1972 Winnebago Brave - Seattle or Bust!

Started by BigAlsVehicleEmporium, April 14, 2023, 08:24 AM

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BigAlsVehicleEmporium

To complete my cooling system rebuild I wanted to replace the thermostat, thermostat gasket, water pump gasket, upper & lower radiator hoses, fan clutch, water pump belts, radiator caps, heater hose, and heater control valve. I also read about the horrors of having your radiator's internal transmission cooler start leaking and the bad news that happens when coolant begins to flow into your transmission. Because of that, I wanted to bypass the internal cooler and come up with an external cooler solution. Also, while I had the whole front pulled off, I decided it would be as good a time as any to replace the motor mounts - pancaked flat due to five decades of carrying this big block over countless potholes.

I only found one place online that makes the wide 2 1/2" flange skirted thermostat that our rigs require (here). Considering the solid gold plated radiator I'd just approved, I looked for NOS thermostats on eBay to save a little money. For less than the price of one new one, I ordered three NOS thermostats: Robert Shaw 370-195, Stant S-370-XH, and Mopar 3514181. I tested all three simultaneously by suspending them in a pot of water and bringing it to boil. They all opened between 195 F - 198 F, though the Robert Shaw one opened exactly at 195F and seemed to open further than the others. I decided to go with that one and save the Mopar unit as a spare. If anyone needs a thermostat, let me know and the Stant model is yours for the cost of shipping.



I couldn't find any hits on the Mopar # 1679148 five bolt water pump gasket. Eventually, I found the gasket on eBay for $25 from the same people who sell the $400 remanufactured pump. They list it as Mopar # 2846037. At that price, I decided to save the original they sent and cut a new one from Fel-Pro # water gasket material using the eBay gasket as a template. My girlfriend (user Winnebaby if it wasn't obvious  :laugh: ) kindly stepped in to cut the new gasket as she is much, much better at it than I am. The new, blue gasket came out perfectly!

The lower radiator hose proved to be the most difficult to locate, as a replacement is not manufactured. I found many posts on this site looking for a replacement but one was never identified. I poked around on the Gates website and looked for hoses with the right 2.5" ID and a sharp right angle. I came up with several possibilities and ordered the two most likely candidates from O'Reilly's. To my surprise, one of them fit perfectly with a little trimming! Gates 20987. Now we finally have a currently made replacement part for the '72 413 lower rad hose! To be fair, the original radiator hose seemed in surprisingly good shape and has the thickest wall of any radiator hose I've ever seen. I set it aside to put in the spare parts box.

The upper hose was easy, as someone had already replaced mine in the past with a NAPA 7658 hose that they'd trimmed to fit. I re-ordered that hose and it worked.

Fan clutches apparently come in several different types: Standard Duty, Heavy Duty, and Sever Duty. After spending way to much time figuring out the differences, I used the Hayden Heavy Duty model as that appeared to have a stronger engagement and a more complete disengagement due to an external thermostatic spring, while not being too gigantic or aggressive. While the Heavy Duty model was longer than the existing fan clutch, it was still comfortably far from the radiator fins once installed. I'm hopeful that it will aid in stop and go traffic and save gas on the highway.

Gates listed a couple of different length possibilities for the fan belts: 56.25", 57.25" and 58.25". The one that was on there was 56" long and the alternator was almost out of tension adjustment, so I went with a 55 1/4" version of the same belt. It turned out to be the right size - once installed and properly tightened, the alternator adjusting bolt was right in the middle of the slot. However, the pulley on my alternator is clearly made for a narrower belt, with a narrower spacing between pulley grooves so the belts rode high and are not in perfect alignment with the crank and water pump pulleys.

