UltraVan 436

UltraVan 436 Blog-ish story of our purchase of UltraVan 436 and all the trials and tribulations getting it to the road.

Merry Christmas all!
12/24/2023

Merry Christmas all!

Seven years and a month in.. yikes. But a 70 degree day in November doesn't come often, and "free time" even less. Up go...
11/12/2022

Seven years and a month in.. yikes. But a 70 degree day in November doesn't come often, and "free time" even less. Up go the garage doors and back on the welding of the subframe. So.. all cross members are fully welded, corner trusses were added just because. Welds aren't pretty (well.. pretty ropy) but they'll hold. And the integrity of the frame was tested as I took the coach off the jack stands I had it on to get everything level. Rear stands came off no problem; front stands.. released one and the corner barely drooped. A good sign! Release the other stand and let the coach back to the lift.... and heard a sound I don't want to hear again: the engine that was carefully balanced on a lift table toppled - from 4' in the air. Engine and transmission wound up somehow perched transmission end up on the bumper of my truck. Obvious damage to an idler pulley mount and the crank pulley - won't know any more until I try to crank the engine over. I'm hoping that is the extent. Defeated for the day... I'll get back I'm there another weekend.

09/08/2022

Sorry for the lack of updates. Between weather, work and life, that's just how it goes! I'll be back on it soon!

07/24/2022

Been a while since a post - I'll get there! Been way too hot to work in the garage :-)

Cooling the Beast....Radiators will be a big concern with a rear engine setup. Not only getting enough air to flow throu...
07/05/2022

Cooling the Beast....

Radiators will be a big concern with a rear engine setup. Not only getting enough air to flow through them, but having enough radiator for the engine. I had a couple custom rads fabricated to fit between the floor ribs at the front. With a pair of high CFM fans and a fully enclosed .. uh.. enclosure, I'm hoping these will be enough. They aren't quite the full square inch coverage of what the donor car is/was, so I think I'm going to need to add a third radiator somewhere towards the rear. Thankfully there are multiple open compartments that can be utilized for that.. getting airflow into those compartments will be a challenge to be met!

In between all this foolishness gathering suspension parts, the front end needed attention with the fab work. I employed...
07/05/2022

In between all this foolishness gathering suspension parts, the front end needed attention with the fab work. I employed a local auto body shop that I work with from time to time to repair the fiberglass quarter panel. Some of my crunched one was salvageable, and I had bought another piece from another wrecked coach to graft on. The shop did an admirable job with the repair. It's a bit thick, but that can be ground down where needed. underneath that are repaired/remade ribs and struts for the body panel supports. They're not perfect, but they'll work. I'm not 100% happy with the windshield support, so I have a replacement section to graft back into that spot. Luckily, it's only aluminum and some rivets!

So, in an effort to get this page into the current state of build, I have to keep going with the backstory :-) . Now tha...
07/03/2022

So, in an effort to get this page into the current state of build, I have to keep going with the backstory :-) . Now that the drivetrain has been decided, it was time to look into upgrading the suspension components. Stock rear suspension is (almost) all Corvair - trailing arms, big springs with spring perches welded to the trailing arms, and 1" threaded rod for the upper supports and alignment adjustment. Stock Corvair drive axles connect to the Corvair Powerglide, which make the rear track about 3" less than the front track.. it's very odd putting it on a lift, having the rear tires centered on the rails, but the front tires are off the outside edges on both sides (yes, adjustments were made on the lift runways to accommodate that). It (the suspension) works, but it's comically bad. What makes it worse is the Corvair wheel bearings were never engineered to handle the weight. There is a manual that covers everything UltraVan that was written back in the day - sort of an Owner's Manual - and it was suggested to remove and repack those bearings before every trip. Uh, yeah, no, I won't be doing that.
The front suspension isn't quite as bad - it has a cast aluminum lower control arm which is massive (very well made, but very long from mount to tie-rod end), and those threaded rods forming the upper A-arm. Did I mention drum brakes all around?

