I've been reading and researching the stickies and build threads here, and over at TOS, for quite a while now. I'm adding this info here to give more details about this rail, possible engine and suspension mods, my goals and planned use and limitations. I originally made this post on TOS to answer questions about my rail so I could get educated guesses/replies about my engine upgrade questions. I was thinking about sticking the mostly stock T3 engine (single oil valve case) in the rail and then rebuilding the T1 engine (dual oil valve case) as a 2180.
Use and Location
I live in the mountains of Montana at about 5K feet above sea level. Driving through some of the passes around here I can easily get well over 7K feet above sea level. The 4.0l V6 in my small pickup feels like a 2.3l 4 cylinder at these altitudes. Whatever I do, I'll eventually end up having to deal with that issue one way or another. Either by making the engine larger (ie: the 2180 I'm thinking of) or by adding a forced induction system (turbo) to compensate for the thinner air up here. I'm leaning towards the 2180 since to go that route I'll have to tear the engine all the way down to install the stroker crank and I'll have a basically brand new engine when done. No mysteries of the PO to come back and haunt me later. I've had to deal with enough of that junk already
. As far as my intended use for the rail, I'll be using it probably 80-90% as a daily driver and the rest of the time as a light off road use vehicle. Camping, dirt roads, exploring some of the mountain trails and ghost towns around here, stuff like that. No high speed wide open desert runs for me any more. My doctor, my wife and my back all put the veto on those type of activities for me anymore. I do kind of miss it every now and then, and then my right foot eventually gets a little bit heavier and heavier. That is until I hit that first big pot hole or washboard and the pain shockwave travels up my spine to kick the a$$ in my brain and tells me to reel it back in. Ah well, it was fun while it lasted.
Tires and Suspension
I'm happy with my current tire sizes (31-9.5x15's out back and 7.00x15's up front) so I'll be sticking with them for the foreseeable future. The suspension will stay fairly stock as far as geometry goes, but I may update some of the stock pieces with heavier duty ones. My rear trailing arms may be bent (have to measure them to be sure) so I might replace them with some after market arms. Probably 2.5x2.5's of some sort. The longer and wider arms will help with stability and reduce the need for high angle CVs. On the front axle I am thing of getting a conversion beam from Bugzilla. That will allow me to mount it in the same place as the (bent) BJ beam I have now, but let me use the more common king/link arms on it. Parts availability for the king/link setup is the main reason for this. The beam I get will probably end up being about 6" wider to match up with the wider rear. The wider beam should also help fix the tire scrub I'm getting after swapping to the taller front tires. I'll be sticking with stock torsion leaves and bars for a while. Coilovers may be an option much later on, but stock is fine for now.
Weight
Until it's done it's anybody's guess really. I'm planning on building a Beeline Pack Rat frame and setting it up to be a full bodied (fg or aluminum body) street legal vehicle. As a ball park guess I'd say it will be somewhere between 1500 to 2000lbs. I know that's a wide margin to work with, but until I have more of the pieces firmly sorted out there's too many variables to narrow it down any further.
HP (wants and needs)
I like HP but don't want to go much over 100 HP (150 tops) so I don't have issues with the reliability of the power plant and grenading transaxles as a result. If I ever get away from the ACVW power plant sometime down the road, I have a few other options available to me. Either a Corvair (I have a freshly rebuilt one sitting under my workbench in wraps) or a '90-94 Subaru EJ20 (22?), either one would most likely be kept NA for cost and simplicity. Either way, I'm looking at a self imposed upper limit of about 150hp. EJ25's are around as well but they cost more, have OBD2 and are interference engines. Boomskis are a lot more expensive if you snap or jump a timing belt on the EJ25 engines. My thoughts are that I should be able to build an ACVW up to about that HP range since I'll want to have a transaxle in the rail that can take at least that much HP. I'm not after numbers so much as having enough to play with but not so much to be more likely to compromise reliability. I think I'd be happy with anywhere between 100 to 150 HP out of whatever I build. With those thoughts in mind, I'm leaning towards either building a new Rhino case with the strengthening mods or getting an 091 and stuffing it into the new frame as I build it. I'd like 930 CV's but I don't really want to pay for them. Since I'm not going for long travel suspension, I think Type 2 CV's would be a better solution in my case. Given that I don't have a gigantic stockpile of spare VW parts to draw from, either trans option is going to add significant cost to the project. That may slow down or set back the new frame I want to build to replace my current twisted one.