It took quite a while, but I finally found all the parts that I needed. Below are the part numbers that I went with:


PartMopar #Replacement #
Upper Radiator Hose    2959567NAPA 7658Gates 20933
Lower Radiator Hose2959568Gates 20987
Thermostat (195F)3514181Robert-Shaw 370-195Stant S-370-XH
Thermostat Gasket3830016Fel-pro 35063
Water Pump3420225 (repair kit 3420226)    N/A
Water Pump Gasket1679148Mopar # 2846037
Radiator Cap (7 psi)2516443Stant 10328Murray 7007
Heater Control ValveN/AMurray 277814
Fan Clutch3462182Hayden 2747
Fan Belts3633494Gates 9550HD (55 1/4")    Gates 9560HD (56 1/4")   
Power Steering Belt2532786Gates 9480HD
Motor Mount2264675Napa BK 6021115

While I was in there, I painted the front of the engine and all of the easily accessible frame and support metal. I used Dupli-color engine primer, DE1619 Chrysler Green, and DE1635 black engine paint. I think it came out looking good!
Before:




After:

1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

BigAlsVehicleEmporium

While I had the radiator out and easy access, I replaced the chewed and rotten piece of screen that served as a cabin air filter with a combination of fine and course filter material meant for window A/C units that I picked up at Home Depot.



After all the paint had dried and parts had finished trickling in, I reassembled my cooling system and filled it with coolant. The petcock on top of the water pump made bleeding the system easy - I wish more vehicles had that.



As I posted on LJ-TJ's topic on transmission coolers, after getting my radiator re-cored, I decided to not use the internal cooler. Since the rest of it was so bad, I didn't trust it to not leak coolant into the transmission and ruin it. I plugged the two 1/8" NPT ports in my radiator and ran a completely external cooler.



I went with a TRU-COOL MAX LPD4739-1 cooler as it was large, wide, and short. I wanted a good sized cooler, about the same width as the radiator, that wouldn't take up the whole height and rob too much cooling capacity from the engine. I paired it with a Derale 25011 oil thermostat to speed up transmission warmup times and keep it from running too cool in colder weather. This oil thermostat runs in bypass until the ATF gets to 180 degrees and then it flows through the cooler. The transmission cooler has 3/8" inverted flare fittings and the oil thermostat has 3/8" NPT fittings, so some adapters were required to interface with the original 1/8" NPT cooler hoses.

At this point it was Friday, the day we were supposed to leave for Gatlinburg/Pigeon Forge! I fired it up and had Winnebaby checking for leaks. Several tightened or replaced hose clamps later all the leaks were gone and it was purring like a kitten! We loaded up and got on the road to Gatlinburg. We had a restaurant reservation for the Oyster Bar in Gatlinburg at the latest possible time of 10:45 PM and expected ETA was 10:35 PM. With one stop early on to temp the transmission (bang on 180F!) and other parts with an IR thermometer we hit US 441 through the Great Smoky Mountain National Park with an expected ETA of 10:50. Figuring this would be the perfect, responsible way to do a shakedown test of the new cooling system, I kept the pedal to the floor for most of the the climb to the top of the pass, before coasting down into Gaitlinburg on the other side. The needle stayed rock steady at the half way mark for the whole trip! After squeezing through an all-to-narrow paid parking gate, we made it to our reservation on time! No oysters ever tasted as good.

The next morning, a trip to Dollywood followed by a trip to the Pirate's Voyage Dinner Show rounded out our Pigeon Forge experience and we headed to Maggie Valley to meet friends. Winnie ran great the rest of the weekend and we had a blast! The only wrinkle was the exhaust leak at the driver's side manifold that started to develop on the last day. By the time we got back to Atlanta it was LOUD. The great thing about this RV is I'm never unsure about what I need to work on next - Winnie always lets me know  :laugh:

1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

BigAlsVehicleEmporium

Reading up on Dodge big block exhaust leaks I found two things - 1) the exhaust manifold is always warped and 2) the copper gaskets are the gold standard for sealing and not blowing out 500 - 2k miles down the road. Original Mopar aluminum fiber gasket p/n is 1859761. Fel-pro replacement p/n: MS9705B. The copper gaskets for these industrial 413 V8s are SCE 4264. Summit had three pairs of them in stock so, never optimistic that I"m only going to have to do this once, I bought two pairs. I also ordered a few of the 4 bolt exhaust pipe flange gaskets, Mahle brand from RockAuto. Mopar p/n: 1924887. Fel-pro p/n: 9269. Mahle p/n: F7153.