A common upgrade to the front suspension is to install Nova/Chevelle/Chevy II disc brake kits - pretty much a bolt on affair. Not so much for the rear without a little work. But, one is still checking those bearings more often than is practical if the coach is going to be used as a coach.

So... my brain, as scarce as it is, went to: if I'm using Corvette components... why not use all Corvette components, from the suspension to the wheel hubs. Mid year C5 Corvettes weigh in at around 3200 pounds.. dry weight of a typical Ultra is right around that number (stock). Wet weight will add an additional 1000 pounds easily, so I'm hoping that Chevrolet engineered their suspension pieces well. I'm figuring if people track day their Corvettes, the suspension is under far more stress than simply adding some weight and sending it wallowing down the road. I could be very wrong.... it's all in the testing :-)

To support said suspension (which, by the way, comes on it's own subframes front and rear), a company called Dobbertin Performance sells beautifully engineered adapters to install C5/C6 Corvette suspensions on any hot rod that uses frame rails. And yes, it's the same Dobbertin that built the world famous Dobbertin Surface Orbiter - the first and only amphibious vehicle to travel 28 countries and 38 states (https://rick486.wixsite.com)./dobbertinperformance/about-us). I think Rick Dobbertin knows his stuff!
So... rear adapters were ordered and here. I'll be ordering the front adapter set in a little while. They're salty, but take all the guesswork out of setting up the suspension geometry. And... all it takes is a 2x4 frame member to hang them from, so that is part of the equation with the upcoming updates :-)

And now that everything is out - no engine, transmission or interior (or wiring), it had been decided when I was strippi...
06/29/2022

And now that everything is out - no engine, transmission or interior (or wiring), it had been decided when I was stripping everything that this coach would be brought as up to date as I could feasibly do in terms of suspension, engine, transmission, wiring etc.. Too many club members were having engine failures with their Corvair powertrains, and I wasn't going to deal with the antiquated way the suspension was set up. Having an initial idea in mind of what I wanted to do, things went sideways fast. My research into a drivetrain kept pushing me to torque over horsepower - not that this vehicle is heavy, but it's a brick in the wind. I chose a supercharged 3.8L Buick engine - a Series II engine from a 2002 LeSabre (I think), complete with custom aluminum heads. Horsepower should be right around 240 with 280 lb/ft of torque - starting around 1200rpm. Perfect for a breadbox. Weight.. eh.. a little heavy for my taste (hence trying to shave some with aluminum heads). I can hear the cry's - Why not an LS??? well, because, the LS was still a hundred pounds or more heavier, as well as longer with the extra 2 cylinders. I didn't want that weight hanging that far to the rear - I need to build a subframe to hold everything, and that would be extra stress on the aluminum.
To move the power.. something another club member was contemplating but I think I beat him to the punch - a 4L65E transmission. Common as bread and used in 1000's of Gm vehicles up to and including their light trucks (1500 series). But I needed a differential - and didn't have the space for a traditional driveshaft and pumpkin. The 4L60 was also used in C5 Corvettes (this has direction later) - the transmission was at the rear of the car to help the weight balance.. With that "Aha!" moment, I located a used Corvette differential for a test. I'm still going with the traditional rear engine layout - engine at rear, transmission pointing towards the front - which meant any differential would need to spin "backwards" or.... be mounted upside down. And as fate would have it.. the Vette differential mounts beautifully upside down. A few modifications had to be made for the internal oiling and drain/fill locations, but otherwise it bolts right into place. Almost. It has two bolts that miss mounting holes, but with a cradle to hold it in place... no problem at all. I had the internal gear changed to something a little more suitable for a slower moving vehicle (hopefully!).

