I'm bettin' that engine cost a bit more than my engine budget, matter of fact I'm betting I could buy a certified pre-owned V-12 Astin-Martin, throw away the car and be cheaper. That looks like Ryan Falconeer kind of cash.

[truckeez]

Originally Posted by skorpioskorpio

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.

The nv3550 5 speed stick from a h3 hummer works i hear, pretty hard to find one though. they got a removable bell-that bolts up to this orphaned inline 6
The old nv3500, -earlier ones have a rep of being fraile like the typical t5's, later versions had upgrades but they used the typical sbc / ls pattern in the chevy speak version.

My vison of granduer would be, if GM had never invested the capital to build this engine, but rather came out with a 6 cyl version of the 2.4 ecotec, the yank version (sorta) of the german opal 2.0 original , opal make's 1.8's even a 3 cyl whick are good for econobox's.

[watahyahknow]

there is actually a 3 liter 24 valve version straight 6 made of the older CIH opel engine called the C30SE that was fitted in the omega
https://www.youtube.com/watch?v=A0HtdtOUG5o
those where available with manual gearboxes as they where made for DTM racing

seen a 2004 subaru legacy 6 speed transmission a while back that had the starter comming in from the gearbox side intoo the bellhousing ,

said to be good up to 450Kw
thinking about that it would solve some of the problems if they would make a belhousing that would fit a strong enough box and mount the starter in the bellhouse itself under the transmissiontunnel instead of against the motor

[skorpioskorpio]

For transmission I'm doing a paddle shifted 6 speed 4L80E. Going to mill off the bellhousing and do an adapter plate on the pump to mount the 4L65E Bellhousing.

[watahyahknow]

you mean a case saver bellhouse like they used on the older th350 400's and powrglides
https://www.youtube.com/watch?v=HL93XAc4MGs
oh hang on adapterplate to the pump then stock 4l60e belhousing , forgot those are split cases