While I waited on parts to come in for the exhaust manifold, I decided to try and get the windshields replaced. The driver's side was foggy around the edges and the passenger side one was spiderwebbed with cracks. I only found one shop that would cut the flat glass and install it for a reasonable price. Brian Diamond Glass in Austell (678-309-3377) charged $450 to cut both 18" x 42" panes of AS-1 glass and install them, re-using the original rubber gasket that was in good shape. They came out looking great!

Here's how bad the original looked:



The new one looks just like that, except the glass isn't cracked or faded and is perfectly clear  :laugh:

Surprisingly, all seven manifold bolts came out without a bit of complaint. It was clear from the anti-seize on the threads that someone had been in there before and bless them for it! An hour's work with a fairly straight aluminum level and a large flat file left me feeling good about the flatness of the manifold. The manual specs 0.008" warp per foot of manifold and I was less than 0.007" in the middle compared to the ends.




I bought new black-oxide grade 8 bolts with a satisfying flange and tall hex head and installed the manifold with the copper gasket. As I was tightening it down, it became apparent that the two strips of metal that connect the middle ports to the outer ones were hitting the spark plugs and would cause the gasket to stretch or crack the insulators if I continued tightening the bolts. Since those strips serve no purpose other than keeping the gasket together so it can be assembled in one piece, I snaked a pair of tin snips in there and cut through them. Doing this again, I would cut through them before installing the gasket as snaking the snips in there was a really tough job.




The manual called for 40 ft-lbs of torque for the bolts but the gasket instructions called for 24 - 31 ft-lbs. I went with 24 ft-lbs to start with and it tightened up nicely. The manifold outlet nuts got the factory spec 40 ft-lbs.

Again, it was down to the wire. We had a camping reservation at Florence Marina that night so we could do the Tails on Trails hike with Winnebaby's corgi Zelda in Providence Canyon State Park the next morning. I fired it up and it sounded so much better, but sadly not perfect. Feeling around the ports I could feel exhaust coming from the rear of the #1 cylinder port. This was different from where it was leaking before, #3 & #5, so I figure that the copper gaskets are a little more sensitive and the front manifold port was likely warped. We got on the road and it was hardly noticeable!

The next day, before the Tails on Trails event, I torqued the manifold bolts to 28 ft-lbs figuring that it had been through a heat cycle and I was still shy of the grade 8 bolt's rated torque value of 35 ft-lbs. This seemed to help a little but the leak was still noticeable on the drive to Providence Canyon State Park. The park is beautiful by the way, and I recommend anyone passing through that area check it out!




That night we had ribeye steaks grilled over a camp grill wood fire. Winnebaby is impressively good at cooking over an unregulated open flame and the steaks & veggies came out great!



The next day I went all the way to 31 ft-lbs but noticed no change on the drive back to Atlanta. When we got back, I pulled the exhaust manifold again and found that I could slip a 0.007" feelter gauge on one side of the #1 port but not the other, so it was significantly warped. I took it to Cobra Engine in Austell and they resurfaced it using their belt sander for $40. I rechecked flatness when I got it back and could not get a 0.002" feeler gauge anywhere under the straight edge. I checked the installed depth of all the bolts in their holes without the manifold to make sure they were not bottoming out and all looked good. I added Grade 8 lock washers under each bolt head as well. I cut the middle strips out of the copper gaskets before installing them this time and that worked well.



After reinstalling everything and re-torquing a couple of times after a couple of heat cycles, the slight leak was still there. While the manifold is now flat, the head has significant corrosion/erosion damage around the leaking areas. If I was doing a rebuild, I'd get that area resurfaced, but I don't want to pull the head just to fix this. My next plan is to try doubling up two of the Fel-pro fiber-aluminum gaskets, on the assumption that they're more malleable and will fill the pitted surface on the head better. I'll report back how that goes.
1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

BigAlsVehicleEmporium

On the first trip we took, I found out that the horn button does nothing, when someone pulled out right in front of us and we locked the tires up to keep from hitting them. On each subsequent trip, it seemed like something like that happened in the first 20 miles without fail, so I decided the horn had to be fixed. One of the horns was missing and the other was dead, so I decided to locate some replacements. I"m a firm believer that a horn sound should suit the vehicle, so I wanted the throatiest option available. There were a number of fancy, expensive options online but I've seen so many horns in junkyards that I figured I could save a little money by going that route.