I can hear the other cry's now: Why not use the 3800 in a front wheel drive conversion, using the entire FWD subframe and suspension and transmission? Great question! And here's the reason - the torque convertor. A FWD transmission has a small torque converter. I can't think what the size is off the top of my head, but let's say 9". On a traditional rear wheel drive that same converter would be around 12". And the difference between the two is the stress they can handle in terms of moving heavy (or windloaded) vehicles - I worked with a very well known transmission shop and explained what I was doing (and they really want to see the finished coach) and it was strongly suggested to go with the largest converter I could fit, which meant a RWD transmission bellhousing. Which also means an additional transmission oil cooler just to be on the safe side.

It's getting complex under here!

06/29/2022

You notice in the previous post about the rear door that there is a mysterious lack of bumper that was there previously. Yeah, that's also gone. Those "bumpers" were basically pool noodles fiberglassed to the body, and both front and rear were pretty well dinged up. I have to do a little research into what is "needed" for inspection.. technically they were a factory option; I'd like to see a set of T-bumpers front and rear even if they didn't protect a damn thing!

Since I figured I'd be doing some metalwork up front, I would "practice" with something almost impossibly difficult on t...
06/29/2022

Since I figured I'd be doing some metalwork up front, I would "practice" with something almost impossibly difficult on the rear. These coaches always had a solid rear window and a small access hatch in the rear, which basically was an "escape" hatch at the back and a way to load gear in the storage bay under the bed and over the engine. Of course, I couldn't let that stand... if we wanted an escape hatch - I wanted one that opened full length. I'm not that spry! So, some grinding to remove rivets along two vertical ribs that supported the window and the hatch lid revealed that yeah, you could build a door here. But not just any door of course - one has to have ventilation. A quick eBay search netted me a cheap RV window with a casement section and screening, and tinted to boot. A couple of weeks on and off fiddling with angles (it actually tapers towards the top... measure twice, and still cuss when it doesn't work), riveting, re-riveting and figuring out how to mount a flat window in a curved surface (make an eyebrow ledge - pushes the rain away from the window, gives you the mounting area you need!), and a new rear door is born. Gasket material isn't installed yet - still some fine tuning to do.

Moving to the outside, I removed the damaged fiberglass cap and all the bent aluminum panels - all buck riveted in place...
06/29/2022

Moving to the outside, I removed the damaged fiberglass cap and all the bent aluminum panels - all buck riveted in place. Another club member had a portion of that fiberglass panel that he sold to me so that I could cut and patch ours.. Since I hate fiberglassing, I sent those pieces to a local bodyshop to be married. In the meantime, I was full bore on trying to remake some of the ribbing and windshield supports. Sorta successful.. But I did purchase some used pieces from another club member that's going full custom on his coach and had some spares - I will cut those in at a later date. I'm not totally happy with some of my repair work.

Let's see... where did we leave off? Oh yes, stripping the interior and taking stock. Well... yeah, all the panels are o...
06/29/2022

Let's see... where did we leave off? Oh yes, stripping the interior and taking stock. Well... yeah, all the panels are off the interior, insulation is gutted and tossed (I think 10 trash bags worth), rug (gag) gone... all that's left is the ribs and plywood floor that's over the 3 containment tanks - gas/water/blackwater. Plywood in the "bedroom" is tossed; plywood in the main area is staying for the moment to provide at least a modicum of support with the tanks in place. Up on the lift, we get to see more goodness: the "jacking points" on the coach. Understand, these vehicles are sort of based on an aircraft design - there is no frame like a truck would have. So, to get some lateral support and to provide anchor points for the front and rear suspension, box beams were built from aluminum sheet (aircraft grade, as is the rest of the coach), and riveted (the "right" way - bucked into place) to form 5" tensile beams that span across the coach. Great idea - if the aluminum doesn't get bent. Unfortunately, I don't think the engineers back in the '60's who worked on these understood that once aluminum is bent, it loses quite a bit of it's tensile strength. A formed bend - one that's been in a press or flanged - is a different story. But a soft bend.. no, that's no good. And that's what we have here. Owners manuals suggest to place a piece of wood at each corner when need to be jacked to change a tire - obviously the previous owners didn't do this and mangled all four corners. This will come back to haunt me later....

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Downingtown, PA

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