Torque (my favorite engine subject 
)
Closely related to HP, but often not given the attention it deserves. As you may have guessed by my username, I'd been working on big block Mopars for quite a while. I got out of them mostly because the money I was dumping into them was getting stupid expensive. When I retired from the military that also ended almost all of my discretionary income for the big buck toys. With my back messed up my job prospects were looking from slim to grim, unless I wanted to be a greeter at wally world. Rolling Eyes No thanks. Sorry, got off track there for a bit... Anyway, I like torque. I want that stump pulling torque. Pulling the house off it's foundation torque. Stuff like that. I like the feeling of being pinned back in my seat when I mash the skinny pedal on the right. But I know all too well that you got to pay to play. This is one place I want to set a goal for the engine that is based solely on my personal desires. I can't lie about that to you guys, or to myself. If I did I'd always be regretting it. Torque. Gotta have it in whatever I do for, or to, the rail engine. Enuf said.
RPM's and MPG's
Simply put, I'd like to get better MPG's than my current DD gets now, which is about 20-21 MPG. I would think that shouldn't be too hard to do, even for a bored and stroked ACVW. For RPM's I want to have the engine turning optimum cooling RPMs (?) at highway cruising speed (70-80MPH). I don't know how much having a completely open rail and trimmed tins will effect the proper cooling RPMs. The ring and pinion I have in the T3 SA trans should be 4.12:1 IIRC. I'm not sure what R/P ratio is in the T1 IRS trans axle that's in the rail right now. I'll want whichever R/P ratio will work best with the 31's to meet these goals, even if I have to find a different ratio elsewhere.
Carbs (Dual or Single)
My current plan is to use the short T3 intakes and a pair of Solex 34PICT-3's. This is still not set in stone though because I see the merits of both single and dual carb setups. Single is easier to setup with half the parts, but requires heat to keep the fuel in suspension and keep the carb from icing up. Carb icing can be a big problem around here given the cold temps and high altitudes I'll be driving in. Duals have the potential for more power if the engine can utilize it, but is more difficult to setup. Duals also warm up quicker being directly over the heads which is a big plus for me. Carb icing is probably the biggest reason for wanting to go with duals over a single carb. I've read good and bad stuff about EMPI products in general, but there seems to be a good track record for the HPMX carbs they are putting out now. Wimpy dual linkage and filter mounting setups being the most common negatives I've come across. Those are both external to the carbs though so they don't bother me so much. I'll probably just make up my own solution for a linkage when it comes down to it. It's cheaper for me that way and I get to play on the mill and lathe and express my creativity to solve those problems. To me that kind of stuff is actually quite fun to do.
Heads
Here I'm on the fence with not too much direct knowledge to go on. I know that I'd like to keep the valve sizes reasonably small since I'm not trying to build a upper RPM drag engine here. Smaller valves, all other things being equal, have been proven to maintain that low end torque at the cost of upper RPM HP. That's fine with me as long as I can cruise on the highway (70-80 MPH around here) and not be absolutely topped out when I get there. I'm trying to find the right balance here to make the whole engine package happy to work together.
Cam
This is probably the place I need the most help figuring out. I hope I've given enough details about the rail and it's intended use here to give enough data for someone to help me come up with a few options to choose from. Right now there is just way too many options for me to figure out without some help. If I ask a vendor I'm sure whatever they're selling is what they'll try to steer me towards. Not necessarily what is the best option for my application.
Induction (N/A, EFI or Turbo)
The altitude is the is the key factor here. EFI would be nice up here, but I'd like to keep it simpler than that if possible. I don't have any EFI parts so I'd be starting from scratch there. Once the rail is jetted properly for my altitude, I'm willing to live within the limitations of that jetting setup. Turbo would be the easy power path, but I'd want to know the condition of the engine before just strapping one on and crossing my fingers. I figure if I'm going to have to build the engine anyway, I may as well go big when I do. That way I can get the added torque that comes from a bigger cc engine.
Pistons and Cylinders
I'm not locked into this engine size (2180) for any real reason, other than the fact that it's big enough to offer added torque over a smaller engine. I've read in a number of different places that thick walled cylinders were the way to go for long term reliability so that's what I'm leaning towards using. If they have the potential to cause problems I don't mind stepping down to a true 92mm setup or something similar.
Exhaust
Similar to the heads and valves, bigger isn't always necessarily better. I already have a plain EMPI 1&1/2" 4 into 1 stinger that came with the rail when I got it. The stinger was bent so I got a new bolt on mid-pipe and added a glass pack muffler to it. The entire exhaust will be sand blasted and then I'll Cerokote it once that's done. That stuff is
very durable so it should last me a long while. I already have a few colors of Cerokote on hand, so that's one thing I won't have to buy.
....point is, you're going to want a wide torque band for your usage (especially since the gearing will probably be less-than-ideal) even if it means sacrificing 15-20 peak HP. It's a whole lot easier to live with a cam that's a little too small than one that's too big, so choose conservatively. Many 1.1:1 grinds will tolerate 1.25:1 or even 1.4:1 rockers, too, making it fairly easy to step it up a little down the road if necessary.