After a bit of research, I found out that many Cadillacs and Buicks from the '70s - '90s came with a four note horn system, with four different horns that supply A, C, D, and F notes. After watching this video showing how they sound, I knew I'd hit on the right combo.  I went down to the local U-Pull It yard and pulled two full sets - one from a '93 Cadillac Fleetwood and one from a '92 Buick Roadmaster. I tested them back at the house and only one out of the 8 was dead, so at $5 each, I consider that a bargain! I had purchased a new horn relay back when I first realized that the horn didn't work, so I used that as a 2nd horn relay to run the other pair of horns. I mounted a pair of horns facing down on each side of the radiator. I like how the install came out and am really pleased with the sound! Gives off satisfying train vibes.

1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

BigAlsVehicleEmporium

When I bought Winnie way back in February, the owner let me know that it needed a new bathroom roof vent because the cover for the old one was smashed. Clambering up on the roof, I found that the plastic frame was also cracked so I decided to replace the whole thing rather than try to find a cover that I could make work. I bought the MAXXAIR 0004500K fan back in March, but hadn't made enough progress with the automotive side of Winnie to justify spending time putting it in until now. After removing the 24 or so screws that held it in, it was time to try to remove all the old sealing material.



Sara and I set to work with paint scrapers and every caulk remover compound we could find. The caulk removers didn't seem to make a bit of difference, so I looked into other options. Ultimately, a combination of scraping, a rubber eraser wheel chucked up in a drill, and regular Goo-Gone (not their caulk remover flavor) on a rag got the remaining sealant off pretty easily.



The next step was to apply "a continuous bead" of butyl tape to the underside of the new vent flange. I was not prepared for how awful this stuff was to work with. It sticks to absolutely everything and stretches entirely too easily. Inconsistent thickness is one of the last things you want in a mechanical seal, but that's what I ended up with.



The astute observer will note that the rounded corners of the hole in the roof don't match the square corners of the new roof vent. I had to square up the corners of the roof hole using a sawzall to get the fan to fit.


 
It's advertised as working with a 2" minimum roof thickness but I didn't realize that my Winnebago roof is only 1" thick until I got the old fan pulled out. Setting the fan down in the opening, it seemed like it would work, so I figured that was Future Alan's problem. The twelve #8 stainless Phillips screws that came with the fan seemed like a poor solution. No inherent sealing and dabbing the heads with sealant would make removing the Phillips screws in the future an exercise in patience as all the sealant would need to be dug out of the head to fit a screwdriver. I picked up some #9 non-self drilling hex head screws with a sealing washer, for use installing tin roofs. I like the built in compression sealing feature of tin roof screws. I smeared a little bit of Dicor self-leveling roof sealant between the sealing washer and the head of the screw for extra protection, pre-drilled the holes through the aluminum roof, and drove them in. The fan's flange had many more bolt recesses than supplied screws and since my roof is a little weak, I figured I'd use as many as I could. I ended up attaching it with something like 26 screws. Finally, I ran a bead of Dicor sealant along the joint between the fan's flange and the roof. I'm pleased with how it came out!





Replacing the fan also fixed the short that was blowing fuses on that lighting circuit. Now, I have a new fan and more available lighting! The only downside is that on the way down, the lower ladder feet started to pull out of the wall. There's always a new project!


1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

RockwoodMike

It is hard to make new parts fit into old machines!! We all have to admit that these Winnebago were not built for duration of any sort..That new fan looks like it will vent the whole motorhome and not just the bathroom..

You are going find that there is either rotted wood or nothing but foam that ladder was screwed to..

Mine had a rollout awning on the side and the only thing holding it was the screws and the paper thin aluminum siding..No wood structure for it to screw into..
The best mechanic is the one that can make it run with the least amount of parts!

BigAlsVehicleEmporium

I'm definitely worried about finding that, and worse. I need to dive into the front passenger wall next. It flaps as I'm going down the road  :shocked:
1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

RockwoodMike

Quote from: BigAlsVehicleEmporium on July 14, 2023, 03:30 AMI'm definitely worried about finding that, and worse. I need to dive into the front passenger wall next. It flaps as I'm going down the road  :shocked:

Yea..That is the reason the whole side of my project is open..Right at the belt line, where the wall screws to the floor is a 2x4..Mine was rotted dust..At the very bottom edge is a 2x2 that the aluminum trim pieces are stapled to..Dust..I am missing the aluminum piece on the starboard side that is the bottom edge from the door to the rear wheel well..It fell off long ago as the 2x2 was rotted dust..

I will be rebuilding my walls with 1.5 square steel tubing..with wood placed where it is needed
The best mechanic is the one that can make it run with the least amount of parts!

Mlw

QuoteWe all have to admit that these Winnebago were not built for duration of any sort..

Ain't that the truth...  And not only Winnebago's.

BigAlsVehicleEmporium

Quote from: RockwoodMike on July 14, 2023, 01:52 PMYea..That is the reason the whole side of my project is open..Right at the belt line, where the wall screws to the floor is a 2x4..Mine was rotted dust..At the very bottom edge is a 2x2 that the aluminum trim pieces are stapled to..Dust..I am missing the aluminum piece on the starboard side that is the bottom edge from the door to the rear wheel well..It fell off long ago as the 2x2 was rotted dust..

All the bottom 2x2s on mine have disappeared too! Everywhere else seems pretty solid, except for that front passenger wall. My 2x4 there is probably gone too. Not looking forward to having to tear into that...
1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

RockwoodMike

I am in the process of reloading the lost photos and these 2 are part of the list..

The first is the same front right location you are saying..Rotted dust..

The main reason for all the rot around the lower area is the second picture..The way it was made in the factory was the lower panel over lapped that upper panel at the floor belt line.

Unless the aluminum trim piece was perfectly sealed to the wall, water running down the wall was actually flowing into the interior of the wall because of the lapping of the siding..In my picture if the brown siding was applied first then the white siding, the water would not has entered the walls as it did..

Just those type of construction methods ruined so many of these motorhomes
The best mechanic is the one that can make it run with the least amount of parts!

BigAlsVehicleEmporium

Wow, that's unbelievable! I went and checked my front passenger side where most of the damage is, and fortunately they have the overlapping correct so that it sheds water rather than funneling it into the walls. I hope it's that way all the way around...

1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

BigAlsVehicleEmporium

I pulled the 2nd set of copper exhaust manifold gaskets, and here's what I found on the head-side of the gaskets.


You can see a couple of small areas where they'd started to leak in the center dual gasket section, but the bad area was on the rear of the front driver's side port.


You can see where the leak was significant by the trail of exhaust soot. Short of removing the heads and getting the exhaust side resurfaced, I wasn't going to be able to fix this with the copper gaskets. It didn't sound too loud, but I could definitely hear the leak and didn't want to put 5k more miles to/from Seattle with that leak eating away at the already compromised mating surface. So, I took a gamble and followed what someone else on here had done. I bought a set of the Fel-pro MS9705B aluminum/fiber gaskets and doubled up, using both gaskets on the driver's side. I torqued the bolts down incrementally to the factory-spec 40 ft-lbs.

From what I've read on here, these gaskets can work well if they're kept tight. So, I fired it up and ran the engine for 15 minutes or so, until it came up to normal operating temperature. Then I shut it down, let it cool, and re-torqued the bolts. I'm glad I did too because they had to be turned a decent amount to get to 40 ft-lbs again. I repeated this process a 2nd time and that time the bolts hardly had to be turned at all, which was confidence-inspiring.

I've put a few hundred miles on it since then, and these gaskets sealed up to the corroded head surface nicely! I can't hear or feel any leaks.
1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

BigAlsVehicleEmporium

The only part of the braking system that I hadn't addressed was the vacuum booster. It worked enough but definitely leaked a good bit of air. From another thread on this forum, I found out about BB&K Auto in south Atlanta. I took my Mopar # 3633549 brake booster down to them on a Friday and they had it ready by 11 AM on Saturday. Incredible service and at $216 out the door it seems like a fair price. In case anyone needs it, their phone number is: 404-761-3102. Address:
511 85th Circle
Atlanta, GA 30349

I ordered a Wearever MCA71259 master cylinder because I am suspicious of the O'Reilly Brake Best NMC21936 that I installed back in February. The brake pedal goes way too far before the brakes engage. When they do engage, the pedal is firm so I don't suspect air in the lines. It acts like it would behave if the outlets were missing the 10 psi residual valves. When I installed it, I remember not seeing anything in the port openings. Also, this part is no longer available from O'Reilly and I wonder if that was because they found that a bunch of them were bad.

The new Wearever master cylinder arrived! Before filling the Wearever part with fluid, I checked it for residuals and they were present. I tried a crude test of putting an air hose up to each port and slowly increasing the regulator from 0 until I could hear air comig out of the resevoir. They both started to flow air near enough to 10 psi that I was happy! So I bench bled it and then swapped it for the O'Reilly brand MC. Sure enough, there were no residuals in the O'Reilly master cylinder. I haven't power bled the brakes yet, but I can already feel an improvement. The pedal doesn't go as far before the brakes engage, and if I pump it up a little, I can get a pedal with very little travel before engagement. I think once I re-bleed the brakes I'll have a pedal that feels like it ought to. But, even if it doesn't get any better, it's much more driveable than with the O'Reilly part.
1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

BigAlsVehicleEmporium

So, I looked over the generator for the first time. It is an Onan 4.0 CCk model putting out 4kW of power.


After unbolting the tray, I slid it most of the way out and supported end with a pair of jackstands. At 340 lbs, this generator is not light and this job definitely has to be done with a good rolling floor jack or two strong people. After cleaning up grounds and spinning it over by hand a bunch, the starting circuit came around and it would spin itself over! It sounded pretty uneven, but I was hoping that valves were stuck from sitting. Filed the points and managed to get a weak spark out of it. Poured some 2 cycle gas down the carburetor and got a few random pops out of the exhaust and a couple of backfires out the carburetor. That told me it was definitely valves, so I pulled the spark plugs to do a compression test. The outboard plug looked like it had been firing, but it was pretty well caked in oil, not a great sign. The inboard plug however definitely had not been firing for many hours. Outboard compression was 100 psi, not terrible for a cold engine that has been sitting for a few decades. Inboard was 0 psi. At this point, I knew that it burned oil and had stuck valves or a rounded camshaft lobe, or some similar issue. Parts for these seem expensive and if I did put the time and money into fixing it, I'd just end up with a very loud, inefficient generator that burned oil. So, I decided to pull it and I'm keeping my eye out for a deal on a Predator 3500 generator. They do 3 kW continuous, are very quiet, and burn very little fuel. On top of all that, they only weigh 98 lbs! A bunch of people have retro-fitted their RVs with them and seem happy. There's even a door lock actuator based electric choke conversion kit out there that would let me start it from inside the RV. I'm eager to get this done, because I really want to have A/C while going down the road and when I don't have access to shore power haha.

I plan to get the new generator in during the next week or two. Once that's done and I'm certain that I won't be reusing the Onan, if anyone needs parts, let me know!

1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

RockwoodMike

The fuel tank of the Predator is located on the top..Will you need to create a pull out shelf to be able to fill the tank?..

Wondering if there is a kit to use the vehicle's fuel tank with a pump.

So if you have a pull out shelf, it needs to be bolted to the shelf to keep it in place as you are going down the road and to be keeping safe from being stolen..
The best mechanic is the one that can make it run with the least amount of parts!

Eyez Open

A note here..don't be so hard on that old genset.
Is it a opposed set up like a Subaru..
Does it run at all.



I took one from death to a well functional genset. They are remarkably well built.

Does it use a dual points system..It should. If it runs your 70% home.

I assume the generator also starts the engine...no separate starter right?

I was ready to toss it until I decided to see what makes it tick...it's very very basic 60s tech. Very easy to get it running again.

Aside from all that...a running functional old onan is well worth $8/1500

BigAlsVehicleEmporium

Rockwood Mike,

My plan is to bypass the tank entirely and use a very low pressure electric fuel pump straight to the carburetor that pulls from the chassis fuel tanks. I got a dual tank switch valve that is set up for a 5/16" return line. Instead of using it as a return, I plan to use it to feed the generator. That way, which ever tank I'm running the engine off of, the generator will run off of it too. The generator pickups in each tank don't go all the way to the bottom, so the generator can't run me dry and leave me stranded. LJ-TJ started a good post about doing the Onan to inverter generator swap here:
https://www.classicwinnebagos.com/forum/index.php?topic=16782.0
1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

BigAlsVehicleEmporium

Eyez Open,

It is indeed the opposed twin, but with single points and a dual coil. It doesn't run at all, even with starting fluid. It'll pop off but never twice in a row, nothing that could be called running, and half of those are coming out of the carburetor rather than the exhaust.

Yep, it's got an appealingly simple starter setup that uses the generator. Fewer parts, but no gearing advantage so starting it pulls a whopping amount of current.

If I thought I could get $800 for it, I'd probably go to the effort of rebuilding the motor and new rings, etc. But in this part of Georgia, they go all day for $200-$400 running. At that price it's not worth the trouble and I'd rather give it away, or ship some parts to people on CWVRV that need them.

Plus, the Predator 3500 uses half the gas, or less, that the Onan does. That'll save me a few hundred dollars on this Seattle trip alone and go a long way towards paying for the generator.
1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"

RockwoodMike

Quote from: BigAlsVehicleEmporium on July 31, 2023, 11:07 PMuse a very low pressure electric fuel pump straight to the carburetor that pulls from the chassis fuel tanks

I think you will be needing a regular electric fuel pump because it needs the power to draw up to the top of the tank and then all the way to the generator ..So a pressure regulator that can reduce the pressure to next to nothing will be needed..Never seen one before..Usually a regulator is made for 3-5 pounds..Which is a lot more than your gravity feed that the Predator works on ..

Every set up of a invertor generator is usually run once you are at the camp ground..Open the door..set it on an open platform..

To run it while you are going down the road will need to be thoroughly tested..Bumps in the road pot holes, causing the fuel to flood the engine..This engine that is designed to run on the ground without major movement like it would have going down the road..
The best mechanic is the one that can make it run with the least amount of parts!

Eyez Open

I'll find my old rebuild thread, those Onans are a ancient design but built to last forever. Hmm that thread maybe on this forum...LMAO I've forgotten.

RockwoodMike

I would set up a sliding shelf that others have done and just use the stock tank..With the air conditioner running, I think you could get 5 hours run time..Look at the run time for 25% load..11 hours!!..After 5 hours, you pull into a rest stop, pull out the 5 gallon jug you have and refill it..Off you go again..
The best mechanic is the one that can make it run with the least amount of parts!

RockwoodMike

When I bought my Indian, the PO started the generator to show it runs.So I plan on going through mine..
But I have the time to do that..I have the 4.0 CCK unit also

That September wedding is fast approaching!!
The best mechanic is the one that can make it run with the least amount of parts!

Eyez Open

I've found one of first attempts of online posting. Smokestack below was my journey, I had no ideal where to start, but once done it is extremely simple to get them back up and running. A functional onan is easily worth 1200 on the open market. There is actually a cult following out there. Onans can run 24/7@ full power.

A very odd experience occurred there, one of the posters lived about 5 city blocks from me..only after completing the task we figured that out.

https://www.smokstak.com/forum/threads/onan-6-5nh-attempting-to-bring-it-back.187088/

BigAlsVehicleEmporium

Rockwood Mike,

I'm too lazy and get too annoyed at tasks that I have to repeat to stick with the stock tank. I'll spend 4 hrs of work to save a 5 minute task I might have to do 10 times  :laugh:

I definitely want to do a slide out shelf like LJ-TJ did. That's a great idea.

I plan to start on this generator swap next week, so we'll see how it goes!
1972 Winnebago Brave D20 - 413 V8, A727, Dana 70
"That leaves only me to blame, 'cause mama tried!"